Author Topic: 1909 Mercedes Aero Engine  (Read 45600 times)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #195 on: May 22, 2019, 10:14:27 PM »
Not sure, Mike. It is a bit I found in the corner whilst looking for material for the bender!

Steve  :)

Offline Vixen

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Re: 1909 Mercedes Aero Engine
« Reply #196 on: May 22, 2019, 10:46:21 PM »
It is a bit I found in the corner whilst looking for material for the bender!


Ha ha, only the best stuff then.

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline john mills

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Re: 1909 Mercedes Aero Engine
« Reply #197 on: May 22, 2019, 10:56:04 PM »
The bend look great  I have turned bullets or the end of mandrels for tube bending the end was profiled i get to fit around the corner as much as possible .the only cnc machine was the machining centre was using so i held them
in acollet in the spindle and a tool held in the vice.the profile on the end was much longer on the end than what yours look .these ones were made of a plastic.

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #198 on: May 24, 2019, 08:35:16 PM »
Thanks John. I have never seen another one so it was all a bit of guesswork. It could probably do with a bit of refinement but time will tell!

Steve   :)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #199 on: May 27, 2019, 09:39:56 PM »
Time to put my pipe bender to work so I started with the exhaust pipes which are brass, bent at 30°. The brass was much harder to bend than the copper, even when annealed and the securing plate marked each one. Actually, you can see in this photo that I actually have the hole centres too far apart and the plate does not sit straight allowing the edge to cut in.





After cutting to length, I turned up some threaded ferrules which I silver soldered into place.





A couple of hours in the pickle and a quick polish and they look OK although each does have a mark from the bender. I may be able to polish it out but we shall see.



On to the inlet manifold which isn't drawn at all so I had to make it up as I went along. This item proved tricky, even with the bender, There are two bends very close to each other in each part and I haven't quite sorted out how to achieve that. To that end, I started by making a new securing plate with the correct hole centres. That helped. I also filed the larger hole at an angle to allow it to move further along the tube.





It all helped but the I could not get the bends as close as I wanted. Still, the result was acceptable in the end.



I sketched and filed some flanges.



Then I held all the bits with a plug between the tubes and a clamp gripping the flanges to hold them in line.





This worked surprisingly well and I am pleased with the results. I did use 10"of copper pipe to do them though!



Onto more bits which aren't drawn. I started with the pump cover/inlet which is a fun piece of turning. I drilled and tapped for four 10BA screws to secure it.



Then the propellor flange. I felt that it should be secured using studs and a cover plate and so laid them out.



The effect is quite pleasing. I also took the opportunity to try the timing gears for mesh. They are OK too!



I am running out of bits to make. I have just ordered some suitable metric taps and die for the carburettor so I can get on with that and it is time that I started thinking about the distributor. Then it will be time to put the thing together and see if I have any compression!

Steve   :)

Offline Ye-Ole Steam Dude

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Re: 1909 Mercedes Aero Engine
« Reply #200 on: May 27, 2019, 09:44:56 PM »
Hello Steve,

Sure looking good, and the bender is really neat.

Have a great day,
Thomas
Thomas

Offline TobyTetzy

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Re: 1909 Mercedes Aero Engine
« Reply #201 on: May 27, 2019, 10:30:32 PM »
Hello Steve,

looks very good.

Do you have some more infos about the bender?
My father had some problems to bend pipes.

Toby

Offline Art K

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Re: 1909 Mercedes Aero Engine
« Reply #202 on: May 28, 2019, 03:37:36 AM »
Steve,
The bender looks like a handy tool. I made one for 3/16 tube at work and It does a very tight corner but the tube being flat or not isn't a concern. But it isn't nearly as elegant as yours. Everything is coming along very well & looks very good.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Lars

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Re: 1909 Mercedes Aero Engine
« Reply #203 on: May 28, 2019, 12:27:34 PM »
Steve,
Tubes looking great,  and what a nice bending tool !

When bending my inlet tubes I also used up a fair ammount of tube length.  I did not have any pictures of my solution, but it was much less elegant then yours :)

Keep up the good work

Lars

Offline Vixen

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Re: 1909 Mercedes Aero Engine
« Reply #204 on: May 28, 2019, 01:16:38 PM »
Hello Steve,

Nice work and good progress. I like the neat pipework and also your design for the pipe bender

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #205 on: May 28, 2019, 08:25:29 PM »
That's it! Blow the engine, look at the pipe bender!

Thank you chaps. You are all very kind. As the years have gone on, I have come to the conclusion that time spent making tools is never wasted. It is certainly much more satisfying doing the actual job easily and quickly. Mind you, I haven't shown you the pile of bits of bent pipe which have gone in the scrap! There is room for some refinement with this tool. Putting a bend in is easy. Putting in four which are supposed to be the same is much more difficult! It could do with a rotation stop which I may do if I have to do any more. For now, the tool has gone on the shelf until the next time.

What would you like to know, Toby? I only did one outline drawing just to lay it out. The rest, I made up as I went along using whatever bits and pieces I could find. The base is a piece of quarter plate with three blocks on it. One is the anchor for the mandrel, one is tapped for the roller adjuster and one is bolted underneath just so that I can hold it in the vice. The rollers are just slices of brass with a drilled hole in them running on silver steel pins. The backing block is a piece of 1/2" square aluminium with the groove cut with a ball-ended slot drill. Actually, it is too short but it was the only piece I had! The main pivot is a piece of 1 1/2" steel bar pressed into the plate and with a 1/2" hole through the middle for the quadrant to drop in. I turned the quadrant with a spanner to start with but it was a lot easier and more controllable with the greater length of my socket wrench tommy bar. The only quadrant piece I have made so far is for 8mm tube with a 12mm centre line radius. The key part for bending nice curves is the mandrel and this is a freely fitting plug which goes up the end. I had to play with the position to get it to bend nicely but it was fine with a drop of oil on it.

I'll take a couple more pictures but if there is anything you would like to know in particular then please just ask. Always pleased to help!

Steve  :)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #206 on: June 07, 2019, 08:57:52 AM »
Here are a few more details of the bender. Nothing very clever about it. If there is anymore you would like to know, Toby, please say!













I have been doing a bit more finishing off of the crank case. First job was to drill holes for the breather and oil filler.



i have also drilled for some anti-rotation pegs for the bearings. The bearings have oil holes drilled in them but if they rotate in use, they won't work!





Time for the carburettor. This is starts as a small casting with a couple of chucking pieces. They help no end but it is still a pig to hold. There is not much metal around to spare either.







Holding it for the second hole was a challenge. I think I cut the chucking piece off too early but I got away with it in the end.





Not much meat around the holes!



On to the brass bits next.

Steve  :)

Offline Vixen

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Re: 1909 Mercedes Aero Engine
« Reply #207 on: June 07, 2019, 10:02:46 AM »
Hello Steve,

Good progress, you are nearly there. :ThumbsUp: :ThumbsUp:
It's the attention to all the small details, like anti-rotation pins for the bearings etc. that take the time. Not much to show, but essential for a reliable running engine.
And thanks for more detail of the pipe bender

Mike :popcorn: :popcorn:
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Lars

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Re: 1909 Mercedes Aero Engine
« Reply #208 on: June 12, 2019, 11:19:59 PM »
looking good Steve! The counterbores you have in the crank case, are you planning on using o-rings in them for a seal between the cylinders-liners-casing ?  I also made counterbores but use them to guide the liners (they stick out a few mills from the cylinders). I regret that though and would recommend O-rings, when I run my engine I get oil sipping after a while

You are getting close to first start!  My engine at least runs now, however still poorly as it won't rev properly so I am changing to another prop, I beleive the one I have may be too large ( I have a size 22) for the power I get out of my build currently)

Lars

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #209 on: June 16, 2019, 08:14:51 PM »
Thanks for your thoughts, Lars. I shan't put an O-ring underneath the blocks as the groove wouldn't really trap it. I shall fit only a thin paper gasket.

I have managed to have a day in the shed today and have concentrated on the carburettor. The throttle is a barrel type with two outside threads and an internal one with a cross-hole to boot.



I lapped it into the housing using metal polish.



The fuel inlet tube was very tricky and I made quite a lot of scrap. It is 2mm OD, 1.5mm bore with a 1mm cross-hole and 0.5mm orifice. The main problem was in getting the machining sequence right. I started by putting the cross-hole in first whilst the brass was at maximum diameter and stiffest. This turned OK afterwards but when drilling the bore, the bit wandered out of the side and the tube bent. I eventually settled on drilling the bore first, turning the OD to diameter in steps so that I could put the cross hole in next to the largest diameter and then returned it to the lathe for final turning. On parting off, I reversed it and drilled the 0.5mm orifice from the other end, holding the chuck in my fingertips so that I didn't break the bit. I succeeded but it was a bit of a painful exercise.



Then turned up the needle valve for the jet and the mixture control. The 'needle' is really a pin stuck in a hole with Loctite. I have not quite fathomed how the mixture control functions.





A kit of parts ready for assembly.



There must be an actuating lever fitted to the barrel beneath the nut but this is not drawn. Neither is the dummy float chamber but I shall have a go at these shortly.

Steve   :)

 

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