Thread: Mounting a Chuck on Rotary Table.

By mounting it to the 4 slots .
Do you want someone to walk you through the steps.

Originally Posted by pipeclay

By mounting it to the 4 slots .
Do you want someone to walk you through the steps.

Although I suspected it may be simple, it does not seem obvious to me.

Slots in the back plate in the manner of the lathes compound?

Dean

Originally Posted by Oldneweng

Although I suspected it may be simple, it does not seem obvious to me.

Slots in the back plate in the manner of the lathes compound?

Dean

Dean,

Given the chuck and table are the same diameter, you would need a subplate with a spigot that provides registration with the table's bore. The subplate would replace the chuck's backing plate. The subplate would be fixed to the table with recessed fixings and tee nuts then the chuck would be fixed to the subplate. Not overly convenient. Much easier if the rotary table is a larger diameter than the chuck.

Bob.

Originally Posted by Anorak Bob

Dean,

Given the chuck and table are the same diameter, you would need a subplate with a spigot that provides registration with the table's bore. The subplate would replace the chuck's backing plate. The subplate would be fixed to the table with recessed fixings and tee nuts then the chuck would be fixed to the subplate. Not overly convenient. Much easier if the rotary table is a larger diameter than the chuck.

Bob.

Convenience and registration were both on my mind. I could make a back plate 125mm diam and clamp from the overhanging edge back into the slots. This plate would be mounted permanently on the chuck and could have a 100mm registration recess turned in the rear.

I am not really keen on the idea of an overhanging back plate tho. This is a tilting table.

If the sub plate is attached to the table first, how could you fix the chuck to it?

Dean

Chucks come with two sorts of fixings - mounting screws that go through a back plate and screw into the rear of the chuck and ones that go through the chuck and screw into the mounting plate. If you had a 100mm chuck with front mounting holes and a 3 T slot rotary table, all you would need to do would be make up some T nuts, get some long bolts and you would be set.
As it is it sounds like you have a rear mounting chuck and with a size for size RT, that could require more than a simple adaptor plate.

Michael

You could make a plate approx 25 mm thick, with a square bottom U machined into the side approx 15mm high, and deep enough to access the chuck studs, both sides drilled to suit the chuck (for accessing the C/S/heads, that fasten the chuck to the plate), the other to suit your table with the holes offset so that the plate can be fastened to the table. The U cut out is for the fasteners, the T nuts will need short studs and nuts.
Doe's your chuck have 3 or 4 studs, your rotary table 3 or 4 T slots? If you want more details, can do a CAD drawing for you.
Regards
Kryn

I'm not at all clear on what Dean has got... maybe a picture would help. If you don't want to make a backing plate, just get a front mounting chuck. Done and dusted.

Ray

I'm struggling without pictures also
My two bob's worth is about registration, with a 3 jaw chuck I'm not sure you want any. Of course it depends what you have an mind, but if you want to turn something then set it up spot on, the 3 jaw chuck might not get you "close enough".

Stuart

Originally Posted by Oldneweng

Convenience and registration were both on my mind. I could make a back plate 125mm diam and clamp from the overhanging edge back into the slots. This plate would be mounted permanently on the chuck and could have a 100mm registration recess turned in the rear.

I am not really keen on the idea of an overhanging back plate tho. This is a tilting table.

If the sub plate is attached to the table first, how could you fix the chuck to it?

Dean

Dean,

My suggestion was based on an assumption that your chuck was face fixed to its backplate. Given that assumptions are more often than not the source of many a f... up I'm probably wrong. Kryn's suggestions are therefore probably more appropriate.

Bob.

Originally Posted by Stustoys

I'm struggling without pictures also
My two bob's worth is about registration, with a 3 jaw chuck I'm not sure you want any. Of course it depends what you have an mind, but if you want to turn something then set it up spot on, the 3 jaw chuck might not get you "close enough".

Stuart

I have a 4 jaw 8" and a 3 jaw 7" mounted respectively to back plates. One chuck bolts from the front, the other from the rear, so it its case I used CSK bolts and had to get the holes aligned properly when I did the layout. No big deal.

In each case there's enough perimeter available to bolt down to a 10" RT so no dramas mounting them.

WRT the 3 jaw, I agree, often they're not good enough. Mine is a nice P-B but still has a bit of runout. Solution, make the mounting holes - there are 4 to match the T slots - slightly oversize, mount a bearing outer of the appropriate size in the chuck jaws, and tap for alignment using a DTI. Fiddly but works. For those more picky, making a 2 piece mounting adaptor with push screws would be a bit faster on setup. My way suits my simple purposes. If I want dead nuts accuracy I use the 4 jaw anyway, the only reason I made up the 3 jaw assembly was to machine radial grooves in a bunch of porthole castings and 0.002" runout is irrelevant.

If I had a chuck the same diameter as or bigger than the RT I'd make a 2 piece mounting plate.

PDW

No pics at the moment. I will get a couple of quick ones tonight.

I have a 4 slot rotary table and the chuck is mounted from the rear of the backplate with 3 bolts.

I will remove the chuck as well. As far as I can tell the existing backplate is integral to the grinder's spindle so I will have to make a new one.

Another reminder of why I hate doing this on the phone. Arrrrr.

Dean

I am starting to think skeletal. It is only a 100mm rotary table. I don't have a suitable bit of 25mm thick plate but I have some 10mm. Studs can pass thru the bottom plate. A gap between the 2 plates allows access to put on and do up the nuts. A stepped thru tube can allow the chuck mount bolts to pass thru both plates and gap. Stepped to maintain the gap between the plates. This tube can be welded at both ends. I may need to draw it.

Dean

Dean, you could get away with 6-8 mm for the mounting plates with a piece of tube or pipe welded in between, would have the same effect as my reply.
Kryn

Originally Posted by Oldneweng

...I don't have a suitable bit of 25mm thick plate...

There I can help - I did some skip raiding before Christmas and I reckon I have a 25mm thick piece of 100mm diameter (I can probably manage 110 and 120 as well). I think you mentioned being down this way soon, so if you want it, let me know.

Michael