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Ray:
Thank you very much Tim. I read the thread and looked at the pics and drawings very carefully.Appreciate your assistance and Bogs for his thread. Ray

spuddevans:
I got a couple more hours in the workshop today. I started by finishing off the holes in the flanges that I had spot-drilled last time, and tapping the rear flange. Then it came onto sizing the valve itself. I started by just fitting the valve into the valve body and fitting both front and rear flanges to see how much was to be removed from the valve spool. Notice the little gap between the body and the front flange.

Then it was over to the lathe to skim off a shallow cut ( about half the size of the above gap ), then re-assemble. Still not there, so back onto the lathe, another skim, assemble, getting closer. This went on for about 8 times before it got very close. The reason for doing this in tiny stages is that if you cut too much off you have to re-make the spool, and I thought that taking small cuts and trying to fit, then taking another small cut, etc etc, would be quicker than having to remake the spool valve from scratch.

Anyway, as the plans suggest, when the valve got very close I switched from cutting with a hss tool to using a piece of 360 grit W&D backed by a flat piece of metal, to just sneak closer to the right size. The right size was when the spool could just rotate with the flanges bolted tight together.

Once that was done it was time to mill the slots in the spool valve, 3mm wide and 3mm deep slots.

Then the only part left to make is a little handle for the spool valve. I drilled a 4mm hole in some Hex and then I chucked it in the 3jaw, rounded a section and then filed the end round ( this was a lot quicker using files than setting up my ball turner ), then I set a 5-10 degree on the compound and turned a tapered section.

Then I cross drilled a 2.1mm hole for the tightening screw, cut a slot through to the 4mm hole and then counter bored a 12mm bore in one side of the 4mm hole to allow the handle to fit closer to the valve body. Then tapped the 2.1mm hole M2.5 and bored out the opposite side to 2.5mm.

Everything put together.

And I think that is all of the parts made for this engine :D :D :D

Next I will be assembling it all together and hopefully seeing if it works ( then we'll see how many parts have to be remade ::) )

Tim

NickG:
Looks lovely that valve and handle, very authentic.

:thumbup:

Nick

Brass_Machine:
Tim,

Looks good! :clap:

Eric

spuddevans:
Well I have spent a slightly frustrating afternoon on this engine. I built up the engine into 2 sections, top and bottom, the bottom holding the crankshaft assembly and the top that had everything else. Then I timed the eccentrics with the crankwebs as per the plans and then assembled the top and bottom sections together.

Feeling very excited I hooked up the little air compressor and fired it up.....

FFFFFFFFFFFFFSssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss

Lots of air escaping around the spool valve straight out the exhaust pipe. The only thing I can cling some hope on is that I havent put the O-ring in yet, but I think that is just vain hope. I reckon I will have to remake the spool valve.

Undeterred I decided to press on and just hook up the air to one cylinder at a time just to see if I could get it to kick over. I then found that all those parts that I made that fitted together firmly add up to an engine that is nigh on impossible to turn over by hand, let alone by air :doh:

I had to remove one of the piston valves and ream the packing nut, and also polish the shaft of the piston valve, then put it back together. Then I tried again but no joy. Again broke various parts down to free them and adjust, re-assemble and try again.

This cycle repeated itself for about 1.5hrs until I started to get close to finding out how many times it would bounce :D so I gave up for today. At the last go it did give a good kick and tried to go, but it was binding up so it wouldnt give a full turn. I finished by removing the top from the bottom in order to make sure that the crankshaft assembly will spin freely by itself, then I'll work on getting the valves and cylinders working free as well, then re-assemble the 2 parts and see if it'll run.

Oh, and I've got to sort out the reversing valve, as I mentioned before, in almost all positions it was leaking ( more like gushing ) air straight out of the exhaust, so the remake looks like it is on the cards.

So, no video of it running yet, but give me some time and hopfully I will get something up for you to see, either an engine running or an engine flying. ( through the air towards a wall-shaped object )

Tim

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