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Building Tips and technical articles. => Building techniques => Topic started by: ray copeland on May 31, 2008, 03:14:56 PM
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Building an FS fuselage, is basswood exceptable for motor mounts , or does it have to be maple or other hardwood? Also , how about .078 wire to mold landing gear, too small or okay?
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Basswood is light and quite soft----not at all suitable for engine mounts, IMO--I wouldn't even use it with aluminum pads.
For the gear, I would use 3/32 music wire, that's about .096 or so.
Cheers,
Jim
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Thanks Jim, the advice and experience on this forum is absolutely priceless! If not for this type of advice a lot of people including myself could get discouraged easily especially living in an area where there are not a lot of control line flyers ! I will hunt down some better hardwood before progressing , i think i know where i can get 3/32 wire locally. Thanks again, Ray H^^
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For landing gear I use 1/8" ,for pushrods I use 3/32".
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I suggested 3/32 music wire because the Flite Streak is fairly light---for something much heavier I would use 1/8 inch also. I use 5/32 music wire on some of the larger/heavier stuff.
Cheers,
Jim
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If you have to fly off of grass, 3/32" will probably start bending back quickly. I use 1/8" for most stuff, and even then sometimes it's bordering on too soft. Maple motor mount stock should be available from Sig.
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Basswood is nice to work with. It is soft and engine mounts not good. I have built two Sport Jets using bass wood that came out very nice.
Dan
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i use it never had a problem ( but i dont fly to much) may maybe once a month
roger %^@
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I have found bass is OK if threaded inserts are used, but I make my own from flat head screws, 10-32s threaded 4-40. I make them a little (1/32") longer than the thickness of the mount then install them with the screw head under the mount and carefully file them down flush with the mount material. I use a dab of epoxy when installing. They don't pull out and provide a good hard point. Sometimes I'll use an aluminum pad but usually only if I'm making a universal plate that I can use to change engine types.
I found that the usual hobby shop type inserts don't hold up very well and are a disaster if used in harder wood mounts, they'll split out in a minute.
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A top team racer told me that he uses basswood for his engine crutch because it flexes enough that it lets the motor move the way it wants to when it is at running temperature so that the motor is not in a bind as it would be with a more solid crutch. It doesn't seem to be what you would want with a vibration machine like a fox 35...
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Ty...I used a lot of basswood (SIG) in a bunch of speed models, and I would describe it as about like pine or cedar, but with virtually no knots. The few knots were tiny. Maybe SIG does a better job with selection? Our local lumber yard (NOT Home Depot) has Poplar that is pretty similar, maybe a bit harder, very clean cut, smooth and straight. Tom Morris sells/sold some engine mounts made with Spruce or Maple. How about asking him about how the Spruce engine mounts are used? D>K Steve
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The best is Maple. I had a friend that used oak once and his plane vibrated like crasy. If you want to dampen your engine run use Balsa doublers.