Need a bit of Motor Advice.

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Need a bit of Motor Advice.

This topic has 8 replies, 5 voices, and was last updated 8 January 2014 at 17:11 by Oompa Lumpa.

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7 January 2014 at 16:59 #23059
Oompa Lumpa
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@oompalumpa34302
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7 January 2014 at 16:59 #139961
Oompa Lumpa
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@oompalumpa34302
So I 'won' a single ended polisher/grinder.

First thing is the starter, I was wondering if I could swap it out for one of those £10 replacements from That Auction site?

Next up is the fan. i cannot see what it does, apart from spin around? It is a totally enclosed motor (which runs lovely by the way) and there is a cover which sucks air in and blows it around but not anywhere useful that I can see. There is no way air can be circulated anywhere, not to my mind anyway.

As they say, a picture is worth a thousand words:

The starter mounts on the rear, over the fan cover.

graham.
7 January 2014 at 17:39 #139968
Swarf, Mostly!
Participant
@swarfmostly
Hi there, Graham,

I'm afraid I can't help you with the starter part of your question.

However, I can reassure you about the fan. It will cool the motor as long as you fit the shroud. The stator of the motor is assumed to be in good thermal contact with the casing. There may also be an internal fan that picks up the heat from the rotor and blows it to where it too can be shed to the casing. The fan in your photo then sucks air in through the pretty pattern of holes and blows it out around the motor casing to remove the heat.

I used to have a woodworking machine that had a Brook Gryphon 'totally enclosed fan-cooled motor', similar to yours except that the shroud was plastic. That type of motor is good where there's lots of light stuff like sawdust or grinding dust that wouldn't do any good if it could get into the innards of the motor.

The rating plate of your motor may even bear the description 'totally enclosed fan-cooled'.

Best regards,

Swarf, Mostly!

Edited By Swarf, Mostly! on 07/01/2014 17:41:38

Edited By Swarf, Mostly! on 07/01/2014 17:42:03
7 January 2014 at 18:01 #139971
john fletcher 1
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@johnfletcher1
Swarf mostly is correct.What is the reason for not using theON/OFF switch which is shown in photo one.I realise that the switch as shown doesn't give No-volt release, but most grinders have a simple on/off anyway.Ted
7 January 2014 at 21:13 #139985
Oompa Lumpa
Participant
@oompalumpa34302
Very very helpful, thank you for taking the time.

John you first – The 'ON' button of the starter does not always lock in the on position and you need to have a couple of goes sometimes to make it lock in. So as I have it in bits I thought I might replace it but I am not going to be throwing money at it.

Swarfy, very informative. The thing was just completely choked in crud so I have scraped most of it off and I will go over it with a stiff brush before I put it back together. The switch was fastened to a plate which was bolted across the pretty holes blocking most of it, I will fabricate something a bit more substantial and make some standoffs or something.

Pretty pleased with it overall, I didn't give much for it and it is going to make a terrific polishing machine. My ony snag is buying a mop for it, I have seen some really nice thick mops down at Chester tools so I will look into that but the spindle is 1" so there is no doubt I am modifying anything I get.

graham.
7 January 2014 at 22:06 #139995
daveb
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@daveb17630
Polishing mops usually fit onto a pigtail (threaded cone). These are available with right and left hand threads to fit onto shafts. They are not expensive but look simple enough to make.
7 January 2014 at 23:40 #140003
Trevor Drabble 1
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@trevordrabble1
Graham,

For your information , and as an alternative to Ebay , Axminster Power tools do 2 NVR switches which you may find of interest ; part no 600072, rated up to 2Kw for £11.45 and also the other, part no 340181 , rated up to 1.5Kw for £15.95. I have had one of the latter for a number of years used for swiching a cutting-oil pump and it is sited under the front of my lathe drip tray, so far without problem.

Hope this helps.

Trevor.
8 January 2014 at 09:15 #140011
Swarf, Mostly!
Participant
@swarfmostly
Posted by Oompa Lumpa on 07/01/2014 21:13:59:

SNIP

Swarfy, very informative. The thing was just completely choked in crud so I have scraped most of it off and I will go over it with a stiff brush before I put it back together.

SNIP.

graham.

Hi there, Graham,

Well, you can imagine how much easier that was to deal with than if all that crud had got inside the motor and choked up the centrifugal switch and got into the bearings, to say nothing of blocking the motor's airways and causing overheating.

If your machine had been used for polishing, maybe the crud was bound with the polishing soap and that made it more tenacious. I'd suggest a wipe over with a rag moistened with white spirit or IPA before repainting and reassembly – you need to remove anything from the motor casing that might act as a thermal insulating coating.

Best regards,

Swarf, Mostly!
8 January 2014 at 17:11 #140035
Oompa Lumpa
Participant
@oompalumpa34302
Well, all cleaned up and put back together – works great. I had a 1" bore Scotchbrite wheel in the "stores", it has seen better days but it will do for now. I will look around for replacements.

Trevor, thanks for the heads up on the switches, if I decide to get one it will be from Axminster. DaveB, although a great many industrial polishers use pigtails for easy mop on and off, there are some polishing machines, such as this one, which are designed to take a mop or wheel – usually of the Scotchbrite type – which have a substantial spindle and are designed to have the wheel fastened on.

Thanks everybody for all of the advice.

graham.
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