OK, I've been lurking off and on for a while now. I have scavanged some good linear rails to make the X and Y sections. I'm in the considering stages at this point. What else do I need? I know nothing about the drives, motors, power supply options that are available. I also am ignorant when it comes to the interface between some type of CAD progam and the machine. I work with AutoCAD LT all the time and can whip out a mean drawing, but how do I get it from the screen to the machine in a format that is usable? Any help would be appreciated. Thanks.

What else do I need? I know nothing about the drives, motors, power supply options that are available.


Then keep on reading. ;) What size machine do you want to build, and what do you want to do with it? That will help to determine what size motors you need. Also, how much do you want to spend?

I also am ignorant when it comes to the interface between some type of CAD progam and the machine. I work with AutoCAD LT all the time and can whip out a mean drawing, but how do I get it from the screen to the machine in a format that is usable? Any help would be appreciated. Thanks.

There are a couple of free options. One is ACE converter at www.dakeng.com

In LT, you draw lines where you want the tool to travel, typically the center of the tool. Save as a .dxf (v12 works usually works best), load it into ACE and convert to g-code. ACE will let you set the cutting depth on a per layer basis. If you want to cut at different depths, draw on different layers.

You then load the g-code into a machine control program. The most popular is Mach3, at www.artofcnc.ca It's free for running up to 1000 lines of g-code at a time. Mach 3 can be installed in demo mode, so you can learn how it works on your everyday PC. Download the latest version (1.90.081) and install. Near the end of the install, you'll see a checkbox that says "install driver". UNCHECK the box and Mach3 will be installed in demo mode. Watch the setup and tutorial videos on the website to get you up and running. Once setup, you can load g-code and run the program.

Mach3 also comes with a simple CAM program, called LazyCAM, which will also convert your .dxf files from LT into g-code. It can be found in Mach3's file menu.

Yo

A good idea is to post any drawings, photo's of your rails etc so people can have a look and give some input as to suitability. There is a LOT of info on this site as you have probably noticed, make the search function your friend, at least you live in the US where you can get ballscrews without having to take out a bank loan and deposit body parts for security...

Another thing, this stuff is VERY addictive, you will probably start planning your 2nd and 3rd machine before you have finished your 1st. Most people's first machine's end up making parts for their next one, and so on. Also the first may not be the best of machines, it is the learning curve that is important.

Personally I am approaching it one small piece at a time, instead of trying to figure out everything, breaking it down into manageable "chunks", I find things are progressing well for me, and no I haven't finished my first machine yet ...

So get reading and start building, RACE YA !!!

Might sound unfair as I am halfway through my machine, but don't worry, I am a slow builder :D

Russell.

How does one go about determining what size motors are necessary?

Motor sizing depends on a number of factors, weight of you gantry or bed, required/desired speed, required resolution and lead of the lead/ballscrews.
Their are a lot of people here that can offer some good rules of thumb but size of machine and meterial to be cut will need to be decided upon first.