Fixing motormount

Hello people.

I have a little problem with my motor mount. Like I told in my build log, I made my own motor mount and this works quite good. But it is getting lose from my trucks.

Video

I’m thinking of buying new, just squire, trucks without any rounding’s and making a new mount ring. Are there people with a beter idea here?

Is the problem the clamping pressure or the bolts coming loose?

Does it have only one bolt for clamping? If so, then that could be part of the problem. You are also using bolts for clamping where you should use set screws instead. They’re made of stronger steel so they can clamp harder. Another question is, what size is your clamping hardware? Most mounts I’ve seen using a similar arrangement use m6 screws. If yours are smaller, that could be contributing as well.

It haves 3 clamping bolts. And these are machine bolts. I worried that I would rip out the heats of setscrews, I had this problem multiple times with my old mount.

I think the biggest problem is that my trucks are tapered and are slowly slipping of.

I can’t re tighten the mount because I ripped of the bolts head by hitting a rock.

For my first build I did this. Worked out great. image

Yh looking at your trucks they seem very much like paris trucks which are a pain to make mounts for without milling or filing down a side. Options for you are buy a proper paris truck mount and replace the diy one, weld the existing mount in place or try and drill out /remove the headless bolt and re-drill and tap. Also when using bolts make sure to use loctite threadlocker to secure those bolts and to prevent any vibrations from the drive system loosening them

Check this motor mount it might be appropiate

Buy some grade 12.9 setscrews and a set of Wera hex-plus allen wrenches. Yes, they’re expensive, and yes, they are worth it.

One way to avoid stripping the head of the setscrews is to go another size up. Are you using m6?

I feel like your setscrew is in the wrong place. You’re constraining a single plane when you tighten it down.

If you add a setscrew on the red line/plane (inline with the hanger rib) you’ll be engaging two surfaces (yellow) instead of one.

MM

That might help with the looseness, depending on how square the trucks are to those planes on the mount.

If you want to have a more permanent solution then drill a small hole through the mount into the truck and tap it for a screw, the loctite it in place…almost as good as a weld

If you want a better fit and have access to a lathe then chuck the truck in it and turn it down to a constant diameter and ream the mount to an interference fit with it and tap it on with a pipe

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That looks great!

That is what I want to, but I don’t now if the steals I use are weldable. But I am gone try.

Oh no. If it’s steel it won’t work. Only for aluminum.

I already use 3 bolts to secure it.

IMG_20190131_202232

That sounds like a good idear, i could try that. But then I have to get the old screws out first.

In this case, two is better than three. Specifically two at 90 degrees to each other.

Get a screw extractor and remove that broken bolt, then replace it with a m6 set screw.

I will tell a little bit more about wat I have done.

I custom designed the mount to fit on my trucks. I drilled 3 holes from each other and taped thread in it. Than I put the ring on my trucks and tried to put it on as tight as possible with a hammer and tightened the screws with combination of some locktite.

After that I mounted the rest of the parts.

So the two opposing bolts work against one another - tightening down one works against the other. You want to get the surfaces to mate, not the setscrews. If anything I’d remove one of the opposing bolts and try that.

TBH I’d just weld this guy on and call it a day. It’s not worth messing around with. One and done. Hopefully you get the mount orthogonal to the trucks! Good luck!

His problem is he made everything out of steel. No welding that thing to aluminum.

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Whelp, that’s a problem.

JB weld?

Ayup. Possible, but this thing looks like he’s beat the shit out of it already. I dunno if JBWeld will take that kind of abuse for long.

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Whel, when the welding doesn’t work I just have to buy new trucks.