Topics

1

General Mach Discussion / Simple question: Z-Axis and the Feed rate

« on: February 15, 2007, 12:14:40 PM »

If I set the Z-axis feed rate to less then 1In Per minute, I.e. trying for 1/2" (F0.50)to go r e a l l y slow, either my servo controller or Mach3 isn't interpreting it correctly and it goes faster then a bullet. I darn near blew the servo on the Z-axis due to this. 1In per min is just a wee bit to fast when your using 1/16 and smaller end mills.

2

General Mach Discussion / Still breaking bits... Jump start from a mid run stop...

« on: February 06, 2007, 10:24:06 PM »

I'm using very small diameter bits (1/16 and smaller) to cut out my widgets with. So far I've snapped off about $50 bucks worth. Lubrication helped allot, slowing down the feed rate helped... but... If I stop the run, and then restart it, it goes into over drive. I had it happen with a 1/8th bit and it actually survived something like a 50in per min rate when it jumped. Of course, the aluminum I was cutting looked like it had been ripped apart, not milled. When this happens with the smaller bits, *poink* more money down the drain. Is this a bug in the software? Anyone else run across this?

3

General Mach Discussion / 'Mill dust' and breaking bits... Advice please...

« on: February 03, 2007, 01:21:00 AM »

So you guys here got me through my last major hurdle so I could actually use Mach3 on my new CNC mill. Back to ask another question.... This is more in line with milling itself.

I'm using Sheetcam to generate tool paths so I can cut patterns out of 1/16th" aluminum. Once I got my machine figured out, and actually got to cutting, I have a weird problem. (I have a manual mill and this doesn't happen on that one.)

What I'm getting, I'll call 'Mill dust' for lack of a better term. (Think saw dust) Anyway, On my other mill, the dust falls away or hops up on the piece I'm milling or generally, just stays out of the way. But on my CNC mill, using a 1/16th end mill. It not only doesn't get out of the way, it binds itself into the cut. And when I say bind, this is almost like welded in there. (I know it not a heat problem, the metal is ice cold) It binds so bad that even after a part is cut, i litterally have to pry it out. I posted a picture along with this post to give you a better idea of what I'm up against. The holes you see, are where I had to pry the little pieces out. The other 'holes' you can see the part is still stuck in there. This 'binding' has cost me two bits so far. I'll be going along cutting and then I hear that dreadful little *poink* that means I'm out another $15.00. I tried vacuuming the 'dust' while it was milling, but even with a mega shop vac, the binding still occurs. Ideas? Words of wisdom? Experience?

I'm luv'n this CNC jazz so far despite the setbacks!




A bad picture, but a good illustration of the issue. The line that suddenly ends there all mangled like, is where the end mill met it demise. As you can see, even thought the cut was all the way through, the 'dust' 'welded' its way right behind the end mill. Even when I take a piece out, this 'dust' of mine is very well attached to the cut out parts. Although, the hole is very clean...


Hep me!

4

G-Code, CAD, and CAM discussions / Blender 3D and Mach3

« on: January 24, 2007, 11:11:45 AM »

I'm sure more than one of you has either heard of, or more importantly, is an avid user of Blender 3D. (For those of you scratching your head, prepare to be amazed and go here: http://blender.org/cms/Home.2.0.html)
I am a bonifide expert at modeling in Blender 3D, so my obvious question is. Making widgets in Blender, and then going from there to G-Code --> Mach3.

I have exported some very basic models into DXF and tried to use them in Mach3 but so far, I haven't had much luck. The general issue I have is that when exporting to DXF, the DXF itself isn't very well supported with other CAD/CAM programs. I had a long session with a fella you runs a waterjet with me trying to get him a DXF that he could actually use. So I know the limitation here is with Blender. (Or thats my edjumacated guess)

I have read through http://www.becausewecan.org/blog/ where these folks are doing just what I am asking about, but they are using a $500.00 CAM program between Blender and Mach3.

So... Anyone... Anyone out there with this same type of set up?

Hep me!