Which chuck to fit 6" rotary table??

[m_c]

You need to think about what you're planning on doing with the rotary table.
A 3 Jaw self-centreing will be better if you'll be doing lots of round/hex bits, but a 4 jaw independant does give you more flexiblity, however it will mean you become very proficient in the use of a dial gauge! I've never used a 4 jaw self centreing chuck, but it could be a good compromise.

Personally, I've not got any jaw chucks for either of my rotabs, and I've never missed having one for what I do with them. Most of the bits I do get held via T-nuts, however, I do have an expanding mandrel holder that fits in the rotab taper which is very handy.

[wiatroda]

You need to think about what you're planning on doing with the rotary table.

The first job i need to do is to cut 12 tooth 3m htd pulley from steel bar so I'm thinking about holding a stock in a chuck. Another issue is to produce a cutter to cut 3m hdt profile. I searched internet but it looks like the only option is to make cutter myself

[Jonathan]

Another issue is to produce a cutter to cut 3m hdt profile. I searched internet but it looks like the only option is to make cutter myself

That's what I did for XL pulleys ... but then that's only a trapezium.

Small ball nose cutter and several passes to get the right profile? Would take ages but if it's a one off why not?

P.S. I've got some 3m HTD pulleys if you're interested... I'll go and check what sizes.

[wiatroda]

That's what I did for XL pulleys ... but then that's only a trapezium.
Small ball nose cutter and several passes to get the right profile? Would take ages but if it's a one off why not?

The profile for 3m looks like this

What about to drill 12 holes 1.8 mm dia then turn it to proper outside size???? Eventually tweak corners a bit
Jonathan I have those pulleys, but I need something like shaft ending with a pulley on the end. The stock one are not any good, I tried:sad:

[Jonathan]

That looks like the profile for the belt, not the pulley. There's generally a small difference.

I've seen pictures of it done by drilling, so I suppose it's worth a try. I can't think of any reason for the holes not to be accurate. I would use 1.9mm as you'll be a bit stuck if the cut-outs are too small and it does not fit.
You might be able to 'tweak' the corners well enough with a chamfer. Maybe put it in a lathe and spin whilst holding a piece of wet and dry to it.