Is lack of penetration going to be a problem?

[JimM]

I need some advice about a motor swap I'm doing on my milling machine. The old motor had a larger foot than the replacement and the mounting holes therefore do not line up.

No problem I thought, I'd just make a larger foot plate (thanks Jay !) and bolt motor to plate and plate to machine. However just realised that the 2 sets of bolt holes overlap and will interefere with each other

No problem I thought I'd just weld the plate to the motor (this is a welding forum afterall !) However my MIG is only 150A and the plate and motor foot are both 12mm thick ! Obviously I'm not going to get anything like full penetration here but is that going to be a problem ??? The motor hangs upside down and would guess it weighs 10-15Kg, it's a 1HP jobbie and has a bit of a kick when starting.

If I only get half penetration will it be enough to hold everything in place or is it more likely the vibration, torque etc will just rip it loose eventually.

Thanks

Jim

 

[weldingscotty803]

cant you bolt straight through both plates?

 

[JimM]

cant you bolt straight through both plates?

Unfortunately not, and this is another reason why my original plan wouldn't have worked . The motor has to mount to a flate plate within the machine itself so any additional nuts/bolt heads would foul this.

Cheers

Jim

 

[weldingscotty803]

wouldnt really want to weld plate to the motor. is that what you mean, or weld the two plates together. if the latter then you may get away with it. i would weld all the way round. 3 passes if possible
pics would help

 

[rtbcomp]

Is there enough room to use some channel on its side? Bolt the motor to the top rails and the bottom rails to the machine.

 

[JimM]

OK guys here's a couple of (ropey) pics

The red spots are where the mounting holes need to be ie right on the edge of the foot. As the top of the foot isn't flat where the holes would go I was thinking of cutting away the corners (ie cut on the green lines) welding a larger plate to whats left of the foot and bolting through the plate to the mounting on the machine.

Plate would therefore be securley bolted to machine and motor would in effect hang by the weld

 

[JimM]

Just had another thought - is the motor foot & housing likely to be cast iron How do you tell CI from steel

 

[Paul.]

Not a good idea to weld on that cast motor body or cut it about, one way or another you'll need to make an adapter plate, even if it means changing the drive belts and modding the guards, a picture of the machine may help.

 

[Justme]

Why not cut a slot from the red dots to the old holes?

Then use a thick washer & the bolts to clamp it down.

Justme

 

[malcolm]

Is there room for an adapter plate? Something 1/4 inch thick maybe. You could countersink holes in the plate to bolt to the holes in the motor on one side, and countersinking from the other side you could attach to the machine.

If there is room for the 1/4 inch plate then any other method would surely take longer, no matter the pain with cast iron welding. I like the slot idea too.

 

[Drains]

As long as the bolts dont totally overlap. you can use countersunks, or drill and tap/ weld in studs. If you can still get to the nuts, you're sorted.

 

[Paul.]

You should be able to use one of these methods,

 

[JimM]

Thanks for all the repsonses guys - it's this sort of thing where your experience really shows on how to think through problems.

I did consider slotting the holes but didn't know if that would weaken the mounting leaving it liable to cracking ??

However I'm liking the countersinking idea, it didn't occur to me to fit the adapter plate to the machine and then the motor to the plate , I was trying to work out how I would fit the motor and plate as a single assembly

I'll have a play over the next couple of days and report back

Cheers

Jim

 

[TheJoker]

Here's another one. If you can't do that adapter plate with countersunks, etc. suggested by TIG Paul, maybe you could rotate the engine 90 degrees and basically make an L-bracket. A big sturdy L-bracket. Mount side to the milling machine and the engine to the other side. If it's not strong enough, you could build a whole "cage"..? In that case you'd slot the engine into the cage, mount it securely and then mount the cage to the existing holes. Quite a bit of overkill and probably quite heavy.

 

[Paul.]

The adaptor plate doesn't have to be in one piece, it could be made from 2 pieces of flat, say 50 x 12 or similar, probably easier to find and cheaper too, with a belt drive you can probably get away with a slight mis-alignment so if you have to move the motor sideways a bit to make room for the countersunk head it most likely wont be a problem, you could probably also move the motor in the vertical plane then reposition the pulley on the shaft to keep them in line, just check that the pulleys clear the guards if fitted.

 

[breezer]

Lack of penetration is a problem for me....still that's what you get for 10 years of marriage I spose.

 

[Iain Westland]

kaboom tish

 

[NTwoO]

Lack of penetration is a problem for me....still that's what you get for 10 years of marriage I spose.

Are you sure the problem is on your wife's side? (couldn't help it)

 

[Iain Westland]

def on the wifes side, shes the one complaining .....