[xavier2nd]

My Torchmate has been cutting really bad. I bought an upgrade from TM that was suppose to solve the problem (Which did help, but it's still a problem). I decided to open up the cassette and found my problem.

Here are the pictures.

This is the cassette. As you can see the bearings are rusting up. These bearings are NOT serviceable (unless you open everything up).


Here's a better picture of the rollers.


Here's a cleaned up carriage.



I took everything apart and soaked it in parts cleaner then in WD40.


Here's what the bearings look like.


So moral of the story, keep water off the guides and rollers.

[WSS]

Great lesson to share. Thanks! Any ideas on how to stop the spray of water to the critical areas?

We are in the process of building a water table for our Plazpak system from CandCnc. We are a ways off but want to start the integration of the water table on our current system so it is up and running when we retro-fit.

I am open to suggestions.

WSS

[xavier2nd]

There really isn't any way to keep the moisture off of it. We are going to make a shield and that's all I can think of doing.

On the plus side, I found the manufacturer and a vender. The vender is already a vender of mine. The cassette and rail (if needed) isn't all that expensive. Combined they are about $350 bucks.

I'm confident once I get my new rail and cassette that the machine will cut a lot better.

[BBchevy396_]

I hit my rollers and rails with a spray lube once in a while (NOT WD40, it leaves a sticky residue after awhile), to keep corrosion from starting, and also run plasma quench in the water. Rusting doesn't seem to be an issue anywhere.

[xavier2nd]

What does plasma quench do? Plasma quench is out of business it seems.

Keep the ideas coming.

[xavier2nd]

I just had a thought. I think the metal dust that the plasma creates is where the rust is coming from.

[flyinwilly]

There is a recipe for a homebrew plasma quench somewhere here on the zone.

Basically, it is 1/4 LB of sodium nitrite (NOT NITRATE) and a tsp of Physan 20 for each 75 gal of water. I've been using it for over a year and not a bit of rust anywhere. However, I have very little plasma dust since I have a downdraft system and a water tray so I can't comment on the dust causing rust.

The only place I found the sodium nitrite was on ebay. The physan 20 can be picked up at a garden center.

Willy

[Dustin407]

Hey guys,

I built a plasma skirt not too long ago.. It keeps the sparks and water isolated under the nozzle.. I highly recommend that you install one to keep things like this from happening. Here is a few photos to help get an idea.. Basically it is an alum. ring with water/flame resistant material.

[WSS]

Dustin407, how does the flame resistant material do with pierces on 1/2" to 3/4" plate? I have yet to find anything that can handle a direct spray for more than one or two hits.

WSS

[BBchevy396_]

What does plasma quench do? Plasma quench is out of business it seems.

Keep the ideas coming.

Actually, I found a source for Plasma Quench. It's the real stuff for large industrial tables.

My LWS aquired a 5gal bucket for me, after prodding the company. I think they usually sell in larger quantities.

Knight Enterprises

It's a corrosion inhibitor, biocide, and has the neon green dye........ mixed in a concentrated liquid form.

It's labeled "Plasma Quench 44".

[Dustin407]

Dustin407, how does the flame resistant material do with pierces on 1/2" to 3/4" plate? I have yet to find anything that can handle a direct spray for more than one or two hits.

WSS

To be honest I have only had it on my machine for a few weeks, so I am still keeping an eye on things... The fabric seems to be just fine so far. WSS how close is your material to your nozzle? You dont want it too close where it burns up.. Im sure you can find an industrial flame/water resistant fabric that is better than the one I purchased but it is doing the job just fine for me. The mcmaster carr part # 8776k6 , if you guys would like to try it out. Plus you can add more than one layer two or three .... the only thing I would do differently is build a wider dia. alum. ring. I think the one I have is 3.5 inch wide I would probably go to 5" on my next design. The reason why is a small percentage of water slips by the shield skirt when it is moving to the next spot (safe height).

[xavier2nd]

Looks like I need to make or buy plasma quench, add a shield, and spray down the slide.

[gurew]

this is precisely why i chose NOT to use metal linear slide bearings in my cnc plasma table...plastics only! and they last just as long if not longer than the metal type

[Dustin407]

this is precisely why i chose NOT to use metal linear slide bearings in my cnc plasma table...plastics only! and they last just as long if not longer than the metal type

I do not agree they last just as long.. plastic versus metal...:bs: This thread is just to fine tune some ideas from water getting everywhere to stop rust, but once these ideas are in effect and working properly the metal will outlast the plastic 20x.....

[gurew]

go do some research before you make that claim. you are clearly wrong

[gurew]

http://www.igus.com/_Product_Files/D...s-brochure.pdf have a read. the bearing issue was 1 of my choices for NOT going with torchmate. their use of plain bearings and roller type linear guide and normal ball bearings didnt seem like a good idea to me.

really...plastic is the new metal....this is 2011 guy, technology has come a LONG way

look into the iglide® R when your plain bearings are out of spec and your drive shafts wiggle from having too much play.

[WSS]

Plastic? Not a chance. I am of Dustin407's thinking. One nice hot spark and what happens to plastic (of any type)? Plasma dust is a really good valve grinding compound, again what happens to plastic? COF plays a big part here, do you oil the plastic? Maybe if you are working with wood or engraving dog tags on aluminum, but not on my table. I took a reading with a IR thermometer of my rails last week after oxy cutting a 1" plate and had 325º f in spots close to the cuts. How do you account for the varying sag and stretch? Ok, my machine was built in 2009, but I have not heard of any monumental discoveries since then.

Have I missed something?

WSS

[gurew]

you have missed something, i used to be just like you...plastic bearings?! ya right!!! then i got educated....


they use plastic bearings for all kinds of stuff now days and esp in our application of linear motion for applied robotics...plastics make a WONDERFUL option and its really worth going to their website and doing a little research.

igus® - iglide® Plastic Bushing Application Examples: Overview

there are some of the uses of plastic bearings...neat eh?

yes they withstand high temperatures, yes they can withstand some of the most harsh environments, they are self lubricating with dry lubrication not oil based like sintered bronze bearings.



iglide® M250
Thick and rugged

Features
excellent vibration dampening
resistant to edge loading
high impact resistance
thick walled according to DIN 1850
dirt can become embedded for shaft protection
Properties
max. long-term temperature 176ºF
rotational and oscillating motions
coefficient of friction 0.10 to 0.30
PSI 2,901
max. PV 3,400


iglide® R
The low-cost, bronze alternative

very low moisture absorption
low wear at high speeds
highly cost effective
maintenance-free
self-lubricating
max. long-term temperature 194ºF
rotational and oscillating motions
coefficient of friction 0.08 to 0.26
PSI 3,335
max. PV 8,700

iglide® J
The fast- and slow-motion specialist

low wear against different shaft materials
low coefficients of friction
vibration dampening
good chemical resistance
best performance behavior with soft shaft materials
low moisture absorption
withstands temperatures reaching 194ºF
rotational, oscillating, linear motions
coefficient of friction 0.8 to 0.18
PSI 5,075
max. PV 9,700

iglide® GLW
Strong and reasonably priced

diverse applications with static loads
maintenance-free
cost-effective
resistant to dirt
resistant to vibrations
max. long-term temperature 212ºF
rotational and oscillating motions
coefficient of friction 0.10 to 0.24
PSI 11,600
max. PV 8,600

and thats just a few if what they offer

[gurew]

iglide® X6
Nano material for high temperatures

continuous temperatures possible up to +482°F
up to 50% better pressfit
lubrication- and maintenance-free
high compressive strength
very good chemical resistance
PTFE free

like i said they have many to choose from....

[Al_The_Man]

Do these fall into the same category?
Linear Plain Bearings PTFE Coated for Maintenance-free Linear Motion
I have used their product in a few harsh environments.
http://www.pbclinear.com/Download/Do...on-Booklet.pdf
Al.