Lathe tool rest arm cracked

[adrianpglover]

Was using the lathe a while back and the tool rest arm cracked. Sorry, no photo at the moment. The casting cracked where the tool rest inserts into the arm, from the clear hole on the side that was likely used for drilling/tapping the screw hole in the arm around to the top of the arm where the tool rest inserts into it. Basically the place on the arm with the most stresses when you're using the lathe. I showed this to my wife, who is on the FB owners group, and before I said anything she said someone over there had the same thing happen to them.

Honestly, this is pretty thin material for the amount of stresses that will be seen by it. Has anyone else been hit with this recently? I'd like to do some lathe work, but with this cracked I can't get the tool rest tightened down enough to keep it from spinning. I don't really want to spend another $40+s/h+tax on a new tool rest arm that'll just break in the same manner, as it seems to be a design flaw to have that hole on the end of the arm, but I also don't know if I want to spend $320+s/h+tax for something that is better constructed.

If someone has seen this, have you tried to repair it? I can't weld (tried, but it all looks like snot when I do it on steel), and this would require TIG welding, I believe, since this is an aluminum part. I don't think JB Weld would do a good job here, especially since the hole the tool rest sits in is widened out since the crack. I'm just at a loss as to what to do to see if I like lathe turning.

[JPG]

I WAS going to suggest E-Bay, but things over there are apparently out of control!

[chiroindixon]

Hmm. Perhaps this observation/hint from Scott will be some help.

At the 1:38 mark https://www.youtube.com/watch?v=rGnur6VzljA

Doc

[DLB]

Question for one of the Model 10 guys, can the tool rest arm be used with a Mark 5/V/7 post? Is the tool rest arm cast iron? If yes to both, is the center to center distance from post hole to rest hole vertically and horizontally compatible with a Mark?

I have an old Greenie tool rest, and the hole in question was not present on those. They have the less-desirable threaded post and the post is not intended to be removed from the arm. Makes me wonder if the later Model 500 tool rest has the hole in question.(?)

- David

[rogersk]

Post deleted.

[adrianpglover]

There is a larger hole in the tool rest arm opposite the set screw that holds the tool rest in place. I figured they did this to handle shorter length drill bit and tap for the manufacturing process, but it makes it weaker.

[rogersk]

Deleted post

[JPG]

Model 10 arm IS cast iron. Length I think may be shorter. Post mount to the carriage is NOT compatible(smaller smooth shaft - uses collar for height control) Tool rest bore same as M5....

[benmcn]

I saw this on YouTube. Looked like an interesting solution.

https://www.youtube.com/watch?v=PCV_8Obbt2s

[adrianpglover]

Where his broke is the same place mine did, just not nearly as bad. Took some pictures this morning. As you can see, the crack extends down both sides and leaves the tool rest just loose enough that it moves around even after you tighten the wing screw. It's cracked just enough that it's loose, but not quite enough to fall off. I do like the option in that last video, but again, I can't weld and I don't happen to have a piece of stock the right size to use for this purpose.

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