Messages

1571

General Mach Discussion / Re: CSMIO-IP/A and max velocity setting?

« on: June 29, 2016, 10:46:38 AM »

Just been playing again, its the max following error topping out that causes the ePid fault, at 98% vel it reads about 500 or so, at 99% it just goes up and up until the limit trips.

Any help

1572

General Mach Discussion / Re: CSMIO-IP/A and max velocity setting?

« on: June 29, 2016, 10:34:37 AM »

disclaimer - Don't forget this is all on the bench so no load etc on motor.

I have a max follow error set of 10,000 in pid tuning, using the pid tune jog buttons, if i set max el at 98% it all works well and the Max I accumulator bar graph shows just two blocks.

If i increase to 99% it faults out when the Max I accumulator tops out.

I have no idea what the Max I accumulator is telling me though???

The value limit is set for 1000,000 in Max I Acc.

This is with max vel set at 7620 in Mach3

1573

General Mach Discussion / Re: CSMIO-IP/A and max velocity setting?

« on: June 29, 2016, 10:06:48 AM »

Ah, thats interesting then as that is just what i tried, it seems I have a DAC offset so if it set max RPM it works perfect in one direction (negative offset) but in the other direction (positive offset) it faults out with ePid error.

I Have to reduce max el to something like 7550 to allow it to run in both directions without fault.

I doubt whether i'll be running 7500mm/min rapids though on an old mill

1574

General Mach Discussion / CSMIO-IP/A and max velocity setting?

« on: June 29, 2016, 08:57:41 AM »

I'm going through the settings on my bench setup of ac servo drives and the CSMIO-IP/A controller with Mach3.

I have steps per set as shown for my leadscrew/drive connection ratio but how do you calculate max velocity - It seems that if it is too high the drive faults on ePid error, too low and the 0-10v output does not reach 10v so velocity is wasted/lost.

How do you calculate the correct velocity to give 0-10v output or does it not work that way??

1575

General Mach Discussion / Re: VFD problem

« on: June 29, 2016, 04:29:58 AM »

Keep the capacitor close to the board and extend the lead that goes to ground

1576

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: June 27, 2016, 02:21:57 PM »

All I do is have the encoder input on the IP-A jumpered across to the Enc module.

Hood

THAT explains a lot, thanks, did not know you can do that

Academic though as some of the figures I'm looking at for power required really do need all the clout i can get so wouldn't want to fit a weaker solution. It explains why she used to get warm on a busy day

1577

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: June 27, 2016, 01:56:59 PM »

Thanks Hood, that explains it nicely, seems I would need to go 3.8kW / 15Nm to get equivalent performance - that is not only too expensive but a lot more power needed PLUS its only 2500rpm.

That has made my mind up to refit the existing motor and run until it fails totally, speed control will likely be a bit hoo-ha but I doubt it will hurt.

The encoder module would have been a ball-ache to fit anyway, I wrongly presumed it uses the motor encoder signals but fitting a shaft encoder would be pretty hard on a Bridgeport.

Enough of this nonsense

One day the damn replacement Y axis screw will turn up and i'll be able to start moving ahead again, it's stuck in the post somewhere

1578

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: June 27, 2016, 07:43:16 AM »

So, what i'm really saying or asking is:-

I have a 1.2kW fixed speed motor connected to a transmission of 77% efficiency with a ratio range of 2:1 to 1:2

Can I replace that with a variable speed 1.8kW AC servo and high efficiency drive (toothed belt is around 98%) ??

And of course, will it work??

I will be keeping the back-gear for low speed / high torque stuff in the 40-400rpm range as now.

1579

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: June 27, 2016, 06:48:54 AM »

Ah bum, the dreaded torque/Hp confusion again

So I have 1.5Hp regardless (fixed speed motor), at 1:1 speed setting the spindle will only see 1.15Hp though due to the transmission efficiency?

Thats how i figured it - i'm still wrong though?

1580

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: June 27, 2016, 05:53:18 AM »

From what data I can find, a dual-cone Reeves drive is about 77% efficient so I only really have about 1.15Hp anyway which is 0.86kW, so at min speed its around 1.72kW and at top speed around 0.43kW, this is ignoring all other losses of course - spindle bearings etc.

So, maybe a 1.8kW servo would be pretty well suited to this job after all??