Bridgeport Interact 4 Series 2 to Acorn6 build

[richardb15]

I need a new spindle motor and drive as the DC Contraves drive died, and that makes the existing motor obsolete. I have a 20amp 3 phase supply for the machine, so that means about 7.5kW available for the spindle. The spindle motor is geared 1.5:1 so as standard it was a 60-6000rpm motor, giving 40-4000rpm at the tool.

I will use the machine for rigid tapping, thread milling, boring and general milling work. What are the preferences for using an induction motor+VFD vs using a servomotor and drive? It seems both in that sort of speed and power range would end up being a similar cost, what are the pros and cons? I've had a search through the forum and can't really see much discussion on this. Just to add, I have the Centroid spindle encoder ready to install so have that closed loop feedback for either option.

[richardb15]

My question comes from the availability of cheap clones from China. I'm on 415v 3ph but a 380v would be okay, its within 10%. Something like this:

https://www.aliexpress.com/item/1005005 ... 00169437_8
7.5kW 6000rpm Servo, drive and resistor for around AU$2100 delivered

Or a VFD for less than AU$160 delivered, and buy a local motor (too heavy to be worth shipping from anywhere)
https://www.aliexpress.com/item/1005008 ... cification

[suntravel]

I do not trust a super cheap Chinese VFD...

Uwe

[tblough]

I've had great luck with ABB ACS355 VFDs and Baldor IDNM inverter rated motors (0-6000rpm).

[suntravel]

I've had great luck with ABB ACS355 VFDs and Baldor IDNM inverter rated motors (0-6000rpm).

What could go wrong with ABB and Baldor?

Uwe

[richardb15]

I'm in Australia, the shipping for a Baldor would be more than the motor cost I expect! I have to deal with what is available here, and generally that means Japan or China stuff. Europe and USA just travel in a different supply chain universe to us here. I'm exploring options for TechTop and Mitsubishi drives so will see what that turns up, they are commonly available here. I've a few enquiries out on these. I haven't given up on the CHRH drive but there must a parameter in there to change it from frontpanel speed control to the 0-10v input. Until I find that its pretty useless for the mill.

More wiring progress today, I tidied up the bits I did yesterday. I then checked and rewired the X, Y & Z limit switches, one on the end of each axis travel as already fitted so it made sense just to daisy chain them and use whats already there. I also wired the axis home switches (one on each axis at one end of each) and again daisy chained them so its now a simple job to connect to the Acorn6.


The leadshine drives use DB44 pin connectors for the signals, which seems totally overkill considering only 8 pins are used! Anyway my eyesight and patience is not compatible with soldering to the back of those connectors so I had delivered some breakout boards for these and the 15pin ones. Much easier to wire, DMM pin check and can be reused.


Next job I think is to sort out the main contactors then mount the drives and acorn6 into the cabinet.

[richardb15]

More wiring done today. I fitted a 24vdc coil 50A contactor and momentary switches (Start NO, Stop NC) to a temp control panel to energise the machine on startup and to take power off when shut down. I just re-used the old Bridgeport buttons as the "on" has a 24v light in it so works nicely to see when things are powered up. Te configuration also acts as a no volt release so if there is a power cut the machine will not self start when power comes back on.


I added 4 of the drives (for X, Y, Z and W) into the main cabinet, mounted the Acorn relay boards and the Meanwell supply that will sit under the Acon6 board just to use that space for something useful. I don't need access to that as I've put a DIN rail with 0v, 5v and 24v connector blocks just under the relay boards to wire all the stuff into that will use those voltages. The Meanwell is energised when the start button I mentioned above is pressed and K1 kicks in.

Last job was to install the Acorn6 board



Next job is to wire in power the to Acorn6 and get the E-stop, e-stop relay and drives contactor wiring in place

[Chaz]

That looks great!

[richardb15]

After a few days of wiring and messing about I got the e-stops, NoFaultOut contactor and power to the 4 drives I've put in the main cabinet. I'll deal with the other axes in the future when I get a 4th/5th axis sorted.

I had all this working on the bench with both types of drives so I installed it all and wired up the X (HBS2206), Y (HBS2206), Z (H2-2206) and W (H2-2206) drives to the break out boards and Acorn and used my wiring notes from my laptop. Well..... I should have taken better notes

I also had to extend the wires from the servo motors as they came out of a bin so someone had cut the wires at about 6" long. I needed more like 10 feet to get from the motor positions and into the cabinet. I didn't want connectors as these will be exposed to coolant/swarf, so I did solder joints and double shrink wrap, adhesive lined, so I hope that will be robust. So having extended the 4 motor power and 6 motor encoder wires, ran them into the cabinet and wired the Acorn to the drives, and drives to the main terminal block, and motor power/encoder to the other side of the terminal block (so I can dewire stuff without having to take plugs off) of course nothing worked

I have a few of each drive but only had one of each working on the bench, of course I hadn't notes which two they were and had just put them into the cabinet so I knew one of each type had the right parameters, I just didn't know which ones! I had to go back a step and validate all my wiring and settings on one drive I knew worked then gradually go through everything again. I had set both drives up the same, but clearly on the bench they were not as the HBS2206 has normal 24v for ALM+ and EN+ signal, but I went round in circles with the H2-2206 until I realised the ALM+ and EN+ are inverted with the same parameter settings. Swapping those parameters got things doing the correct stuff and right signals into the Acorn IN14, 15, 16 for the drive alarm signals.

Once all that was sorted I had the Z motor laid on the machine working okay when jogged from the VCP so time to sort the mounting plate and broach the pulley, thread some grub screw holes and get it fitted up. They are NEMA 34 motors so 14mm shaft and 5mm keyway.





The motor mount plate is clamped in place between the runs of the spindle belt, and it drives two ballscrews, one each side of the quill so its a pretty meaty setup. All I've done is change the motor and kept the same plate and centre distance so it all fits very nicely





Final job with the belt tensioned up is to check it jogs, and finally get something on the machine moving from the VCP!



Now I have that one done next job is to broach the pulleys for the X and Y, extend their wiring into the cabinet and wire them up. Provided they jog okay I can then wire in the limit and home switches to the Acorn and get the home macro sorted

[tblough]

I recommend Trantorque keyless bushings instead of keys and keyways.