Arnold building the "Little Blazer"

[sbwhart]

Looking good Arnold you make real quick progress 

Stew

[madjackghengis]

Hi Arnold, It was good to see the crank being machined according to the instructions, and from the looks of the cam, it's right, and in keeping with my last post, I still think you will do just fine with the piston you have, and you definitely made a good choice in your deliberate decision.  It looks like you're right close to being ready to start it up, just a few more pieces.  Very nice work with the log as well, very easy to see your work.  Now I'm really looking forward to that video    The "Mad Jack" came out of the fact I used to run when I was a Marine, and did so both in the morning, with my Marines, and at noon, for my own pleasure, hence the "mad".  Just a couple more pieces..... I really want to see how that cylinder works out for you  mad jack

[arnoldb]

Thank you very much Dean : ) I don't know about "just like a machinist" yet, but I must admit that I'm pleased with the progress I've made in learning to use my machines.  I have a lot to learn still, but that's all part of the fun!  I forgot completely about using an old ball bearing for whacking down the threads on the bottom of the T-nuts - must have been the heat-of-the-moment .  The last couple of times I made T-nuts, I actually just didn't tap them all the way through with the last tap in the set.  It might be better to tap them through though and then flatten the last thread; I think the bolts/rods screwed into them will stop more solidly and not try to seize up as much in the taper thread left by not tapping all the way through...

Nick & Stew, thanks !

  OK Mad Jack - you won me over with your explanation ;) and thanks!  There's still quite a couple of small parts to make, and these take the most time    The cam fork (and I have been known to end up with a "forked" fork!), roller wheel, valve, valve plate, valve spring, M2 set screws, -bolts, and -nuts and of course the base, flywheel and burner.  Winding the spring from an old guitar string will most likely require a jig as well and I have to make the slitting saw to slit the valve face (or cheat a bit!).  So I'm only about half-way there!

By the way, does anybody have a suggestion on "soldering" the valve plate to the valve ?  Mr Duclos does not specify anything beyond "soldering" it - would ordinary electronics solder (the old 60/40 type with real lead and tin) do the job, or is it better to silver braze it.  I don't know how hot the valve gets in operation; maybe the solder would melt?

Kind regards, Arnold

[madjackghengis]

Hi Arnold,  I'm glad the name thing is cleared up, but I answer to almost anything, as far as soldering, I have taken a worn out valve and soldered a piece of fresh brass to its face, and it lasted a few minutes and the solder was melted.  It was Sn63 Pb37, technical grade electronics solder.  In making the valve, Mr. Duclos suggests making a one tooth slitting saw, and putting a slot a few thousandths wider than the thickness of the spring, and having a radius at the bottom of it, matching a radius put on the end of the spring which is bent to be at right angles to the cylinder.  I used an actual slitting saw I had, fifteen thousandths thick, and it has worked well, however I have seen several other engines of this design where the builder simply bent the "spring", which in my case is a piece of brass shim stock, such that it was held flat against the valve face, with a very slight amount of spring pressure, as there is substantial surface area to be reckoned with, friction wise, and those engines seem to perform better.  With your cast iron cylinder, I expect a bronze valve would work fine, but it is a bit of work to cut out the area around the raised section in the middle where the slitting should be, and then cut the plate its self off the bar it is made on the end of, and then face off the cut side afterwards.  I've done it about three times and it's much easier the second time, but I wished I'd have made the valve just out of the flat of the spring, or, now with my experience with aluminum cylinders, made it using similar technique, but out of a motor brush of graphite, which would be both lighter and non-galling on the aluminum.
   To make the spring its self the valve, I'd go with a piece of brass shim stock about fifteen thousandths or so, cut to width a bit wider than the port, leaving extra length, clipping the corners on the other end and rounding it out, then bending it at just less than ninety, holding it against the valve face and finding where the valve rod will hit the bent up end, drilling it with the barest of preference to the outside, to allow for some spring force against the cylinder, then setting it up with two nuts centering it in the threaded area of the valve rod, and cutting off the excess about twenty thousandths past the outer edge of the port, then removing the shim stock and radiusing the corners by the port, and putting a radius on the end edge so the tip of the valve spring won't catch in the opening of the port, as it slams shut, as the cam is designed to do.  From there, it is a matter of adjusting the nuts to ensure the valve completely seals the port, but has no excess travel which would reduce the open time of the port.  To do the valve as Mr. Duclos specified would be to do essentially the same thing, except a couple of millimeters past the bend for the valve rod, you would have to bend it away from the valve face, with about a forty five degree angle, then bend it parallel to the port face for a short distance, and then bend it sharply in a right angle, to return back to the port face, and cut off the end, so it just about touches the face, and then put a radius in the end, to hold the bronze valve and keep it from sliding down under the influence of gravity, (it's the law) but having just enough spring to hold the valve plate in place while running, while not enough pressure to insert too much friction in the valve action.  With such a valve, a piece of spring wire could be used with a loop for the double nuts for adjusting the valve opening, and with two ends bent at right angles, and cut off to insert in two shallow holes in the valve, not penetrating the valve its self.  I will try to find a picture of an engine of this sort with the flat valve made straight out of the shim stock or spring steel if I can.  mad jack

[Gerhard Olivier]

Nice job on the engine Arnold

And congrats on the Engine of the month!!!!

Gerhard

[arnoldb]

Thanks Mad Jack - I thought the electronics solder would melt...  So it's silver brazing for me then; I'd better find the pencil torch!  I'm for once trying to stay as close to the original plans as possible on a build 

Double thanks Gerhard  - The engine of the month thing was totally unexpected!  Feels a bit funny to see the photo sitting there every time I look in on HMEM...

Tomorrow's a public holiday here in Namibia, so I should get some more done on the engine 

Kind regards, Arnold

[arnoldb]

Today's shop time 

First order of the day was the cam fork - a straight forward milling job to get to size:


And after sawing off from the parent stock, drilling and tapping and a quick rub over emery:


Then I made the cam roller:

This is the second one I made; the first one went on a flying trip while I was trying to clean up burrs - I just heard it hit a wall and something metallic; didn't even see where it went...  At least the shop monster got a bit to eat   

A little M2 bolt followed to act as roller pin - just some brass threaded rod turned down, threaded, and the head section filed to a hex while on the lathe:


Then I had to re-make the cam roller again  - I made the original one 3/16" and when I started putting things together, it looked way too small.  Misread the print; it was supposed to be 5/16"!  Parting off on the lathe no longer intimidates me like it used to, but on these smallish bits I always end up with quite a big burr that have to be removed from the parted face afterward.  I tried something different for this one: before drilling the center hole, I parted it to just under the drill size, then center drilled and drilled the hole to size.  Works a treat; I ended up with the roller sitting on the drill and only a very light burr:


The finished fork with the roller installed on it:

While posting, I happened to notice this photo was the 2000th one taken with my current digital camera - and I've only had it for about a year.  A quick calculation, and it has paid for exactly half of it's purchase price in saving on having 35mm film developed!

The valve plate needs a 0.28mm slot cut in it, and Phil very kindly describes making a small slitting saw for the job.  I deviated slightly from his design, but used the same principle.  First some 12mm silver steel turned down on the lathe; the section closest to the chuck I just cut using successive parting cuts with the rear toolpost, and then slowly and lightly faced the front section down to obtain the correct width.  A very sharp HSS toolbit made this a no-brainer though I was a bit apprehensive of machining to such a thin width initially:


Then some delicate-but-rough-looking milling on the rotary table followed.  The first person to spot the boo-boo I made has a choice of one of two prizes:

The prizes to choose from are a) an under-water hair dryer or b) a steam loco catching kit consisting of a bag of charcoal and a bear trap  - UK members don't qualify for option b though, as it would just get used to heat shops 
Fortunately, my mill can run in reverse....

I very gently filed cutting clearance behind the teeth, and then hardened the cutting teeth by heating red hot with a blowtorch and dunking vertically in oil.
For this cutter, I didn't bother to temper afterwards; it did not come out quite as well as I would have liked, so will most likely be a single-use one for brass only.

I then started work on the valve plate.  Some brass, carefully milled down to size:


And then used the cutter made earlier to slit the top - worked a treat  :


After using a bigger slitting saw to separate the valve plate from it's parent stock, it was just clamped by the protrusion in the middle, and milled down to the correct thickness of 0.3mm:


A bit of clean-up, and careful flat-lapping of the face (to remove toolmarks and get it really flat and smooth) followed - and that's the valve plate done:

I noticed something interesting while doing the flat-lapping.  Normally I can see the lapping starting to take effect very slightly on the outside edges first, but on this one, it started in the middle and took quite a bit of lapping to reach the outside edges...  I think while milling the bottom flat, the milling cutter bent the thin outside edges slightly down.  Just a tiny detail to consider in future....

At this point my woes really started...  I had the bit of 0.1mm feeler gauge to make the valve spring plate from.  Mark-out went easy and a pair of tin-snips made short work of trimming it down.  Then I had to consider drilling a 2mm hole in it to fit on the valve pushrod.  Thin plate and drills don't go well, so I sandwiched it between some aluminium scraps clamped with a toolmaker's vise:

Drilling went well, but I could feel that this feeler gauge plate was something different; it was tough to get through with the drill...

When I tried bending it, this happened:

  - this steel plate does not like bending...

That was the only bit of 0.1mm plate I had... The off-cuts are too small to use, but I used the busted bit to do an experiment; I tried bending it around some 1mm rod, and that went OK:

Except, when I tried the minutest adjustment after the original bend, it promptly snapped again. 

I tried bending it while heated red-hot with the pencil torch; same result.  I had a closer look at the feeler gauge set this came from, and it's made by Gedore in South Africa - pretty good quality kit - hence good quality, but frustrating, steel in this case.  I thought it was a cheapy set of imports; what a waste of good tooling.  At that point I decided to call it a day and have a good sleep over what to do next for the valve plate spring.  Besides, it had started raining here and rain is best appreciated sitting on the stoep (porch) with a very cold beer in hand.

Regards, Arnold

[arnoldb]

  It helps to sleep over problems...

This morning when I woke up I knew where to find some plate that should work; amongst the scrap from the old dot matrix printers that I'm stripping for parts.  I found a bit that was 0.12mm thick - and appears to be stainless steel:


The third time round making a bit goes quick; a couple of minutes later, I had the valve plate spring:


All set up for silver brazing; I squashed a tiny bit of flux into the groove before fitting the two pieces together:


Poking at this lot with a thick silver brazing rod was hairy, but I got the job done - sort of.  After some cleanup:


Next I raided my acoustic guitar for its high E string - Its been years since I played it as I tend to hurt my ears - and started making springs; something I've never attempted:

I made a booboo on this one; I need a compression spring, not a tension spring; but it was good practice.  The spring's internal diameter must be just over 2mm in my case, so I used a 1.5mm drill bit chucked in reverse in the pin vise.  The start of the wire was just squeezed between the jaws of the pin vise with a sharp bend to get started, and I turned the chuck manually by left hand - while just keeping tension on the wire and guiding it with my right hand.

After making a compression spring, I had this:

Not the most beautiful - but functional.  It would have benefited from a proper guiding setup instead of just trying to wind the spacing by eye...

Next call of the day was the flywheel.  Roughly trimmed down to size on one side:

The boss in the center is called for in the plans; I nearly missed it - and would have had to make a spacer later on if it was not there.

When I built the Grasshopper engine, I made up this double-sided tool for doing undercuts in flywheels    :


Flipped around, and the other side done.  For now, I left the excess on the outside, and only after I took this photo realized I had not completed the hub:


On to the RT on the mill; some 8mm holes drilled:


And then milled further with a 10mm end mill:


Back to the lathe, and this time with some suitable short stock chucked in the 3-jaw, then press the flywheel against the jaw faces with the revolving center - and with a bit of cardboard in between the wheel and jaws to provide friction.  Turning the rim to final size was then a breeze:


Then back to the mill to spot face, center drill, tap drill and thread the hub for a grubscrew:


I needed some M2 grub screws...  Some bits of M2 threaded stainless steel were slotted 0.5mm for a flat screwdriver:

I just used a junior hacksaw to saw them off after slotting while still held in the vise.

Hmmm, let's see now....  Going back through the plans, there's little check marks next to all the engine parts, and I made the additional ones I needed...  Al that's outstanding is the base and burner.  Some assembly followed, with some careful adjustments to work out a couple of tight spots, and a test with a recalcitrant pencil torch that does not want to stay lit with a smaller flame:

  - it's alive; not very well yet, but a good sign   
I'll try and finish the base and burner tomorrow and get it running properly   

  Arnold

[scrapman]

Hi Arnold  interesting build and it's a runner ,

Ray.

[Stilldrillin]

Arnold.
A runner!  You're wearing that big long distance smile! 

Very well done, and shown...... 

David D

[jamesemery728]

Very nice build Arnold and excellent pictures. I noticed in many of your mill pictures that it looks like you are using a small Dremel chuck to hold small drills. Can you tell me where you got the arbor that the chuck is mounted on. Did you make the arbor because I know that the small Dremel chuck has a very fine thread inside of it. Thanks and again what a great build.

[Dean W]

Arnold, I wasn't expecting to hear a running engine that soon.  It makes a great sound, and gets with it, too!
Your builds have been going very well these past months.  Well done.   

[sbwhart]

Great work Arnold

 

It will be a real nice looking and running engine when you've got the base finished/

Stew

[NickG]

Well done Arnold - another runner on Madmodder! It's fantastic! 

[Rob.Wilson]

 Cracking Arnold  ,,,,,,, Cracking 




Rob 

[arnoldb]

Thanks Ray!

Thank you David - the smile is even brighter today!

Thanks James; yes it's a Dremel chuck on a home-made arbor.  I'll dig up some photos and post it in the tools section in a bit, as it is a really handy piece of kit.

Thank you Dean; I think the powers that be is looking down kindly on my escapades; I'm really having a lot of fun in the shop of late!

Stew, thanks mate; I hope today's post meets expectations!

Thanks Nick - much appreciated!

  Rob; it's all your fault for giving me so much  in the past mate


Time to tidy up this one 

I started with the base, which I decided to make from wood for this engine.  A bit of Rhodesian Teak trimmed to rough size with the jigsaw:


Sacrilege! - but the flycutter works a treat in trimming down and cleaning up some wood :

I will really have to invest in some proper woodworking tools at some point!

I used a router bit to pretty up the edges of the block; the mill's top speed is a bit slow for routing bits, but it does get the job done:

Just needs some oil and a good rub-down with floor wax now...

On to a 3/4" to 1/2" copper pipe reducer; trimmed up and tidied up in the lathe:


A bit of scrap HRS turned down to a fairly tight push fit in the 3/4" section of the reducer:


The above was needed so that I could clamp the reducer at an angle in the mill vise without squashing it.  I only have 5.5mm diameter pipe for a spout, and no 5.5mm end mill, so I used a 4mm end mill to drill the hole for the spout, and then very carefully followed that with a 5.5mm drill bit.  A generous serving of cutting fluid was used; copper is one of the less fun metals to machine:


One of the projects I have on the back-burner is an experimental boiler build - and I learned one good lesson from that; It takes quite a bit more heat to re-melt silver brazing that was already done than to do new brazing.  With that in mind, I first silver brazed the spout in the reducer, then cleaned the bottom edge and bottom inside edge of the reducer very well with sandpaper, and made a ring from silver solder that fit in there:

Then I liberally coated around the silver solder ring with flux, being careful not to get any flux on the outside edge.  The foot plate is some 1.6mm brass that I just cleaned well with sandpaper.

I just carefully plonked the reducer part down in position on the foot plate, with a lump of steel on top to keep it in position, then let it sit like that for a couple of minutes so that the flux would gravitate down onto the brass foot plate as well, then used a blow torch to heat the lot up, concentrating the heat directly on the joint.  After a short while I could see some flux bubbling to the outside as it followed the flame, then it went black and then clear, and a second or so later I could see some silver brazing wicking through.  I used the flame right around the entire joint to draw the silver brazing through and let things cool down:

I'll happily admit that this is the best bit of silver brazing I've done to date   

The tank was then dropped in some citric acid to have a bit of a pickle, and I started on the cap for the tank - a simple turning and knurling job:


Wicking was a bit of a problem; I'd used cotton based wicking on Fred the Loco's burner, but when the meths run out the wicking is inclined to smolder and burn off.  Amongst my junk prized collection, I have a sheet of fiberglass mat... Some judicious peeling away of fibers was done, and then all aligned and rolled into a kind of string; a bit fiddly, but I got it fed into the spout in the end:

(Now it had more hair than me  )

I played barber a bit, and filled the tank with meths; A purple glow quickly appeared at the top of the wick, and I tested it:


Earlier while I was waiting for the meths tank to pickle, I'd also thoroughly oiled and lightly waxed the base, So I assembled the lot, and ended up with this:




A puff of graphite powder into the cylinder, a drop of oil on each of the running bits where needed; and a lot of fiddling with wick position; it's a choosy little bugger - but it runs 

The second part of the video was taken in my study; in the shop it was 35C and in my study with air conditioning 26C - It seems to like running in the cooler environment a lot better!

A fun, but challenging little project!

Regards, Arnold

[Bogstandard]

Fantastic runner and build sequence Arnold.

I just can't believe how fast those ones run, mine just plods along at a few hundred RPM. Yours almost becomes airbourne.


John

[madjackghengis]

Hi Arnold,  You've got a fine runner there, it sounds and looks great.  I was going to ask the purpose of the solder, as the instructions in the magazine article made no mention of it, and my valve "spring" is a piece of copper about 15 thousandths thick, with a radius on its end fitting in the radius slot in the valve, and it holds fine although you can see the valve plate slide up and down a few thousandths when its running, and I was afraid it would cause a bind, when I saw you soldering the two together, but it obviously works well, and causes no binding or loss of vacuum.  You definitely proved out the superiority of iron, for the cylinder, and in keeping with the last video posted, I am going to machine an iron cylinder and replace my aluminum one with it, and put an iron piston in it as well.  I just finished boring out my latest ali cylinder about five thousands, turned a graphite piston for it, fitted it all together, and it runs, but barely so, and only for a minute or two, as well as being very finicky about where the flame is.  I found out a while back, once it is running up to speed and warmed up, it runs best with the flame as far away as possible, so it can get the hottest part, the top, sucked in, but too far will instantly stop it.  Kudos for a fine build, a fine log, and a fine looking and sounding engine.  I don't think I've seen anyone's build go as smooth and without hitches as yours has unless you kept all the frustrations bottled up inside, and didn't share them with the rest of us   Great Job, and I hope mine runs as well with a better set of bits and pieces. mad jack

[arnoldb]

Thank you John - much more than just for your compliment.  I'd like to count myself very gratefully as one of the newbies who has learned a great deal from what you and other experienced machinists/builders have shared!

Thanks Mad Jack.  Yes, it is finicky about where the flame is; I had a look, and it runs best when it is sucking a nice blue bit of flame into the piston.  Setting the valve was fairly easy; I just tensioned the valve spring plate so that it barely holds the valve against the face, and also manipulated things that the valve is very flat against the face.  I didn't spend all that time flat-lapping for nothing ;)

Kind regards, Arnold

[Bogstandard]

Arnold,

Only a couple or three years ago, people were having all sorts of trouble getting these flame lickers running, and because of that, at that time, not many were ever built, and a lot of those that were, got thrown under the bench in frustration at getting them to run.

By everyone sharing their info about such things, it seems that anyone who builds one now can get the knowall to make a running engine.

Only by sharing, mistakes and all, does everyone become a winner.


John

[Stilldrillin]

Arnold.
That's beautifully finished, and a superb runner. Well done! 

David D

[Dean W]

Really runs great, Arnold.  I sure like the sound, too.  Very much like the sound of a small IC engine.
Well done, again!

[scrapman]

Lovely runner and a nice build  ,

Ray.

[NickG]

John is right,

Not an easy engine to get running because of their low specific power output, therefore there must be many under the bench or on the shelf having never run. People sharing ideas and problem solving on forums like this have undoubtedly helped a lot of people, I don't think I'd have got mine running without it. At Harrogate show somebody had built the same Jan Ridders (to a higher standard than mine I must add) but couldn't get a peep out of it. He was asking all sorts of questions so I took him through all of the findings that have been shared and we almost had it running at the show. With a couple of minor tweaks he would definitely have had a runner.

I haven't seen the 2nd (finished) video yet so something to look forward to tonight. I think the reason this, poppin and the like run much faster is because with a cam controlled valve you can play a lot more tunes with it.

Am looking forward to finish my poppin off, would be over the moon if it runs at all, let alone like yours arnold.

Nick

[madjackghengis]

Arnold,

Only a couple or three years ago, people were having all sorts of trouble getting these flame lickers running, and because of that, at that time, not many were ever built, and a lot of those that were, got thrown under the bench in frustration at getting them to run.

By everyone sharing their info about such things, it seems that anyone who builds one now can get the knowall to make a running engine.

Only by sharing, mistakes and all, does everyone become a winner.


John

  I think John is dead on target here, I built my "little blazer" almost twenty years ago, spent probably six months trying to figure out why it didn't run, and left it lying on different shelves as I moved.  It was only seeing someone else build one, look intensly through the build log, and seeing it running that made me pull mine out, find the errors I'd made, fix them, and finally have a good runner, good enough to be banned from running in the house.  It is particularly satifying to see someone like Arnold, start the project, follow a very nice build log and see success right off the bat, and recognise the amount we share with each other, particularly when we show our problem children, and get them running.  I can't speak for anyone else, but this forum makes me feel almost like I am in a club, and I really wish I could get together with the many fine artists I've watched build things of great interest to me. cheers to all, mad jack