Centroid Community CNC Support Forum

Hey guys, I bought this machine a couple years ago for my garage at the house and have been using it to do some over flow work for the company I work for. When I originally bought the machine it needed a turcite replacement on both the x and y axis and the control would not boot. fixed the turcite and played around with the control bios settings only to find that the hdd settings needed to be changed. machines been worked fairly well for its age (1997) but have found limitations that the older control and software have. Also really need to have one of the servos rebuilt (DC Servos) which is not cheap! I debated long and hard on retrofitting the machine and finally decided to bite the bullet and give it a shot! I am a machinist by trade and not an electrical engineer or even electrician so as I have been researching all of this, its been a steep learning curve but im started to finally make sense of some of it. I thought I would share the build on the forum for much needed help and also in hopes that this thread will help somebody else that goes this route.

My machine is a 1997 Hurco Hawk 5 with Ultimax single screen control. The machine has a 3 phase 5hp spindle motor, DC baldor servo motors, dc drives, a 486 computer that runs the control and hurcos proprietary ultimax software. The mill has variable speed via a variable ratio pulley system in the head of the mill. It works similar to a variable speed torque converter where the pulley rides up and down on a coned pulley to variate the ratio of the spindle to motor. I plan on pulling all of this out and going to a fixed 2:1 belt drive as the current belt drive vibrates a lot and is loud as hell. for this I opted to go with a variable frequency drive(VFD) to control the spindle RPM utilizing the analog output on the acorn board. My machine has a air controlled spindle break that I plan to keep using along with a breaking resistor to go along with the vfd. I will be utilizing flood coolant and mist coolant on this machine. Will also be providing power to the existing lube pump. The spindle will need a cooling fan added since it will no longer be running at a constant speed. I also plan on adding a rotary encoder for spindle positioning.

Here are some pictures of the machine and components that I have acquired for the retrofit.











I purchased the Centroid Acorn board utilizing cnc 12, DMM DYN4 Servo Drives, DMM 1.3KW A.C. Servo motors, a 7.5KW Huang Yang VFD with the breaking resistor option.

miscellaneous electrical components I have on hand so far are as follows:

• DIN rail, slotted, 35mm, 7.5mm height, 1m length x 2
  
  Standard DIN rail support bracket, 25mm height, zinc plated steel
  
  Eaton miniature supplementary protector, 50A, 480Y / 277 VAC / 96 VDC, 2-pole, C curve, thermal magnetic, 5kA SCCR, 35mm DIN rail mount (plan on using this to provide power to the servo drives)
  
  Eaton miniature supplementary protector, 50A, 480Y / 277 VAC / 96 VDC, 3-pole, C curve, thermal magnetic, 5kA SCCR, 35mm DIN rail mount.(this will be providing power to the VFD which I plan to be feeding with 3 phase power from my phase converter)
  
  Fuji Electric IEC contactor, 65A, (3) N.O. power poles, 24 VDC coil voltage(Using as the Emergency stop contactor for acorn)
  
  LR series line reactor, 230 VAC, 10hp, 3-phase, 30.8A, 3% impedance
  
  Eaton miniature supplementary protector, 15A, 480Y / 277 VAC / 96 VDC
  
  Relay socket, 35mm DIN rail or panel mount. For use with 784 series cube relays.
  Ice cube control relay, socket mount, 24 VDC coil voltage, 4PDT, 15A contact rating, 14-pin configuration, LED indicator, push-to-test
  
  Roxburgh EMI input filter, 120/240 VAC, 1-phase, 1A (line filter for the signal side on dmm drives)
  
  Mean Well EDR-120-24 Single Output DIN Rail Power Supply 24 Volts 5 Amps 120 Watt (provides power to the 65 amp contactor)
  
  Schaffner FN2410-45-33 250VAC, 45 Amp Line Filter (power side line filter for DMM drives)

The computer I opted to go with for the control is a 23" All in One Dell desktop. Computer has in intel i3 running at 3.2Ghz per core, 8 gigs of ram and 500 gig Samsung solidstate hdd. This is a touch screen computer which I feel is a must.

Awesome! Excited to see it come together! There’s an awesome community of people here that help when issues arise.

slodat going to need all the help I can get! Imagine your going to see a lot of components that look familiar to you as I have went through your build thread several times!

If you have not read already, my biggest piece of advice is to bench test all of it BEFORE you down your machine.
Guys are seemingly having better luck wiring the DYN4 drives to the DB25. I've had good success wiring them to the Acorn Terminal Blocks. You might try the terminal blocks first.

Any cables you use should be shielded.
Take all grounds and shields to ONE point. That is where the power earth ground comes in.

Looks like you have Acorn and the PC communicating. That is step 1
Step 2, wire ONE DYN4 drive and ONE motor and get them turning.

You will have to use the DMMDRV software to setup the drive,but that is covered in a video.
Let us know when you have got the motor turning....


Another tip, measure out the size of the current back panel in the cabinet, go to a metal supplier and buy yourself a sheet of 5052 aluminum the same size. (I tend to use .1-.125" thick aluminum) drill it to match the mounting holes. 5052 comes with a protective plastic skin where you can layout all your components, mark, drill and tap.
This is my favorite marker for reaching into tight places and I only use it for layout work:
https://www.amazon.com/dp/B002NQPEE6/re ... zEbN1ADBRX

Lots of pictures and learn to create a report and post it when you are working with the software. F7 Utilities, F7 Create Report
You might create a google photo album of your build too.

Good luck, eat the elephant one bite at a time.

Marty

Did you measure your current DC servo motors, mounting flange, center to center bolt mounting and shaft diameter and give that information to DMM?
They do have some NEMA size motors. I wonder if your Hurco didn't use NEMA42. It helps make it a more bolt on fit. You don't need reduction with the 1.3KW AC servo motors. But on an open machine you don't need super fast rapids either. (IMHO)

I would think that 1.3kW motors should have sufficient torque to run a mill of this size at 1:1 (e.g. 5 or 5.08 turns/inch).

Obviously a more powerful machine but for reference the 750W D4 motors will pull the 2HP spindle on my bridgeport down to a stall

I went with the 1.3kW motors because they bolted in place of the DC servos that came on my machine. They are right at 10% more powerful that the original motors.

Guys are suggesting more success using the DB25 output. Slodat can explain what he just went through with his similar Tree Journeyman mill or you can check his build and post thread on it.

Thanks for the advice Marty! The wire I purchased is mtw wire and it’s not shielded. Are you saying all power and signal wire should be shielded? Any recommendations on a good source? Thanks for letting me know about the back panel material will defiantly keep that in mind. I was also hoping for a suggestion on a good spindle encoder that I would like to add to the machine. I see so many different ones with different counts. I know I read on centroids website that the acorn like at least 2000 counts. Any reason I should have more than that? Thanks!

As far as the 1.3 kw servos, I went with them because I did some google searches and found that the 40in lb dc motors were comparable to around 1.1kw if I’m not mistaken and I figured I would rather be slightly over powered vs under. As much as it costs to do a retrofit I did not want to have ANY regrets later on down the road!