Hello Geoff

JB Weld would be of use here. Patch up the old area. Might want to use masking tape to cover one side as best you can to hold the JB back. Probably have to build it up in layers to keep it from running out too much. Trim it with rasps and files just before it fully sets. Then when that's done, move to a different spoke and mill it out to suit, drill and tap to fit the new handle. I think you have enough metal on the rim to dispense with the boss. An Option. Good Luck with whatever you opt to do.

Bill

Good Evening

The best way would be to clean up the area by plunging in an end mill of the correct diameter to create a circular hole. Then machine up a boss the same diameter as the end mill but a close fit in the hole. Drill and thread the centre to match the male spigot on the handle then use your magic aluminium welding rods to weld the boss to the hand wheel. The secret of the welding rods is a) clean all the paint from around the weld b) make a angled prep around the weld area c) puddle the weld at the joint and use the stainless scratch rod through the puddle to scratch away the oxide on the parent metal beneath the puddle. It works very well and gives a strong joint.

Best of luck

Peter

Looks very much like Cast iron to me as well. I would just plus one on using JB Weld metal binder, dress it all up with a rotary burr.

Drill, tap and spot face alternate position.

If it is cast iron, then a good preheat and weld will likely do too much damage and scaling.

Possibly worth laying a piece of copper or stainless round bar in the remains of the threaded hole to prevent it getting filled up, if thinking of using TIG. Could be pretty challenging trying to fill such a massive void without anything to contain the filler. That way you'd have something to work around.

I doubt very much that someone conversant with TIG welding aluminium would have a problem with the size of the hole. As for the handles on ARC they are a little small as the x and y axis are 7" and the z 9" diameter, the slides are heavy hence the large handles.

Bob

I bought some large chrome hand wheels of Ebay some while ago of that type to modify to put on my Bligeport [ Chinese clone ]

Off hand they were 8" I think. I bought them to replace the standard ball type, similar to the Myford cross slide type as I find the ball type don't lend themselves to a steady hand feed that you can easily achieve going hand over hand on a large circular hand wheel.

I found it amusing that at roughly the same time on another forum a guy was removing circular hand wheels on a smaller machine and replacing with ball handles as they looked better.

Well if all else fails send it to me and i will tig weld it for you FOC. I'ts a 15minute job for an experienced welder.

Mike Young