How would you chuck this part on a lathe?

[tylersteez]

I was making a bronze bushing and on the final operations of parting off the excess material and facing it down to spec. while parting off the excess, The force of the part off tool overcame the chuck's clamping force on that narrow edge and the part popped out the chuck. Luckily zero damage to me or the machine but the part is damaged cosmetically. it should still work fine for its application luckily, just a non critical bronze bushing.

I've attached a basic drawing of the part, it is 5.5" in diameter with a 4" bore thru it. The raised ends are only 3/8" which doesn't give me a lot of material to bite onto with the chuck after I flip the part around and start to finish the other side. I should have just let the bandsaw cut the excess off and then took light cuts to face it off but tried to save time, however I know there's got to be a better way to chuck this part.

 

[Finegrain]

Make a sleeve:
ID = the part's small OD
OD = a bit bigger than the part's large OD

Split the sleeve in half.

Put the sleeve halves around the part's middle, and clamp on the sleeve.

Regards.

Mike

 

[tylersteez]

Make a sleeve:
ID = the part's small OD
OD = a bit bigger than the part's large OD

Split the sleeve in half.

Put the sleeve halves around the part's middle, and clamp on the sleeve.

Regards.

Mike

This is what I was thinking but hoping there would be something quicker.

 

[bigjon61]

Chuck on OD, chamfer face bore all the way through. 2nd op chuck on ID and do the OD.

 

[tylersteez]

Chuck on OD, chamfer face bore all the way through. 2nd op chuck on ID and do the OD.

My worry is the chuck digging into the bore when doing this since it is a bronze bushing.

 

[BoxcarPete]

My worry is the chuck digging into the bore when doing this since it is a bronze bushing.

Then use soft jaws, or pad your jaws with something soft like slices of copper pipe.

 

[Zeuserdoo]

I would use an aluminum pie jaw cut to the diameter of the flange, with a step to stop on for depth.

 

[gbent]

Good, cheap, safe. Pick two. Last time you chose poorly.

 

[Peter from Holland]

Turn the ID Then turn a piece of scrap to 4"
Glue the bushing on with some dots of loctite Not to much Not to strong
Then turn all the other features
Heat a bit and remove piece of scrap
Clean up the ID from the loctite

Peter

 

[RC Mech]

3/8” is plenty of clamp area for that part. Use soft jaws. I’d have faced one end, centre drilled, supported with centre, finished OD, roughed groove, finish groove, drilled and bored.

Sleeves, loc tite, this is way easier in reality than those rabbit holes.

 

[Nmbmxer]

I’m in the mount it on a mandrel camp. I’d probably make an expanding mandrel and finish the OD and face both ends while on the mandrel.

I assume it’s an oilite / sae 841, that is hard to clamp on without it crushing in my experience.

 

[RC Mech]

3/4” walls at the flanges- skookum enough?

 

[deltap]

Press a plug in the end and support with live center.

 

[cyanidekid]

depends on quantity, tolerances, and how much of a waste stub you are willing to wind up with.
if you cut near net, basically no parting off, do the id, half the od, flip, face to length, chamfer and support with bull center or rotating tailstock chuck on the ID, finish OD? could leave .003 on the OD minor dia, and turn to final in second op to avoid a line there if it matters.

 

[Tyler337]

I was making a bronze bushing and on the final operations of parting off the excess material and facing it down to spec. while parting off the excess, The force of the part off tool overcame the chuck's clamping force on that narrow edge and the part popped out the chuck. Luckily zero damage to me or the machine but the part is damaged cosmetically. it should still work fine for its application luckily, just a non critical bronze bushing.

I've attached a basic drawing of the part, it is 5.5" in diameter with a 4" bore thru it. The raised ends are only 3/8" which doesn't give me a lot of material to bite onto with the chuck after I flip the part around and start to finish the other side. I should have just let the bandsaw cut the excess off and then took light cuts to face it off but tried to save time, however I know there's got to be a better way to chuck this part.

Buy longer stock or saw cut it a bit longer. Bore step jaws and allow enough room to part it off. This can be built in 1 operation. Use the narrowest part off insert to help prevent egging. And id probably use a part off tool from the ID and tape some styrofoam paper around the whole bar on just about everything except the cutting edge. Let it part off onto your bar so it safely catches it. I’ve been doing jobs like that since I graduated hight school. Just don’t chuck too hard to avoid irregular run out. And if you build up residual stress and the concentricity or diameters or out of tolerance then part off from the od half way then part off the rest from the ID.

 

[Peter from Holland]

3/8” is plenty of clamp area for that part. Use soft jaws. I’d have faced one end, centre drilled, supported with centre, finished OD, roughed groove, finish groove, drilled and bored.

Sleeves, loc tite, this is way easier in reality than those rabbit holes.

Clamping this with any force on a 3jaw makes it unround

 

[RC Mech]

Clamping this with any force on a 3jaw makes it unround

He’s got 3/4” walls at the flange, with care and soft jaws it would be fine.

 

[Philabuster]

ID chuck on the 4" diameter using pie jaws. Done. Some of the suggestions in this thread are comical.

 

[Peter from Holland]

He’s got 3/4” walls at the flange, with care and soft jaws it would be fine.

Py jaws yes So it depends on what you have laying around Like mostly
Peter

 

[Overland]

I’m in the mount it on a mandrel camp. I’d probably make an expanding mandrel and finish the OD and face both ends while on the mandrel.

I assume it’s an oilite / sae 841, that is hard to clamp on without it crushing in my experience.

How would you make your mandrel expand ?
Bob