View Full Version : Help !! Grinder not running

11-06-2004, 12:06 PM
Can anyone help me with my problem.
it's the contactors on my shipman surface grinder ...I think they need cleaning.
below is a picture of them .....they can be switched on from the panel or direct.
At first they where covered in crud and would not work at all
so I blew them off with an air line now they are intermitently working ....sometimes pulling in with a few sparks and smoke from the actual brass contacts .
Both motors work ..but the contactors are making more noise than the motors ....so I've only been running for a few seconds.
this I'm sure is down to the state of them
they need to be pulled apart and cleaned in situ .
Any one know how ......without loosing springs etc.
any tips appreciated.
all the best...mark


11-06-2004, 12:31 PM
I see what your problem is. Your machine is full of wires!!!

Get a can of contact cleaner and shoot the contacts. At this stage it's the cheapest and simplest solution.You don't have to disassemble anything. If it still doesn't work after that, I'd suspect the heaters.

[This message has been edited by Rustybolt (edited 11-06-2004).]

11-06-2004, 01:24 PM
Radio Shack and a few other places sell "tuner cleaner" I have used it to do exactly what you want to do but on a smaller scale. I sprayed it let it evaporate and hit it again. It usually works for me. Fred

11-06-2004, 02:22 PM
WD-40 works well as a contact cleaner and it might help the contactors get moving properly.

11-06-2004, 02:31 PM
WD40 .....may give that a go
because I cant get any contact cleaner until monday

J. R. Williams
11-06-2004, 03:24 PM
I would take the contactors apart and clean the magnetic mating surfaces. Any debris that gets into that space will keep the cores from coming together and cause the noise.


Ian B
11-06-2004, 03:39 PM

Nothing you can do, I'm afraid, this is a common problem. The whole machine's scrap. If you like, send it to me and I'll look after it.


It looks like the contactors are open, ie. you can see the contacts and get to them. I had a similar problem; it could be that the points at which the contactors close the gap are burned & not making contact, and a quick rub with abrasive paper will clean them.

It may be a good idea to unplug the machine first, though...


Alistair Hosie
11-06-2004, 06:58 PM
if you have no abrasive and can't unplug it try licking the contacts with a rough wet tongue http://bbs.homeshopmachinist.net//biggrin.gif first make out a will leaviing your machines to me an then no delays http://bbs.homeshopmachinist.net//biggrin.gif Alistair

11-06-2004, 07:23 PM
It's ok guys a nice chap called Ken Widdal has come to the rescue.
he has three of the contactors identcal to mine spare.
He says the top red bar unscrews and the whole contactor buzz-bar assembly can be lifted out easily .
He is going to send me some pics tommorow ..on what to expect.
thanks for all the help so-far.
all the best.......mark

Alan in Oz
11-06-2004, 09:49 PM
I had a similar problem with my J&S which looks the same era as yours. The contactors are easily removable and also the contactor points are easily removed from the unit itself for cleaning as some of mine were badly pitted. Use a small file. Give contact cleaner a go as mentioned but as I found out they ultimately need a clean up.

J Tiers
11-06-2004, 11:18 PM
<font face="Verdana, Arial" size="2">WD40 .....may give that a go
because I cant get any contact cleaner until monday</font>

WD isn't good for much, but one thing it WILL do, is foul up power contacts with burnt oil = carbonised crud.

Don't use WD or other oily stuff unless the maker says to.

11-07-2004, 12:43 PM
Well not good news I'm afraid, attemped to clean the top contactor ..bad results it's too far gone.
On the main body of the unit, the contacts were impossible to get at and put back in , So I took the whole thing out.....and they are either going back in with new contact strips or they get replaced in there entirety.
As you can see by the following pics..says it all.
The good news is I have a friend that may be able to get me complete new units for nothing ...but he is on holiday at the moment, another week before he is back...will just have to keep fingers crossed and hope he has them.
other than that will have to phone "MEM" the makers, up and ask if they have a service kit for them.
all the best..mark

Main body of contactor after removal of top contacts...one of the contacts was missing as you can see ...dont know how, it must of shaken loose in transport.....it must of been arking across for the motor to run.

Top contactor before attempting to clean

Top contactor after cleaning........not good!!!

Allan Waterfall
11-07-2004, 02:20 PM

I know very,very little about electrical things,but could you clean the old contact squares off and sweat some new ones on?

Ignore this if it's a stupid suggestion.


11-07-2004, 02:42 PM
I supose I could Allan, but it would be more trouble than it's worth .

Like I said I'm waiting for a friend to come back from his holidays ......then I may have brand spanking new ones for naff all.
or maybe the new kit of parts to fix these is cheap..i dont know
all the best..mark

Alistair Hosie
11-07-2004, 03:29 PM
Mark I think Alan is on to something a good clean with a file and these should take new tips soldered on to them they don't look like the backing plates are worn just the contacts.Alistaie