Intermittent relay problem

To make a three week odyssey to nowhere as brief as possible I seem to have an intermittent relay on my 2006 TM-1P. The Renishaw OMI (this is the unit with the cable to the back cabinet) would not turn on when commanded to. I reloaded the Renishaw VCC software and even purchased a new board for the OMI for $475.00. Still no joy.

There are little green terminal blocks sitting above each of the relays, ( M21 through 25) into one of them the signal wires from the Renishaw OMI are attached. These are removable and connect to the board by pressing them onto three very small pins. In desperation I removed the little green terminal block, shot it full of electronics contact cleaner and pushed it on and off the pins several times. That fixed the problem for a couple of days but it's intermittent again today.

The relays are now soldered to the board, under the assumption I guess, that their failure rate is matched by that of the other components on the board. This is extending a lot more credit to mechanical devices than the electronics industry used to do. A replacement board is $1,200.00.

Has anyone else had problems with relays becoming intermittent?
Has anyone else tried to solder in a replacement relay?
Any other suggestions besides buy a new board?
Do you disagree with the diagnosis?

The machine has less than 400 spindle hours so I would not consider this a normal wear and tear issue.

Vern

This is my quarter-assed guess; worth half as much as a half-assed guess.:D

I think the problem could be that the probe puts logic level signals through a relay that is really intended for power circuits. What happens is that the contacts oxidize and do not make good contact and the logic level voltage does not have enough oomph to drive through the oxidation. Relays with gold plated contacts are needed for reliable logic level conductance.

Try carefully treating the relay with contact cleaner.

Test it on one of the other mcode relays. Easy Nuff to try. And yes, relays can be intermittent for sure. I have found some of the items like that on the haas may not be the highest quality, and sometimes you just get a bad one. I've had fuji relays bad right out of the box, so it does happen.

Geof, from your track record on the forum I do not doubt your 1/4 assed analysis. The problem is the relays are soldered onto the board so I cannot remove them to clean them. The only thing that I can remove is the little green terminal blocks above the relays.

Switching to another relay is my next option but that will require changing the relay calls in all the Renishaw Visual Quick Code programs. No big deal with find and replace functions but I do not have anything on my computer that will open them. I will get back in touch with Renishaw about this if necessary. The people at Renishaw have been very very helpful with this problem. My local HFO will not even call me back about it.

Has anyone tried replacing the relays on the board?

Although not on a HAAS, In the past I have replaced many PCCT relays, and the main thing is to use a high enough wattage iron and a solder sucker and or Dry Wick.
It is not unusual for the board to be double sided so you need to get someone to apply removal pressure while you get heat into the pins ASAP.
Some kinds have a DIP footprint, these are the same outline as a IC chip and with these type, a socket can be inserted after removing the relay and this allows easy replacement in the future.
Al.

I'll check with Haas and see if they will tell what relay(s) to buy as replacements. The soldering part does not bother me if I can find the relays. Thanks for the tips :)

The problem is resolved for the time being. The Haas rep who monitors this forum responded immediately and quickly provided me with information including the part number of the relays on the board of my machine. They are soldered on and the Haas recommendation is to replace the entire board. This seemed a little silly for a relay that is worth a couple on bucks. Geof also pointed out that they should have gold contacts for the probe application so I didn't think I would be getting much for my money.

The fellows at Renishaw are amazing in their efforts to satisfy a customer, even when the problem is not theirs. One of their engineers figured out a neat work around for me. He effectively replaced the M23 relay with the M24 relay by using jumper wires. He then told me how to modify the Renishaw software in the Haas VQC programs to accommodate the changes from M23 to M24 relays. All is working fine at the moment, and should continue to do so until another relay croaks.

The only sour note in all this is the lack of any interest from my local HFO. I love Haas machines for what I do but I guess I need to move out of Florida :) , fat chance, today it was 76 degrees, sunny with winds from the NE at 7 mph.

As you can see, I'm a little anal about folks that start threads on this forum and never finish the job.

Vern

It might be worth sourcing the relays for future reference, is the part number a manuf number or a OEM part?
Some are pretty obscure but I have often tracked down a sub.
Al.

Thanks for the follow up.

I to have always had excellent help from Renishaw and glad to hear Haas Californial helped you out also.

AL,

Ken Foulks supplied me with the following information about the relays on my board;

relay 12V 10A spdt pc
mnt1formc w/ag-cd cntcts
global comp g83-csc-dc12

The Haas part number seems to be 67-1423 although this could be the relay manufacturers part number as well, it's not defined.

Google chokes on all this information :D

Vern

Here is a little more information on the M21-M25 relays...

I have a TM-2p that I took delivery last May (2011).

Following is a picture of my I/O board showing the relays that are used.

http://phutcheson.net/images/The Shop/Haas 0087.jpg

These are Fujitsu series FTR-F1 ... a 2 pole 5a Low Profile type.

Link .... http://www.fujitsu.com/downloads/MIC...ays/ftr-f1.pdf


And can be bought from mouser ...
Link ...http://http://www.mouser.com/catalog/catalogUSD/644/1846.pdf


Interesting that I'm missing M23 and M25 relays ...
I didn't order the Renishaw probe but I may ... if I do does that mean I have to order a new I/O board? :confused:

So I may order the relays, then I just need to find the surface mounted LED and the VR8,9 parts. But I won't do that until my warranty is up!


Ken ... any thoughts on why I'm missing M23,25?


Pat H.

You will need an IO board replacement to run a probe.