My CNC Router Progress Reports.

[oldvan]

Several months ago I started assembling a CNC router table out of parts I had laying
around my shop. Linear bearings and rods left over from a machine that a friend's
shop scrapped, stepper motors scrounged from dead copiers, a computer from a yard
sale, etc.


I got a bargain on 3 ball screws on eBay, so used those for the X and Y axis, and used
threaded rod and a nut for the Z axis. I also purchased a Gecko G540 stepper controller.

I initially installed Windows XP and MACH3 on the computer, it worked correctly and
was easy enough to install and configure. The hard drive in the computer developed
problems, so I had to install a replacement.

As long as I had an empty drive anyhow, and having read that EMC2 has better
support for servo motors like those on my recently acquired Bridgeport mill, I
decided to give Ubuntu and EMC2 a shot. If I liked it, the machines could both
run EMC2 and I'd have less to learn when the time comes to work on the Bridgeport.

Ubuntu & EMC2 installation went quickly and painlessly. Configuring pins and tuning
the stepper motors went smoothly. I believe I shall stick with EMC2 from now on.


I slapped together some G code and mounted a pen to the spindle plate for a test.
Here is a video of the test: http://www.youtube.com/watch?v=_OtgiPw_5po

Next I'll be mounting the spindle to the spindle plate. I have a ER16 collet holder I'll
be powering with a DC motor for low-RPM cuts in plastics, and a Bosch Colt router
for higher RPM cutting in wood.

{to be continued soon}

[ZipSnipe]

Looks good !!! What will you be making with it? ANd what cad program are you using?

[Harold_V]

{to be continued soon}

I hope so. I'm watching with considerable interest, in spite of not having commented.

Harold

[oldvan]

Looks good !!! What will you be making with it?

The first use of this machine and the impetus for me to assemble it into something more interesting than a pile is
cutting lids for the Xeros controllers my company is selling. Xeros is a product to help those who have lost their
salivary glands to radiation therapy; you can read more about it HERE where I ruthlessly hijacked Bill's thread.

The plastic enclosures we are using are from Hammond and measure approximately 1.5" X 3" X 3/4". Hammond
will mill openings into the enclosures for a fee plus a minimum order, but until our company grows large enough
to order 10,000 boxes or more at a pop, milling will be done in-house.

The lid needs a rectangular opening for the display, plus three holes for push buttons like so:

Thus far I've machined the rectangular opening on my Hardinge UM horizontal mill with a custom vertical spindle
I cobbled up. That works, as long as the clown at the controls turns the knobs in the correct direction every time.
I'm surprisingly human and have goofed up a few lids that way. The box itself also requires two holes and a slot.
It's monotonous work, and best suited to a computer.

I often find myself in need of a one-off electronics project, either for prototyping or to fill a one-only need. I'll soon
be using this machine to mill circuit boards so that I can save both the time and expense of ordering the boards from
a board house. I have several hundred pounds of copper clad FR4 here that I was given many years ago.

I know that this machine is only vaguely stiffer than under-cooked spaghetti noodles, as the 1/2" rods I used for the
X axis are FAR from ideal, but they were free. For cutting soft plastic, it will be adequate. There is no hurry to get
things cut,so I can keep cutting forces low with light feeds. I'll upgrade the machine to something much more robust
if I need to, but I just gained a Bridgeport CNC Mill and that will soon be upgraded to modern electronics and ready
to take on the more strenuous jobs.

... And what cad program are you using?

I designed the blocks holding the pieces of the machine together in SolidWorks, that allowed me to tweak their
dimensions to fit material I had on hand.

The G Code for testing was chicken-scratched by me. I didn't need anything fancy, just a test to see how things
would work.

For circuit board work I use Eagle. I'm proficient in Orcad as well, but prefer Eagle.

[oldvan]

Here is a video of my machine cutting Plexiglass!

I outfitted my CNC table with a Bosch Colt router and ran my test program using a piece of 0.200"
thick Plexiglass spray painted red and a 2-fluted 1/8" carbide router bit. Cut is at 18 IPM.

I forgot to set focus on the camera to MANUAL, so focus is inconsistent.

The machine has about 0.1" of backlash in the X axis, I need to make a spacer for the X ball screw's
bearing block to resolve this. The backlash shows in the lower left corners of the letters O and D in
this test.



All in all, a pretty good test.

[Harold_V]

Pretty cool!
You commented on backlash being .1". Did you mean less?

You likely know that Lucite isn't all that good to machine, so the results you're getting are most likely better than you think. Imagine how well it would cut Delrin, or even aluminum.

[oldvan]

You commented on backlash being .1". Did you mean less?

No, it really has about 0.100" of backlash in the X axis, SOMEONE messed
up making the end cap for the X axis ball screw's fixed mount, now it needs a
spacer to take up the oopsie.

You likely know that Lucite isn't all that good to machine, so the results you're
getting are most likely better than you think. Imagine how well it would cut Delrin,
or even aluminum.

[Harold_V]

You commented on backlash being .1". Did you mean less?

No, it really has about 0.100" of backlash in the X axis, SOMEONE messed
up making the end cap for the X axis ball screw's fixed mount, now it needs a
spacer to take up the oopsie.

Ahhh! Now it makes sense. Not to worry---it's in good hands.

Harold

[oldvan]

Progress report, July 18, 2011.

The CNC router now correctly cuts the openings in the lids for the Xeros
dry mouth pump controller lids. This was the major reason for making
the machine, since I will (hopefully) be making thousands of the Xeros
controllers over the next few years.

Here's a video of the machine in action:
http://www.youtube.com/watch?v=GaSUpmOqTGE

[Marty_Escarcega]

Nice work Old Van. Thanks for keeping us posted of your progress. Worthy reason for the project.
Marty