DIY CNC Plasma Table

How much can you afford? Most CNC's use post-processors of CAD programs to translate the data to G code or some other CNC language. With that said, then one will need the servo controller made to accept G code, etc.

Building the overhead router-type gantry isn't that difficult, and if the precision you wish to achieve isn't high, it can be made fairly inexpensively using gantry column wheel trollies, bicycle chains, sprockets and servo motors.

P. S. We had a pantograph-type cutting machine around here a long time ago, and it worked pretty well for our oxy-acetlyene cutting. We had to tighten the joints up every so often, and the precision was fairly good.

I was thinking the gentry would be the best option for a home builder, which is the idea of the article. There are a lot of very skilled fabricators out there in hobby land who could benefit from this form of tool.

I have looked at a lot of machines on the net, this lead me to the idea of saving people some cash.

Turbo Cad is a nice inexpensive option and allows people to import JPG files as well.

I start to stumble when it comes to the mechanical controllers and associated electronics..

Something like this has to be less to make than buy, most hobbiests can handle the table and gantry with some direction, the other parts are the problem.

If cheap is your aim, then I have some suggestions.

I have been looking into a project like this myself, not just for a plasma cutter, but also for cnc for a lathe and milling machine. I may still make a plasma cutter table one day, but I acquired a small robot arm that should work (if only I was a programmer) also.

Anyhow I would look into utilising stepper motors, simply because they are cheap and plentiful.

Driver circuits are easy to find, along with software that will drive everything.

Check out these links for motors, drivers and cnc software.

Surplus motor that I would recommend, although also look at the other motors on the site, in case you like them better.

Site with stepper motor drivers, personally I like the L297-8 design, but almost all should work. With the motor I recommended, you can drive it bipolar for more torque, or unipolar and just use a simple drive circuit.

Last is the software, it seems like most DIYers use Mach 3 as their software of choice. It will send the step direction and pulse outputs out of a pc parallel port. Their is no reason however that you couldn't use other software.

When you build this, I expect a writeup and pictures for the workbench creations blog.

you bet I will send along a write-up and photos.

the idea is a step by step for a home user, or even a club to put something together that will get them the capability to make their own parts EASIER. For the most part all those brackets and bits are being made already. Considering how inexpensive controllers and motors have become, tied with loads of computing power very cheap, seems like an easy thing to do.

the table, and gantry is the easy part for me, the motors and controllers is the catch.

me lazy? Well it is summer, must have caught something from Del, cats do sleep a lot

I will check out those links to see what I can learn.

This is not the first time someone has tried this. Have you looked on the web for inspiration as others have posted their DIY CNC plasma cutter designs in depth (I even remember someones DIY CNC gas laser cutter).

A quick search of "diy cnc plasma cutting table" produced a number of hits and videos that would be of help.

If this doesn't help I suppose we could "Macgyver" something up out of number 8 fencing wire, duct tape and Del's fur (the duct tape is for removing the fur)

Just kidding Del.

thanks for the hint.

Del's fur is safe, my pride of 7 cats provide far more fur than I will ever need...

Hi.

Constructing a plasma cutting table fun educational and doable in a garage shop, but it does take some research. I would suggest going to the Mach 3 website where you can find data on the software and links to numerous suppliers.

My experience would indicate some serious scrounging and E-bay lurking would allow a 4' x 4' table to be constructed for $2000-$2500 not including the plasma cutting unit which would be about $2500 new, (50Amp minimum)

Please don't forget a good ventilation system and easy access for cleanup.

Good building

For your software check out Aliber. Their basic 3D cad and machining software is free. You only pay when you buy their advanced programs. You can do your whole design in 3D and then build the cutter....and the 3D router/mill....and all your mates will come play at your house.

Not sure, but I think it should be written "Alibre".

The website is here:-

http://www.alibre.info/

Parallel Printer port infos can be found here:-

http://www.winfordeng.com/products/brk25_parallel.php

Thanks Andy. Silly Typo. Great comments, specially the extended X axis and point of start.

For the plazma cutting table An idea is to build a saw-tooth cutting surface in a tray with an outlet via a metal cyclone linked to a vacuum cleaner / central vac. The metal cyclone will separate hot metal that may otherwise attract the local fire department and a lot of water!!! The catch tray and vac saves getting the dust all over. Dropped sparks in a small shop with different materials all around are a hazard of note.

To convert to router table with a vacuum tray you simply drop a sheet of low density MDF on top of the sawtooh table that fits the tray snugly and presto you have a vacuum table to hold your sheets of wood or plastic or foam in place for machining. Make sure you clean all wood/plastic waste from the system and cyclone before going back to plazma cutting.

I forgot to mention that if anyone wants to build them selves a smaller CNC router for PCBs and woodworking/Hobby etc, I have a method that I copied and adapted from a website using MDF instead of metal for the table etc..

You can read all about it here:-

http://cr4.globalspec.com/thread/32226

Go to cnczone.com and check out the work that is already being done by DIYers like yourself. You can build a very accurate (enough for plasma cutting) on a budget of just a couple thousand bucks. I've been meaning to make one of these homemade routers for a long time but have the perpetual list of priorities to take care of first.

Obviously you'll want to make yours out of metal...I'd recommend something like this so you can quickly assemble with some very standard parts. The 'hybrid' part of the name means that it's made from a mix of different kinds of parts (metal, plastic, etc) to reduce cost. You could either shield the plastic bits or replace them with something tougher. You can either buy just the plans or order a kit which includes everything except the electronics (which can also be bought in an appropriate sized kit).

For a purely cnc plasma cutter I'd dispense with the z axis and just do x-y with a manual adjust on the height...cheaper and quite a bit simpler. You also don't need to worry about the regular cutting forces so any of these home made setups would work...just make sure to take you spatter into account and protect any budget wood or plastic bits..

Good luck and keep us posted...

Take a look into Digital Machinist Magazine, http://www.digitalmachinist.net/, an outgrowth of the Home Shop Machinist and Machinist's Workshop. I believe they've got forums as well as the magazine itself; you should be able to find LOTS of support and ideas that way. Check the archives for older articles in all three magazines.

As others have pointed out, the cutter puts little load on the drives, guides, etc., so you may be able to adapt designs from units originally intended to work with other forms of cutting or processing materials.

consider logging into the forums at http://www.cnczone.com/ and asking there about your project.

I have seen a low cost cnc plasma cutter, just like your project, advertised in the home shop machinist mag as per poster #14 Ron. I know I could not build one for the price they have it at.

thanks everyone, not had this much homework since school

I am sure you realise it as well, but do spend several months reading and planning before investing any money.

I got some good electronics and secondhand Stepper motors off ebay......all of it hardly used, 9 motors (one needed a new bearing) for about $20 plus postage and an Steooer motor complete controller board, new & unused for $1......because nobody else bid!!!

Keep in touch.....

Hi Andy

E-bay was an early idea, and I will list it as a resource, however the idea is to publish a how to for my off road readers with links to readily available bits and pieces.

I have the table part ironed out, going to make a table capable of holding a 4x4 sheet with a water tray, safer for catching slag. The water tray can be made of either folding up some light steel sheet or from plywood and resin coating.

Legs will be steel to support the x and y axis structure.

cables will be routed through old vacuum cleaner hose I think...

I'm in the middle of finishing building a DIY CNC router and and used the monster kit from Probotix which comes with motor controllers and breakout boards (parallel port).

The whole thing can be controlled by a regular PC (I will use Ubuntu and their free EMC2 software). More info on the Probotix site.

As for the actual gantry, I got the linear bearings from a dismantled surface mount machine my old company was throwing away (lucky me) and the leadscrews were acquired from Ebay .

I used 1/2-10 ACME Lead Screw with Delrin Nut for the X and Y axis (I have 22" in the x-axis and 48" in the Y-axis). The Y-axis uses a leadscrew on either side for rigidity and a single motor (linked by timing belt). Lots of trial and error so this has been a long project for me since it is my first machine and I work on it between regular work and family life.

Hi Rick

Thanks for that. I know who you feel about fitting in the project, this one is the smallest of three I am working on.

Which reminds me I really have to get my 55 Chevy listed for sale so I can make some room.

Where in Canada are you?

Hi Dances with Trees,

Montreal. Our company just announced some 700 layoffs (CAE inc. and I'm ok for now...). This was a hell of a week. Just glad the week's over and I can grab a beer and relax.

I hope the links I provided will be of help. Some of the motors out there are pretty expensive. I've tested these and and they're quite powerful for the price. All in all, a pretty good deal. Servos were out of the question $$$.

I still have a couple of ballscrews taken from the same machine but they were too big for what I had in mind (about 1.25" dia. x 6' long). If all goes good with this one, I might build one that will accept a full size sheet of plywood (4'x8') and have the option of plasma. We'll see....

We are indeed living in interesting times.

Every link is a good link, so much to learn so little time...

I have been looking into the idea od a small router mount, something in the range of a Durmel for 3 dimensional plastic work.

First I have to get the planning finalized.

We do alreadyhave a CNC blog, if anyone needs a link just let me know and I will post it here.

Please do post it....I'm interested in all cnc discussions...

As if I didn't have enough to do, my car "decided" that I've been neglecting it and sprung a leak on the rad this weekend. And the CNC was put aside so I could build a wall-saw (panel saw) for my brother as he is building new cabinets for his appartment building. The projects keep on coming and still no time is "added" to my schedule.

I think the summer is just gonna zoom by without me realizing it...oh well...

Try here:-

http://cr4.globalspec.com/thread/32226#newcomments

Thanks Andy...

I would like to point out for anyone reading that "length" can be a problem sometimes, but with proper planning at the "Building" Stage of the CNC machine, this can be erased.

The "table" needs to be open ended and generally speaking this also needs to be the "X" Axis. (Many small commercial machines have the long Axis as the "Y" sadly...)

The reason for having the X axis the longer AND open ended can be seen in this simple graph:-

The X axis is at the bottom and is easily extended....most CAD programs have the long bottom axis as the X as well and you really want to stay compatible so that you do not need to do extra work to convert your work. That can easily bring in extra errors....

It could of course be the Y axis, but certain work will become more prone to errors if it has to be transposed!

So when looking from the top, the 00 point mus be at the lower left, the gantry must start on the left and move to the right, for the Y. axis, it must start at the bottom and move up......

This can usually be finally set up when the electrical connections are made to the motors, but it should also be born in mind while building, just in case there is some mechanical reason later, that will make things awkward for you.......

Here is a picture of a nice homebuilt machine that will not allow long material to be machined because of mechanism aprts blocking the ends of what hopefully is the X axis.

For reference I have marked what should be the 00 point with a small circle, and the X and Y axis.....:-

So long as the machine is wide enough on the Y axis for the width of the material to be machined, start at one end of the material in the X axis and work your way along it, machining a part at a time.

It is most useful to have a guide to slide the material along after each machining operation and a point that you can use as a zero reference each time the material must be moved.....

Its a small point really and if you only want to machine out some small PCBs for example, not worth worrying about........Its more important for people that need to be able to work on long boards etc....

Have a great weekend Guys.

What happened this thread? I was really enjoying reading about your endeavours of building your own cnc plasma table and it seems to have finished. Has the job stalled since 2009??