Putting a Chuck on the rotary table.

Ok. I’m a bit stumped. I have a rotary table, it’s an hv4 I think with an mt2 taper and three slots.

I want to fit my three jaw 100miles Chuck from my Amadeal cj18. It has only mounting points on the back. So do I bolt the Chuck to a mounting plate and rely on the taper to hold it?

Or do I buy a Chuck with front mounting bolts? Or a smaller 75mm Chuck?

This apparently simple question has me stumped!

I bought a chuck with front mounting bolts specially for my rotary table.

Although having to spend money completely ruined my week, it was a good choice. Surprising how many jobs need both lathe and mill. Not having to share one chuck between two machines saves me loads of time.

Dave

My rotary table has 4 slots so I made a sub plate for my spare 3 jaw chuck, I bored the backplate so I could use a setting piece in the morse taper to locate the chuck quickly with the bored hole, the setting piece can be removed by opening the jaws wide enough to remove it through the chuck. The morse taper on my table is a press fit in a plain bore so I would be wary of machining anything held only by the taper although I have done so with a very light cut on a small part. The setting piece doesn’t need to be removed if you don’t need to pass the job into or through the rotary table.

Mike

High Nick,

I also need to fit a chuck to my HV4 (Warco) Rotary table. So I bought the Warco 80mm chuck and backplate to suit. While Warco were very keen to resolve the issue I had with their chuck/backplate, don't bother.

While their "no need to clock" statement sounded like a blessing in disguise, I couldn't get it to work. Firstly, the register dia on the backplate was out of true by around 0.12mm (with the backplate 2MT set in the Rotary Table). Add the inevitable runout with a 3 jaw chuck, and it was never going to work. It doesn't stop there. When the 2MT is set in the Rotary Table, there is a gap between the backplate and the table, so when the 2 clamps are tightened, the backplate has a tendancy to distort and add axial misalignment.

I ended up with a backplate from Chrono's (for their SOBA chucks) and an 80mm chuck from ARC. I will need to machine the spigot from the backplate (it's a snug fit in my HV4, giving me no wiggle room) and then get/make some M8 tee nuts to take M6 studs.

It should give me enough wiggle room to clock the work true.

My HV4 has 0.02mm runout on the 2MT, so for a relatively inexpensive Rotary Table, I'll live with that.

I too have an HV4 with 3 slots for my small WM14 mill. I opted for a suitable bolt through chuck which makes life much simpler than trying to fiddle making/adapting a backplate. Only minor difficulty is getting the chuck centred on the table. I was fortunate in having a parallel (straight) mandrel about 120mm long with an MT2 end. Placed that in the rotary table, dropped the chuck over it, pinched up the jaws then bolted chuck to RT with T-nuts and suitable length bolts. Loosen chuck and tap the mandrel out before fitting to the mill table.

John

I've just bought a 4 hole ER32 chuck which is for mounting on my HV4. Fine for round things up to 20mm, but not great for bigger stuff.

Iain

A 100 mm chuck on a HV4 seems a bit big to me.

A HV4 suggests a fairly small mill, so it would use a lot of headroom.

On my HV6, with a 2 MT bore, I fit a smaller chuck, with a Myford thread 3 or 4 jaw, and a Myford / 2 MT adaptor.

For a flange mounted chuck, you could make your own adaptor.

Take a suitable thickness plate, face it, .

Bore a register in the centre. See later for possible size.

Buy a 2MT stub arbor, and turn a short length (Same as the thickness of the plate ) to produce an interference fit in the bore in the plate. Think in terms of 0.001" for a 1" diameter (0.025 mm for a 25 mm bore

Put the plate int the freezer overnight.

Put the plate into the oven and cook for a couple of hours at gas Mark 6

Carefully retrieve plate and drop 2 MT arbor into the machined side of the hole, and tap home.. It should be an easy sliding fit, until everything warms up! Hopefully the two will then be inseparable.

Locate the 2 MT arbor in the lathe by the taper, and face the unmachined side of the plate, and any of the arbor that may be protruding a little.

Turn the the plate to produce a register which is a snug fit bin the register of your chosen chuck

Turn the OD to suit the chosen chuck..

The Register and OD should then be concentric with he taper.

Make up pointed screws so that the position of the holes can be determined.

The Arc Euro catalogue gives dimensions of the chucks for mini lathes (Register and mounting hole PCDs )

Drill the clearance holes.

You should then be ready to mount your chosen chuck onto the Rotary Table.

Be warned.

If you use any form of drawbar to hold the taper in to the table, IN THE VERTICAL POSITION, it will be possible to remove the arbor from the RT by slackening the drawbar and tapping the end with a mallet, to break the taper.

In the HORIZONTAL position, without removing the RT from the table of the Mill, this will be impossible.

HTH

Howard