New Machine Build- Small Steppers and Electronics Help Needed

[RMS]

I am interested in making some circuit boards for me tube guitar amp projects, and I always wanted to build a CNC router. My question are:

• What is the smallest z axis stepper to hold a small dremel 200?
• Who makes a good quality board kit for all related electronics?

I found these steppers and the price seems good, not sure if I should do a direct connection or use a belt.

stepper:
what do you make of these, any good?
3.6V, 1.8 DEG VEXTA STEP MOTOR-MPJA, Inc.

driver:
MINI STEPMOTOR DRIVER CW230-MPJA, Inc.

[brtech]

127 in-oz is pretty small. Probably depends on what the rest of the Z axis sliding part weighs. If you used aluminum like the cncrouterparts design, it's probably too small. You don't need 300+ however.

The drive has to be matched to the motor (voltage and current). The MJPA drive looks pricey, you should be able to get a less expensive drive.

Start with the router design, then select motors to fit, not the other way around.

[RMS]

Well, maybe I should have addressed the design goals of the actual machine more. Structural wise I am going to use slides from old ink jet printers just for the z-axis, with one lightweight aluminum bracket to hold the Dremel 200 tool. I am trying to do this very low budget just to get my feet wet. I do not expect perfect results first time around by any means.

My main design goal is to do pcb routing only, so I am thinking I can build a light machine with small steppers, and making my own driver boards based on open source designs, keeping my costs low.

Any suggestions by anyone who has gone this route with info on open source driver designs and matching motors that worked?? I want to avoid the wrong purchase mistakes.........

Thanks!

[sirkossorg]

If you're still looking for some cheap DIY stepper driver designs, here are two:

Easy to build CNC Mill Stepper Motor and Driver circuits

Stepper Motor Controller

The first is the Tom McWire one, which is what inspired me to build a CNC. The second one, which I found later, is a little better, especially for weaker motors (in my opinion).

The advantage of commercially available drivers are many, and you'll go to those in time. If the journey is the destination though, like it was for me, I recommend a DIY at first. You'll learn a ton, and it won't cost much money.
It will cost you time.

As to whether your motor is strong enough. The answer, as with many things, is "it depends". If speed is not your concern, you can build mechanicals to account for a weaker motor. I've got an eBay 177 oz.in running a pretty heavy Z with a router quite nicely.

Good luck.

[RMS]

Thanks for the help, and yes I am still looking for motors and a driver, but I am still in the design phases of the machine. So for now I am gathering data, and I will keep those links handy. What do you think the next step up would be to the drivers you posted? How about this one:

HobbyCNC EZ Driver Board Kit | HobbyCNC

[sirkossorg]

Probably fine. I didn't do a ton better in price with the drivers I'm currently using (used Vextas). It looks like it would get you up and running quick.

Personally, I'm not too crazy about all-in-ones because the whole thing needs to be replaced if one part fries, but I'm guessing that doesn't happen very often. That kit also saves you the trouble of a separate break-out board.

I'll bet there are lots of people here with experience with that particular kit. There's probably even a thread dedicated to it.