Author Topic: Three Cylinder Radial Engine (Read 82694 times)

dsquire · « **Reply #25 on:** December 07, 2009, 12:29:53 PM »

Stew

Starting to shape up nicely. I love watching those parts crawl out of a block of metal and take on a life of their own.

Cheers

Don

NickG · « **Reply #26 on:** December 07, 2009, 01:27:51 PM »

Nice 1 Stew, starting to look like engine bits already!

Nick

bogstandard · « **Reply #27 on:** December 07, 2009, 02:51:42 PM »

Very nice Stew, it is bringing back memories of making mine.

Mine was a lot more difficult, because it was a commercial castings kit that I used, and that was definitely a time it would have been better to do as you are doing, make it from bar stock. In fact it was the next set of castings that I used that put me off using them for life.

That is a bit of good advice for almost any thinking of making an engine from castings. A lot of the parts can be made from barstock much easier and cheaper, and only buy the castings that would be very difficult to produce.

John

Rob.Wilson · « **Reply #28 on:** December 07, 2009, 05:10:00 PM »

Geart work Stew

looks like allot of work in that crankcase ,,, i will not ask how big it is

I have allways fancey'd having ago at a raidal engine ,keep it up great read

Regards Rob

NickG · « **Reply #29 on:** December 07, 2009, 06:44:43 PM »

I cant wait to hear it, intrigued as to what it will sound like. I always used to look at the cygnet package in Woking Precision Models catalogue when I was a teenager - it looked so simple in there but now I know better!

Nick

raynerd · « **Reply #30 on:** December 08, 2009, 03:15:15 AM »

Stew, a really smart and well written bit of machining! Even I understood it all..... well ok, most of it!

sbwhart · « **Reply #31 on:** December 08, 2009, 06:54:36 AM »

Nick It'll sound Prrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

John Built one a few years ago and he showed me a video of it running I can't remember where though

Stew

bogstandard · « **Reply #32 on:** December 08, 2009, 10:14:32 AM »

Mine sounded like a muffled ic engine, no vids left only a couple of piccies.

But Stews version will be different to mine as he is using a different cylinder setup, whereas mine was all integrally cast, Stew is using external porting tubes, which IMO will look a lot better.

John

sbwhart · « **Reply #33 on:** December 08, 2009, 10:58:49 AM »

Having slept on it I decided to take some of the meat off the cylinders before I made the liners.

So first job turn up a mandrel thats a nice slide fit on the cylinders with a M12 thread.

Like this

This required some quite heavy cuts and I was a bit concerned the liner would come lose, so decided to get rid of quite a bit of the unwanted material before fitting them.

Then turn down the 35 mm dia sash weight down to 19.25 to give a 0.02 mm interferance fit in the cylinder and part off to length.

Then set back up in the lathe, again concentricity with OD not that important, centre drill and with increasing in diameter drill rough all three out, then they were set back up to finish with boring bar at the same cut so they all ended up the same size.

As I'm going to use the mandrel again to finish off the machining its easyer if they all have the same size bore. The actual size of the bore is not that important, I'll just make the piston to fit, its easy to work to an accurate OD than it is a ID, what's important with the bore is that its parallel and the finish is reasonable.

I just gave the liners a polish to give them a square start into the cylinder, then with a bit of high strength loctite they were squeezed together using the vice as a press.

And her we are all three liners assembled to the cylinders.

I give the loctite 24 hrs to cure before I do any more machining to the cylinders

Cheers

Stew

bogstandard · « **Reply #34 on:** December 08, 2009, 02:30:13 PM »

Stew,

If you need it, I do have some very nice ali or brass tube that you can use for the transfer ports on the head.

Those cylinders do look very tasty. I have some of the fine cutters left over from the Halo cylinders if you want to do some finning.

Any problems with the very old cast iron?

John

Darren · « **Reply #35 on:** December 08, 2009, 02:33:12 PM »

I do like the liner idea Stew

sbwhart · « **Reply #36 on:** December 08, 2009, 02:38:23 PM »

Hi John

I was going to use some 1/8" copper tube for the ports but brass would match in nicly thank you.

I was going to ask for a loan of those thinning tools, and I was going to ask for a loan of those gang slitting saws to make a gang up to cut fins in the brass extention to the cylinder head I'm planning.
That old cast iron cut lovely.

thank you.

Cheers

Stew

bogstandard · « **Reply #37 on:** December 08, 2009, 02:54:08 PM »

No problems with any of that Stew, give me a call just before you come around, to make sure we are in.

John

NickG · « **Reply #38 on:** December 08, 2009, 06:36:48 PM »

Stew, as always, taking shape really nicely. You make it look easy!

sbwhart · « **Reply #39 on:** December 10, 2009, 11:46:46 AM »

Spent a bit of time today knocking the cylinders a bit more into shape.

Set the mandrel back up in the lathe and turned it down to a nice fit on the sleaves, this is why I wanted all the bores the same size, so that one mandrell can be used for all three.

Then same trick as before:- chuck taken off the lathe with the mandrell still in place and fixed on the Spin Indexer.

Her we have one in the indexer with my crib sheet and two assy in the crank.

Close up of three in the crank case, I've got some more meat to take out and some holes to drill but I nearly made a couple of mistakes so decided to call it a day.

Just taken delivery of this from the US, I saw these in use a few years ago at one of our subcontractors, he was using a big one 6" dia to hone the bores of some hydrolic cylinders, have any of you guys ever used them and have you any tips.

Cheers

Stew

Bernd · « **Reply #40 on:** December 10, 2009, 01:22:40 PM »

Interesting Stew. That place is a few miles to the east of were I live.

I believe those are used more to take the glaze out of a bore than it is for honeing a perfect round hole. If the hole is egg shape to begin with this hone will not fix it. But if you have bored the hole perfectly round first then it will give you that cross hatch you are looking for in honing.

Your build has me leaning toward building a 3 cylinder engine as a next projcet. Keep up the good work.

Bernd

Divided he ad · « **Reply #41 on:** December 10, 2009, 02:13:06 PM »

Looking good Stew

The hone..... All I can think of to add is Lots and lots and lots of oil! Well that's what I was always told

Looking forward to seeing this taking shape

Ralph.

Bluechip · « **Reply #42 on:** December 10, 2009, 05:59:13 PM »

Very impressed Stew .. looking forward to seeing the completed engine.

Quick question.. I've always left a gap for Loctite, never used it on things pressed together.

Can I ask why you used it on the cyl/liner asm?

So what's next ..

This one ??

http://en.wikipedia.org/wiki/Lycoming_R-7755

Dave BC

sbwhart · « **Reply #43 on:** December 10, 2009, 06:49:33 PM »

Hi Dave

It depends on the type of loctite and the application, I worked with loctite company for many years, and know some of their technical guys quite well, using high strength loctite with an interferance fit increases the strength of the joint considerable:- its the method BR use to fix the wheels on loco axles.

Cheers

Stew

Bluechip · « **Reply #44 on:** December 10, 2009, 06:58:31 PM »

Tks Stew

Another urban myth I've been the victim of !!

Was once told there was no point in Loctiting (not sure if it is a verb) an interference fit.
Do one or the other. Still, if it's come from their folk, then I'll accept that.

At least until I'm smacked in the kisser by some errant BR rolling stock ...

Dave BC

bogstandard · « **Reply #45 on:** December 10, 2009, 10:45:22 PM »

Dave,

It isn't an urban myth, but a fact, you only have to read the literature supplied with the product.

Loctite has thousands of different formulae that never reach market, it is devoloped for a customers personal sticky problems. When I worked in computer peripherals manufacture, the Loctite guy almost had a permanent home in the factory, they were making up special blends for us all the time, even ones that would work in the slightly reduced pressure of a cleanroom.

I too use normal Loctite in an interferrance or press fit, but I make sure at least one of the surfaces is slightly rough, to make sure that at least a little of the adhesive is carried into the joint.

If I want a real non come apart joint, but on metals that would be liable to distort if too much pressure is applied, I actually make the parts a tight sliding fit, then put a very fine straight knurl on the male part (not mine), then put the adhesive on before assembly. At a real push they can be got apart, but only after the Loctite is destroyed by heat, otherwise it is a joint for life.

John

NickG · « **Reply #46 on:** December 11, 2009, 03:47:24 AM »

Interesting stuff guys.

Quote

put a very fine straight knurl on the male part (not mine)

now that would hurt!

Nick

Bluechip · « **Reply #47 on:** December 11, 2009, 05:41:51 AM »

Loctite ??

No wish to wander

gone to 'How Do I ??' for a new post

Dave BC

sbwhart · « **Reply #48 on:** December 14, 2009, 10:53:55 AM »

Some more progress

Keeping the mandrell still in the chuck set it up on the mill and centred the mill quill on the mandrell zeroed the DRO.

Then just as with the crank case indexed and drilled the fixing holes for the cylinder.

With most of the key features machined in the cylinder time for a bit of bling.

Again still kepping the mandrell in the chuck it was transfered over to the lathe, then with one of Johns finning tools some fins were added to the cylinder.

I was going to use some 4mm brass tube for the air ways but the gap between the two pipes would only have been 0.75 mm so I bottled out of that and decided to use 1/8" copper tubes, did a lose assembly to see how the bling would look.

That doesn't look too bad, and I was realy pleased how the cylinders holes lined up with the crank case, this was all due to the accuracy I got out of the DRO, without out it I would have resorted to opening out the holes a fiddling arround to get things to assemble correctly.

Cheers

Stew

Darren · « **Reply #49 on:** December 14, 2009, 11:01:13 AM »

That looks superb

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Author Topic: Three Cylinder Radial Engine (Read 82694 times)

bogstandard

Rob.Wilson

bogstandard

bogstandard

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