Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
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Thank you everyone for the advice / knowledge sharing! I've realised that for my case, backlash is from both handle assembly (maybe 30% of the backlash) AND cross slide nut (majority of the backlash)? While I accept some backlash will?always be there, I can't help but think of other possible?ways to minimize it. Might this idea be feasible: The cross slide nut is approx 10mm x10mm x 10mm cube.? Is there enough material to modify?the nut into an anti-backlash design, i.e. a) Cut a slit through the nut b) Tap a tiny thread for a screw to finely adjust the size of the slit gap (so as to apply pressure on the threads, minimizing play)
Alternatively, replace the entire nut with some anti-backlash design. The only thing is that its going to be a pain to adjust it, as my UNIMAT PC doesn't leave much room to access that nut with the slide assembled fully.
@Quinn
- One option might be to just replace the cross slide nut, and / or the entire leadscrew, ASSUMING the backlash is due to heavy wear on the threads. - Arceurotrade has a that looks like it could fit with some minor modification.
Yeah that completely makes sense, I have a Taig CNC machine that uses the same technology as a Unimat, and I program the backlash compensation into it.? When it reads the code it compensates for backlash due to its design. ? ?
What were the part numbers of the thrust washers that you settled on ??
I wound up settling on about .0035 backlash on the Y(cross slide) and .0025 on the X.?
However in my case I am convinced that the backlash on the cross slide is in the Cross slide itself and not the handle. ? ?
I¡¯m not sure buying another used one would make it any better, I might buy another ¡°new old stock¡± if I can find it. ?
On Thu, Apr 6, 2023 at 02:37 PM, Quinn Golden wrote:
you always back off a couple of turns on the handle and then go forward to remove the backlash and make your cut.
This is what I was taught to do and have done on all my larger lathes, but on the small SL it was a problem that needed more looking at if I was to use power on the screws, my first thought was I could not get the backlash down to an acceptable level because the cast was a little rough and the aluminium hand wheel was dragging and wearing off creating more backlash, I could have turned some hard plastic washers but having used very small bearings in other work I opted to use the small thrust bearings and I found I could get a really good feel turning by hand and under power it works so well for me.
With a wipe of grease on assembly these fit well, feel well and one less thing to worry about when machining.
 ??
Phill
Quinn Golden
603-491-1451
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