RE: [GrizHFMinimill] Re: Y Axis Thrust Washers and Locknut
- Hi David,
I knocked out a thrust washer from some scrap HDPE bar I had to hand several months ago when saw the post and it certainly works for me - big improvement on stock without the hassle of making a ball bearing set up.
> To: GrizHFMinimill@yahoogroups.com
> From: winklmj@...
> Date: Mon, 5 Sep 2011 00:40:58 +0000
> Subject: [GrizHFMinimill] Re: Y Axis Thrust Washers and Locknut
> I know this is an old post but Holy Cow...the thrust washers made a
> huge difference in my y-axis! I had a small bit of unknown plastic rod
> (I suspect it to be HDPE) so I made up a few washers. Thanks for
> sharing that.
> --- In
> "a3sigma" <dcclark111@...> wrote:
> > Good morning group,
> > I've posted a pdf on the subject.
> > http://groups.yahoo.com/group/GrizHFMinimill/files/D.C.%20Clark%20stuff/
> > These mods seem to me to make a significant difference. The Y axis
> now feels smooth and consistent throughout it's range, and backlash an
> acceptable 0.005 inches. There's no endplay that I can detect.
> > The thrust washers were made of PTFE Delrin from McMaster.com part
> number 8579K28. I also coated them with PTFE grease.
> > Since it takes very little more time or effort to make several
> washers, it seemed a waste of time to make just one of each. Hence, I
> have several pairs. It anyone would like to try this mod, and lacks a
> lathe to make their own, contact me off list and I'll mail you a set.
> You'll be doing me a favor as well, since I'd like to get some other
> opinions on whether this really makes a difference. "Feel" of a machine
> is pretty subjective, and I am always wary of confirmation bias.
> > Best regards,
> > David Clark in Southern Maryland, USA
- Hi Chuck,
Not really a press fit, since it spins and there are no bearings. Sounds to me like the end of the shaft is buggered -- possibly by galling due to the lack of a thrust washer. I don't see any choice but a hammer or wheel puller. There is a danger that the inside of the lead screw bracket will be scored in the process. The shaft should be make of harder stuff, but I don't know for sure. In any case, you need to carefully stone down any dings in either part so that the block slides on and off easily. If it's really bad, it may be necessary to replace one or both parts, but I doubt it will come to that. Even if the fit ends up slightly loose, it should make no discernable difference in the performance of the mill.
Good luck, and let us know how you make out.
David Clark in Southern Maryland, USA
--- In GrizHFMinimill@yahoogroups.com, "chucketn" <chunk07@...> wrote:
> FWIW, I found a description of removing the Y axis leadscrew and bearing block at http://www.fignoggle.com/machines/x2mill/howTo-removeYScrew.htm . It describes removing the block by driving the lead screw out of it with a hammer and block of wood. Sounds like a press fit, but why if there is no bearing?
> Chuck in E. TN