MD3 Max 2 - A few issues...

[gthlm]

I'm hoping someone can help me with a few things that I need to sort out on our old workhorse.

Firstly I'm looking for the dip switch settings on the personality board. Switched the board with a spare so I could replace one of the opto-IC's, spare board had different switch settings and a few things are different (no diagnostics on startup, text screen doesn't sleep) and I accidentally/stupidly moved some switches on the original board while handling it.

Secondly I'd like to know the functions of the switches for the spindle on the Z/spindle board. When I first got the machine I discovered that they had been altered to try and fix an orient problem. There was a written report in the spindle drive cabinet talking about high range fast/slow and low range fast/slow switches. That bit of paper is long gone unfortunately, but the problem was mechanical and I've fixed it now. Again spare Z/spindle board from identical machine has completely different switch settings for the spindle and does crazy things if I try it in the machine. Identical machine, identical (Yaskawa) spindle drive!

Thanks in advance, Gregor

[bloke]

Hi,
This should sort you out for the personality settings:
SW1:
1 on
2 off
3 off
4 off
5 on
6 off
7 off
8 off

SW2:
1 off
2 off
3 off
4 off
5 off
6 off
7 off
8 off

SW3:
1 off
2 off
3 off
4 off
5 off
6 off
7 off
8 on

The switch settings for the Z-Sp board are best left set as they are and a note made of their settings. The reason for this is when I fitted the spindle drive to that machine, it was set up using a special EPROM that used the switch settings on the card to control tap dwell. Each machine was slightly different so there is no set list for it.

Also, the orient was controlled from these switches. If wrongly set, it can change from an orient gearchange to a run spindle gearchange (yours is a run spindle type). You can jam the gearchage if it's set wrongly.

[gthlm]

Haha! I take it word has made it's way back to you about the legacy of the machine in question! As always I am very grateful for your response.

I'll be onto the pers. board settings ASAP, I was worried that I'd end up burning out the text screen because the machine stays on 24/7 these days.

Your notes about the spindle control and drive are VERY interesting. What you describe re. unexpected gear changes is exactly what happens if I swap the z/spindle board. However both boards have the same spindle eprom, so am I correct in assuming that I could copy the switch settings from the original board to get a working spare?

About the tap dwell, that is one of the exact problems I was hoping to fix. Tapping much above 250rpm is hit or miss, as the spindle takes too long to stop at the bottom of the hole. However, I am not sure if this is a dwell issue or down to the other problem which is the painfully slow spindle accel/decel. All the accel/decel times on the drive are zero, and the control ramps the speed output, but very slowly. Your tech. that replaced the power supply last year said he'd never seen this behaviour before.

Obviously normally I would take your advice and leave alone, but I am pretty sure the switch settings as they sit are not correct.

Oh, I was asked to relay a message: Elvis says you're a t**t!

Many thanks, Gregor

[bloke]

Yep, that about sums Elv up. We had him round for tea and drinkies last night. That's where he told me about your machine. I'd always wondered where it went to after Ilmor sold it.

I'm going to see if I can find the documentation for the tap dwell switch settings. If possible, could you find out what the checksum number on the spindle EPROM is? I wonder whether board has been changed at some point without taking the special EPROM out of the old board and putting it in the new. It may explain your painful accel times.

Cliff.

[gthlm]

Cliff, finally managed to find 10 minutes away from the new machine to take a look at the old one!

Set all the pers. board switches as per your instructions and all is back to normal.

On the z/spindle board, the eprom is labelled:

MD3 Yaskawa Spin
Separate Orient
4F14

Sounds about right?

I wrote down all the switches as I couldn't remember which ones were relevant to the spindle. They are:

S1
1 off
2 off
3 off
4 on

S2
1 off
2 off
3 off
4 on
5 off
6 off
7 on
8 on

S3
All off

S4
1 on
2 off
3 off
4 off
5 off
6 on
7 on
8 off

S5
All off

Thanks again for all your help.

Gregor

[bloke]

I don't think that EPROM you have does the tap dwell function. It's possible it was changed at some point for a standard Yaskawa drive EPROM. The one you have does the following orient only functions:

Z / SPINDLE DUAL AXIS PCB

SWITCH BLOCK 2: LOW GEAR SPEED ADJUST
POSITION ( S1 on D / A2 )
1 ON = SLOWER OFF = FASTER
2 MOST SIGNIFICANT BIT
3 SPEED ADJUSTMENT
4 SPEED ADJUSTMENT
5 LEAST SIGNIFICANT BIT
6 NOT USED
7 ON = SHOT PIN ENABLED OFF SHOT PIN DISABLED
8 ON = MD3 MACHINE TYPE OFF = MD1 MACHINE TYPE

SWITCH BLOCK 3: HIGH GEAR SPEED ADJUSTMENT
POSITION (S2 on D/A2 )
1 ON = SLOWER OFF = FASTER
2 MOST SIGNIFICANT BIT
3 SPEED ADJUSTMENT
4 SPEED ADJUSTMENT
5. LEAST SIGNIFICANT BIT
6 NOT USED
7 NOT USED
8 NOT USED

I'll continue to look for the documentation for the tap dwell issue.

Cliff.

[gthlm]

Thanks cliff, that looks very much like the old scrap of paper I used to have!

I'm thinking (feel free to correct me) that the problem is all down to the speed ramping. I was doubting myself about it so I put the meter across the speed signal wires tonight and watched the voltage ramp slowly up and back down again as I turned the spindle on and off.

The problem when tapping is that when it reaches the depth and the z stops, the control ramps the speed down to stop before reversing out again. It's the time it takes to stop the spindle that makes tapping so unpredictable. If you were to run a tapping cycle at more than 250 rpm then it will take a good number of turns to stop and you run the risk of bottoming the tap out!

There's probably nothing that can be done about this right?

Cheers, Gregor

[bloke]

Hi, Gregor.
Despite searching, I can't find any of the info on the tap dwell EPROM (including what it's checksum is to identify it). A look through the boxes of master EPROMS for the machines didn't help either. This is one problem I may not be able to help with, unfortunately.
If anything does come to light though, I'll be sure to let you know.

Cliff.

[gthlm]

No worries Cliff. It's a small complaint for a machine that's paid it's dues many times over!

Thanks for all your help.

Gregor