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Building Tips and technical articles. => Building techniques => Topic started by: Gary Anderson on April 08, 2008, 12:16:04 PM

Title: Motor Mount Material
Post by: Gary Anderson on April 08, 2008, 12:16:04 PM
Hi guys,

 I was to lazy to go to the hobby store to purchase maple for my motor mounts. I have some red oak material, so I cut that up and made motor mount for my new toy. Question, has anyone used red oak for motor mounts? The red oak seems to be harder than maple, might break easier than maple? I guess I'll find out, if I crash. (Not If but when) Would appreciate any input. Weight didn't seem to be bad, of coarse did all the lighten things, drill holes, trim down in tank area. Have a great day and God Bless, Gary
Title: Re: Motor Mount Material
Post by: Randy Powell on April 08, 2008, 01:19:52 PM
Gary,

I've used all kinds of stuff for mounts. Maple or beech seems to be the best compromise. Hard enough and not too brittle. Ash is probably second. Any sort of oak is going to be a bit more brittle than maple, but perhaps, depending on the type of maple, somewhat harder. Much like using alder or poplar which are not nearly as hard, but offer very good compression and tension properties. I've tried all kinds of exotic hardwoods and they are generally either too brittle, too oily or too hard (vibration transmission). There are a couple of African woods that work as well as maple like zebra wood and babinga, but why bother when maple is pretty readily available?

Oak should be fine, though Red Oak may be too brittle.
Title: Re: Motor Mount Material
Post by: PatRobinson on April 08, 2008, 01:36:46 PM
Hi Gary,
I started a thread about motor mount material that had a huge response of suggestions. I vaguely remember a post from someone who does a lot of woodwork and I believe he said that red oak is too brittle and would be subject to splitting from the pounding of a running engine. I think he said that white oak would be a more suitable. there are several other woods that were mentioned by several different posters in the thread that were considered to be "tougher" and more usable for motor mount material.
Igor Berger provided pictures of his phoenolic motor mounts and Randy Powell described how he makes laminated wood mounts. This thread is a good read from a lot of smart guys. Look it up under "Engineered Wood For Motor Mounts".  Best of luck with your project.  Just saw Randy's post & it is excellent as usual. Good Stuff!

                                                          Pat Robinson
Title: Re: Motor Mount Material
Post by: Gary Anderson on April 08, 2008, 03:58:40 PM
Hi Gary,
I started a thread about motor mount material that had a huge response of suggestions. I vaguely remember a post from someone who does a lot of woodwork and I believe he said that red oak is too brittle and would be subject to splitting from the pounding of a running engine. I think he said that white oak would be a more suitable. there are several other woods that were mentioned by several different posters in the thread that were considered to be "tougher" and more usable for motor mount material.
Igor Berger provided pictures of his phoenolic motor mounts and Randy Smith described how he makes laminated wood mounts. This thread is a good read from a lot of smart guys. Look it up under "Engineered Wood For Motor Mounts".  Best of luck with your project.  Just saw Randy's post & it is excellent as usual. Good Stuff!

                                                          Pat Robinson
Hi Pat,

   Thank you for the article, Engineered Wood for Motor Mounts, great stuff. I believe they're correct about the red oak but I haven't had any problem with the set up. I epoxied and sealed the motor mounts also used a u-shaped metal motor mounts. I only have several flights on her, if I don't crash soon her motor mounts might break. The plane is a nobler wing and a ares fuselage, using a Merco 35, nice looking junker, flys well. Now that I know better than to use red oak, I'll give the plane to my brother, Ha Ha, so he can crash her. Thank you Pat and Randy for your help and input, Gary