Assembling/Holding Round parts

[radsqd]

Iam tasked with designing a fixture to hold a Hollow round part 16 ga steel ( various diameter 1"-7"). Is there something off the shelf that does a 3 jaw chuck going outside. My thought is to place the round part and then depending on the diameter expand the jaw chuck to hold the part from inside.

Thank you for your suggestions

 

[MikeHalloran]

A part that thin should not be supported on only three points.

The usual solution is a 'pot chuck', which is usally just a thick-walled ring of appropriate diameter, with one radial sawcut through, interposed between the chuck jaws and the workpiece.

Another alternative is 'soft jaws', if your chuck has demountable jaws. You just make up three pie-shaped jaws of aluminum plate, close them together, and turn the appropriate diameter on them. In this case, you would turn the jaws so they support the ID of your workpiece.

Soft jaw blanks are available from typical tool suppliers, e.g. Reid.




Mike Halloran
Pembroke Pines, FL, USA

 

[radsqd]

Mike thanks for the suggestion. To clarify, the parts are being assembled vertically. The round part is the base to other parts being assembled on top. My idea was to use something similar to a 3 jaw chuck to prevent the part from moving while its being assembled.

 

[MikeHalloran]

So just bolt a chuck to a bench.
Start here for pie jaws and chucks:

http://www1.mscdirect.com/eCommerce...tegory-_-LeftNav-_-Lathe+Chucks+&+Accessories

Mike Halloran
Pembroke Pines, FL, USA

 

[mfgenggear]

rad

It is difficult to say if this will work, but my thoughts are I don't know?
reason you failed to give length of the parts & how it will be assembled.

Mike is correct for this thin wall tubes there will be a tendency to make the tube out of round. clamping force vs wall thickness.
if these are short lengths then pie jaws a better solution. bored to the size of the tubes diameters.
if the ratio of length to dia exceeds approximately 3:1 then it will require better support.
such as a expanding mandrel from the inside. or a pie jaw clamping the outside as enough surface to
maintain & support the parts.

HTH
Mfgenggear

 

[mfgenggear]

I want to adjust the ratio of length to dia.
I would say more like 6:1

Mfgenggear