CNC mount issues: JB Weld?

[mikdavi84]

How 'bout this?


Fill original holes with aluminum putty:
http://www.cotronics.com/vo/cotr/rm_putties.htm?gclid=COSz0JuT2tMCFZFKDQody9cLww

Then drill/tap new 6mm holes?

 

[Frankenstein]

OK so let me show you this, a simple trick I used to mount a u bolt to my front mount of the engine.

You can mount a piece of angle steel in a similar way, I used helicoils on this one but also drilled right through closer to the front on a different motor and bolted a couple long bolts from one side to the other.

If you look at this you see I drew in a right angle and 2 different bolts, you can match the front up to the mount holes by drilling holes in the angle steel, and then add 2 more to go vertically through the front of the engines mounting 'foot'.

You can go and even remove part of the engines mounting foot by cutting in towards the crank from the front, which can make room for the bolt heads that would screw into the mount adapter.

 

[mikdavi84]

OK so let me show you this, a simple trick I used to mount a u bolt to my front mount of the engine. View attachment 76637
View attachment 76638

You can mount a piece of angle steel in a similar way, I used helicoils on this one but also drilled right through closer to the front on a different motor and bolted a couple long bolts from one side to the other.

If you look at this you see I drew in a right angle and 2 different bolts, you can match the front up to the mount holes by drilling holes in the angle steel, and then add 2 more to go vertically through the front of the engines mounting 'foot'.
View attachment 76639
You can go and even remove part of the engines mounting foot by cutting in towards the crank from the front, which can make room for the bolt heads that would screw into the mount adapter.

Seems like I'll either have to do something like this utilizing the sides of the CNC mount or go with the "fill the holes with liquid metal and retap" idea

 

[Frankenstein]

Seems like I'll either have to do something like this utilizing the sides of the CNC mount or go with the "fill the holes with liquid metal and retap" idea

I personally wouldn't rely on any putty or epoxy to act as a retaining point on the engine, I have had enough experience tinkering with that stuff to decide that the threads created by it aren't good enough for mounting an engine. The only way I could trust it is if I used a helicoil, and more than 2/3rds of that helicoil are embedded in the original metal and not the epoxy, at which point the epoxy is acting more like a wall to keep the coil from warping rather than actually keeping the motor tied down.

Stop talking about it and start putting the engine in the freakin bike. Grab a drill, angle steel, and an angle grinder and MAKE the missing link. You'll have it done in an afternoon filled with interruptions, and be on the way to the finishing touches just as your futile cranks arrive.

 

[mikdavi84]

The only way I could trust it is if I used a helicoil, and more than 2/3rds of that helicoil are embedded in the original metal and not the epoxy, at which point the epoxy is acting more like a wall to keep the coil from warping rather than actually keeping the motor tied down.

Seems like this would be the case in this situation. Helicoil is an awesome idea though.....

 

[Frankenstein]

Or elongate one or both holes, or just drill a new one, if it's really close or on top of the original hole, put a heavy washer on before the bolt, that will help redistribute the bolt's force against the mount.

 

[mikdavi84]

Or elongate one or both holes, or just drill a new one, if it's really close or on top of the original hole, put a heavy washer on before the bolt, that will help redistribute the bolt's force against the mount. View attachment 76641 View attachment 76642

Those are pretty good suggestions, soon as I get home I'll take another look and see if there's anything I can work with.

 

[Frankenstein]

I can't tell if you moved the mount between images, you say the motor mount is wider but it's like your showing it as the mount as too wide, I think I might be confused as to how it fits to your motor, if the motor is too wide at the front then maybe check the back mount too, if you modify the front make sure you check the engine alignment with the rear mount installed first, because if you mount to the wrong hole with a bolt then your engine WILL be turned towards the left or right in the frame.

It might even require you skipping using either bolt hole on the engine and instead centering the mounting points between the 2 engine bolt holes. Double check that first, THEN figure out exactly how the front must be mounted to ensure proper alignment.

 

[mikdavi84]

I can't tell if you moved the mount between images, you say the motor mount is wider but it's like your showing it as the mount as too wide, I think I might be confused as to how it fits to your motor, if the motor is too wide at the front then maybe check the back mount too, if you modify the front make sure you check the engine alignment with the rear mount installed first, because if you mount to the wrong hole with a bolt then your engine WILL be turned towards the left or right in the frame.

It might even require you skipping using either bolt hole on the mount and instead centering the mounting points between the 2 engine bolt holes. Double check that first, THEN figure out exactly how the front must be mounted to ensure proper alignment.

Yeah I moved the mount itself to show that if I lined up either hole I've got very little engine to drill into. I can see how that wasn't very clear now.

 

[Frankenstein]

Yeah I moved the mount itself to show that if I lined up either hole I've got very little engine to drill into. I can see how that wasn't very clear now.

That's fine, just check the alignment with the rear mount in place on the motor, then find out what your real options are.