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Old Jun 09, 2012, 09:18 AM
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I finished up my fake LeRhone.
Shapeways? Shapeways? You doan need no stinkin' Shapeways!

Gene K
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Old Jun 09, 2012, 01:17 PM
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West of California Speedway, East of LaLa, North of Disneyland
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Originally Posted by mtflyr View Post
..............I finished up my fake LeRhone.....ete
Care to describe how you made the cylinders?

I saw a WWI model some time back where the cylinders were made from the corrugated section of a flexible straw!! Cool, but it constrains the scale size. Did you use balsa/foam wrapped with carpet/button thread?
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Old Jun 09, 2012, 04:32 PM
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356Jim,

I posted some pic's I used an aluminum tube on a drill spun into blue constuction foam (at first I used Depron), put a pin hole in each cylinder through then CF rod it to the center section. OSD = 42mm

Each cyinder is wraped in two lenghts of fishing line CA'ed a real pain, but results were ok and it all adds strength without much weight. Exhausts are copper wire crushed flat, rods are steel. The cylinder caps are foam cut with the same aluminum tube. I cut some fins in them but the paint I used kinda damaged the foam. Oh well it looks ok is light weight and will free wheel around the extended PZ P-51 gear shaft.

Pete
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Old Jun 09, 2012, 05:31 PM
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Amazing bit of work. As an old stick and tissue builder I am AMAZED at what is being done with foam these days and am looking forward to giving it a try.

I'm going to be attempting a PT 19 and I think the technique that you used for building the Nieuport's fuselage should work nicely.

I have questions:

I see that you didn't put any internal structure of formers under the 3 mm depron skin. I'm thinking it would be a bit stronger ... at least for a trainer ... if it had a couple formers in the fuse. Your thoughts?

What about some type of doublers for wing saddles?

On a separate note, do you think that this building technique would be OK for a roundr fuselage, such as that found on the PT 17?
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Old Jun 10, 2012, 10:37 AM
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Oddshot,

Thanks.

For these Micro builds I use 2mm Depron for the fuselage and wings and I use 1mm for the tail areas rudder and horizontal stabilizer.

Formers are not needed except for the motor mounts and brick.

I have built 5 P-38 micros, 2 MiG-17's ( including a EDF-30), a MiG-21, 4 Yak-1's, a P-47, a DR-I/FI, a Spitfire, 3 Nieuports and a Micro Mosquito FB. You can do a search for each build of these birds I did and the how to's I posted on each here in the Indoor Micro Forum. So yes, I'd say a P-17 should be no problem. It all depends on the paper plan you use some are better than others FG are nice and easy but not so scale and parts don't always fit together.

Pete
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Old Jun 10, 2012, 11:41 AM
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Pete,

I've got a couple questions for you.

1) I noticed that you put your exhaust on the back of the crankcase. I've seen some engines with the exhaust on the front. Either way, it seems that all the engines have "dents" where the pipes would go on the side that the exhaust wasn't placed. You can see this in the photo below. I''m trying to decide where I want to put my pipes.



2) I am wondering what the weight of your engine is. I need to number to work towards.

Thanks,
Kody
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Old Jun 10, 2012, 01:59 PM
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Hey Piper,

I'm no expert, I just like to get things looking the part. That's why I asked, what motor your CAD drawing was since all period pic's of the LeRhone have the exhausts on the right side of the cylinders.

I'm not sure what's right perhaps both. Mark Millers renderings are pretty much spot on.

Here's mine, I'm not happy with it but I'm going with it and just finished mounting the e-motor. My friend Toin who's an awesome artist is working on designs of these motors that Shapeways will make. They will be very cool, only thing is he's doin a Clerget as he's doing a Sopwith Camel. The older Nieuports I think had Clergets. The early NP-11 had the LeRhone's.
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Old Jun 10, 2012, 02:38 PM
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Originally Posted by PiperCub49 View Post
Pete,

I've got a couple questions for you.

1) I noticed that you put your exhaust on the back of the crankcase. I've seen some engines with the exhaust on the front. Either way, it seems that all the engines have "dents" where the pipes would go on the side that the exhaust wasn't placed. You can see this in the photo below. I''m trying to decide where I want to put my pipes.



2) I am wondering what the weight of your engine is. I need to number to work towards.

Thanks,
Kody
It appears there are differnt HP versions of the Le Rhone. The 80 HP has intake tubes in front, the 110 HP has Intake tubes behind.

It also appears that there are no "exhaust pipes" The Exhaust valve opens and the Exhaust comes straight out the top of the head.

The Attached picture i took at the Deutches Museum from a later rotary engine (1918) that had dual pushrods so it was more efficient (the Single Le Rhone Push rod operated both intake and exhaust valves)
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Old Jun 10, 2012, 02:54 PM
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Thanks UNGN. I thought the copper pipes were the exhaust pipes their connection is near the top of the cylinder. Then again what's the pipe on the fuselage of all the Nieuports for? I could never see a real good picure of how those pipes are tied into it all they could be air pipes. Hummm...

Pete
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Old Jun 10, 2012, 03:28 PM
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Thanks UNGN. I thought the copper pipes were the exhaust pipes their connection is near the top of the cylinder. Then again what's the pipe on the fuselage of all the Nieuports for? I could never see a real good picure of how those pipes are tied into it all they could be air pipes. Hummm...

Pete
Pete,

It appears that intake air came in through the bearing tube that engine was mounted on, so that side port in fuseage would be for intake air. Because of the crappy "carburation" if you can even call it that, gas would likely run out these intakes and they would be dirty/nasty and look like an exhaust port. The throttle valve appears to be a flat plate that partially blocks off the bearing tube (the gold wire tied piece in the pictures).

Here are pictures of a cutaway Nieport 23 to show this intake on the bearing tube:



Tubes would run out to the sides of the fuselage.

You can see the bearing tube to the right:


The firewall would be out of the picture to the right.

Here is a shot of a Nieuport 23 exhaust valve:

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Old Jun 10, 2012, 06:44 PM
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Originally Posted by mtflyr View Post
Hey Piper,

I'm no expert, I just like to get things looking the part. That's why I asked, what motor your CAD drawing was since all period pic's of the LeRhone have the exhausts on the right side of the cylinders.

I'm not sure what's right perhaps both. Mark Millers renderings are pretty much spot on.

Here's mine, I'm not happy with it but I'm going with it and just finished mounting the e-motor. My friend Toin who's an awesome artist is working on designs of these motors that Shapeways will make. They will be very cool, only thing is he's doin a Clerget as he's doing a Sopwith Camel. The older Nieuports I think had Clergets. The early NP-11 had the LeRhone's.
Pete,

I took the screenshot of my drawing when looking at the back of the engine. If I rotate the viewing angle 180*, everything is in the correct orientation.

Is there any place we can keep up with and/or see your friend's work?

Quote:
Originally Posted by UNGN View Post
It appears there are differnt HP versions of the Le Rhone. The 80 HP has intake tubes in front, the 110 HP has Intake tubes behind.

It also appears that there are no "exhaust pipes" The Exhaust valve opens and the Exhaust comes straight out the top of the head.

The Attached picture i took at the Deutches Museum from a later rotary engine (1918) that had dual pushrods so it was more efficient (the Single Le Rhone Push rod operated both intake and exhaust valves)
I felt uneasy saying that the copper tubes were exhaust pipes. It appeared that some of the exhaust could exit through out of the components at the rear of the engine. I knew that at least some of these old rotary engines had the exhaust come straight out the head, but I didn't see a spot that looked like an exhaust port on the Le Rhone. Thanks for the clarification!
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Old Jun 10, 2012, 07:52 PM
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Hmmm...

It looks like my picture links migh be a little flaky.

Reading up on the differences between the Gnome and the Le Rhone and other WWI motors I learned a lot of stuff I had no idea.

The Gnome just had 1 pushrod/valve and no intake tubes. The Exhaust valve was also the intake valve and a rich fuel/air mixture comes into the cylinder through transfer ports in the bottom of the cylinder bore, like a 2 cycle.. but since it was a 4 cycle, raw fuel/oil mix got dumped out the exhaust valve ever other rotation.

Because of this arrangement, the Gnome was throttled by shutting off the spark to various cylinders.

The Le Rhone had only 1 pushrod, but it operated both the exhaust valve (like a gnome), but also the intake valves and the intake air could be throttled.
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Old Jun 10, 2012, 08:48 PM
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cool stuff indeed... Thanks UNGN you got it down as usual and thanks Piper, I just wanted to be sure what motor you were drawing didn't think about it being the back.

Now I have a better understanding of those fuselage pipes. So UNGN there was no intended exhaust through the copper pipes?

Thanks,

Pete
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Old Jun 10, 2012, 09:06 PM
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Now I have a better understanding of those fuselage pipes. So UNGN there was no intended exhaust through the copper pipes?

Thanks,

Pete
Yep. For the intake to work, it has to be intake air only. Even a little exhaust would reverse frow in the tubes and backfire out though the intake.

With the le Rhone set up, they could use much shorter valve timing than on a Gnome... like a modern engine would have., but with one pushrod controlling both Intake and exhaust, it's not quite modern.

With the gnome, the exhaust valve was open during the entire intake and exhaust strokes (and it sucked in fuel at the bottom of power stroke, just to push it out the exhaust on the way up.) one advantage of this is it would cool the cylinder/head better than a "more efficient" design.

A pilot of a gnome powered plane would eat a lot of unburnt castor oil, where a Le Rhone or Clerget would eat a lot less.
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Old Jun 10, 2012, 09:27 PM
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Here is a few points on the Le Rhone their apparent function based on a picture already posted



It also can be seen how the intake and exhaust valves are actualed with a single rocker, so when one is open, the other is completely closed. That pretty much ensures no exhaust gets into the intake.

A twin pushrod motor could have some "over lap" when both valves are open at the same time, like a modern engine, to have a longer intake duration.
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