Aluminum Cutting

 

 

 

I did a small part on the CNC, my first Al part. I really have not done that much, being distracted with other things like work and family. I did this to see what it would take to do something that was like a "real" part.

It did give me a chance to dig into the CAM program CAMBAM I have been evaluating. Initially I did a wax part which almost turned out ok. Last step I was experimenting with fixturing and it came loose.

One thing is for sure, the experience beats all.

Machinable Wax

I have been trying some machinable wax the last week for a couple runs on the mill. It is really nice to machine and gives good finishes and I like the idea that it doesn't wear tools and is recyclable.

I had a 2"x6"x12" block that I cut down to some 2"x6" slabs on a radial arm saw. The cut surface was messy and the wax did melt on the edge. I caught the chips in a box to melt and reuse, that is what is in the pictures above. I melted and poured into short aluminum tubes I had and tried to slow the cooling by putting a small cardboard box over it but my basement workshop is about 45 Degrees F. End result is that there was a "pipe" on the end going in about .5 inches and visible cracks on the od of the cylinder. The tube id was .540 and the cooled wax was .520. They will go to me trying out the Lathe, which I have never cut a chip on.

The wax when melted has the consistancy of molasses, I had thought I could filter junk out but it sure looks like it is too thick for that. Better to not get junk into it in the first place.




I made some improvised chip catchers to catch the wax chips, the sherline is not set up to conveniently shield the ways and y axis screw plus I didn't want to contaminate the wax chips for when I reuse them.

I am facing the 2"x6" piece of wax and pocket cutting text. I used Cambam the free version. It is fairly straightforward to use. I am still evaluating CAM programs, next will be some python scripts for emc2.

For a long time I have wanted to make a xy plotter from old printer and scanner parts and have been collecting parts for a while. I have one of the plotters taken apart and have been playing with stepper motors with a basic stamp and arduino. I was thinking about ways I could put 2 together with the minimum of actual money input and had the idea of looking on youtube to see if anyone has been doing anything like this, and there were lots of posts up. I stumbled upon a 3d printer that was pretty cool that uses distilled water in a print head and maltodextrin as the powder.

There is a blog on the 3d Printer also and I saw reference to a yahoo group but I am not sure one exists.

Been At It, CAM

Been "reviewing" cam programs, just want to make something.

Came across Cambam, there is a freeware version and also a pay version.

Ran it in EMC and it worked perfect, except for some mistakes I made with a wrong sign on the z depth. Cut air error is all. Wax cuts nice, I like it right now.

Cam Links

Lot of good links:
Cambam commercial site. There is a freeware version, new "plus" version is $149.
http://www.cambam.co.uk

Cambam site cam program, has pcb info also:
http://www.brusselsprout.org/PCB-Routing/

Neat stuff, including "picstep" motor driver control board, including schematics, pcb layout etc.
http://www.fromorbit.com/projects/picstep


Nice writeup of a cnc machine build

http://lirtex.com/index.php/cnc

http://editthis.info/opencam/Main_Page

Link to info on development of axis and EMC

http://axis.unpythonic.net/

Etch n Sketch on EMC
http://axis.unpythonic.net/etchcnc

Site of one of the developers of the EMC axis GUI.

http://timeguy.com/cradek/cnc

An example of PCB that he made on his cnc
http://timeguy.com/cradek/cnc/pcb

Pretty cool site that sells tools etc for PCB making.
http://thinktink.com/

L297 Stepper motor controller Datasheet PDF
http://www.st.com/stonline/products/literature/ds/1334.pdf

L298 Dual Full Bridge Driver
http://www.st.com/stonline/products/literature/ds/1773.pdf

Machinable wax recycling
http://great-lakes-training.com/video/machinable_wax_recycle.html

Make Machinable Wax, he did!
http://www.jarkman.co.uk/catalog/cnc/machiningwax.htm

http://www.buildyouridea.com/index.html

A Few Minutes With G Code

 
Had a few minutes to try some g-code. I really don't have much experience so this is new to me. It came out burred, bad cutter for Al, wrong speed or feed?

Making slow but steady progress at least.

Open Questions: CAM? and Tooling a CNC Mill?

Got to that point in the setup of the Mill that I ran the EMC2 logo. Looking for CAM software that will make running the sherline easier. Nothing really promising yet except for the GNU Cam, will check it out when I get a chance.


 

Some Links:
Engraving tool mfg:
http://www.2linc.com/engraving_tools_conical_bn.htm

CNC videos:
http://www.k2cnc.com/Videos_CNC.asp


Gcode converters/CAM

Open Source
http://gcam.js.cx/index.php/Main_Page

Links to a bunch of "free" gcode software

http://www.freebyte.com/cad/cadcam.htm

EMC2 - Setting Up the Sherline Mill and Links

Started in on the setup of EMC2 with the Sherline Mill. Same computer as with the lathe. Unpacked the sherline rotary table and put the right angle base on. I will have to spend some time later setting it up on the mill table but for now just making sure it works.