Motorcycle crank case repair

[Fazerruss]

Just a little job I'm on with tonight.

Yamaha TDM 850 broken starter motor mounting lug on crank case.

Here is the damage......

Cleaned up ready for Tig.....



Build up with 4043 rods. Tig set to max 130 amp but using pedal....




Filed into shape.....




Just need to put in mill to skim the surface level and drill / tap an m6 hole.
Job for tomorrow now I think....

 

[Fazerruss]

Fixed in mill. Had to raise it at one end with a few sheets of paper as the machined faces are about half a mm out of parallel.




Milled the weld down...

Light touch with some 400 grit to smooth off..,

Then made some studs to get a reference center ......



Measured centres with calipers. Luckily the man brought me a good spare case for measurement...

 

[Fazerruss]

Marked out the lines so they intersect...



Drill...

 

[Fazerruss]

Tap a new 6mm thread......






Job done!!!

 

[MattH]

Nice job. Did you check the concentricity of that bore after welding? I’d of thought it might of pulled out of round from the contraction of the weld filler.

 

[Fazerruss]

Nice job. Did you check the concentricity of that bore after welding? I’d of thought it might of pulled out of round from the contraction of the weld filler.

No I didn't bother. The bore isn't a bearing face, it's just where the starter motor locates so not super critical.

 

[zx9]

Good work, I was wondering how you located the hole centre, nicely explained.

 

[Fazerruss]

If it had been a bearing face then I would have machined a tight fit plug to go inside and hold it from warping.

 

[Carl Wilson]

Very nice repair and very interesting explanation of all the steps involved. I really enjoyed reading about it.

 

[addjunkie]

Nice work, what mill is it, the spindle nose to table is a good size

 

[Wallace]

 

[Fazerruss]

Nice work, what mill is it, the spindle nose to table is a good size

It's a Tom Senior M1 with a Bridgeport cherrying head

Here is the thread on the conversion

http://www.mig-welding.co.uk/forum/threads/theres-going-to-be-a-wedding-sort-of.69529/

 

[doggone1]

Thats a good job youve done there nice mill to

 

[Fazerruss]

Thank you. Here is a better pic of my mill.