# Welding the motor frame



## Woodsmith (Jun 5, 2008)

My 11" motor was originally mounted on the DE and so has no other mounting points.

I want to foot mount it and so I will need to weld a foot to it. I was thinking of using a couple of pieces of angle steel cut with a curve on one side to act as a cradle for the motor. I will then weld it on.

The frame is about 3/4" thick. Could I get away with just welding it slowly allowing it to cool between short stitch welds or would I need to remove the field windings and check for roundness afterwards?

I'm not really able to do anything about it if it were to go out of round unless I spend some money on it.

Thank you.


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## Jimdear2 (Oct 12, 2008)

Woody,

My take is that there is so much metal mass there that if you stitch and cool with your MIG cranked up you are not going to get it hot enough to cause a problem. The only thing is, you might not get much penetration with that light duty rig. Got some scrap stock about the thickness of the frame? If your not sure see a weld shop. Got one at the school?

I can't see magnetic problems because it is electromagnetic fields not Perm Mag.

That's my feeling on it maybe someone else will have something to say. 

I would give it a try to my own motor.

Jim


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## major (Apr 4, 2008)

Woodsmith said:


> My 11" motor was originally mounted on the DE and so has no other mounting points.
> 
> I want to foot mount it and so I will need to weld a foot to it. I was thinking of using a couple of pieces of angle steel cut with a curve on one side to act as a cradle for the motor. I will then weld it on.
> 
> ...


Hi Wood,

That's a thick frame. I think you're pretty safe using short weld sessions. Stuff wet rags around the field coils and take a break from welding when they steam out  You keep the heating that low and I suspect you won't distort the roundness, but I'm not sure. We used to weld brackets on those 6 and 7 inch pump motor frames. But I'm gettin' old and don't recall if that was prior to finish turning or not.

Cheers,

major


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## toddshotrods (Feb 10, 2009)

I wouldn't be afraid to weld on mine. I can't imagine getting enough heat to pull it out of round. Well, I can but I can't imagine needing that much weld penetration. Well, I can but you should need it on a trike! 

On the other hand, why are you welding a foot mount instead of making a bolt-on part, and tapping some mounting holes?


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## dtbaker (Jan 5, 2008)

Woodsmith said:


> My 11" motor was originally mounted on the DE and so has no other mounting points.
> 
> I want to foot mount it and so I will need to weld a foot to it.


yikes.... why don't you use a CLAMP mount with a foot on it? Pre-made for less than $200 I have seen around?!


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## MalcolmB (Jun 10, 2008)

I've heard of others welding motors successfully, doing just as Major advises. I would make the curve of the foot very close-fitting and place the first stitch at the centre of the curve, followed by stitches at the outer ends of the curve. That way the curvature of the frame can't change.

I thought of doing this myself but in the end opted to make a giant pipe clamp to secure the tail end, but my motor frame is only about 10 mm thick.


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## Woodsmith (Jun 5, 2008)

Thanks guys.



Jimdear2 said:


> Woody,
> 
> My take is that there is so much metal mass there that if you stitch and cool with your MIG cranked up you are not going to get it hot enough to cause a problem. The only thing is, you might not get much penetration with that light duty rig.
> Jim


I was going to stick weld it for the penetration. Lots more heat from my stick welder.



major said:


> Hi Wood,
> 
> That's a thick frame. I think you're pretty safe using short weld sessions. Stuff wet rags around the field coils and take a break from welding when they steam out
> Cheers,
> ...


That's a good idea.



toddshotrods said:


> On the other hand, why are you welding a foot mount instead of making a bolt-on part, and tapping some mounting holes?


I do have a couple of tapped holes already but not in the right place. I could drill and tap some more but then I would have to pull the fields out.
That is a possible solution but I was hoping not to pull the motor completely apart at this stage as the field windings ends are bent and poked through the frame. I am worried about damaging them or the insulation if I move them too much.



dtbaker said:


> yikes.... why don't you use a CLAMP mount with a foot on it? Pre-made for less than $200 I have seen around?!


I'd make one as another option, no money to spend. This month is a washout. Two weeks out of work for half term and Easter, two bank holiday Mondays and a royal wedding. I only get paid for less then half the days I do work and there is no pay for the days I don't work. Such is teaching!



MalcolmB said:


> I've heard of others welding motors successfully, doing just as Major advises. I would make the curve of the foot very close-fitting and place the first stitch at the centre of the curve, followed by stitches at the outer ends of the curve. That way the curvature of the frame can't change.


Yes, that was the intention.

I will look at the options and see which will *look* the best.


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## Woodsmith (Jun 5, 2008)

Despite being ill and being banned from the workshop boredom got the better of me and I tried to do some work today.

I managed to measure and mark out some steel to make a pair of feet for the motor.
I have a length of 2" square box section at 3/16" thick. Two bits 12" long with a curve cut out to act as cradles. I will ask a friend, who has a plasma cutter,to do the cutting. I doubt that I am up to using a hacksaw and file to to get the curved bit cut out on four thicknesses of steel.

I have figured the design for the back of the trike where the motor and rear swing arm will mount and to maintain the clean lines the motor will hang on the back of the cockpit frame with the foot mount vertical.
I am hoping the motor will just be a cylinder with minimal visible framework around it.
I might even get around to changing the field bolts from hexagon heads to countersunk to clean up the cylinder.

Photos when the bits are cut out.


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## toddshotrods (Feb 10, 2009)

Cheater!  (I'd be doing the same thing... )


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## Guest (Jun 23, 2011)

Put a ring around the motor with a foot to hold the motor. You could even use a thin rubber pad to place between the motor and ring holder. I have one. If you do decide to weld the motor I'd take it all apart and weld only the bare frame. Then clean and paint the interior and make sure it is still reasonably round. I don't think you will warp the case but I'd weld with no field coils on the motor. Be sure you do a good job. You only have one chance. Do you have gas for your MIG? Or did you think about TIG? It is cake to Tig Steel. Just practice. Do you have a dead motor you can practice with? Maybe an old Starter case. Small size but still like the big motor. 

Pete


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## DIYguy (Sep 18, 2008)

gottdi said:


> Then clean and paint the interior
> 
> Pete


Hey Pete,... just one note... there should be no paint or insulation between the pole shoes and the yoke (frame). (Major taught me this.  ) 

GTAW (TIG) is probably not the best choice on thick sections. It does have one of the lowest over all heat inputs with highly concentrated energy...but when welding thick sections, you have to prep the joint so you have a thinner edge. Think of pipe welding where it is often used for the root only and the pipe is bevel cut to present a thin edge. GMAW (mig) is probably the best choice and not to weld too much at one time as suggested.

edit.;;; just wanted to add a pic of the mount that was originally on my motor. I cut it off as I didn't need it.

Cheers.


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## Woodsmith (Jun 5, 2008)

I did a pressure pipe welding course a few years ago so in theory I could weld this, with a stick welder, upside down with one arm tied to my leg.

It was a while ago though.



I want to avoid having bands around the motor with bolt clamps showing. The motor is going to be completely smooth on the visible sides so even the terminals are going to be hidden where the foot mount is. The only exception will be the brush band. It is currently a beaten up strip of thin steel and I want to roll a new 'sharpnal proof' one from 3/16 flat bar.
I may even file back all the welds to get a smooth profile.


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