What Servo motors for milling machine and acorn help

[TSW]

Just joined and glad to be here good stuff!


First i am not into alot of this stuff and dont know much about computers to say the least so sorry for stupid questions but i do want to learn!

I have several older knee mills and am looking to upgrade the retrofits to a newer more uniform system like Centroid. I have 2 YCM-30 mills one with a 3 axis prototrak which is working but i dont like the cost of exchanging the pendent $3000 every 1-2 years and they want $15k to swap it all out. The other YCM is a older Allen Bradley summit Bandit and i have two controllers but it is a pain to program and i never use it. I would like to start with this machine so i will use it and if it takes a while to get going i am not losing anything either. I am told by Scott at Centroid the older servos cant be run by the allinone and i think with computer and other stuff i will be near $8k with Centroids servos and other stuff needed so i think the Acorn will work?

I reached out to Teknik and they have servos which will work with the Acorn but they need all this info to spec the right servos which i dont know or have so i was hoping for some help here. I am hoping i can offer some info to help the helping with this or maybe somebody knows what spec i can use or maybe another servo that can work on the knee mills for me please?

Couple of other questions about what i will need.

Acorn, software from Centroid, i assume a VFD for my spindle motor a enclosure.
I know i can buy a computer from Centroid and screen with jog wheel?
I know i need a 3 new servos but will i need anything that goes with the servos that attaches to the servos or acorn or do they dirrectly plug in?

Again sorry for the silly questions just trying to get to where i can sort out my path and start moving ahead.

Thanks for any help

[cnckeith]

I moved this post to the Acorn Forum.

[Richards]

I would start by looking up the specs on the motors typically installed on those machines and then look at Teknic's selection guide to see what they have that is similar. Teknic is a good choice for Acorn users. Connecting and driving one of their servo motors is as easy as connecting and driving a typical stepper motor. As Teknic told you, you'll need more information before choosing motors. Do you have ball-screws? How much torque do you need to jog? How much torque do you need for heavy cuts? How fast do you want each axis to travel? Are you going to connect the servo directly to the screw (1:1) or is there room to add a belt drive or precision gearbox (more torque, less speed)?

Teknic lists three motors per size on their charts, D, P, and S. The D-size has highest speeds and lowest torque. The P-size has less speed and higher torque. The S-size has lowest speed and highest torque. The torque charts show two torque levels, peak and continuous. For instance, the CPM-SDSK-3421S-RLN motor has peak torque of 1,094 oz in and continuous torque of 289 oz in. Its torque drops quickly at speeds over 1,250 RPM. If the screw had a 5mm pitch, each revolution of the motor's shaft would move the axis 0.19685 inches, so 1,250 RPM would have a maximum jog speed of 256 inches per minute. By knowing your torque requirements, you can look for a motor that has enough torque at the speeds you need. Typically, as torque goes up, speed goes down. Motors that have both high speed and high torque are out there but they aren't inexpensive.

[cnckeith]

750 watt AC servos such as Leadshine, JMC and Dyn4 work well on knee mill sized machines. you can find hookup schematics for typical Acorn to servo drive connections here.. https://www.centroidcnc.com/centroid_di ... browse.php
type in "acorn" in the search bar to see all Acorn schematics. or "Acorn dyn4" , "Acorn leadshine" or "Acorn servo" to see specific schematics.
https://www.centroidcnc.com/dealersuppo ... 103.r1.pdf