# Bandsaw motor not starting



## Terryjb (18 Jan 2012)

I am having difficulty sorting problem on my Elektra Beckum BAS315 bandsaw.
On start up I get a humming noise, but motor does not spin up.
I can get it going by pushing the blade with a stick- it then functions perfectly.

I found and read an earlier topic suggesting replacement of capacitator and decided to do the same.
I emailed support at Metabo (they now I think have bought Elektra Beckum) and they promptly responded and agreed that it was probably the correct diagnosis and gave me the part number and source for a replacement. I got this yesterday and fitted it today , but to no avail.
The motor still hums, but does not spin up, and now cannot be encouraged into to life with a push.

Went back to Metabo who now suggest that it may be the motor. I will tomorrow put the old capacitator back on and hope that the push start works again while I try to find a permanent solution.

In the meantime I would be pleased to accept advice from anyone with a better understanding of how electric motors work and any suggestions on how to proceed.

Many thanks


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## Dibs-h (18 Jan 2012)

Bob is your man - PM Bob9Fingers if it's urgent. I suspect he'll be along shortly.

Dibs


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## Argus (18 Jan 2012)

.


As it runs after a push and assuming that you don't have two dud capacitors one after the other, the motor may have (some bigger motors do, some smaller ones don't) a centrifugal switch to switch out the start windings when the motor reaches run speed.
Sometimes these things either jam up up or require the contacts being cleaned. 
Basically it's just a set of insulated electrical contacts strapped to a set of weights, attached to the rotor shaft.
If it's jamming, a quick squirt of WD40 up the rear end may do the trick

Otherwise, to sort this out, (if it does have a switch), it is a strip-down job.

.


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## Blister (18 Jan 2012)

Sounds like a capacitor fault 

Not expensive to replace :wink:


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## Digit (18 Jan 2012)

If the motor used a mechanical switch you could often hear a click when the motor ran down after being switched off. Was this so? If so can you still hear the sound? If not the switch is stuck in the 'run' position and a strip down will be needed as Argus stated.
BTW, don't buy capacitors from machine suppliers, nor bearings either, the price rockets.

Roy.


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## Terryjb (18 Jan 2012)

Thanks all for advice. 
Metabo gave 3rd party supplier details for replacement capacitator which pleased and surprised me- price was OK at £6. But it hasn't fixed problem. 
There is no obvious 2nd capacitator that I can see.
The centrifugal switch sounds an interesting possibility.
I will look again in the morning and see if putting the original capacitator back in gets it running with a push.
Thanks again
Terrjjb


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## 9fingers (18 Jan 2012)

Please DONT put WD40 or any other fluid on the centrifugal switch mechanism.
Whilst this might free up a stuck switch for a while, it will later turn into a sticky mess and jam up once more.

What is the power rating of the motor and what is value of the capacitor - look for a number followed by mfd or uF

Post back with an update when you can.

Bob


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## Terryjb (19 Jan 2012)

Thanks Bob
Power is 0.55 KW
Plate on motor says Cb 20 mF

terry


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## 9fingers (19 Jan 2012)

Hi Terry,

This motor power is right in the middle of the range where there may or may not be a centrifugal switch.
generally for economy reasons they try and design out the switch but starting torque is reduced.

Take the blade off and see if the motor will spin start. try it in both directions. As the motor is slowing down, listen for any click or start of a rubbing noise and report back please.

Bob


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## Terryjb (19 Jan 2012)

Thanks Bob
I hope to follow your instructions shortly.
As it does not currently spin up at all with the replacement capacitator I have checked by part number that the correct one was supplied - it was. However I have a new concern as I note that it is rated at 12 mF. I think I will therefore, before proceeding, refit original capacitator and see if I can get back to where I was.
Will get back to you later today.
terry


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## Terryjb (19 Jan 2012)

Hi Bob
Refitted original capacitator.
Removed blade
Push started in both directions
No click heard in either direction on slow down
Slight rubbing noise heard - I think- in each direction
terry


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## 9fingers (19 Jan 2012)

OK, a rubbing noise as it slows down suggests a centrifugal switch.
The fact that you can spin start in either direction means that the starting circuit is not having any influence.
This is causes by 
1) open circuit capacitor ( not likely in this case as you have tried a new one)
2) defective contacts on centrifugal switch (if fitted and in this case possibly so)
3) open circuit starter winding - bad news very likely not to be repairable but usually rare.

A few motors have the switch behind the fan but outside the main case but most are inside.
If you can see how the motor goes together, then carefully take the back end off very carefully
Take photos and mark all the wires with where they go especially if you have more than one of each colour - there are no standards of colour coding.

If you can't see how it comes apart, take a few photos and post here or email them to me
[email protected]
Do you have a multimeter capable of measuring resistance and AC volts up to 250 minimum?

Bob


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## Terryjb (19 Jan 2012)

Thanks again Bob
I have to go to a tutorial soon which will take up most of the afternoon, so may not be back with photos until tomorrow.
Nothing to indicate that there is an external switch. I think the back should be easy to remove and I think also that I have a suitable multimeter.

Terry


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## 9fingers (19 Jan 2012)

OK Terry,

When I say external, that type have the switch behind the fan cover and behind the fan so unless you are part way through dismantling, it would be regarded as internal. The easy thing is that you don't have to open the main motor casing.

Bob


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## Terryjb (19 Jan 2012)

Bob
Sorry I misunderstood
I have just removed the cover to expose fan
Behind fan is cast iron plate secured by 3 bolts
Rotating fan by hand definitely produces rubbing sounds

Running out of time now, but very grateful for your help. Will try to get photos when I have removed the back plate perhaps this evening
Terry


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## 9fingers (19 Jan 2012)

Ok Terry,

I'll be online this evening and on and off during the day.
I'm waiting for my timber supplier to confirm my order is ready for collection so kicking my heels a bit.
Might even have to tidy up the workshop this afternoon :shock: 

Out of interest, what are you studying?

Bob


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## Digit (19 Jan 2012)

> Might even have to tidy up the workshop this afternoon



Now, now, now! Careful Bob, those sort of actions can lead to all sorts of mental problems! :twisted: 

Roy.


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## Terryjb (19 Jan 2012)

Archaeology. Distance learning with Leicester Uni. Just one of my retirement projects


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## 9fingers (19 Jan 2012)

Hi Roy,
I'm currently doing the sympathy bit sitting with SWMBO who is feeling c r ap at the moment with a heavy cold but daytime TV is starting to affect my mental state anyway.

Give that I will have to plane up some sawn timber (when I get it Grrr!) I'll need the space so a mild tidy up is probably needed as well as empty the cyclone ready for the flood of shavings.

Bob


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## Digit (19 Jan 2012)

> Archaeology. Distance learning with Leicester Uni. Just one of my retirement projects



http://www.google.co.uk/url?sa=t&rct=j& ... _A&cad=rja

This group might interest you, if you can put up with me there as well as here.

Roy.


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## kirkpoore1 (19 Jan 2012)

9fingers":2pgzgxoh said:


> OK, a rubbing noise as it slows down suggests a centrifugal switch.
> The fact that you can spin start in either direction means that the starting circuit is not having any influence.
> This is causes by
> 1) open circuit capacitor ( not likely in this case as you have tried a new one)
> ...



Bob:

What about a bad connection in the wiring itself? Say, a loose wire nut? Terry, have you double-checked the connections inside the junction box?

Kirk


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## 9fingers (19 Jan 2012)

Could be Kirk, although mercifully we not used wire nuts here for decades - they might even have been banned for all I know. If Terry has been in and out fitting capacitors then he will have moved nearly all the connections already.

Bob


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## SurreyHills (19 Jan 2012)

I have the same type of saw BAS 315 GWN 55, my capacitor is rated at 16uF at 450v even though the saw is only 230V. I don't hear the centrifugal switch click off when I switch mine off so I suspect that there isn't one. Hope this helps you to try and troubleshoot your machine.

Let me know if you need me to check anything else out to compare against your machine.


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## 9fingers (19 Jan 2012)

Andy, The only thing to be careful of is that most machine manufacturers don't always use the same motor throughout the production run.
I'm not expert on EB machines but certainly Startrite bandsaws use all sorts of different motors even different speeds and pulleys sizes.

So it would be quite likely to find the same machine with different motors which may or may not both have centrifugal switches.
There is even one manufacturer who is now fitting electronic switches so we have a switching type motor design but no audible clues that it is of that design.

Bob


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## SurreyHills (19 Jan 2012)

Bob - you raise some valid points, just to clarify my saw was made in 1999 and the motor is a EB one rated at 316W.


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## Terryjb (20 Jan 2012)

Hi Bob
Sorry to be so long getting back to you.
I unbolted back plate and pulled it out, with attached fan, as far as it wished to come, about an inch. I could see only the shaft, nothing else.
Took photo on iPhone, but forum rejects it as invalid, so will try to email to you directly.

Cheers
Terry


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## Terryjb (20 Jan 2012)

Thanks Digit
Your recommendation noted, looks an interesting forum
Terry


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## 9fingers (20 Jan 2012)

Hi Terry,

It rather looks like your motor does not have a centrifugal switch from what I can see but that is not consistent with the rubbing noise unless that was bearing noise in the motor of from any belts etc inside the saw.

This is a diagram of a typical single phase motor







Assume for now that the starting switch is closed all the time ie you don't have one.

Make sure the machine is unplugged from the mains!!

Locate the wires coming from inside the motor - seem to be the yellow ones in your photo. You might have four with two connected together or that connection could be inside in which case you will have three (maybe plus earth?)

Set you meter to read resistance (ohms or the Omega greek letter)

one of the three (four?) should go to the capacitor only connect one meter lead to that junction.
Measure the resistance to the common connection going to both windings ( far right on the circuit). Note the reading; this should be the resistance of the Start winding. 
Put one meter lead on that common connection again and the other to the winding terminal that so far you have not tested. This is the left hand end of the top coil on the diagram. Note the reading; this should be the resistance of the Run winding. 
I would expect both readings to lie in the range say 5-25 ohms

If your meter has a capacitance range (not all do) disconnect one end of the capacitor from the motor, short it briefly to the other capacitor lead (it may spark - we want to make sure it is discharged!) Then measure the capacitance of your old - maybe suspect capacitor. Note the reading it should roughly agree with the value printed on the case.

Please report back.

Bob


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## Digit (20 Jan 2012)

There are a couple of pros on the forum Terry, but the input of another would be good, hope to see you there.

Roy.


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## Terryjb (21 Jan 2012)

Hi Bob
I have tried to follow your instructions, but have had difficulty getting the info back to you through the forum.
Email with diagram of my saws wiring etc has been sent.
Regds
Terry


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## 9fingers (21 Jan 2012)

OK I'm continuing by email as you are having trouble through the forum

Bob


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## Terryjb (22 Jan 2012)

Bob completed diagnosis off line- problem was failure of starter coil windings. Solution a replacement motor.
Many thanks to Bob for his generous help and advice.


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## Carpenter D (28 Aug 2018)

Hi I have recently received an electra beckum bandsaw. 

The person I got it off said it worked but was not good to him as it didn't havery a kill switch. 

I was also talking to another fella about it and he told me the motor went on it and that's why they got rid of the bandsaw.

I plugged it in and nottin is happening in changed the fuse and still nothing is there anyway of telling if I is the motor or could it be something else?


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## Ttrees (28 Aug 2018)

Did you check the capacitor for any bulging?
This is a common thing with single phase motors
You can buy them for less than a fiver, if there's no shroud covering it you can buy near any one
with the UF (microfarad) rating for cheaper, rather than one that needs to be a specific size to fit into the shroud.
Good luck
Tom


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## Carpenter D (29 Aug 2018)

I have cheacked the capacitor and don't see or feel any lumps how else could I tell ifrom it is the capacitor?


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## Ttrees (30 Aug 2018)

Nothing to loose, at the very least taking the motor terminal cover off and having a smell.
If it smells suspicious like its burnt out, I would investigate further, it might be OK.
It may be clogged with sawdust either, so I wouldn't be in a rush to just be on the look out
for burnt windings.
Take the motor off and have a look, I suppose.
If you do decide to do so, draw a continuous line with marker or whatever, markings the length of the motor before disassembly, to aid putting it back together if its not obviously only one way it goes.
You might as well get a capacitor if you see nothing wrong with it, only costing less than a fiver.
Don't know much troubleshooting with single phase motors, only that it's nearly always the capacitor that's the fault.
It might clear up some things before someone more knowledgable comes along.
Good luck
Tom


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## Carpenter D (6 Sep 2018)

Hi I had a friend look at it and it works it's something to do with the on and off switch that's not letting it work. He was able to bypass the switch so it would work. He doesn't know why the switch isin working so I think I need to buy a new one. I haven't really looked at it since last Friday so I don't know if I can clean the switch or just buy a new one. Have you ever heard of this happening before? Do I need a new switch?


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## lurker (6 Sep 2018)

I assume it's a no volt switch
These often get choked with sawdust and can be cleaned out.


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## Carpenter D (7 Sep 2018)

I took it apart and Its clean I think something is broke in it as the switch won't flip unless I hold down a spring of some sort. I think I need a new switch or to find out how to fix the spring?


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