You'll want to order the ball end mounts for both ends if mounting on the side like I did.
I measured the force required to move the head upward without the torsion spring at 70 lb so anything less won't be enough to keep the backlash out of the rack/pinion. You do need to deal with the nature of the head to always want to rise back to the top but I've gotten used to it now. In fact I often release the quill handle and allow it to return to the top where it comes to a nice cushioned stop due to the gas spring end cushions. Milling is much nicer since I can advance or retract the head without worrying about the backlash.
The 20" length collapses to 12" but I found I actually got 8.5" of travel, perfect for the standard rack on the HF mill. A mounting similar to the Little Machine Shop version inside the column would be a more centered counterbalance, but this offcenter one works fine for me. I removed the top stop bolt to get just a bit more travel, the gas spring provides the top stop.
Thanks to Paul Gloger for the inspiration for this mod.
--- In GrizHFMinimill@yahoogroups.com, "miner49r" <miner_49r@...> wrote:
>
> http://www.use-enco.com/CGI/INPDFF?PMPAGE=767&PARTPG=INLMK3&PMITEM=319-9761
>
> --- In GrizHFMinimill@yahoogroups.com, "bbass408" <bbass408@> wrote:
> >
> > Rick is running with an 80lb gas spring as I recall from another post. He can follow up with details if he reads this one.
> >
> > One thing I remember him mentioning is that that always applies upward pressure to the Z rack since 80lb far exceeds the 30-40lb estimates of the weight of the head.
> >
> > Finding a gas spring with the exact length, extension, and weight specs for our mills didn't seem so easy. Perhaps folks can post back with specific products they've had good luck with.
> >
> > In one of the photo folders, someone extended the top mount for the gas spring above the head with some modified angle iron. That allowed use of a longer spring with enough extension to give you the full travel on the Z. That was cool. The mill is blue in those pics.
> >
> > All that said, I like the webbing pulley setup. It's so clean and compact, and seems to work just fine for our little mills. I just might not have the room behind the mill to put the counterweight. So, maybe I'll try the angle iron idea.
> >
> > --- In GrizHFMinimill@yahoogroups.com, "Rob Potter" <rob@> wrote:
> > >
> > > So in that vein, has anyone ever replaced the gas spring in the LMS kit with
> > > one that's stronger? Which is to say, simply used their mounting hardware?
> > > I'm working on a counterweight system, and have purchased the longer rack
> > > from LMS, but I don't want to overlook other options that may have worked
> > > for someone else.
> > >
> > >
> > >
> > > Rob
> > >
> > >
> > >
> > > From: GrizHFMinimill@yahoogroups.com [mailto:GrizHFMinimill@yahoogroups.com]
> > > On Behalf Of bbass408
> > > Sent: Friday, January 20, 2012 1:07 PM
> > > To: GrizHFMinimill@yahoogroups.com
> > > Subject: [GrizHFMinimill] Re: Air spring and spring
> > >
> > >
> > >
> > >
> > >
> > > I bought the kit and just installed the new rack for now. I'm more inclined
> > > to wait and do a counterweight like in the other threads today yesterday.
> > >
> > > If you used both, you probably would not get too much head lift to cause
> > > inconvenience. But, most people buy that kit so they can get rid of the
> > > existing torsion spring which:
> > > * Limits downward travel.
> > > * Can hit big workpieces on its way down.
> > > * Has a locking ring on the right side of the column which makes it harder
> > > to install Z axis DRO.
> > >
> > > --- In GrizHFMinimill@yahoogroups.com
> > > <mailto:GrizHFMinimill%40yahoogroups.com> , "eedowens" <eedowens@> wrote:
> > > >
> > > > I just recieved the LMS spring conversion and wondering has anyone just
> > > left the tortion spring on along with the air spring and if not what
> > > problems would this create? thanks ED
> > > >
> > >
> >
>
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