CNC Upgrade and Fretboard program

[Diane Kauffmds]

Hi guys,

I needed a longer cnc with an eye towards eventually cutting necks. I had a working length of 16". I want 24". So I've built an aircraft carrier.

The cnc is 31" long now. My table, which is my y-axis, is now 28" long with an active cutting length of 24.08". I also refined some aspects.

On that subject, I want to start cutting my bridges, fretboards, and necks on the cnc. I made a big step in that direction. I've Programmed a fretboard in Fusion 360 (free version). I've made it with parameters. So I can put different scale lengths as needed, and it'll recalculate the fret slots. I can change everything from scale to fret tang width and depth, the radius, etc. It took.me more than a week to figure it out. I pulled an all-nighter and finally finished at about 7am this morning.

These aren't screenshots. I just quickly took photos.

[Kevin Sjostrand]

Oh boy
This will be much fun to watch you make this work!!

[rcnewcomb]

Excellent work!


For those that run Vectric VCarve or Aspire software , there is a free gadget written by Stefan K that handles different scale lengths including multi-scale. If you have Aspire it will also handle the fretboard radius including compound radii.
->Link to the gadget on the Vectric Forum

[Diane Kauffmds]

I found a YouTube video made by Austin Shaner, who walks you through the fretboard program in Fusion360. Even with watching the video and having a 1200 page kindle book on Fusion360, it took me days to get it right. He made his board multi-scale. It wouldn't be too hard (famous last words) to making it a compound radius. I stuck with a single scale and my preferred 15" radius.

[sylvan]

Use Vectric's Aspire or VCarvePro. It is so much easier to manipulate everything on the CNC.

[Diane Kauffmds]

VCarve Pro is next on my list. I'll download it and compare it to my VCarve Desktop.

[Diane Kauffmds]

BTW, As of today, the cnc is officially DONE! I test it by making a 1" circle. It was perfect. I had to make 3 changes:

I had to replace the y-axis (table) stepper motor with a larger motor. I'm using the same high torque, low current motor (340oz.in/2.4Nm) that I use on my z-axis.

I replaced the regular micro limit switches (nor800mmmally open) with nice roller lever switches, that I wired NORMALLY CLOSED. That way if a wire breaks or something else happens, the machine will stop.

The last upgrade I made was to add a backlash spring with adjustable tension.

I measured the distance between the edge of the frame to the edge of the table on both ends. It's 1/128" off from being dead straight. I can live with with it.

The machine sounds like R2D2 when cutting I guess it means it's happy.

All wires are now wrapped in copper, then with a plastic wrap protector, and they're plugged

[BlindBo]

Congratulations, Diane. I am so impressed AND jealous! I’d love to get into the CNC world, but, I don’t even have room in my shop for my dog’s bed, much less a CNC! What a great effort on your part!

[Diane Kauffmds]

Just when I thought I was done....Murphy and his law strikes again!

After more test circles, tweaks, and fixes than I can count, I came to the conclusion that:

1. The lead screw couldn't handle the table.
2. The stepper motor was woefully undersized.

First, I replaced the motor with a high torque, low current motor, the same one I have on the z-axis. That helped in that the motor was more than powerful enough for the new table. But, i couldn't get the small amount of backlash out of the screw; trust me, I tried everything. I finally decided to install a ballscrew, something I knew absolutely nothing about.

I got the ballscrew, ball nut, housing, etc. I decided to preload the nut. I bought new precision balls to replace the existing. I found 48 balls (3/32") in 3 races in the nut. As I was packing it, I found that it actually held 60 balls. Apparently, that was the magic number, because it tightened up the nut, without tightening too much.

I also replaced the plywood front and back, using the 2080 t-slot sides that I had replaced. This cnc is not only heavy, it's rock solid.

So, after struggling for more than a week, I performed the acid tests. I cut a circle that came out nice. Then I cut part of my logo. The small letters are only 3/32" high. Making the "a" without destroying the round negative area can't be done without absolute precision. The "b", "o", and "d" are hard, but that "a" is tiny. As you can see, the cnc did a perfect job.

Tomorrow. I plan to cnc my first fretboard. It will be out of pine, to test the cnc and the board I've programmed..

[Kevin Sjostrand]

Oh boy can't wait to see how your fretboard comes out