Newbie- PCB machine - get me on the right track

[CaptKidd]

Bet you guys hate all these newbie threads, but I'll throw out another one anyway.

I'd like to get some pointers on where to start a machine that I can route and drill my PCB boards on. Size of the boards will more than likely be around 4" x 6", but some could go up to around 8" x 10", so I guess I need to plan for that.

I'm thinking stepper motors, but being new, recommendations are in order. I'll be doing some fine line traces, so step angles and torque questions come to mind.

I've been looking at designing my own control boards, maybe using an AVR for some controls and either a SN754410 or L297/L298N for stepper control. This might be totally out of line though. I'd like to hear your opinions.

Plans that suit this type of machines would be nice for either a total build or just recommendations for a design of my own.

Unfortunately, I came across this idea from viewing some CNC machines on places like Instructables. They're very inexpensive, so I carried that idea over to this forum. Everyone seems to indicate this isn't a cheap hobby, so I might have been scared off already. I would like to keep this inexpensive though. It doesn't have to look pretty as long as it works well.

I'm getting mixed impressions on control software as well. Mach 3 was what brought me to this forum, where I soon found EMC2 ( free and Linux based). Some of the comments about EMC2 leads me to believe that it might not be all that some of the commercial products are, and yet, others seem to say it's good enough.

There's so much here to read, and the more I read, the more questions I have. What started out as an idea to use a fixed gantry and Dremel tool has now become an idea of doubt about the cost of all of this. I've got tons of on-going medical bills due to my wife's health problems, so it's got to be cheap, unfortunately. So any suggestions should be made with that in mind. A true DIY project is what I'm after from start to finish as I don't think I could afford some of the stuff I see mentioned here.

Thanks for any help. Sorry it's so long winded.

steve

BTW - Just realized this isn't probably the right forum, so if the admin wants to move it for me, I'd appreciate it.

[Jason Marsha]

I cut this PCB with a JGRO machine

First milled PCB

An MDF machine will allow you to build an inexpensive machine and you can still get excellent results

Jason

[epineh]

As Jason mentioned the JGRO is a nice little machine, probably a bit bigger than you need for PCB's only but the plans are free to download and the materials to build it are pretty cheap.

For stepper drivers have a look at the linistepper driver, I have built them and they are pretty cool, you can make your own boards or a 3 axis kit is available for next to nothing, they will drive small unipolar stepper motor's very well and if you are using threaded rod for leadscrews then they may work for you.

Good luck !

Russell.

[epineh]

Oh yeah I also use EMC2 and it would easily cover your needs, installing and configuring it is simple enough. The demo version of Mach also works with up to 1000 lines of code as far as I know which may cover a PCB mill file as well.

[CaptKidd]

Jason,

I've downloaded the viewer and the Solarworks files. I'll take a look. Thanks for the pointers.

epineh,

Thanks to you as well.

Originally Posted by epineh Oh yeah I also use EMC2 and it would easily cover your needs, installing and configuring it is simple enough. The demo version of Mach also works with up to 1000 lines of code as far as I know which may cover a PCB mill file as well.

One of the unknown variables to all this was lines of G-Code involved. I'm sure it depends on the complexity of the board being milled. As I recall, the demo had a limit of 500 lines of code, but I might have mis-remembered. Again, old age strikes. But there's just so much to learn with all of this, it's almost overwhelming. Anyway, I was sure if Mach would work or not. I guess I could run a test board through and count the lines of G-Code it generates. Not even sure how to tell how many lines there are in a file without ever seeing a file.

I might sit down and strip apart the JGRO and downsize it a bit.

From all that I've read, bipolar seems to be the most common type stepper. Can anyone explain the benefits of either if there are any?

Thanks again,

steve