Brook Cub 1/2 hp Motor – Capacitor or not?

[Dave PrebbleParticipant @daveprebble85862]

Afternoon Folks

A complete newbie and my first post – hope I get it right

I have just got hold of a Brook 'Cub' motor (serial S.602073) which I plan to use on a drill press.

The motor does not have a capacitor or any signs of ever having one fitted.

Brook Crompton have no idea and cannot help … the motor is that old they have re-used the serial number and have no records

Any one know if it needs a start cap and if so what mfd & voltage rating I should try?

Thanks

Be good and be lucky

Dave P

[Dave PrebbleParticipant @daveprebble85862]

[Phil WhitleyParticipant @philwhitley94135]

it s probably just a centrifugal switch motor, I have just looked in my "brooks" book and it makes no mention of a cub motor, my book is the 1971 edition. Try it and see, if it needs a capacitor it will just hum and not turn, if not it will start as normal, you cant do much harm as long as you switch off if it doeasnt turn!

[Phil WhitleyParticipant @philwhitley94135]

can you post up a pic of the motor plate, you will need to click on "albums" then create an album, take a pic and upload it to your album before you can put it on the forum

Phil

[Clive Brown 1Participant @clivebrown1]

Some single phase motors are split phase start without a capacitor. As said, try it and see. They are at the cheaper end of the market and suffer from rather low starting torque and should not be started too frequently to avoid overheating the starting winding. Probably OK for a drill though.

[Dave PrebbleParticipant @daveprebble85862]

Thanks for your kind replies

no camera to hand but motor plate details are as follows

The "Cub" Motor

Brook Motors Ltd, Empress Works Huddersfield

No. S.602073…..HP 0.5….Volts 240/250

~50 … speed 1420 …phase 1…. Rating Cont

Cast iron body and pedestal… weighs a ton! £ 1.50 at a car boot … probably get that back in scrap if it is no good

Thanks for looking Phil, my guess is for 1950s/60s vintage

I'll give it a good blow through withe the air gun , put a plug on and try it this evening …. with my usual due caution….i.e .fingers crossed!

Be good and be lucky

Dave

[john fletcher 1Participant @johnfletcher1]

Hello Dave, have a look at the outer to see if there is a difference in an area where the colour changes (faded) where a capacitor might have been fitted. Are there any screw/threaded holes where a capacitor tin/steel cover might have been fitted. It might be just split phase, which will be OK for a drill press. However just to throw a spanner in the works, the bearing will almost certainly for horizontal use only if its split phase, but don't lose any sleep over that, as there are hundreds used in the vertical position and have been for many years. I suggest you don't use your air gun on the motor, I know its common practice, but it forces dust/muck etc inside the motor and compressed air usually contains a lot of water which you don't want, suck it out if it needs it.Before connecting to the mains it is advisable to contact your friendly electrician with his 500 volt DC Megger and have him to carry out an insulation test, just in case sort of thing. John

[Dave HalfordParticipant @davehalford22513]

If it's that old undo the wiring connection plate and check the state of the insulation in there, it might be a bit perished.

[Dave PrebbleParticipant @daveprebble85862]

My thanks to John & Dave for the further advice … saved me popping my circuit breaker.

I just whipped the cover plate off. With the this off, there is indeed a centrifugal switch just visible.
The wiring appears in good condition but a quick play with the meter reveals that there is a earth fault.

The live feed goes to a terminal coupled to one red and one black wire which both lead into to the windings.
The neutral feeds a terminal connected to both a red and a black wire … presumably the other end of the start and run windings.

Both terminals, ie both windings, fault to earth with the motor not running.
Most likely a short in one of the windings but I suppose it is just possible that there is a simple mechanical cause for the short in the starter gear, so when I get a a bit of time, out of curiosity I'll try and take the end off the motor and have a looksee.

The motor did however come with a pair of good solid 4 speed pulleys so at the price I paid I am still way, way ahead

My thanks again to everyone

Be good and be lucky

Dave

[Dave PrebbleParticipant @daveprebble85862]

Quick follow up

With the wires now uncoupled from the terminals, the run winding appears to test OK.

It is the starting circuit (black wires) faulting to Earth

Dave

[Dave PrebbleParticipant @daveprebble85862]

Motor end taken off .

Centrifugal switch seems OK but the wiring inside is way too crusty for my liking and is clearly still faulty.

I'll keep the pedestal and grease caps and , of course the Pulley sets, and the rest can go live in my scrap bin….

the one that never gets emptied

it's been a good learning experience so thanks again guys

Dave

[Geoffrey WrightParticipant @geoffreywright91241]

Hi All,

Sorry to resurrect this post, but I am trying to find what might be the fault with my CUB motor, which appears to be the same as the one you are all describing. Not really able to access the plate, but I can read 'Cont' Rating Speed 1420, and possibly .5 HP, but too difficult to read. However…

My problem is that my old Beaver milling machine has this motor, controlled by a Dewhurst on/off switch (OK I know about the feelings of this switch, but that's not the issue her I hope). When I switch the Dewhurst to forward and carry out what I want to do ( usually just drilling a series of holes), switch off and when I want to start again all I get is a humming noise. I have to turn the Dewhurst switch to off, and usually have to wait for a minute or 2 until there's a 'click' and the Dewhurst will switch on again. I think the 'click' is from to motor, but, as I said, it's too difficult to access where it is.

Any thoughts or advice would be greatly received. thanks in advance.

Geoff

[Les Jones 1Participant @lesjones1]

I suspect it could be the centrifugal switch in the motor sticking in the open condition. The click may be the switch dropping back to the closed position. Have a look inside the dewhurst switch and check how many wires (Other than the earth wire.) go between the switch and the motor. If there are only two then the fault is almost certainly in the motor. If there are four then post a diagram of how they are connected to the switch. Do you have a multimeter ? This is so we can get you to do some tests to prove it is not the dewhurst switch. Is the switch a forward – off – reverse switch or just off – on ?

Les.

[Speedy Builder5Participant @speedybuilder5]

This one looks to be a CUB. and no sign of a capacitor.

**LINK**

[Geoffrey WrightParticipant @geoffreywright91241]

Hi Les,

I have removed the switch (as we speak!) and there's a lot of pitting, which I will try to clean up, possibly in the lathe. There are 4 wires from the Dewhurst to the motor. As you look at it from the top left:Brown, next: Black, next: Blue (bottom peg not used). Then one Black to the 2nd peg on the right.

Just about to follow the Youtube video – Beachcomber Bob. Looked at it before, now I'll try to follow it, LOL!

Can't do anything more right now until I get it all re-assembled. Thanks for your response. I'll be back asp!

Geoff

[Nigel McBurney 1Participant @nigelmcburney1]

I have a Brook gryphon 1/2 hp sp motor,my father bought it new to power a combined wood lathe and saw bench around 1952/3, I inherited(borrowed long term) the sawbench about 50 years ago and the sawbench was used a lot when I built my bungalow then a friend borrowed it to build his house , the saw and lathe was passed on but I kept the motor and it has been on my Rapidohack saw for about 15 years,very good motor, it has a centrifugal switch and does not have a capacitor and never has had one. It does have a high start load and will dim the lights,no problem now as the outside wiring is divided with separate consumer units,and it does not now affect my shed lights,though I do not know why.Bearings are still ok,been greased about every ten years. This week I sliced off four pieces of steel from a 61/2 dia steel bar to make two stationary engine trolley steering turntables,not bad from a near 70 year old good English built motor ,its always been switched on using a MK metal clad socket, you can just about cut 61/2 inch dia on a nominal 6 inch Rapidor,old but good reliable saws,I was about ten when father bought the saw/lathe he let me do would turning but I was not allowed to use the saw until I was a lot older though I thought it was not fair though he was right,a while ago one of my customers came round, with the words "Sorry not been around lately as a sawbench bit me, holding up his hand minus some fingers."The old saw was replaced with a new Makita table saw and the switch failed after a year,typical foreign c–p!

[Geoffrey WrightParticipant @geoffreywright91241]

Hi All,

OK, so I have removed the Dewhurst Switch and cleaned it up, removing the burrs from the pins etc. Put it all back together and onto the motor, and it works as it should:

My camera batteries failed just as I was going to take a pic of the motor. I've been able to swing the mill head around and there is what I assume is the capacitor on the outside – about 3 inches long by 1.5 inches diameter, sealed at base with what looks like pitch. The motor runs OK, but when I've run it for a few minutes, like this morning, it takes several minutes for the power to be restored. I assume now that the 'click' I hear is in fact the centrifugal switch. I don't think it's something that I can actually tackle, so I'll look around for someone that knows what they're doing, LOL! Even if I remove said motor, and remove the base plate I assume there's not much I could do at this stage to find the fault. Electronics are not my specialist subject I'm afraid.

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