New toy: Setting up Colchester Student lathe

[M250cnc]

Jonathan

It seems the chuck is not too bad so why not buy new jaws for it.

Soft jaws are not really high precision they are really made to hold custom parts and being soft will be wearing quickly.

Using a 4 jaw chuck you will be getting jaw marks on your work so should be avoided at all cost you just cannot get the correct even grip without marks. Then add the time for centreing.

Phil

[Jonathan]

It seems the chuck is not too bad so why not buy new jaws for it.

I'll see if I can find some. I'm worried about if I buy new jaws and find it still doesn't hold accurately due to the scroll being worn for instance.

Edit: Found some jaws, not checked if they're the right ones:

http://cgi.ebay.co.uk/Hard-Inside-Ja...item53e7273419

Considering that whole new chuck is £125 they seem a lot...get what you pay for I suppose.

Using a 4 jaw chuck you will be getting jaw marks on your work so should be avoided at all cost you just cannot get the correct even grip without marks. Then add the time for centreing.

I've avoided that in the past on some things by putting strips of aluminium or copper in between the jaw and the work. That won't grip it as well though. Centreing is only a couple of minutes with two chuck keys (I'll make another) - but still annoying to do.

[Jonathan]

I've just wired the coolant pump up - took the end plate off the pump and changed it to Delta. To test it I've taken the main motor off the VFD and just connected the coolant pump without changing any settings on the VFD. It works fine, although there's not enough coolant in the tank to actually pump it round at the moment. I'll have to get some, again I'm not sure which to get and where.

The question that remains is if I'm OK to run the main motor and coolant pump on the VFD at the same time. The pump is 2 pole, and the main motor 4 pole, however the pump worked with the VFD still set to 4 pole. I've searched on other forums and people have done it.

The pump only draws 0.22A, but with a 3Hp motor on the VFD I'm right on the limit - especially with it being in delta(?) ... the problem is when the main motor has a big load on it is when I want to be running the coolant! If I do put the pump on the VFD I'll put a relay and switch in so that you can only connect the pump when the VFD is off.

This implies it is ok:

http://web.applied.com/base.cfm?page_id=3124#q5