[Thomasvank]

Hey guys, I wanted to share my linear bearing install/ upgrade on my grizzly PM 45 clone. I decided to do the linear bearings when I figured out the ways on the z where worn pretty badly. I had been trying to figure out why this mill always had a hard time with chatter. It turned out that the used mill wasn't taken care of too well and there was .020 ware toward the bottom of the ways. The linear bearings are HIWIN HGH25. I bought them from ebay new at a great price, around $200 bucks. So far I machined the z axis saddle and the ball nut mount. I then cut the dove tails just behind the top. I had to remove them to clear the new bearings and still be able to use the scrapped surface to mount the slides to. So far they are nice and smooth. I hope to pick up the z rapids to 100 ipm or more. Before I was only able to get it to 75 ipm.
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[pastaman]

I'm liking what I see. Nice job! Please post more pictures and information on your mod as you progress.

[gearhead406]

Look like things are going well. Nice work so far keep us updated.

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[Thomasvank]

Here is an update videohttps://youtu.be/zEU7Rmwr6PI

[CS900]

looks great! Throw a counterweight or some air shocks on the head and you'll be able to bump up your rapids a bit more.

I'd be interested to see a part machined before and after the upgrade. I know my surface finish improved a bit when I did mine, but I did all 3 axis at once so it's hard to say what was just from the Z axis.

Also...what motor are you running on it? it looks to be fairly substantial and direct drive.

[Thomasvank]

I had gas shocks on it before the upgrade. They didn't do much so I left them off. I am running a 4025 oz/in stepper on the z. The driver for it is a bit bigger then the 3hp vfd running the spindle.
The surface finishes had improved quite a bit. I haven't really run the machine a whole lot yet. Just to make parts for the ATC I am building for it. I will be making some parts for a vw tdi swap I am starting. machining the fly wheel and adapter plate should be fun.