Sprocket

[digr]

I two blocked my one ton hoist The last it was made was in the 50s so parts a hard to find. What do we think the odds are for me to make one? Its a six tooth sprocket for a #60 chain.

[toprecycler]

It was built once before. You can do it again. The more challenging part might be deciding if it should be heat treated or not.

You might be able to face off the piece with the gear flat, drill a 1/8”- 3-16” hole, and then weld on a new shaft, that has a nib that centers it into the gear. I would leave the shaft oversized, for turning true to the gear after welding.

If you can get almost 100% penetration, it would probably hold up.

And you have learned what not to try to lift now.

Since you modified the motor to runit in the first place, I am confident you can pull off this repair. I’ll try to draw a picture to better explain this.


Sent from my iPhone using Tapatalk

[digr]

That would save a lot of work. That shaft is super hard, its worth a shot

[Whitetrash]

If anyone can make it work Ted/Digger can

[digr]

Originally Posted by Whitetrash

If anyone can make it work Ted/Digger can

Thank's for the confidence!

[digr]

The shaft is only .785" next to the sprocket to allow clearance for the chain. If I go for it I would chuck the sprocket end in a four jaw and chuck the add on using a drill chuck holding the oversize add on n the tail stock and weld it in the lathe, then cut off and drill a center hole and finish turning. What do we think?

[Ironman]

Originally Posted by digr

The shaft is only .785" next to the sprocket to allow clearance for the chain. If I go for it I would chuck the sprocket end in a four jaw and chuck the add on using a drill chuck holding the oversize add on n the tail stock and weld it in the lathe, then cut off and drill a center hole and finish turning. What do we think?

It sounds good. I would not use anything harder than cold rolled stock. 4041 will without a doubt crystalize and break over time. I have seen it happen to a 5" shaft repeatedly, until I went to a hot rolled.

[digr]

Originally Posted by Ironman

It sounds good. I would not use anything harder than cold rolled stock. 4041 will without a doubt crystalize and break over time. I have seen it happen to a 5" shaft repeatedly, until I went to a hot rolled.

Did you preheat the 4140?

[toprecycler]

Originally Posted by digr

The shaft is only .785" next to the sprocket to allow clearance for the chain. If I go for it I would chuck the sprocket end in a four jaw and chuck the add on using a drill chuck holding the oversize add on n the tail stock and weld it in the lathe, then cut off and drill a center hole and finish turning. What do we think?

This method should work too, as long as you are comfortable welding parts while they are in the lathe. At work, we use the "small button in hole" way to align parts when welding. But, then again, we do not have the welding machines set up to reach the lathes. If I was the machinist, and weldor, then I probably would change this up, but since our shop has a "dedicated" weldor, I don't need to rock the boat in making this change. (usually, I can only touch the welders at work, only when he is off, otherwise he gets butt hurt. :-) )

Biggest part will be leaving the shaft slightly oversize so you can turn it true afterwords.

Preheat probably would be a good idea too. Although, I am just starting to realize how important it is, and have to think that this might be a reason as to why we have had some part failures in the past at work. It is hard educating "the welder" when he thinks he knows best.

[Ironman]

Originally Posted by digr

Did you preheat the 4140?

Before welding, yes. After, when installed it would fail in a bit less than a year. It was a pin on a oscillating axle.