Newbie with CNC conversion questions

[Rich K.]

Hello, all! I have over 15 years' experience working in CNC shops, and now I want to convert my Harbor Freight 44991/Sieg X2 mini-mill to CNC. I have the blueprints from FigNoggle, plus I have three Wantai 57BYGH633 270oz-in 3A stepper motors on order.

I am on an extremely tight budget, unfortunately. This is going to be a "Johnny Cash" project in the first place ("One Piece At A Time"). I can save some money by making the motor mounts and other assorted brackets on the machinery at work. One thing I am somewhat ignorant about is drivers for the stepper motors.

If I am not mistaken, I need an interface board of some sort to hook up between the computer and the motors, and possibly individual boards between the motors and the control board. Does anyone make an inexpensive 4-axis all-in-one board that I can just plug into the computer and hook the motors and power supply to? Gecko is way too expensive - I'd prefer under $100 if possible (I can upgrade later).

[SteveHGraham]

I am going through this right now, with a Big Dog mini-lathe. I don't know anything, but I am doing a lot of research.

You will need CAD software to draw parts. You will need CAM software to turn it into Gcode the electronics understand. You will need some kind of software like Mach3 or KmotionCNC to feed the code to the electronics.

After that, you need a controller board and a driver board. The controller board tells the driver board what to do, and the driver powers the motors. You will need a power supply for the driver board.

You can simplify things by running the motors off a parallel port on your PC, and this will allow you to do away with the controller board, but if your PC does anything while you're machining, it will quit talking to the lathe briefly, and you will get a defective part. External controllers supposedly prevent this from happening.

If you want to do threading, you will need a sensor on the spindle.

I think this is correct, but I'm sure people who actually know what they're doing will come in and fix my errors.

CNC is expensive. My motors were 50 bucks each. My controller and driver (4 axis) ran me $450. My power supply cost about $130. The box to hold everything was almost 50. You can get cheaper stuff, but it will still cost a fair amount of money.

[hammermill]

Look and read up on a rep rap printer it uses a Adriano processor and is 4axis.


In the world of cnc 100.00 isn't much.

Look at some copiers , they can be full of driver chips and stepper motors

Read study learn read some http://m.ebay.com/itm/380961865697?cmd=VIDESC

This maybe a little light.

[SteveHGraham]

MeshCAM is $250. Mach3 is $175. Buying CAD software is like buying an engagement ring.

[DICKEYBIRD]

Mach3 has a free trial download, I used it for over a year for 2 1/2D milling projects with very few problems. The support people on the ArtSoft/Mach3 forum are great & will help even though you haven't bought it yet. However, they have no tolerance at all for pirated copies! Once I made a little money with it, I purchased a license to shut up my guilty conscience.

There's tons of free CAD options; hopefully you're somewhat CAD savvy and don't have to start from scratch. Mach comes with a bunch of "Wizards" which will handle most common 2 1/2D milling ops. It also comes with LazyCAM which is a .dxf to G-code/CAM program that is said to work pretty fair for simple stuff. AceConverter is a free .dxf/G-code converter I've used that works well for simple milling & routing jobs. CamBam is a good CAM program that has a free trial download as well. StickFont is a free engraving program that's easy to use. My milling jobs were all pretty simple and I either wrote the code myself or used the Mach wizards.

3A stepper motors don't require expensive drivers & power supplies, there's tons of 'em out there but be careful, the cheap-o chinese TB6560 ones on ebay are reported to be pretty bad.

Dave Rigotti at http://www.hobbycnc.com/products/hobbyc ... board-kit/ sells a good 3 axis kit if you're OK with soldering up your own. US made with quality parts that can be repaired if you blow up something. It's an older design but probably will do what you need to get going cheaply. There are probably a lot more kits out there as well if you root around.

If you choose to control it with the parallel port instead of a separate motion control device, you'll need a break-out-board (BOB) and there are many options; just stay away from the cheap ebay chinese stuff. Mine is from CNC4PC, it works well & is good value.

I'd suggest searching the web & reading all you can find on this stuff & you'll find something you & your pocketbook are happy with. There's tons of info out there, much of it adamantly stating you must have giant motors & the latest digital drivers to do anything but that's hogwash. I cobbled my lathe together with hand-me-down 3A motors, an old 1995 Denford 2A stepper driver & bits & pieces of used/cheap stuff from ebay. It works very well & is plenty fast enough to get myself into trouble as I continue climbing up the learning curve. As my Pappy used to say "There's more than one way to skin a cat.":)

[ctwo]

These are the drivers and breakout board that I use. I have no problems with them. I got them from the same seller, and they may have a package more suitable for your needs.

http://www.ebay.com/itm/4-Axis-Digital- ... 27c6608983

I do not know if those drivers will work with your motors, however.

I've also used the CNC4PC $25 breakout board without any problem. I use that one to drive Gecko motor drivers