Gantry rail question

[millman52]

Was wondering about the use of linear bearings & hardened rails to build a gantry for a CNC operated burning table.

Is dust a problem with using bearings & rails such as these?: http://cgi.ebay.com/Two-New-Thomson-...em130058992151

Opinions please.....

[massajamesb]

I wouldn't think you would have any problems, just wipe them off from time to time to prevent too much dust accumulation.
I believe plenty of people use those on their plasmas.

[mlaws1172]

They will work great. Most bearings have wipers on them.
mike

[millman52]

I am completely new to CNC work. I do get around very well with a pc & have a good bit of experience with AutoCad V14. I own a sizeable machine shop & can build/fabricate most anything I need. Have been operating for several years with an old Linde pantograph magnetic tracer. (radigraph I think they call it) I only have need for a 5 X 9 cutting area.

Have been looking at Torchmate kits Dynatorch etc. Just seems pretty pricy to me fo no more than is in the kits.....

[massajamesb]

I would still wipe off the rails from time to time, as well as clean the wipers on the bearings. Just to prevent any problems, you know.

[massajamesb]

Originally Posted by millman52 I am completely new to CNC work. I do get around very well with a pc & have a good bit of experience with AutoCad V14. I own a sizeable machine shop & can build/fabricate most anything I need. Have been operating for several years with an old Linde pantograph magnetic tracer. (radigraph I think they call it) I only have need for a 5 X 9 cutting area. Have been looking at Torchmate kits Dynatorch etc. Just seems pretty pricy to me fo no more than is in the kits.....

I got started because of a pantograph cutter I built a while back. Those things are handy, but babysitting them kinda sucks.
Yes, I thought the same thing about most of the machines on the market, as well as I could not afford the initial investment.
If you have a good machine shop, and are a decent welder, you should have no problems building a machine whatsoever. Good luck

[millman52]

I have done quite a bit of reading, here as well as Geko etc. I have yet to see a basic wiring diagram or parts list of what is needed hardware wise to make a 2 axis system work. I see all sorts of different voltages mentioned when it comes to drive motors. I assume some sort of power supply is needed.

[millman52]

I am completely confident in my ability to build all the mechanical aspects of a table. It's the electronics end I am decidedly lacking.

[massajamesb]

Without trying to take up too much space here, you will need the following:
PC running Mach 3 www.artofcnc.com free demo available on site(or equivalent, Turbocnc, EMC, etc.)

Cad software (which it seems you already have)

CAM software (check www.sheetcam.com, great stuff for plasma cutting, free demo)

Breakout board (check www.campbelldesigns.com, www.candcnc.com for a couple of great BOB's, I got one from Hubbardcnc on Ebay, has built in relays for the plasma torch)

One Gecko 201,202, or 203 for each motor (If you go the Gecko route that is, there are also a lot of other drivers available from other manufacturers. Geckos being at the top of the list, IMO)

Power supply, minimum 24 volts DC, max voltage dependant on driver manufacture specs.

Stepper motors. For a table that size, minimum 400 oz in motors if you have a lightweight gantry
with decent gear reduction (i.e. timing belts and pulleys, gearboxes, etc.in a minimum of 1:3 gear ratio, that is optimum,IMO)

I am sure that others will chime in with their preferences and opinions, but this is just to nudge you in the right directions. Sorry for the long post.

[millman52]

Will Most likely be building an oxy/fuel table as I regularly cut 1/2" & often need to cut thicker up to 1" steel only.

I have downloaded sheetcam & played around with it some. It don't seem like it would be much of a problem for me to pick up. I don't remember if sheetcam has nesting capabilities. Nesting is something I definitely will want.

I'll take a look at the other links in your post(s) Thanks a bunch NM

[massajamesb]

Sheetcam only does manual nesting. This in itself is not bad, but not quite as nice as an autonesting program.

Glad I could help. That's what the Zone is for!

Edit: since you will be doing mainly oxyfuel, you will not need much in the way of speed. I suggest as far as motors go, most in the 200-500 ozin will work, just gear them down to get some decent torque out of them.

[Torchhead]

Millman, I hear your pain.
Currently we offer a Integrated Power Controller, PC interface and Digital Torch Height controller solution. Comes with Controller software, MACH3 license, etc. Optional NEMA case.

http://www.candcnc.com/PSC650+MP1000Bundle.htm

In this bundle you have to supply the motors, motor cables and connectors.

In a few days we will announce a Total Plasma Cutting Solution that will also include matched motors, (steppers) motor cables, connector panel and the whole ball of wax. We will even recommend the type of pack and pinions and V bearings to use. It will also include a plasma CAM package (SheetCAM) and a disk of sample files. Servo's will be an option in about 30 days.

This is going to be for the guys like yourself that have the ability to fabricate things in a shop but don't want to worry about stuff like "oz-in" or "series VS parallel motor connections" or any of the electronics issues. Everything will be optimzed to work together and leave you to deal with the mechanical aspects of plasma cutting.

Later in the first quarter we will have a series or "how to" tutorials for going from idea to cut pieces the fastest and most profitable way.

There is discussion (at this point) of a 2 or 3 day workshop with hands on training for plasma (and router) cutting in the Dallas area. It will depend on if we can fill a class. Details are still very sketchey.

I field about a dozen phone calls a day from confused builders and I have built a pretty good understanding of what the issues are.

One solution is just to throw money at it. The other is to apply experience. I prefer the latter


Tom Caudle
AKA Torchhead
www.candcnc.com