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Building Tips and technical articles. => Building techniques => Topic started by: Frank Imbriaco on January 05, 2016, 07:26:38 PM
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Building a Riley Wooten Voodoo from plans. Plan on powering it with a ST C 35. Thought it'd be neat to employ an engine mount system on this ship, that would say, also accommodate a Fox 36x.
I've got a few ideas rattling around inside my head, but would appreciate any and all photos/sketches with your ideas and comments, too.
Photos don't have to be of a combat ship - a profile would work.
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This is what I'm doing. Bolt the bearers to the maple motor mounts, bolt the engine to the bearers. When you change engines, make up a new pair of bearers.
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Try this. It's a clamp mount system and my grandfather has used it on a couple of airplanes and it works well for trying different engines:
http://brodak.com/motor-mount-system.html
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This is what I'm doing. Bolt the bearers to the maple motor mounts, bolt the engine to the bearers. When you change engines, make up a new pair of bearers.
This is exactly what I do on virtually all my airplanes.
Pic below was for another reason ... but it shows the mount plates.
(http://www.pbase.com/lakebiker/image/162256438/large.jpg)
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Frank, don't make the mistake of using 1/8th 6061 aluminum tapped for 4-40 on a smokin' combat motor. I've seen so many engines pull out or break across the bolt holes. Use 3/16ths and you're golden. Also be aware the hole closest to the leading edge will have more cantilever on it with this system so use something thicker for the bearer wood like 7/16ths x 1/2 maple.
You could also look at FAI style mounts that bolt on top and bottom but it would look less like a VooDoo without the cheek cowl.
MM
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Frank,
I agree with MM, I have used the system of using 1/8" steel drilled and taped then bolted to the mounts. However, the Brodak clamp mount was developed by Windy and used on 60's to 90's size engines in several ships that he reported worked well.
Best, DennisT
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Frank,
This same setup came with the Pathfinder ARF I purchased.
I don't like it, but it hasn't given me any trouble with loose fasteners. I did balance the prop but have not really flown the model that often.
Charles
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Thanks to those who replied. Actually, I'm familiar with all suggested here so far and have used some of them at one time or another.
It's that out of the box , novel idea that I'm seeking .
Thanks !
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Frank, I think the bolt holes on both of those motors are the same. If so, you could just find a spot where both motors will interchange.
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Since not all motors are the same bearer spacing you could "hack the nose off" build up a bulkhead, use some type of threaded anchor such as T nuts, then use a spacer plate to mount a plastic or metal bulkhead mount, such as the RC guys typically use. Engine change, take the whole mounting system off, put on new engine.
It might work out that enough mounts have the same hole spacing, but I don't think they do in my limited experience.
This could allow a Fox to McCoy type of change, instead of having to stay with a fixed case width.
Phil
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Since not all motors are the same bearer spacing you could "hack the nose off" build up a bulkhead, use some type of threaded anchor such as T nuts, then use a spacer plate to mount a plastic or metal bulkhead mount, such as the RC guys typically use. Engine change, take the whole mounting system off, put on new engine.
It might work out that enough mounts have the same hole spacing, but I don't think they do in my limited experience.
This could allow a Fox to McCoy type of change, instead of having to stay with a fixed case width.
Phil
Adjustable nylon rc bulkhead mounts are available too. The mount screws to the bulkhead remain in the same location but the bearers are slotted to change engine width. I use them up to 60 size engines and mount the engine 3 different ways. I've had no failures in 100s or maybe 1000s of rc flights and drilled the same mount for two different engines.
1. drill/tap for the engine screws - no nuts
2. drill and use a sheet metal screw
3. drill through and mount conventionally with screws and nuts.
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Frank, I think the bolt holes on both of those motors are the same. If so, you could just find a spot where both motors will interchange.
Correct answer. Also Johnsons, if you're so inclined. /DV Steve