Acorn cnc running 750 watt brush less servos
Posted: Thu Aug 09, 2018 2:01 pm
Hi everyone,
We built this for 2 reasons, to test these new servos, and people thinking of a cnc retrofit can come and play with this and see the software and how nice it runs. We are machine builders and do some cnc retrofits also.
This is running on 230 volts SINGLE phase, there is a small control transformer under the circuit breakers to make the 115 volts for the computer.
We used a Asus book size computer, (left of the monitor) Asus touch screen, added memory to 4 gigs. The mouse and keyboard are wireless as is Centroids jog panel. The computers are always new, and we never let them go on the internet. It will spend its life running this Acorn.
We had to turn on the puls multiplier in the drives because the servos have 2,500 line encoders, 3,000 RPM's, and it is set up for 10 turns per inch. The rapid traverse is set to 240 inches per minuet, so in rapid, the drives display 2,400 RPM's which is plenty for any knee mill. 2,500 Quadrature is 10,000, times 10 turns per inch, we had to shoot 100,000 pulses to get it to go 1 inch, thus the multiplier times 2.
If you can see the paper with a line taped by the motor shafts, the line is also on the servo motor key. We ran this non stop for 6 hours to check positioning and it is right on the money.
This is so quiet, the only thing you hear is the motor keys hitting the paper with the line on it.
I have done battle with electrical noise many times, so if you look close, the 115 volt power for the computer is coming off the center top of this panel, and it comes from a "drive rated" noise filter, there is another filter for the drives. If you have positioning problems, #1 suspect is "electrical noise", that's why Centroid advises shielded cables, very important!!!
The yellow jumper wire on the left side is where the E stop button goes, also the limit switches. this will be cleaned up before we let customers see it. We were in a hurry to test this out. This is our second Acorn, the first one went into our tool room machine.
I mounted breakout boards for the drive controls under the Acorn, which is on 2" tall plastic risers. We used 2' serial cables to connect with the drives.
If your in the Grand Rapids Michigan area, and want to come and play with this, drop us an e mail.
We built this for 2 reasons, to test these new servos, and people thinking of a cnc retrofit can come and play with this and see the software and how nice it runs. We are machine builders and do some cnc retrofits also.
This is running on 230 volts SINGLE phase, there is a small control transformer under the circuit breakers to make the 115 volts for the computer.
We used a Asus book size computer, (left of the monitor) Asus touch screen, added memory to 4 gigs. The mouse and keyboard are wireless as is Centroids jog panel. The computers are always new, and we never let them go on the internet. It will spend its life running this Acorn.
We had to turn on the puls multiplier in the drives because the servos have 2,500 line encoders, 3,000 RPM's, and it is set up for 10 turns per inch. The rapid traverse is set to 240 inches per minuet, so in rapid, the drives display 2,400 RPM's which is plenty for any knee mill. 2,500 Quadrature is 10,000, times 10 turns per inch, we had to shoot 100,000 pulses to get it to go 1 inch, thus the multiplier times 2.
If you can see the paper with a line taped by the motor shafts, the line is also on the servo motor key. We ran this non stop for 6 hours to check positioning and it is right on the money.
This is so quiet, the only thing you hear is the motor keys hitting the paper with the line on it.
I have done battle with electrical noise many times, so if you look close, the 115 volt power for the computer is coming off the center top of this panel, and it comes from a "drive rated" noise filter, there is another filter for the drives. If you have positioning problems, #1 suspect is "electrical noise", that's why Centroid advises shielded cables, very important!!!
The yellow jumper wire on the left side is where the E stop button goes, also the limit switches. this will be cleaned up before we let customers see it. We were in a hurry to test this out. This is our second Acorn, the first one went into our tool room machine.
I mounted breakout boards for the drive controls under the Acorn, which is on 2" tall plastic risers. We used 2' serial cables to connect with the drives.
If your in the Grand Rapids Michigan area, and want to come and play with this, drop us an e mail.