The sows ear, a Clarke Metalworker Mill / Lathe conversion to cnc

[Swarfing]

Well i have a choice either sell it for a lot less than i paid for it or convert it? Mines very quiet and runs smooth, not happy with the lead screws on the saddle and cross slide. The main lead screw is poorly fitted at the belt end but in general could polish up very well. I have a 13" southbend that does everything i need so was going to get rid of the small lathe but as a cnc machine would work out very well. It is all about justifying it?

Mark
Are you going to complete the rest to make use of it as a CNC lathe as well? would be interested on what you would do about the motor and control?

[m_c]

I'd convert it to CNC (I'm actually keeping a lookout on ebay in the hope I can pick one up cheap), as I think they're an ideal size. Not too big that a conversion is going to cost a fortune with big steppers/servos, yet large enough to handle dealing with big lumps of steel.

The main leadscrew should be poorly fitted at the belt end, as it should be free floating in the coupler. End float is controlled by the cheap and cheerful bush type set-up at the handle end, which as standard is useless. However, the collar on the leadscrew at the handle end, is the perfect size for mounting two angular contact bearing back to back in a new housing, which makes a huge difference to backlash.
And the main nut is a split nut, with a bolt to adjust out play, however you've got to maintain a couple of thou play in it, otherwise it just wears quicker and/or binds.

[FatFreddie]

Mark
Are you going to complete the rest to make use of it as a CNC lathe as well? would be interested on what you would do about the motor and control?

Yes, I've fitted cheap 16x5 ballscrews to the X and Y axes and it works fine as a CNC lathe.

The y axis ballscrew made a big difference, the original arrangement is poor in many ways, 12mm isn't big enough to take the cutting forces without binding so it was loosing steps. The X axis ballscrew is an improvement but not so much of one.

The ballscrews are the cheap chinese ones from Zapp - they seem pretty good for the money. The seals are rubbish so I've protected the leadscrew on the Y axis and on the X axis I've made seals from kitchen sealant which seem to work ok so far but not many cuts under it's belt yet :-)

[Swarfing]

Nice one Fred certainly given me food for thought now? Still what have you done about the motor control? DC motor? or large servo?

[FatFreddie]

Nice one Fred certainly given me food for thought now? Still what have you done about the motor control? DC motor? or large servo?

No mods to the spindle motor yet - I'm going to build a gantry mill from this next and then just use it it as a lathe so I may just leave it as it is.

[Kai]

Hey I have one of those in my garage when you have done yours can you pass me some plans and what to and not to buy lol.
I see you are in sheffield I'm just in hull not far unless there is a lot of snow hehe.
I have two other machines both denford a starmill and a starturn they are good for the stuff I want to do.
All I have to fix is the chair keyboard interface now then everything will be working fine