My 1st CNC Router

[johnmac]

I have not tried aluminum. as far as the Harbor Freight router, well, let's say you get what you pay for. I got it on sale for $19.95. But it sure beats most anything with a 1/8" collet. Having a 1/4" collet gives a much larger selection of bits. And it has lots more power than a Dremal. Since I have a bigger machine in the works, I don't want to spend much money fixing design flaws on the small one.

I use Kcam. It was simpler for me to figure out. But it is far more limited in what it can do. I would recommend Mach 2 or 3. Otherwise you get to spend money on software twice. Mach has much more help support.

With kcam, if an axis hits a limit it will tell Kcam to stop travel. You can jog away from the limit switch. With Mach, I think you can choose whether to stop travel, or slow down motion. (don't remember for sure.)

If I knew then how much I didn't know about this, I probably wouldn't have built my first one!

John

[robertf03]

I downloaded mach3, but there wasn't much it did without having a machine hooked up. Kcam looks pretty sweet and it was able to take nc code generated in meshcam using .stl files without errors, but meshcam has that 30 day limit.

If I knew how much inventor sucked when it comes to actual production type stuff I think I would have switched to something else. I'm taking a class in the fall that uses mastercam, hopefully I'll be able to use that for personal stuff until I can pay the big bucks for something of my own.

[robertf03]

I think I'm going to try a maual control first

This should provide an adjustable square wave pulse to change the stepper frequency, and all of the buttons to move it along the 3 axis.

http://people.tamu.edu/~robertf2003/...yschematic.JPG

[tajord]

If I knew how much inventor sucked when it comes to actual production type stuff I think I would have switched to something else.

Do you mean drawing files or outputting files, cause inventor does output dxf files.

[johnmac]

With kcam, you can import DXF files and produce G-code. Then run it in a simulation mode while it plots back on the screen. Mach 3 uses Lazycam to do the same thing. It will let you practice making CAD drawings that will produce good G-code. With Mach, you can continue to use the trial version with no time limit but are limited to 500 lines of code. Kcam gives you 30 days.

John

[robertf03]

will it do 3d dxf files? My version of inventor will only export sheetmetal parts as dxf, I'm stuck with .stl or .dwf (why does dwf even exist?)

Maybe I'll have to upgrade from the student version in the future, didn't know that was an option.

[johnmac]

Both Mach and Kcam do 2-1/2D. The depth of the Z is entered in the setup. You can also tell how many passes to get to that depth. To get 3D G-code, you will need CAM software (don't worry, it's only money!) that supports 3D.

John

[robertf03]

cool, thanks for the explantion. I'm afraid to ask what meshcam costs, it looks expensive.


Got the controls about halfway done. The local electronics shop didn't have everything in stock so I'm waiting on mosfets and a few IC's.

[johnmac]

Although some people hate it, I shopped ebay and found a copy of BobCAD/CAM with the BobART v20. It is new enough to do everything I can figure out how to do, yet old enough to be affordable. Be aware, the BobCAD sales staff can be quite pushy. I guess it works different from other programs and a lot of people don't like that. I'm starting from zero, so it doesn't really matter to me.

If your wanting to do a lot of carving, Vcarve seems to be a good choice. If I were going to pay full price, I would give it a good look.

John

[robertf03]

had this on the backburner for a little bit.

Just got in some thompson 1/2" pillow blocks and 1/2"-10 acme thread. For now I'm going to use regular nuts welded to a plate in the same flange pattern that dumpster cnc sells. The backlash is definately there, so once I get it running I'll swap over. I haven't cut the boards for the gantry yet. I raked it back to get the center of gravity closer to the middle of the bearing. Its kind of a guess since I'm not totally sure what I'm going to use as the spindle.

I'm anxious to see if the nema-17 motors will be enough for this. I tried to design it as modular as possible incase I have to swap to bigger units.

the acme lead screws will be supported with some fr8zz bearings and clamps on the outside. The only thing I'm worried about is my Z axis. I'm still planning on using brass bushings with the blocks I've already cut.

I may add some webbing to the spacers on the Y and Z axis motor mounts, but other than that I plan on building it exactly as shown. Any obvious problems other than stepper motor size or the mockup spindle I have show?