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Sheet Metal Engine Mount?

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Bigshu

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The Hummel H5 and the UC both Bed mount I believe. I attached th eH5 pictures I got from the factory.

Matt
Pics are worth a thousand words! I've got a pic somewhere of the H5 that I saw with a welded mount. If I find them, I'll post, but the engine box design on the H5 is very easy to fabricate.
 

103

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I agree I wonder if a Sheet Metal mount could be used on a 4130 Tube Fuselage or Wood fuselage like the SSSC.

Flywheel Drive VW are more conducive to bed mounting.

Matt
 

Bigshu

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It seems like the box has plates thst tie back behind the firewall, into the front fuse structure. Not sure if it would translate to tube or wood. I guess the trusses could be bolted or screwed to a plywood fuse structure in back of the firewall...rather than riveted. Anything that replaces welding is ok in my book!
 

12notes

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Well, my H5 plan set from 2008, on sheet 2 clearly details the engine box (bed mount) for the full size VW engine. Another well known Hummel builder who's local to me, did use a welded mount, but the built in bed mount is clearly what Hummel has in mind for the H5.
Well ****, I've only seen conventional mount H5s, and bed mounts on the Ultracruiser, guess I just assumed the H5 plans were like the Hummelbird I'm building.

I'm obviously wrong about the H5, sorry for the confusion. I'll update my original post to reflect that.
 

Bigshu

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No problem, I had to take a look to make sure the H5 plans are like I thought! Dennis Brooks, the builder I mentioned earlier, has a nice H5, to go with his Ultracruiser (or is it a Hummelbird?). He's built two nice airplanes, and I can't wait to see his H5 after it gets painted. You can follow his aircraft on you tube, he's got tons of videos.
 

pfarber

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I don't think a sheet metal monoque mount would be as good an option as a tube steel or cradle mount.

First would be that you would need a lot of of fairly thick metal, and it would act as an amplifier for engine noise.
Second would be access to the rear of the engine.

By the time you put in strengtheners and access holes you'd have the traditional tube steel mount.
 

Bigshu

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The Hummel engine mounts are pretty simple and light. I call them bed mounts, but they might be what you consider a cradle mount.
 

Tiger Tim

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I don't think a sheet metal monoque mount would be as good an option as a tube steel or cradle mount.
Generally I agree with you completely. I started the thread because I’m very slowly thinking my way through how I would build a maybe-UL-but-probably-LSA replica Buhl Pup and the original airplane’s fuselage was just one big tin can from engine mount to fin post. I still think there are definitely ways to do it, it just sounds like ai won’t get the benefit of copying someone else’s homework.

Good point on it being a big megaphone for the engine though, I hadn’t considered that.
 

Bigshu

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Whether the engine bolts directly to a fuselage bed mount, or bolts to the firewall on a welded tube mount, it's still sitting in the sheet metal megaphone. I don't think I've ever heard the argument that engine noise is more of an issue in a metal airframe with a bed mounted engine.
Talk to the folks at Hummel about how they designed the bed mount for their designs, and any thoughts on excessive noise from having the fuselage support the engine rather than direct connection to the firewall. I'd think input from an aircraft manufacturer would be more definitive than a builder's opinion (mine included).
 
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