View Full Version : cnc mill with plastic "shims"?
I have a small hobby/job shop that i have been piecing together (cheaply of course). I've wanted to add a cnc machine so I bought a cnc knee mill for scrap value, and got around to the rebuilding of it (5bvk Hurco like machine). I was taking the table off to clean the ways surface rust(no biggie vaporust is the shiznit) when i saw these plastic shims on the jib and saddle ways (http://s1072.photobucket.com/albums/w370/toagger/):confused:. i've been to several state fairs and a cat rodeo, and i've never seen something like that. My thoughts are to remove check for suareness and shim if needed behind the gib with brass/steel shimstock.
Also the gib adjustment screws seem odd, anyone seen or worked on something like this?
05-09-2012, 12:36 PM
I don't have any experience with that machine nor did I sleep in a Holiday Inn Express last night but maybe the plastic is what's left of a high-tech plastic (Rulon or the like) anti-friction shim? Put there by the manuf. to reduce ye olde stick-slip issues? Seems plausible to me.
You can probably get the replacement shim for only $15,387.98.;)
Thats what i was thinking but they weren't on the operation manual/parts list. I am removing the table to clean the ways, and i can buy some 1/32 Rulon from mcmaster carr for $50 or so, but would it work without them, or would it mess the ways up?
05-09-2012, 04:26 PM
Normally to put down turcite the surface is rough so the glue will stick. It is just going to depend on if someone added it later. You just may have a machine that is totally clapped out and this was someones attempt to make it usable.
05-10-2012, 01:27 AM
Yeah, pretty much. So what you are going to have to do is pull the table off an inspect. If it was designed for turcite and the rough machined metal comes into contact with the slide way below it will ruin them. And you just cut replace the turcite and put it back together. It must be scraped in just like cast iron ways.
If not and the machine is just worn out then there is no real fix other than a complete rebuild. $$$.
I'm pulling the table off tonight if the kids go to bed at a reasonable time. I'll update with some pictures and maybe you guys can recommend if i should rescrape or scrap. I have the operators manual and parts list for the machine and neither mentions a turcite or rulon shim. So thats depressing.
thanks for the help so far!
05-10-2012, 06:03 PM
It won't mention it because it is part of the table. It not something that would normally be replaced. Its like they don't list the friction material separate from the brake shoe on the spindle brake.
If it really is supposed to have it the Y axis will have it as well.
In the manual, does it show the gib adjuster being like that? That does not seem to be stock.
Oddly that is how the gib adjuster is supposed to be. i thought it looked hokey too. I was thinking of drilling and tapping a set of holes and run allen head screws with lock nuts like a bridgeport table. though that doesnt sound like fun.
here's the exploded view from the 16 page manual... talk about skimping. I haven't tried calling the manufacturer, doubt they are in business or that they would admit they made it. But i will give them a call in the morning.
05-10-2012, 08:58 PM
Nah, just leave it as is if it gets that far. I am not a fan of pointless mods. Whatever works, works.
Once you pull off the table we will know for sure.
I took some pictures of the turcite and ways (the boy hid the camera, so i used a cell phone... i know). Aside from the rust and ripped up strips on the ends, the ways look "ok". I can get better pics if needed for a better assesment.
I have read up a bit on how to replace this, and if she is salvagable i think i'd like to have a go at it. I think whats the worst that can happen? i waste $200 of material and have to reclean everything for a professional (or scrap her but the daughter would be heartbroken) I read the turcite can be ground or flycut depending on the thickness after curing. I didnt mic the strips but i would guess they are at least .1 thick.
05-11-2012, 07:48 PM
Awesome! Looks fixable and you'll have a beast of a machine when you're done. There ought to be a HSM method of applying the Turcite and molding the surface in-situ to reduce the amount of scraping??
I'll bet some smart person has been there, done that!
05-12-2012, 03:17 AM
I am pretty sure the machine did not have turcite. The turcite would have been stuck to the saddle, not the table.
the top pic is looking down on the saddle, the bottom is the table flipped over. you can just make out the ball screw on the top. I'll take some better picsthis afternoon/tonight.
I'm wondering if i should remove the saddle to check it also.
05-15-2012, 04:52 AM
Couldn't hurt. Might as well clean out the oil passages while it is apart.
Hi Mac and all,
I found the camera and took some better images of the table and saddle ways.
here's the table, it looks decent, no gouges, some surface rust.
the next are of the saddle ways with the turcite (rulon etc). they look like hammered cat poop. but, i think i can clean them up, and have someone regrind or flake the turcite. I ordered new lines and meters for the one shot lube system. 2 of the lines were broken from corrosion, probably why the turcite got ruined. I should walk away from this but, in for a penny, in for a few thou as they say. I figure for about 1250 i will have it up and running. any takers on the over/under?
I'll keep you guys up to date on the restoration. and hopefully get better at resizing...
05-16-2012, 05:37 AM
I would talk to a company that rebuilds machines about doing the turcite. I think it will be somewhere around what you are guessing. If the screws are good, I say go for it.
If you have not ordered the bijur metering units, Monarch has about the best prices on them.