Are we going about this the wrong way?

I have been giving a lot of thought about bushings these last few weeks. I ordered a batch of self lubricated ones from China to use with ordinary polished half inch stainless rod and they worked wonderfully.

I tried printing a batch of bushings from PLA+ and ended up making 20 units of the Tinyboy style printer using stainless rod and printed bushing.

Today, acting on a hunch I visited my stainless guy downtown Manila, and he surprise, had some brass tubing that was a perfect 1 inch ID bushing. It fit a little tight at first, but after a bit of sanding with 1000 grit on the stainless tubing, it slid smoothly.

So Im asking why are not using bushings?

spent the last hour messing with this stuff. got it broken in now and added a bit of teflon lube spray to it. I am really amazed, so smooth running. My first attempt at making brass bushings.

I made some delrin and UMWHDPE bushings in the past along with some PLA+ ones but these take the cake.

Im seeing a 6090 mill in my future with a 1.5kw spindle made from some lasered steel parts using this stuff…

Hopefully it’s dry lube. Wet lube and routers is the devil.

Also, if your rods/tubes are out of round anywhere you’re going to have issues. If you’re using precision ground rods, then large machines are going to be ungodly expensive. You’ll also have to beef up your steppers to deal with the mass of the gantry. Now that you’ve beefed up your steppers, you’re going to find out rubber timing belts aren’t going to cut it anymore either. So you’ll either need to go with chain, which works quite well, or use a rack and pinion gearing system, which works really, really well, just not with this kind of gantry design.

My guy downtown has consistent stuff vs the decorative guy up the road from my shop so I make the 2 hour trek downtown for it. I got hosed on a batch of the decorative stainless awhile back leving me with 18 meters on unusable stuff.

Printed holder for a bushing and a nema17 will be fine, a bushing will have significantly less weight than the roller bearings and assorted bolts on the MPCNC.

As far as friction goes, after a bit of work, it runs smoother than the china lm12uu I use on my printers.

I use wd40 dry Teflon from Ace hardware (yes there is ace and true value here)

I build big routers also, v groove I make here and rack and pinion also made here. I would not put this stuff on a high dollar router, but for a cheap signage router, bushings and good 1 inch stainless tubing is great.