CNC Milling Thread - Tips tricks

[CodeMonk]

Just a little note/tip...
Back in the day when I ran a wave solder machine at one company, after soldering, I would cut off the leads on a cutting table.
It was basically a 1/2 hp electric motor mounted similarly to what you are using (X/Y axis movement). I bit more heavy duty though.
With a frame that had a notch cut into it to keep the PCB in place.
I used a vacuum to hold the PCB's down.
Now, these PCB's were around 12"x12" so when mounted and the vacuum was applied, the board would flex down.
I got around this by putting these little cones (Think like miniature traffic cones) on the table under to board. These cones also had thin double-sided tape on the bottom to keep them in place.
Gotta be careful with those cones though. All it takes is a little lead getting under the cones to @#$% things up.

[Mustachio]

@Mac I used a 30 degree 0.2mm tip carbide V bit on that one.  I've only done that one engraving on the mild weldable sheet steel so far, and the bit seemed to hold up pretty good for a 50 cent bit. I think if I make the passes more shallow and feed rate a little slower it will be good and should be able to engrave a couple full sheets at least per bit. Will have to test more and see how it works out.

@CodeMonk Wow that sounds pretty cool, although I'm having problems picturing it. So this wasn't a vacuum table ?  Maybe a vacuum clamp ? Still sounds like some pretty cool equipment.

Currently I'm using double sided carpet tape on a separate melamine board so I don't cut into my table surface. It's working out pretty good, I'm using a wooden rolling pin to help flatten and secure it down to the tape before I start auto level probing.

Sorry I'm a little late replying , Had really strong winds here yesterday, Toppled over a rather large pine tree in my yard which ripped the power and cable lines off the side of my house. Had a pretty cold night , Running extension cables from next door now to run a space heater and my computer for now until I can get the weather head repaired and power back on

If it wasn't for bad luck, I wouldn't have no luck at all.

[CodeMonk]

Picture this blade on a router:


Mounted on this:


With an adjustable fixture that held the PCB above the table.
The fixture/frame had grooves in it (notches was the wrong word for this) that the PCB would drop into to keep the PCB from moving around.
Frame sides A, B, C, D;
A and B were fixed while you could adjust C and D to allow for different sized boards. C and D were usually made up of several pieces to make those sides the proper size for a PCB. Imagine them as just shims.
There was a hole in side A that you would attach a vacuum to.
That's what held the board down.

I tried to find a picture of something at least similar to what I used, but not all pictures of industrial machinery from the 80's is online

[Mustachio]

Ah I think I get it now! Nice! Sorta like a fancy router jig. I never really thought about how they cut leads on a large scale that's pretty handy!

I can understand how that flexed the board with the vacuum, I've been looking at building something similar to an air hockey table with larger holes that sucks instead of blows.

[rousejeremy]

This stuff looks great. I recently found a co-op lab close to my work that has a cnc router amongst other things. Looks like there's a massive learning curve, but the end results are worth it. Especially after watching Youtube videos of guitar bodies being made.