MadModder
Gallery, Projects and General => Project Logs => Topic started by: spuddevans on May 09, 2011, 12:40:56 PM
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Some time ago I started designing a little V4 wobbler in Alibre and made a 3d rendering in pdf format to give some idea what I hope it will look like when built.
Click here for interactive pdf rendering (http://www.timevanswindows.co.uk/spuddevans/images/velvet_v4/v4.pdf)
Anyway, over the last few days I have been finalising some of the details and also printing out some plans, and today I have made a little start on this little engine.
The design is to have a V4 configuration, 8mm bore 12-14mm stroke (cant remember which :scratch: ), double acting wobbler.
I hope to keep a good record of the build with plenty of pics of all the processes, cos I know you all like pics :worthless: :lol:
Actually, todays progress is pretty boring, just some sizing of stock.
Normally, as many other builders, I would have liked to have started on the most complicated part 1st, which on this build is the main frame, but I am awaiting the arrival of some materials for the frame, so I made a start on the cylinders.
I started by putting the ER32 chuck on the lathe, and gripped a length of 20mm round brass bar in it, squaring the end up, then using my patent-pending method of marking up, I traced a mark at 21.5mm from the end.
(http://velvet-art.smugmug.com/photos/i-jGtfT9p/0/L/i-jGtfT9p-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1283835647_jGtfT9p-A-LB)
(http://velvet-art.smugmug.com/photos/i-cFCTFDD/0/L/i-cFCTFDD-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1283836039_cFCTFDD-A-LB)
I then used a thin parting tool to put a cut in at the mark to a depth of around 3-4mm, it's not important what depth, just so long as it is deep enough to be still there when I reduce the bar down to 16mm.
(http://velvet-art.smugmug.com/photos/i-cDNDRRq/0/L/i-cDNDRRq-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1283834812_cDNDRRq-A-LB)
Then I swopped over to a 6mm round profiling tool ( as recommended by Bogs ages ago, and well worth getting ) and reduced to required size, just needing a quick swipe with some emery to clean up.
(http://velvet-art.smugmug.com/photos/i-jXH4wSZ/0/L/i-jXH4wSZ-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1283834592_jXH4wSZ-A-LB)
Then I swopped back to the parting tool and finished parting off. Then loosen the chuck, extend the bar out a little more, tighten, mark up and measure off another 21.5mm, make the initial parting cut, reduce to 16mm, part off and repeat another 2 times, or perhaps 3 times to give you a spare. (as I did knowing that it will be needed :lol: )
(http://velvet-art.smugmug.com/photos/i-VHvfL9J/0/L/i-VHvfL9J-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1283835127_VHvfL9J-A-LB)
The reason for making the initial shallow cut with the parting tool was just to give me an indication of how far to reduce the diameter of the 20mm brass bar to each time, and to therefore hopefully stop me from trying to cut too long a section down to 16mm. You might have a firm enough lathe to turn down much longer sections, but on my (as yet, completely unmodified, straight out of the box condition) rubber lathe, I have learnt to keep the minimum stock sticking out of the chuck when trying to keep to dimension, and so the visual reminder that putting on a partial parting cut gives is a helpful reminder to me to only turn down one piece at a time. Plus the parting tool is already in the QC changer from parting off the previous blank, so it only takes a moment to do.
These cylinders are not totally straight-forward in themselves, as, just to be difficult, I have designed the bore to be offset by 1mm from the center of the cylinder blank, so I spent the rest of my time in the workshop figuring out just how I am going to machine all the features and also in what sequence to machine it, and of course, how to hold it for machining.
Next up will be machining all the cylinder blanks to the same length (hopefully 20mm), and then machining a pivot on the side of each cylinder before boring out the bore :D
Anyway, that is as far as I got today, more updates to follow.
Tim
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Sounds a real nice project Tim.
Tried opening the interactive pdf and got a blank page :scratch:
Stew
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Tried opening the interactive pdf and got a blank page :scratch:
:scratch: Funny, it works on this end, try the attached file.
Tim
Edit, Dang it, managed to upload the same file twice, sorry Eric, just delete one as I cant seem to delete it myself.
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Those links are blank as well
but I am using a beta OS called Lion ( mac )
Stuart
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Yes I got blanks
You always start a project with a blank page :D
Stew
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I've just tried it on IE and it works ok, and on firefox too :scratch: :scratch:
What version of Adobe Acrobat reader are you using? I think it needs v9.4 to open.
I also downloaded it on my phone using Opera, and it opened on adobe acrobat reader LE 2.5 (from 2009) :scratch: :scratch:
So I am completely stumped. I am sorry that you cant open any of the 3d renderings, as the real thing will probably not look anything like the model :lol:
Tim
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Nice design Tim :thumbup:
I'm really curious how your porting will work and how you want to keep the cylinders on the port faces :D; Guess I will have to wait and see :thumbup:
(I can see the engine using Linux - but not interactive - Don't know about the Macs. Stew, do you have a fairly new version of Acrobat ? - you need one of the newer interactive 3D compatible ones)
Kind regards, Arnold
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I opened it in Adobe Reader and was able to rotate it - cool. I don't know about other people. But, although I can read engineering drawings/blueprints just fine, a 3D representation is worth its weight in gold. We'll be following your progress.
-Dick
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Interesting Design Tim :thumbup:
Opens fine in Google Chrome and my Adobe :med:
Rob
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Tim
Works fine on this side of the pond with Mozilla. Looks like it will be an interesting little engine. I'll be watching. :coffee:
Cheers :beer:
Don
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Tim,
Opens for me as well in Adobe,
Tim are you using Alibre?
DaveH
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I'm really curious how your porting will work and how you want to keep the cylinders on the port faces :D; Guess I will have to wait and see :thumbup:
Me too :lol: :lol: :lol:
It's not a big secret, just an unknown quantity. The cylinders will ( hopefully ) be held on by recessed rare-earth magnets in both the frame and cylinders, with just a little gap between the two sets of magnets.
The porting is the standard wobbler type, but the air/steam passages are deep drilled through the frame, then the holes are covered brass tips on the ends of the frame.
I'm glad that others are able to open the pdf's, I thought I was the only one who could see them.
Tim are you using Alibre?
DaveH
Sure do Dave :thumbup:, I've found it really useful. Well worth the $99, or £64 when it showed up on the ccard bill :thumbup:
Tim
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Very nice design Tim.
I was a bit worried where all the piping was, but as you said, hiding it in the standards is perfectly OK.
Not only am I a ball bearing addict, I also have a fetish for magnets, they are stuck all over my shop if you care to search them out. I even think I have some 1mm diameter neo magnets somewhere, so if you need any, don't be afraid to ask, and if I haven't got the right size, I can send you where they will have, very reasonably priced as well.
John
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This project looks very intressting, I will be follow... :thumbup:
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Thanks John :thumbup: hopefully it'll turn out something like the 3d design :coffee:
Not only am I a ball bearing addict, I also have a fetish for magnets, they are stuck all over my shop if you care to search them out. I even think I have some 1mm diameter neo magnets somewhere, so if you need any, don't be afraid to ask, and if I haven't got the right size, I can send you where they will have, very reasonably priced as well.
Funny you say that, I too am fascinated with the neo magnets. And I am also including ball bearings on this build, should be 4 of them on the crankshafts.
Thanks for the offer of magnets, I have got some 8mm x 2mm thick neo magnets on their way off flea-bay.
I had been anticipating using much smaller diameter magnets, but I'm not sure if they would have enough pull to hold the cylinders in place, I too got some 1mm magnets, and some 2 and 3mm ones too. So I redesigned the pivot area to use the wider magnets.
Time will tell if they work or not.
I have been temped to make it a V8 by adding a 2nd frame and 4 more cylinders, but for the time being I am resisting that temptation until I have got the V4 running. Potentially you could add as many of the main frames as you want to make V8, V12, V16, up to a V-whatever.
It is quite a small engine, as a V4 it should be able to fit onto a footprint of just 75mm wide by 85mm deep by 60mm high including the reversing/speed control.
Tim
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I'm trying to see it on a mac,
I'll try on my lap top when I've finished down loading a disc onto its hard drive.
Stew
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I'm trying to see it on a mac,
Ahh, that's obviously the problem, your mac has detected the slightest hint of microsnot that must've crept in from my pc :lol: :lol: :lol:
Tim
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your mac has detected the slightest hint of microsnot that must've crept in from my pc
:lol: :lol: :lol: :lol: :lol: :lol: :lol: Brilliant!
:beer:, Arnold
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I'm trying to see it on a mac,
I'll try on my lap top when I've finished down loading a disc onto its hard drive.
Stew
That did the trick Microsoft rule OK :headbang:
Ahh, that's obviously the problem, your mac has detected the slightest hint of microsnot that must've crept in from my pc
:lol: :lol: :lol: :lol: :lol:
Yes bloody mac:- wife got it despite my objections, and I bought my laptop as I refused to relearn to use the mac software knowing Id have to teach her how to use it same as I did with microsoft, that led to a lot of arguments and time down the pub keeping out of her way, I only ever use it for the internet, all the rest I do on the lap top, any mac problems she has, have to be sorted by her sister who convinsed her that macs were the way to go, they stop speaking to each other for weeks at a time
:lol: :lol: :lol:
:offtopic:
Back on topic ther's a similar engine on her http://jpduval.free.fr/Plans_moteurs_vapeur_p1.htm that may help you sort things.
Hope this helps
Stew
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Hi Tim, super design! I really like the CAD diagrams ... 3D does it for me :ddb:
Not clear how the magnets work but I`m sure I`ll find out soon with all those pictures you are going to post :whip:....
Can`t wait for an update! :wave:
Chris
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Very cool. Will be watching this one.
Edit, Dang it, managed to upload the same file twice, sorry Eric, just delete one as I cant seem to delete it myself.
I will fix that today
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I will fix that today
Thanks Eric :thumbup:
I got another couple of hours in the playroom workshop today, and started by mounting my new vice onto the mill, and then clocked it square with a dti, I didnt go crazy, but just got it down to +/- 0.05mm :lol:
(http://velvet-art.smugmug.com/photos/i-k6vKrkH/0/L/i-k6vKrkH-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1285647398_k6vKrkH-A-LB)
I then mounted all 4 cylinder blanks on some parallels and with two pieces of ali at the front and back to compensate for the minor differences of thickness on each cylinder. If you dont put some soft material between the jaws and the workpieces then the slight differences will cause the multiple pieces to not all be gripped the same, which is perfectly fine unless you actually want to machine any of them. The Ali not only protects the brass from the steel vice jaws, but also will squish a little to compensate for the minor differences.
Anyway, I then I worked back and forth with a flycutter to get all 4 to the same length, 20mm.
(http://velvet-art.smugmug.com/photos/i-9q6D3Xf/0/L/i-9q6D3Xf-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1285646570_9q6D3Xf-A-LB)
I then turned the cylinders on their sides, gripped them in the same manner, and made a few more passes with the flycutter. Here's a shot after I cut the flat down until the required thickness ( 14mm ). Others might prefer to switch to an endmill to get the bulk removed, but as there was only 2mm to remove, and on brass I am able to take 0.25mm depth of cuts with this flycutter, it was quicker to keep using the flycutter. Plus it leaves a lovely silky smooth finish. Don't let the curved lines fool you, they cannot be felt by my fingernail.
(http://velvet-art.smugmug.com/photos/i-FGGNh4x/0/L/i-FGGNh4x-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1285646457_FGGNh4x-A-LB)
Not having a lot of time left I started to set up for the next machining processes. The next thing will be to bore out a 2mm deep, 10mm diameter recess in the center of the flat section, and I will probably drill the inlet/exhaust holes at the same time. Because this has to be done on all 4, I'm going to use my sophisticated vice stop system shown below.
(http://velvet-art.smugmug.com/photos/i-kZZ3Q4s/0/L/i-kZZ3Q4s-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1285647325_kZZ3Q4s-A-LB)
And for making sure that the cylinder flat is positioned true and flat I use another patent-pending system...
(http://velvet-art.smugmug.com/photos/i-P5STLC5/0/L/i-P5STLC5-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1285647166_P5STLC5-A-LB)
It wasnt until I had released the vice after flycutting all the flat sections that I realised that I should have kept them in place and just drilled and bored all the relevant holes using my edge finder on each cylinder and then moving to the right coord's for the holes :doh: :bang: :doh: :bang: :doh:
Oh well, you live and learn.
So next will be a boring post ( oh come come! this post has been boring anyway :lol: :lol: ) and then some silver soldering.
Tim
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Nice work :thumbup:
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I've made a little more progress on the cylinders.
According to my plans I have to drill the 2 inlet/outlet holes, and also a central 10mm diameter hole. The small inlet holes pose no problem, but the 10mm diameter hole is a little more tricky for me as I found that I do not have a 10mm endmill, and this hole must be flat bottomed. (wasnt that a queen song, "flat bottomed something-or-other" :lol: )
I could've made a 10mm D-bit, but I figured out another way. I do have a 3/8" endmill which is 9.51mm approx in new money, and I also have a boring head that I can set to 10mm.
So here are my tools for this task,
(http://velvet-art.smugmug.com/photos/i-2ZGcPVD/0/M/i-2ZGcPVD-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741918_2ZGcPVD-A-LB)
Center drilling the holes,
(http://velvet-art.smugmug.com/photos/i-2dD8NPC/0/M/i-2dD8NPC-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741566_2dD8NPC-A-LB)
Boring out the majority with the endmill,
(http://velvet-art.smugmug.com/photos/i-MKxZTNG/0/M/i-MKxZTNG-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741712_MKxZTNG-A-LB)
Drilling the 1.5mm steam passages,
(http://velvet-art.smugmug.com/photos/i-7TfHvwZ/0/M/i-7TfHvwZ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290739786_7TfHvwZ-A-LB)
Then I swopped the ER32 chuck and mounted the boring head in the mill and then bored out to 10mm, I left the boring head locked at the needed diameter.
(http://velvet-art.smugmug.com/photos/i-VFNX3B7/0/M/i-VFNX3B7-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290740369_VFNX3B7-A-LB)
Repeat the above steps another 3 times, til you have this.
(http://velvet-art.smugmug.com/photos/i-LdbXZCg/0/L/i-LdbXZCg-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290740275_LdbXZCg-A-LB)
Then I turned the cylinder upright in order to bore out the bore :D
Using my expensive vice-stop to position the cylinders to make a little production line, first up after centering up was center drilling all 4 cylinders,
(http://velvet-art.smugmug.com/photos/i-xR2TNbt/0/M/i-xR2TNbt-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290740372_xR2TNbt-A-LB)
Then following through with drills up to 7.8mm,
(http://velvet-art.smugmug.com/photos/i-s8fwz6B/0/M/i-s8fwz6B-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741039_s8fwz6B-A-LB)
Then I reamed all 4 out to 8mm, I was going to bore them with my boring head but I realised I didnt have a slim enough boring bar for it ( something for the shopping list )
(http://velvet-art.smugmug.com/photos/i-X3NSdWt/0/M/i-X3NSdWt-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741034_X3NSdWt-A-LB)
Next I turned up 4 little rings of brass, 10mm OD, 8.1mm ID x 3.5mm depth.
(http://velvet-art.smugmug.com/photos/i-r5wcvrn/0/M/i-r5wcvrn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290740603_r5wcvrn-A-LB)
And this is where they fit,
(http://velvet-art.smugmug.com/photos/i-KwwvszJ/0/L/i-KwwvszJ-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741299_KwwvszJ-A-LB)
And here are the pieces all together with 4 8mm x 2mm neo' magnets sitting in place.
(http://velvet-art.smugmug.com/photos/i-JHqDPSF/0/L/i-JHqDPSF-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1290741317_JHqDPSF-A-LB)
The magnets will be epoxied in place, and I am considering leaving the rings unfixed, they will fit into corresponding 10mm recesses in the main frame, and the magnetic attraction should keep them all in place.
While I have the vice stop set up, I will probably next drill the 4 holes on each end of the cylinders for fixing the endcaps or glands, then that should be all the cylinder machining operations done.
All that and maybe more (or less) on next weeks show.....
Tim
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Well sir, that was a lot of boring, but not at all boring :thumbup:
Good progress!
Kind regards, Arnold
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Great pictures :bow:
I'm looking forward to seeing more of this engine :nrocks:
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Thanks Arnold and Jason :thumbup:
I did a little experimentation with the magnets today, if anything, I've found that the magnets may give more attraction than needed, creating extra friction on the "wobbling" motion. But I have an idea of how to adjust the strength by using a different size of disc of steel in the recess on the main frame, thus giving some adjustability.
Tim
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Looking good :clap: :clap:
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Nice one Tim, I think I get what those magnets are doing now.
Chris
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I never would have thought to use magnets... Brilliant. Also looking very nice, hope it runs as good as it looks so far.
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Thanks for the comments Saw, Chris and BiggerHammer :thumbup:
Tim
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The magnet idea is very clever :clap: :clap:
A friend of mine playes around with magic tricks
I bored out some coins for him and glued magnets in to them i was amazed at the strength of the little things
Great build log by the way :thumbup:
John
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Thanks John :thumbup:
I got a little more done today, namely the drilling and tapping the 32 holes in the cylinders for the packing glands and endcaps.
Having a DRO with a bolt hole function does make the drilling a lot easier, combine that with a vice-stop for repeatable workpiece positioning makes for a relatively easy time.
I got a little carried away with that and forgot to take any in-progress shots of the drilling, Oops :doh:
Then I mounted all 4 cylinders in a vice placed on my tapping stand, and I was really glad to have it. Tapping 32 holes with both M2 taps ( 2nd and bottom ) by hand would've been a nightmare.
(http://velvet-art.smugmug.com/photos/i-MrzbVnt/0/L/i-MrzbVnt-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1293584218_MrzbVnt-A-LB)
As it was, I was able to tap a hole every 20secs, which I thought wasnt to bad. But after tapping 16 holes on the top, then turning them all over and tapping the bottom 16, I started to think if there could be a way to speed the process up a little.
One thing I noticed was that withdrawing the tap seemed to take longer and caused more ache in my arm. Then inspiration hit ( or perhaps it was a particularly bad case of wind :lol: ) and brandishing a hacksaw I made this little mod to the top of the shaft on my tapping stand.
(http://velvet-art.smugmug.com/photos/i-pVkCvWf/0/M/i-pVkCvWf-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1293584107_pVkCvWf-A-LB)
Then I put a slot screwdriver bit in my cordless drill and selected reverse. Then I would wind the tap into the hole by hand until it reached full depth (just before the squeek) then back it out a quarter turn, then it was just a case of slotting the screwgun onto the newly made slot and 2secs later the tap was out, much easier on the arm!!
So at the end of that I have 4 (hopefully) finished cylinders.
(http://velvet-art.smugmug.com/photos/i-zrDTNzZ/0/L/i-zrDTNzZ-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1293583986_zrDTNzZ-A-LB)
Then I had to retire back to the pc to redo some of my plans to adjust some dimentions on the main frame.
Tim
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I got a little more progress today, not much to show, just some preperation work really.
I started off by making a little angle plate, this is needed for milling and drilling the internal steam passages in the "V" section. I have got some angled parallels (now there's a funny thing), but I didnt want to stack up 8 of them to make 45 degrees !!!
So I marked up a scrap of 10mm ali plate and rough cut it on the bandsaw, then mounted it on the mill table using a V-block to align it for finishing it.
I 1st up aligned the V-block,
(http://velvet-art.smugmug.com/photos/i-mFzjCkG/0/M/i-mFzjCkG-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1295489886_mFzjCkG-A-LB)
this is taken before milling, and yes I did notice that one edge is not fully fitted into the V-block, I adjusted it and re-tightened it before milling.
(http://velvet-art.smugmug.com/photos/i-dCsNbNP/0/M/i-dCsNbNP-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1295488638_dCsNbNP-A-LB)
Here's the result. I know that it is a little rough looking, but it will do just fine, it will only be used 2 or 4 times, and each time will only be for aligning the frame in the vice, the angle itself will have no pressure applied to it.
(http://velvet-art.smugmug.com/photos/i-z2vVk7x/0/M/i-z2vVk7x-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1295487774_z2vVk7x-A-LB)
Then I turned to preparing the Ali for the main frame. I cut off a piece of 1/2" thick Ali' in the bandsaw, then cleaned up and squared the 4 edges. This just left the front and rear faces to clean up and bring to 12mm. My present flycutter has about a 30mm sweep, so it was not enough for this, so I sharpened up a new piece of hss and mounted it in the larger flycutter ( I have a set of 3 flycutters, up til this point I have only used the mid-sized one )
Tooling ready I took a couple of shallow cuts off each side (0.25mm doc), then checking with mic I reduced the thickness to 12mm. The last pass took off 0.1mm and left a really reflective finish.
(http://velvet-art.smugmug.com/photos/i-p6kVhxQ/0/M/i-p6kVhxQ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1295488141_p6kVhxQ-A-LB)
Then I spent a while marking out the positions for all the holes to be drilled in the face.
(http://velvet-art.smugmug.com/photos/i-6Q3SQq6/0/L/i-6Q3SQq6-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1295489452_6Q3SQq6-A-LB)
Next time things should get a little more interesting, I will be drilling all the thru holes and then boring on each face the 10mm bore's that the cylinders pivot on, plus some bores for the crankshaft ballraces, then will be drilling the long internal air/steam passages (longest is 46mm)
Tim
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You are doing good Tim :thumbup:
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Thanks Benni :thumbup:
I've got a little more progress made of the frame.
I mounted the frame in the vice on the mill on some parallels and then using an edge-finder I zeroed on the bottom of the frame (actually I zeroed off the jaw of the vice) and then zeroed off one side of the frame blank. I then moved in to the center of the frame and zeroed there. This is because of the way I have marked the dimensions on the plans, working from the center of the frame rather than from one edge.
Then I put a little center drill ( I really must get some proper spotting drills ) in the chuck and center drilled all the holes using the coords off my plans.
(http://velvet-art.smugmug.com/photos/i-FFBp848/0/M/i-FFBp848-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300627263_FFBp848-A-LB)
Then I set about drilling all the thru holes, and all was going well until a little "plink" sound. Grrrrr, I broke a 1.5mm drill halfway thru leaving a small segment of drlllbit stuck fast. :bang:
(http://velvet-art.smugmug.com/photos/i-LgLVLnn/0/M/i-LgLVLnn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300627048_LgLVLnn-A-LB)
I finished off drilling the rest of the thru holes with a fresh bit, and bored out the larger blind bores for the cylinder pivots and for the ball-races for the crankshaft. Then I turned the blank over and bored out the larger blind bores on that side, then very carefully drilled the failed 1.5mm hole from the other side until I heard and felt the drillbit start to catch the stuck fragment.
I then spent an hour or more digging it out using various methods with not much success until I tried using a pointed V carbide burr. I then very gradually fed the burr into the stuck drillbit until I had bored most of the way through the stuck bit, then I took the remainder of the broken drillbit, ground the broken end flat and then I applied a little persuasion with a hammer and the stuck bit popped right out.
Then I took a couple of pieces of 6mm steel rod for the next step.
(http://velvet-art.smugmug.com/photos/i-W4r9knB/0/L/i-W4r9knB-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300628009_W4r9knB-A-LB)
These 6mm rods fit into the blind bores for the ballraces, and are used along with the 45degree angle I made earlier to mount the frame vertically in the mill vice as shown, the two HSS lathe bits are there to raise the frame up enough to allow me to get the right angle
(http://velvet-art.smugmug.com/photos/i-8g8Ctzq/0/L/i-8g8Ctzq-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300627255_8g8Ctzq-A-LB)
Then (once the vice was tightened up) I touched off the 6mm rod with a 16mm endmill, zeroed the DRO and then raised up the Z-axis by 38.87mm (according to my plans the distance from the center of the crankshaft to this edge of the frame is 41.87mm, subtract half of the 6mm rod brings you to 38.87mm) and zeroed again.
(http://velvet-art.smugmug.com/photos/i-DzXfKN5/0/M/i-DzXfKN5-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300627632_DzXfKN5-A-LB)
Then it was just a case of raising the cutter up and then nibbling my way back down to zero. Then I loosened the vice, rotate the frame and align using the 45degree angle and tighten the vice. Then nibble away the 2nd corner.
(http://velvet-art.smugmug.com/photos/i-Vm3VfVZ/0/L/i-Vm3VfVZ-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1300628048_Vm3VfVZ-A-LB)
I did think about shaping more of these upper arms while having it in this position, but I have some long holes to drill, and want to do that before spending any more efforts, just in case I totally mess up the long boring. The shaping of the outsides of these arms are not critical, so the shaping can wait til later.
Next up will be boring these 4 long steam passages between 38-46mm approx deep, then if nothing snaps or gets stuck, I will be shaping the outer edges of the frame.
One handy tip I have learnt from snapping the 1.5mm drillbit, when I started using the new bit I began rubbing a pencil up the flutes. This seemed to stop the ali welding itself into the flutes, and I re-applied the pencil a couple more times per 12mm deep hole, this seemed to work really well, good old carbon lubrication.
Tim
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It's amazing just how things go, when I was designing this engine, the part that puckered my cheeks the most was thinking about drilling the long narrow internal air/steam passages, close to 50mm long with just a 2.2mm bit, drilled into Ali' which I know from experience just loves to gum up a drillbit, break it and weld the broken bit deep in the workpiece.
But what do you know, the deep drilling went without a hitch, no breakages, no gumming up, and no breaking through where it shouldnt.
Here's a picture when I'd drilled the last of the 4 deep holes, and I've drawn on it to show where the internal passages meet. Because the passages are offset from each other the passage on the front (green) is not connected to the rear passage (purple) (I just know someone is going to make a joke about that !!! Get your minds out of the sewer and into the gutter with the rest of us :lol: )
I drilled the first 30mm of each hole with a 2.5mm drill, then finished the hole off with a 2.2mm bit. The reason was not only for ensuring the bit wouldnt break, but also made sure that these long holes would break through into the 1.5mm cross drilled cylinder ports. Then by switching to a slightly smaller bit gives a little more room for error on drilling without breaking into the central crankshaft bore.
(http://velvet-art.smugmug.com/photos/i-SbCfkhN/0/L/i-SbCfkhN-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1302119398_SbCfkhN-A-LB)
(http://velvet-art.smugmug.com/photos/i-Ms8HH2j/0/L/i-Ms8HH2j-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1302118678_Ms8HH2j-A-LB)
Then I moved the frame into a vice on the tapping stand to tap the central hole on each arm M2, this is for attaching a cap to cover and seal the ends of the long internal steam passages.
(http://velvet-art.smugmug.com/photos/i-3mJrbDg/0/L/i-3mJrbDg-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1302119037_3mJrbDg-A-LB)
Once that was done I couldn't resist fitting the cylinders and pivot rings to see how it looks.
(http://velvet-art.smugmug.com/photos/i-3VZVrHW/0/L/i-3VZVrHW-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1302117957_3VZVrHW-A-LB)
(http://velvet-art.smugmug.com/photos/i-N7FMNsV/0/M/i-N7FMNsV-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1302117858_N7FMNsV-A-LB)
Next I will be making some steel inserts to fit into the 10mm pivot bores in the frame to give the magnets something to pull onto. There will probably be some experimentation with the sizing of the steel inserts to get the appropriate "pull force". Then I will be moving back to the cylinders, or rather, to the end caps and packing glands and pistons.
Tim
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Good going Tim :thumbup:
Drilling those thin deep holes in alli can be a bit daunting :doh:
:lol: Glad you did not end up connecting the wrong passages :lol:
Kind regards, Arnold
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You are doing fine, it looks very good. Nice work. :clap: :clap: :thumbup:
-
Tim,
I designed and made two different running prototypes of tiny V-twins, for minivap boats, and I had to use tiny external tubing to connect up the ports, what a PITA, but the holes would have been just too difficult to drill as you have, the drills would have been about 0.7mm diameter, and almost guaranteed to break down the transfer holes.
I gave HS93 (Peter) all the parts to make about ten of them a little while ago.
If I could just make a suggestion.
On the port faces of your cylinders, run an end mill across the centre of them, or across the centres of the port faces of the main standard, they only need to be about 10 thou (0.25mm) deep, so you have equi distances either side of the port holes unmachined. That will reduce friction no end, and help the faces to bed in much more quickly.
John
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Wow !! :drool: Drilling those holes was impressive :bow: It would have gone horribly wrong had I tried! Nice work!
Chris
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Hiya Spud,
All this DRO caper - I thought that you had CNC'd this X2 Mill of yours??
Murray.
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If I could just make a suggestion.
Please do, I appreciate all the help I can get.
On the port faces of your cylinders, run an end mill across the centre of them, or across the centres of the port faces of the main standard, they only need to be about 10 thou (0.25mm) deep, so you have equi distances either side of the port holes unmachined. That will reduce friction no end, and help the faces to bed in much more quickly.
Do you mean like this,
(http://velvet-art.smugmug.com/photos/i-fTSTZvN/0/M/i-fTSTZvN-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303432755_fTSTZvN-A-LB)
If so maybe using a larger endmill may do the trick, centered on the pivot bore.
Thanks Chris :thumbup:
Hiya Spud,
All this DRO caper - I thought that you had CNC'd this X2 Mill of yours??
Murray.
Hi Murray, you are right, My X2 is CNC'd, but for the purposes of this build log I'm not using it except as a fancy sort of DRO system. One reason for this is that I still have some bugs to iron out in the CNC setup, but the main reason for just using it as a DRO system on this build is that I dont want to give the impression that CNC is needed to build this engine. In fact, you dont even need a DRO, although it does maxe it a lot easier, it is very possible to machine it off the dials and via accurate marking out.
Tim
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I got started on the Endcaps today, and started by chucking some 20mm brass bar in the lathe, and then turning down a section to 13.8mm (the OD of the endcaps) and then turned a tiny 8mm spigot (to fit the cylinder bore). Then I marked up the bar to show a 1.5mm line.
(http://velvet-art.smugmug.com/photos/i-QWx4nq4/0/M/i-QWx4nq4-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303827988_QWx4nq4-A-LB)
Then I parted off at the line, then repeated 3 more times.
Then I had to clean up the little pip left on from parting, my plan is to mount them into a 14mm ER32 collet and then skim off about 0.1mm off the face. However, as I have tried to chuck up thin items before in my ER32 chuck and have found that without something the same diameter in the rear of the collet, when you tighten the collet up it tends to pull out of true, so I just used one of the endcaps in the other end,
(http://velvet-art.smugmug.com/photos/i-xgXp8ZL/0/M/i-xgXp8ZL-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303827090_xgXp8ZL-A-LB)
Then I used a plastic handle to "nudge" the endcap into alignment while the collet is only hand tightened with the lathe rotating slowly, then stop the lathe and tighten up.
(http://velvet-art.smugmug.com/photos/i-KJ4fVdh/0/L/i-KJ4fVdh-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303827465_KJ4fVdh-A-LB)
All four,
(http://velvet-art.smugmug.com/photos/i-6cmLvcq/0/M/i-6cmLvcq-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303826245_6cmLvcq-A-LB)
Then I took the ER32 collet off the lathe and mounted it on the mill, and drilled the mounting holes.
(http://velvet-art.smugmug.com/photos/i-JNqXLgc/0/M/i-JNqXLgc-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303827695_JNqXLgc-A-LB)
Then after drilling all 4 holes in the endcaps I couldnt resist mounting one on a cylinder.
(http://velvet-art.smugmug.com/photos/i-4mvXrZS/0/L/i-4mvXrZS-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1303827763_4mvXrZS-A-LB)
Next up will be the packing glands.
Tim
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Nice job, Tim. It is really coming together great!
Chris
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That's exactly what I mean Tim. Most times it is done on the standard, but it can also be cut as you have shown and as I said.
The use of magnets is really intriguing me, I can't wait to see how it turns out.
I'm all for experimentation with new ideas.
John
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That's exactly what I mean Tim. Most times it is done on the standard, but it can also be cut as you have shown and as I said.
I can see how this will reduce the friction, I think I might make the cuts on the frame instead of the cylinders due to holding the frame in the mill being a lot easier than the cylinders, thanks for that suggestion :thumbup: With the strength of these magnets, eliminating as much friction as possible will really help.
The use of magnets is really intriguing me, I can't wait to see how it turns out.
I'm all for experimentation with new ideas.
The idea of using magnets to hold the cylinders on has fascinated me for about a year, but only at the start of this project have I had any chance to try it out. The worst that can happen is that it doesnt work, but having done a few rough-n-ready tests of the strength of pull's of various magnet sizes, and also of magnet to steel strengths, I have come to the conclusion that I will be faced with the problem of too much attraction rather than too little, and that should be solved by adjusting the size of the steel inserts that the magnets attract to, as well as having the option of slightly increasing the operating gap between magnet and steel insert.
At the moment I am still making parts that should not have any adjustments to them, but in a while I will be back to making experimental parts and adjusting them, then updating the plans on Alibre to match, should be fun :smart:
Tim
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Just a brief update, I found a couple of hours in the 'shop and made a start on the packing glands, or rather, the gland nuts.
I was intending making direct copies of the packing glands as designed by Bog's in the paddleducks build, but as these are quite a bit smaller I had to reconsider.
Therefore I came up with an experimental design ( at least I think it is experimental, I havent seen in used on other builds. Time will tell if there is a very good reason for that :lol: )
But just like in the paddleducks plans, I am making the nuts 1st so that they can be mounted on the packing glands for theu drilling to ensure concentricity.
So I started out with some 8mm brass hex in the 3jaw
(http://velvet-art.smugmug.com/photos/i-cCm2nM9/0/M/i-cCm2nM9-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1315462179_cCm2nM9-A-LB)
Then used the round profile tool to form a profile on one end, then centre drilled
(http://velvet-art.smugmug.com/photos/i-Cmv2TNJ/0/M/i-Cmv2TNJ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1315461725_Cmv2TNJ-A-LB)
Drilled to a depth of 3-3.5mm
(http://velvet-art.smugmug.com/photos/i-8Fhjjxw/0/M/i-8Fhjjxw-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1315461724_8Fhjjxw-A-LB)
Then tapped M4, I had to grind the tips off the taps, you can see an unground tap in the background.
(http://velvet-art.smugmug.com/photos/i-Zkj32BD/0/M/i-Zkj32BD-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1315462270_Zkj32BD-A-LB)
Then part off and repeat 3 more times.
I then spent the rest of the time I had figuring out how I was going to turn the packing gland. I did make just one, just to see how and if I could make it. And just to tease you here's a pic of it with the other nuts.
(http://velvet-art.smugmug.com/photos/i-ZvNvrcL/0/L/i-ZvNvrcL-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1315462101_ZvNvrcL-A-LB)
These packing glands are of an inverted thread design, ie the exterior thread is on the gland, the interior on the nut. I reaslise that this is not standard, and am half expecting that it will not work quite as well as the more standard version. I have very little room for anything else on this engine, plus I expect this engine will be operating on fairly low pressure (about 5-10 psi once ran in) and so should run ok even without any stuffing in the packing glands.
Next time I will show how I turned the glands (or at least the 3 remaining ones :lol: )
Tim
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On to the rest of the Packing glands.
I chucked some 20mm brass bar and reduced a section to 13.8mm ( the required od ) and then reduced a 0.5mm bit to fit the bore on the cylinders (about 8mm)
(http://velvet-art.smugmug.com/photos/i-ddLZp9L/0/M/i-ddLZp9L-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274629_ddLZp9L-A-LB)
Then I swapped over for a parting tool and turned a 4mm long section down to 4mm diameter.
(http://velvet-art.smugmug.com/photos/i-SRdk7DQ/0/M/i-SRdk7DQ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274882_SRdk7DQ-A-LB)
Then after parting it off and making the others, I mounted a 14mm collet and reversed the glands in the chuck, then using a tailstock die holder I threaded the 4mm diameter spigot M4 as far as I could get, and then centre drilled the end to form the "V" for the packing.
(http://velvet-art.smugmug.com/photos/i-RG2gPv8/0/M/i-RG2gPv8-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274865_RG2gPv8-A-LB)
Then screw on the packing nut made earlier and centre drill it
(http://velvet-art.smugmug.com/photos/i-NDhXbrj/0/M/i-NDhXbrj-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274399_NDhXbrj-A-LB)
Follow up with a 2mm drill bit and drill thru both the nut and the packing gland (carefully pecking to prevent drill snappage) and make sure that you keep each nut paired with the gland.
And here all 4 are,
(http://velvet-art.smugmug.com/photos/i-8zpXMZD/0/M/i-8zpXMZD-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317273952_8zpXMZD-A-LB)
I then unbolted the ER32 chuck from the lathe and gripped it in the mill vice to drill the 4 mounting holes.
(http://velvet-art.smugmug.com/photos/i-LtrJMLZ/0/M/i-LtrJMLZ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274006_LtrJMLZ-A-LB)
And here is the obligitory posed shot with a cylinder (complete with magnet epoxied in place)
(http://velvet-art.smugmug.com/photos/i-jnhCh6x/0/L/i-jnhCh6x-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1317274406_jnhCh6x-A-LB)
Next up will be the pistons and con-rods, crank webs and crankshafts.
Tim
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Nice work, but why not studs and bolts? :thumbup:
-
Nice work, but why not studs and bolts? :thumbup:
I'm not to sure exactly where you are meaning about the studs? :scratch: But if you are referring to the fasteners for holding the packing glands in place, I haven't decided if I will just use hex-head screws for their ease, or to make up some acorn-style nuts and install studs. I guess I'll get it running before I decide on that one.
Thanks for following,
Tim
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Nice going Tim :clap:
Pete
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oooooo brill
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No I mean the cylinder topp and cylinder botom. I think that your'e engine should look even better then. :thumbup:
-
I agree the unbrakos look a little out of place
Pete
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Ohh you guys mean using studding and then nuts on top like a more traditional engine. They used this to secure the top and bottom cylinder covers on my Stuart 10V and I really never understand the benefit. ... is it purely just looks? In my opinion, they were more of a pain in the arse than anything but I do expect they will look a bit better than the cap heads maybe!? I`m guessing something that could be replaced with no hastle at the end of the build or in the final build.
Any more updates Tim...I`m waiting patiently...now get your finger our :poke: :lol:
Chris
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Ohh you guys mean using studding and then nuts on top like a more traditional engine. They used this to secure the top and bottom cylinder covers on my Stuart 10V and I really never understand the benefit. ... is it purely just looks? In my opinion, they were more of a pain in the arse than anything but I do expect they will look a bit better than the cap heads maybe!? I`m guessing something that could be replaced with no hastle at the end of the build or in the final build.
Yea, they're referring to replacing the socket caps screws with studs and nuts. I do agree that they look a lot better on a steam engine, but they are a lot of hassle. I'm still undecided on whether to do this on this build, I guess if the engine runs without too much trouble I probably will do the studs and nuts route. But if it takes a whole world of fiddling to get it running I may skip any additional hassle.
Any more updates Tim...I`m waiting patiently...now get your finger our :poke: :lol:
Chris
I've been suffering with a bad back this last week and just havent felt up to it this week, however I did think that I had made some progress last week, I made the pistons and got them to a nice tight sliding fit in the cylinders, ready to be lapped in with some T-cut, then realised that to ensure concentricity for getting a good seal through the packing gland, I should have left the piston oversize to be attached to the con-rods and then finished the piston to size gripping them by the con-rod in the ER32 chuck in the lathe. :bang: :doh: :bang: :doh: :bang:
So hopefully at the weekend I will get a bit more progress done.
Tim
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Yes, good point. Chris
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Missed this one, nice work and very innovative Tim. On the last few oscillators I've done I have milled the relief as Bogs suggested and it makes a big difference, lets the port faces pull up nicely to each other.
Nick
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Thanks Nick :thumbup:
I will be milling the relief as suggested by John, but because I have already glued the magnets and pivot rings into the cylinders, I will be making the relief in the main frame itself.
Tim
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keep in mind that these magnets drasticly and permanently lose thier pulling power when they get heated to much,, you might be able to use that in your favour if pulling power is an issue later........just a thought...
....Mike...
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keep in mind that these magnets drasticly and permanently lose thier pulling power when they get heated to much,, you might be able to use that in your favour if pulling power is an issue later........just a thought...
....Mike...
Good point Mike, and one I will file away just in case I have too much attraction ( a problem I have never personally suffered from in the past :lol: )
At the weekend I managed to get a little time to play, erm work done. :lol: Just a small update this time, hopefully get more done next time.
I started with some brass bar that was a bit oversize, and then drilled a 1.7mm hole in the center, to as deep a depth as I dare.
(http://velvet-art.smugmug.com/photos/i-HQhWXJZ/0/M/i-HQhWXJZ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1335243849_HQhWXJZ-A-LB)
Then I blacked up the brass bar, marked off a 5.5mm length, and then tapped the hole M2 for the conrod.
(http://velvet-art.smugmug.com/photos/i-mb3cjZj/0/L/i-mb3cjZj-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1335243752_mb3cjZj-A-LB)
Then part off at the previously marked line, and repeat the tapping, marking and parting off until you have 4. Then I cut 4 lengths of 2mm stainless steel for the conrods.
(http://velvet-art.smugmug.com/photos/i-bsHTxD4/0/M/i-bsHTxD4-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1335243272_bsHTxD4-A-LB)
Then mount the 2mm rods in the lathe to thread each end M2. I put a little spot of tapping lube on the tip of the stainless rod ( after putting a little chamfer on the rod with a file ) and then threaded it with my tailstock die-holder.
(http://velvet-art.smugmug.com/photos/i-QQZxJCG/0/M/i-QQZxJCG-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1335243402_QQZxJCG-A-LB)
Then I cleaned the threads, added a drop of locktite and then assembled the conrods to the pistons.
(http://velvet-art.smugmug.com/photos/i-4LSbkHT/0/L/i-4LSbkHT-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1335243301_4LSbkHT-A-LB)
Next will be bringing the pistons down to final size to match the cylinders, and then starting on the crank-webs and crankshafts.
Tim
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On to truing up and matching the pistons to the cylinders.
I started by mounting a piston-conrod assembly in the ER32 Chuck, but with a couple of washers to space it out from the chuck.
(http://velvet-art.smugmug.com/photos/i-rBffbxS/0/M/i-rBffbxS-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1338889857_rBffbxS-A-LB)
Then I cleaned up the end of the piston and reduced it until it was about 0.1mm oversize, then I put 2 oil-grooves in using the edge of a half-round file, just held by hand to create a shallow groove. ( very important note, any files being used on the lathe MUST have handles installed ) Then I reduced the diameter until the piston just begins to fit into the cylinder bore. ( I was advancing the cross-slide by 0.01mm each pass ) then I used some 800grit wet&dry to just polish the piston until it fitted snugly in the bore.
(http://velvet-art.smugmug.com/photos/i-XWpNBvt/0/M/i-XWpNBvt-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1338888760_XWpNBvt-A-LB)
Repeat that another 3 times and there you go,
(http://velvet-art.smugmug.com/photos/i-W9ZCZCc/0/M/i-W9ZCZCc-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1338890283_W9ZCZCc-A-LB)
as each piston is matched to a cylinder, I now will try to keep them paired up, each in their own compartment.
It looks like I will have to shorten the conrods a bit, I have another part to make that will screw onto the conrod end that links to the crankpins. So until I have those parts made, and the crankshaft assembly too, the shortening will have to wait.
In view of that I thought I would make a start on the crankwebs. I chucked a piece of 20mm brass into the lathe.
(http://velvet-art.smugmug.com/photos/i-Trx4Kts/0/M/i-Trx4Kts-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1338889634_Trx4Kts-A-LB)
Then I was rudely interrupted by my better half returning home, and so I had to go inside for some lunch. ( just think of all the things we could get done if we didnt have to eat. Would save a fortune too :lol: ) So the rest of the crankwebs will be for the next update.
Tim
-
I've been itching to get back into the workshop for over a week now, but I believe that you can get tablets from the doctors to help with that :lol:
I also must give credit for the design and machining order of the crankdiscs to John (Bogs) :bow: :bow: as it is pretty much an exact copy from John's Paddleducks plans, just made a little smaller.
I got a couple of hours more in the workshop today, and carried on from where I left off in the previous post.
I reduced the brass bar down to 15mm diameter.
(http://velvet-art.smugmug.com/photos/i-PMRRMnn/0/M/i-PMRRMnn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354031381_PMRRMnn-A-LB)
Then parted off four 4mm thick discs.
(http://velvet-art.smugmug.com/photos/i-FHp8Ng7/0/M/i-FHp8Ng7-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354031144_FHp8Ng7-A-LB)
Then I chucked each of them in a 15mm er32 chuck and drilled a 3mm hole in the centre.
(http://velvet-art.smugmug.com/photos/i-jBCpKrZ/0/M/i-jBCpKrZ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354031452_jBCpKrZ-A-LB)
I could've just drilled them all before parting off, but the drill could well have deflected during the 25mm depth, and I really wanted to make sure that the holes would be central, so I drilled them all separately.
Then I made up a little jig to hold the crankdisc blanks in order to drill the crankpin holes all in exactly the same distance from the crankshaft centre.
(http://velvet-art.smugmug.com/photos/i-NbGKTbs/0/M/i-NbGKTbs-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354030163_NbGKTbs-A-LB)
It has to be the easiest jig to make, just drill a 2.9mm hole, press a short length of 3mm rod into the hole, then move the mill table over by 6mm ( half the stroke length ) and lock it in place. Then pop a crankdisc on it and then drill it with a 2mm bit.
(http://velvet-art.smugmug.com/photos/i-DWbhRBR/0/M/i-DWbhRBR-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354029898_DWbhRBR-A-LB)
Do that 3 more times, and then it is on to machining them into somewhat balanced cranks. I put a 3mm drillbit into the central holes and a 2mm rod into the 2mm holes :doh: then using some 0.5mm shims ( some feeler gauges ) to bring the 2mm rod up a tad. Press the whole lot down onto the vice and tighten.
(http://velvet-art.smugmug.com/photos/i-8jBHC63/0/M/i-8jBHC63-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354030019_8jBHC63-A-LB)
Then I let loose with a 14mm endmill and nibbled down to what seemed to look ok, zeroing the DRO at the bottom cut. Then turn over and repeat.
(http://velvet-art.smugmug.com/photos/i-cpdqhSx/0/M/i-cpdqhSx-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354030972_cpdqhSx-A-LB)
Then it was a case of removing any burrs raised, then it was on to cutting the compression slot, this is done on each crankdisc individually, so I used a vice stop. Using the same shims and 3mm and 2mm rods to align before clamping. Then I aligned the slitting saw by eye.
(http://velvet-art.smugmug.com/photos/i-xd7BW3T/0/M/i-xd7BW3T-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354030913_xd7BW3T-A-LB)
Then I removed the rods and slitted the slot.
(http://velvet-art.smugmug.com/photos/i-nfpZ6MK/0/M/i-nfpZ6MK-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1354030833_nfpZ6MK-A-LB)
Stay tuned for more updates.
Tim
-
Got the crankwebs finished off today, not that there was much to do :lol:
I started by drilling and tapping the hole for the tightening screw. Then I took some 4mm stainless rod and turned a section down to 3mm to use for the central part of the crankshaft that goes through the main frame, and a section of 2mm stainless rod for the crankpin.
Then I couldnt resist assembling some bit together, and came up with this,
(http://velvet-art.smugmug.com/photos/i-JMq6zCp/0/M/i-JMq6zCp-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1355192151_JMq6zCp-A-LB)
(http://velvet-art.smugmug.com/photos/i-KN3hMKG/0/L/i-KN3hMKG-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1355192384_KN3hMKG-A-LB)
Next up will be the little "L" shaped pieces to connect the conrods to the crankpins. Then a little final modifying of the length of the conrods. Then the outer frames and connecting pieces. Then just a few hundred more operations and it'll be all done :lol: :lol:
Tim
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Now I know what your making next, will you please get a wriggle on. :whip: :whip: :poke: :whip:
Only kidding, looking good Tim. I can really see how it is all fitting together now. It stupidly took me a while to understand how these magnets are working/what they are doing but now I fully understand, great idea!!
Chris
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Nice progress here, looking very good. :clap: :clap:
-
I can't believe that it has been so long since my last update, domestic duties and a week of visiting my better half in hospital have taken my attention til now.
Today I got started on the little "L" pieces that will connect the piston to the crank-pin. I found a piece of brass approx 18mm x 3.3mm x 300mm, made a rough sketch of what I wanted to achieve, and set to it.
(http://velvet-art.smugmug.com/photos/i-JpKCfvn/0/M/i-JpKCfvn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401683002_JpKCfvn-A-LB)
I set it up in my vice on a parallel which was slightly thicker than the brass, so I had to use a second parallel to flesh out the brass to be gripped by the vice. Then I set up a temporary vice-stop and zeroed off the rear of the brass and the end next to the vice stop.
Then I moved to the centre of the 3.3mm width, advanced on the x-axis by 2mm and center drilled, then moved over 5mm and drilled again, repeat until 5 holes were started. Then I swapped over to drill for M2 tapping.
(http://velvet-art.smugmug.com/photos/i-7N6DWnt/0/M/i-7N6DWnt-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401683567_7N6DWnt-A-LB)
Once all those holes were drilled I opened the vice up and turned the brass onto it's side, pushed up against the vice-stop and tightened it up. Then I removed the vice-stop as it was in the way, and moved to the right coords and drilled 2mm holes.
(http://velvet-art.smugmug.com/photos/i-csPGRRm/0/M/i-csPGRRm-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401683791_csPGRRm-A-LB)
Then I swapped the drill for a 4mm end mill and milled slightly more than half the thickness away.
(http://velvet-art.smugmug.com/photos/i-h3F2RQ9/0/M/i-h3F2RQ9-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401682248_h3F2RQ9-A-LB)
Then I tapped the top holes M2.
(http://velvet-art.smugmug.com/photos/i-7dJN6w3/0/M/i-7dJN6w3-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401682164_7dJN6w3-A-LB)
and then carefully hacksawed,
(http://velvet-art.smugmug.com/photos/i-LZ475fn/0/M/i-LZ475fn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401682288_LZ475fn-A-LB)
then I gently hacksawed in the other direction to release them. But prior to releasing them, I cleaned them up as much as possible with a small fine file.
Then I gripped each tiny "L" in the vice and rounded over the bottom end with a file. I made 5 as I thought that would give me one to lose/spoil/have-as-a-trophy, and sure enough I did spoil one.
(http://velvet-art.smugmug.com/photos/i-ZjQTvFp/0/M/i-ZjQTvFp-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401682495_ZjQTvFp-A-LB)
Here they are in place,
(http://velvet-art.smugmug.com/photos/i-hFtRh46/0/L/i-hFtRh46-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401683233_hFtRh46-A-LB)
(http://velvet-art.smugmug.com/photos/i-HgbwKw5/0/L/i-HgbwKw5-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1401683066_HgbwKw5-A-LB)
And that's as far as I got. I think next up will be making the outer support frames and some form of a base.
Tim
-
Tim,
That was very well done, :clap: :clap:
goodness they are tiny.
It's comming on very nice :thumbup: :thumbup:
DaveH
-
Nice work there Tim and great photos as always. Going to be quite a powerful, compact engine this one. :thumbup:
-
Very nice
Should be a very smooth revvy little engine
John
-
Well, I thought I would get my finger out and get on with this build :lol: Having finished with another time-sensitive project I got back on track with this, I made a start on the two outer frames that fit either side of the main frame.
After hacksawing, squaring, and then flycutting to thickness, some 6mm ali plate down to just over 5.5mm thick, then I marked out for drilling for the crankshaft and 4 mounting posts.
(http://velvet-art.smugmug.com/photos/i-PVT8t9K/0/M/i-PVT8t9K-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438236910_PVT8t9K-A-LB)
After drilling the holes I then put all 3 frames together, held in alignment by as couple of 3mm drillbits, and clamped them in the vice in order to drill and tap holes M2.5 for attaching the frames to a base.
(http://velvet-art.smugmug.com/photos/i-43C3zzn/0/M/i-43C3zzn-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438237951_43C3zzn-A-LB)
After drilling for the M2.5 holes I flycut across the bottom as they were very slight diferences between them and while they were aligned with the drillbits I thought it would be an ideal time to skim a tiny cut to level them.
(http://velvet-art.smugmug.com/photos/i-qRXcXbB/0/M/i-qRXcXbB-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438236695_qRXcXbB-A-LB)
Then I moved them over to my tapping stand and tapped them.
(http://velvet-art.smugmug.com/photos/i-MZ4kTc3/0/L/i-MZ4kTc3-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438237527_MZ4kTc3-A-LB)
Then I moved on to shaping the outsides of the frames, 1st up was the outer frames. I have to confess, I did have full intentions of machining them manually using a base-plate jig and the rotary table, but as I had managed to get most of the bugs ironed out of my CNC system I decided to use that method instead.
That being said, it wouldn't take much to set up on a rotary table, and I still had to make a little jig plate to attach the frames to so that they can be held securely for machining, which is what I did next. Using a scrap piece of 6mm ali plate, I quickly squared it up and then drilled matching holes for the 4 3mm holes that are also in all the frames, then I tapped them M3.
(http://velvet-art.smugmug.com/photos/i-cc683h5/0/M/i-cc683h5-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438239392_cc683h5-A-LB)
Then I mounted one of the outer frames onto it and was pleasantly surprised to find that the M3 cap screws aligned quite tightly even before tightening them up, then to make sure everything was held square I ran a dti held in the chuck along one edge of the frame, and again was surprised that it was spot on ( well it was 0.05mm out over the length of the base, close enough for me )
Then I unleashed the CNC and let it do it's thing, just watched and brushed the chips away and squirted a bit of cutting fluid on from time to time until I ended up with this,
(http://velvet-art.smugmug.com/photos/i-9B3mD7C/0/M/i-9B3mD7C-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438238607_9B3mD7C-A-LB)
After doing the other one and a bit of cleaning up I ended up with this,
(http://velvet-art.smugmug.com/photos/i-dJFM3nW/0/L/i-dJFM3nW-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438239127_dJFM3nW-A-LB)
I know that the upper circular part is not centered on the crankshaft hole, I may redo that, but will probably use a couple of filing buttons and just hand file it to the right shape.
Then I set up the main frame in the jig and, because there is so much more work involved in the main frame, and some very critical distances involved with the long drilled internal steam passages, I double checked that the frame was still held perfectly square.
(http://velvet-art.smugmug.com/photos/i-KMt9gnT/0/M/i-KMt9gnT-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1438239104_KMt9gnT-A-LB)
That's all I got done, so next will be the sphincter-tightening stage of cutting out the shape on the main frame, either you will hear from me with joy as it has gone well, or you will not hear from me for some time as I have to remake it :bang:
Tim
-
Well, I didnt screw the frame up, but I have slightly mixed feelings as my CAM output that I made for CNC'ing the frame ended up cutting it a bit too close for my comfort. It didnt break through any of the long-drilled holes, but there isnt much left, just enough to smooth the frame.
Anyway, here's a pic of the frame after shaping and then some cleanup with files and sandpaper (yea, my inexperience with CNC is showing, but I've learnt a huge amount on this)
(http://velvet-art.smugmug.com/photos/i-zMxJhkj/0/L/i-zMxJhkj-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457193807_zMxJhkj-A-LB)
I then marked up the tops of the arms for the frame for drilling the inlet/exhaust pipework that will go to the speed control/reversing valve.
(http://velvet-art.smugmug.com/photos/i-4KtZm8J/0/M/i-4KtZm8J-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457193893_4KtZm8J-A-LB)
When I attempted to drill the holes for the inlets using a 4mm drillbit, it broke through to the top long-drilled hole in the arm (which is only 1mm or less from the top of the arm) and that pulled the drill off line and made the hole oval. :bang: So instead of having a 4mm hole that the copper feed pipe could fit snugly into (soldered to a flange that screws to the top of the arm) I had to enlarge the hole to 6mm using a 6mm endmill ( I should have used a 4mm endmill to start with to prevent it being pulled offline when it breaks into the long-drilled hole )
(http://velvet-art.smugmug.com/photos/i-XQRfcfq/0/M/i-XQRfcfq-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457194244_XQRfcfq-A-LB)
Then, while I had the vice stop set up I moved over 4.5mm and drilled for tapping M2, then went 9mm the other way (4.5mm the other side of the inlet) and drilled again, then I swapped over to the other arm and repeated the process. Once all hole were drilled I then tapped them M2.
(http://velvet-art.smugmug.com/photos/i-jWWWL6t/0/M/i-jWWWL6t-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457196283_jWWWL6t-A-LB)
Then I turned up 2 flanges out of brass, I forgot to take any in progress pics but they are very straight-forward to turn, a section 6mm diameter to fit into the holes I just made in the frame arms, and a 12mm flange with a 4mm thru hole for the copper pipe to be soldered into.
Side profile,
(http://velvet-art.smugmug.com/photos/i-F5PvgTJ/0/M/i-F5PvgTJ-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457196342_F5PvgTJ-A-LB)
Then I had to make a jig up to drill the fixing holes in the flanges. Just a 6mm hole drilled thru some scrap Ali, a 2mm hole drilled 4.5mm away from the 1st hole, and a little pin I have from another jig.
(http://velvet-art.smugmug.com/photos/i-sMXRJss/0/M/i-sMXRJss-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457196355_sMXRJss-A-LB)
Then insert a flange into the jig and drill one hole,
(http://velvet-art.smugmug.com/photos/i-Ps3cBt8/0/M/i-Ps3cBt8-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457195472_Ps3cBt8-A-LB)
Then insert the pin to keep the flange from rotating, and then move over 9mm to drill the other hole.
(http://velvet-art.smugmug.com/photos/i-9XLjnzF/0/M/i-9XLjnzF-M.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457194347_9XLjnzF-A-LB)
Then I just used some files to shape the sides of the flanges, and here is one in place on the frame.
(http://velvet-art.smugmug.com/photos/i-QZHRCw7/0/L/i-QZHRCw7-L.jpg) (http://velvet-art.smugmug.com/Engineering/Velvet-V4/16973866_7wwW5p#1457195254_QZHRCw7-A-LB)
The flanges are a nice fit into the frame, which when combined with a smear of liquid gasket it should seal quite nicely.
Next up will be some form of a base.
Thanks for watching,
Tim
-
Looking great Tim and nice job on the CNC frames - your machine works great!
Chris
-
Looking great Tim and nice job on the CNC frames - your machine works great!
Chris
Thanks Chris, but while the CNC worked great, my programming in CamBam was quite lacking. There was a lot of cleaning up that I had to do. I didnt program a cleanup pass, and so I had to file out all the marks from milling it down 1mm at a time.
Another time I should program it to leave 0.3-0.5mm for a final full-depth pass to clean up.
Tim