Need help making a motor mount..
 

Hello all,
Im trying to make a new motor mount for my Cen matrix tr, Im getting way too much flex from my Al Angle mount. The problem is that as the motor spins, the pinion rides up on the spur, forcing the mount to bend... its eating my pinion right now.. I think my only option is to build a mount off the center diff. I just got 3 feet 1/8th x 2in flatstock from Eovnu87435ds so i have plenty to work with.

is 1/8th thickness too little for a motor mount?

and does anyone have pictures of there home made motor mounts?:intello:

Thanks, Ben

Make a thicker mount out of angle stock. What size are you using now? I think 1/8"+ wouldn't flex.

Would this work?

http://www.rc-monster.com/proddetail...od=rcmcenmount

thats what i have now... and it flexes wayy too much, i even went as far as adding a gusset to it.... still 5mm+ of flex on the top of the mount

It would but i dont have that kind of money :no:

Try to make a brace that goes from the top corner to the bottom corner on the same side if it fits. What kind of metal is it?

Email mike he has some "seconds" that are marked up - he might have a cen one...

You can't be serious?

We teenagers aren't made of money you know....:wink: And besides, if you can make it work for free you'll feel better knowing you saved 45 bucks.:yes:

i did that(gusset), still bends, its aluminum.
I tried that multiple times, no email responce
Im 16 with no job, i am indeed serious.
Thats the spirit :)

Only thing I can say is try using a stronger metal. Ive got a 3 1/4" x 3 1/2 beast of a plate if you want it. It's pretty heavy, but I'm sure you could get it pretty light in a night of grindin.:yipi:
http://i345.photobucket.com/albums/p...1/S7301532.jpg

It sure as hell won't bend... I got it for a go-kart project but that came apart in the end.:sleep: BTW it's STEEL. It really reacts to a 130lb neodymium magnet...:surprised:

I used 1/4" aluminum for my motor mount for my Neu 2215 and it works great:

.125 thick is enough. Its doing doing fine in my revo with a maxx transmission.

hey,
I understand your problem. Do it my way, I don't own a cnc drill or too.

http://s3b.directupload.net/images/090121/egym9ul2.jpg

the mount ist connectet to the diff whith some layers of carbonfiber and glassfiber, some leftovers. glassfiber/gfk is much stiffer than alu, but easy to work with (drill, saw). I glued it together with some good 2k-epoxy. just take some gfk (glass-fiber composite), its bloody cheap. cfk has the better looks, but it 's very hard, that means it "eats" drills and saw blades.

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the mount is connected to the chassis as well with a piece of aluminium, the relatively thin quality is easy to handle with normal tools.

this mount is quite "different", but like that it was easy to get it done with my old drill etc. and I have to say, it's stiffer then my other mount for the kb45xl, made of alu. there is no flex at all. and its lightweight.

I have a flat peices of the 1/4" metal too...

Ok, will 1/8th inch aluminum flat stock hold up to a 1515 1y on 4s...



might just make it and be done, then double the thickness if I need to.

I would go straight to doubling up the 1/8". This will make sure it will have minimal flex.

Hmm, Ill see what I can do I havent had a problem with torsional flex on flat stock before.. hopefully i can have slots etc milled out.

Hey, just bend yourself one of these. (I made you a sweet technical drawing) :rofl:

Quite gangster, I like it... Just use some decent thinckness steel plate, like 1/16" and use a long turnbuckle to brace the top forward to the sevo mount. About the best DIY solution yet that I have seen!

He says he has plenty of the 1/8 aluminum, which I think would be less flexible than 1/16 steel. Steel would be easier to bend, though. ...And thanks! That took me all of 5 min. to sketch in MS Paint! :lol:

Why not simply stick with the L bracket idea, but also secure it to the CD mount? Something like this:

Edit Apparently my site isn't working right now so I attached the image instead...

This was on a CRT.5 using 3mm thick 6061-T6 aluminum, but you could use thicker material (I would go with 4mm 6061-T6 or 7075-T6).

Good idea Brian, my gtp bracket for the kb 45 motor looks very similar. I trimmed it a bit as I used 2x3 6061 angle. Works fine for me. Attaching it to the rear center diff bulkhead does help with rigidity.

as it stands, i have just the 1/8th in aluminum... but one of our Robotics engineers(im at robotics now) just walked in with a huge sheets of 3/16 6061 aluminum sheets... see if i can snag a peice...

You wont be able to bend that stuff... :whistle: But maybe you won't need to. It might be strong enough the way it is.

would be nice.. Gonna have one of our engineers make it for me tommorow
:intello:

I would suggest heating it quite a bit before bending it. 3/16" is almost 5mm thick. Heating it will make it easier to bend and help reduce stress cracks...

I dont think i will need to bend 3/16' 6061, should be plenty strong :)

3/16' ??? Wow, that's 2.25 inches thick! That should definitely be strong enough! A tad on the heavy side though. :wink:

lol, I know what you meant. :smile: If you're gonna drill and tap threads edge-wise into material, I would go with at least ~6mm thick (~1/4") because you'll want to use 4mm screws I would imagine...

:), I havent had a problem drilling and tapping 1/8th" aluminum, thats what i did to my current mount and had no problems.. hope this turns out well

What size screws are you using? 2-56? :rofl: Edgewise would be into the 1/8 thick side..... But yeah with 3/16 that could be a problem. 4mm screws would be too big, but if you used 4, 3mm screws in the bottom (instead of 2, 4mm screws) that would do it. Or try and get 1/4 thick material and use 4, 4mm screws! :yes:

Ohhh i didnt know he ment edgewise, I can drill and tap m4 in 1/4in easily, i dont think i need to tap the edge of this.:whistle:

3/16" 6061 is pretty tough. You might not have to... :great:

I never said i was going to :na:

I assumed that since you said you weren't going to bend it that you were going to use the same scheme that Mike uses for his mounts (4mm screws from underneath screwed in edge-wise to the mount). If so, 3/16" thick is too thin. That leaves a "wall" of less than 0.5mm when using 4mm screws. And I wouldn't use anything smaller than 4mm considering the stress they are under.

If you're not doing this, I would think the only other option is to make a 90* bend and use a screw/nut to hold it in place.

why not just bolted to the center diff mount?

Not enough support IMO. Personally, bolting to the CD mount would be in addition to bolting it to the chassis. The CD mount just helps reduce flex, but the chassis is much stronger.

+1... A decent piece of thickish al L bracket is your bet.

hmmm, I have some little 1x1 anlge i think, bolt the angle to the 3/16's 6061?

I just thought I should reinforce your thinking... :na: :na: :mdr: