Excalibur has a fever

[k9dave]

Hi All,
Returning member here returning after a spell of illness and general apathy Anyhow, decided to reintroduce myself to my scroll saw which is an Axminster Excalibur 21" which I purchased from Axminster about 3 years ago. I was just finishing a project when the the motor/blade started slowing down. I switched off and felt the motor which was extremely hot. Prior to this there was no indications that anything was wrong. Before contacting Axminster I was wondering if anyone else has had any similar problems. I have never taken it apart or replaced any parts. The wood I was using at the time was 9mm thick ply so nothing to stress it.
So before I dust off my wallet in anticipation of forking out for a new motor I was wondering if any one has any ideas I could try first. Thanks

 

[Claymore]

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[AES]

+1 for Claymore's comments. I have the Ex 21 and so far (coming up 3 years now) the motor only gets "hand warm" when used, whatever the job and stock cut, and no matter how for long it's used. I did hear that these saws did go through a period of motor problems a few years ago, something to do with a faulty batch (but I only vaguely remember hearing something about that, and can't remember the details or where/when I heard it, sorry).

Assuming you've checked all the items Claymore's listed and come up nil, I believe that Axi are the UK dealers for this saw, so based on my own experience of them, and many other posters here, at least you have the benefit of having a dealer who is well known for very good service.

And BTW I did buy some spares from my local (Swiss) dealer (no break downs, just "just in case" items), and was struck with how reasonably priced the spares prices for Ex saws are.

Good luck.

AES

 

[k9dave]

Hi All, Thanks for getting back to me. My saw is housed in my garage and has been well covered through the winter. I started using the saw after a layoff of about 3 months and all was working well. After a couple of days I noticed a couple of hesitations where the machine would slow for a couple of seconds before resuming its normal speed. I thought nothing of it at first, putting it down to gremlins. Yesterday while putting the finishing touches to a project I'm working on, the machine started to slow again almost to a stop. At the same time I smelt burning plastic. Looking up I saw that a part of the plastic tarp that I use to cover it was touching the motor. I put my hand on the motor and nearly burned myself it was that hot. Needles to say I turned everything off and left it to cool down. This morning I plugged everything in again and after a few strokes the machine died completely.
I have taken the side plate off and everything seems to be in order. There doesn't appear to be any bearing play and the connecting rods seem in good order. I can move everything manually from the motor side using screwdriver in the slot so nothing appears to be seized.
Clutching at straws now but would failed bushes cause heat? (I am not electrically minded )
Not sure how much a new motor would cost and didn't really want to send it away to get fixed if it was something I could do myself. The other option would be to buy a new 21" Excalibur which appear to be out of stock at the moment.
Sorry this is a bit long winded and I appreciate your advice.
Thanks

 

[scrimper]

Clutching at straws now but would failed bushes cause heat? (I am not electrically minded )

Take the carbon brushes out and examine them, they should exhibit a shiny finish at the end, examine both brushes not just the one, if they look dull and the ends rounded off that indicates that the armature has shorted turns and is causing the brushes to 'burn out', if one brush is shiny and the other is dull and rounded (burnt) it indicates that the burnt brush is sticking in it's holder and loosing contact with the armature, in this case you would get intermittent running.

In the case of one brush being shiny and the other burnt replacing them and ensuring they do not stick in the holders should solve the problem.

If both brushes look dull and burnt it is almost certain to be the armature at fault which would need a new motor as I doubt you could obtain just the armature, changing brushes in this case would be futile.

The other thing that can go wrong with this sort of motor are the field windings (static coils inside the motor casing) they can short out and cause a burning smell and overheating too.

In some motors you can actually see the armature and brushes when it is running and it's easy to spot a faulty armature as described above as you will see excessive sparking and hear the rough arching type noise, however in your case I imagine it is encased so you can't see the armature and brushes when it's working?

( I am not familiar with Excalibur saws but I am assuming from your comments that it does have a universal (carbon brush type) motor? My comments above do not apply to induction motors fitted to some saws)

 

[AES]

The Excali saw that I have does not have a typical 240V "universal" motor but is 60V dc (though it does have brushes).

Even very worn brushes should not cause the kind of overheating you describe (unless there's so much carbon dust collected all around that a virtual short circuit has occurred), and although, as scrimper has described, totally worn out brushes CAN (very occasionally) cause burnt out motors (from the carbon build up), this is rare - what normally happens is that the motor just stops with little or no overheating of the type you describe.

From what you have described about momentary slowing down, then stopping, I'm inclined to think that something's gone "phut" in the internal electronics - the incoming 240 V from your wall socket has to be reduced to the 60 V the motor requires, and then there's all the gubbins responsible for the variable speed.

But as above, all that is pure guess work on my part. Sorry, I don't even know where all these bits & pieces are on my machine, and have no idea what checks to try.

So even though it's a bit of a fag, Axi does have plenty of shops around the UK I believe, so again guessing, I think you're going to end up taking your saw there.

But as a first step I suggest a telephone call to the Axi help line. On the (few, fortunately) occasions that I've called them I've found them very helpful and knowledgeable - you WON'T end up on a long call with a gent with poor English reading from a step-by-step instructions book in a dingy office somewhere in the back streets of Bombay.

Good luck.

AES

Edit for P.S: From what I've heard and learnt of my own Excali, there's no need to think about replacing it - I think there's a very good chance that it IS repairable at a cost of less than a new saw.

 

[k9dave]

Just found the invoice to find that the guarantee ran out 4 months ago :x :x Have just emailed Axminster throwing myself on their mercy asking for approx cost for fitting new motor.

AES - Do you have any links to AXI website? Had a quick google search but can't seem to find them.

Dave

 

[Claymore]

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[AES]

PLEEEEZ! Don't talk about a new motor before you've spoken to someone at Axi and described the symptoms, as you did above. It's quite likely that I'm wrong, I'm only guessing, but I THINK your problem is more likely to be in all the "electronickery"!

Don't E-mail them about a new motor (or anything else), just phone them and discuss first, as suggested above, would be my strongest possible recommendation for your first step.

Why talk about a new motor at this stage? What makes you think that that's your problem?

AES

 

[k9dave]

PLEEEEZ! Don't talk about a new motor before you've spoken to someone at Axi and described the symptoms, as you did above. It's quite likely that I'm wrong, I'm only guessing, but I THINK your problem is more likely to be in all the "electronickery"!

Don't E-mail them about a new motor (or anything else), just phone them and discuss first, as suggested above, would be my strongest possible recommendation for your first step.

Why talk about a new motor at this stage? What makes you think that that's your problem?

AES

I did in fact email them before I realised it was "POETS day" so not expecting any reply until Monday. I explained my problem as above and just to give me an indication of the cost of a motor replacement if that is in fact what is needed. `At the risk of doing them an injustice I'm only assuming that they would replace the motor as most repairers these days seem to replace rather than repair.
I will give them a ring following any reply.

Dave

 

[AES]

OK, good luck with it Dave.

I didn't realise it was a "public holiday" in UK - we don't have such things here!

AES

 

[Claymore]

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[mindthatwhatouch]

If all the linkages appear to move normally have you tried rotating the motor by hand.
Sorry no idea about this specific machine, is it belt driven?
If it is 60v DC as stated above there will be a circuit board somewhere, visually check this for signs of burning, damage maybe a fuse gone or track broken on the PCB.
It's difficult without the machine in front of me but maybe some damp/dust/worn brushes slightly seized has caused heat build up and overloaded the electronic side of things.

 

[Claymore]

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[kfenelon]

I have recently had cause to send my Ex30 back to Axminster via the Warrington branch They quoted me £180 pounds to carry out repairs and on completion I collected it from Warrington 2 weeks later. After getting it home it would not work I contacted Warrington and the Devon Service centre and they both believe it was the transport company that had caused other problems. They returned it to Devon and the stripped it down beyond the original quoted work and it is now back in my man cave and feeling like new The transport company on the first collection and delivery just left it loose on the truck allowing it to move about when I collected it the second time it was well fixed to a small pallet Make sure if you send it to Devon secure the machine
Best of luck
Ken

 

[kfenelon]

By the way I considered the quote of £180 to have the machine like new (5 years old ) was well wreath it
Ken

 

[AES]

Yeah, I can't speak to current labour costs in UK, but as stated much earlier in this thread, I found Excali spares prices to be very reasonable.

I'm not at all sure (I can't get to my machine or to the book right now) but the reason I reacted to Dave's request to Axi for the cost of a new motor was that I have a feeling (only a feeling), from the symptoms he described, that his electronics have gone phut somewhere. As the motor (on mine anyway) is a completely sealed "can", I can only see the electronics being on a pcb somewhere inside the machine (but external to the motor).

Let's wait and see what Axi say after he's called them.

Good luck Dave.

AES

 

[k9dave]

OK, good luck with it Dave.

I didn't realise it was a "public holiday" in UK - we don't have such things here!

AES

Not a public holiday but something that most Brits do at the weekend POETS = P*ss Off Early Tomorrows Saturday

I have been able to manually move the linkages via the spindle that emanates from the motor which can be operated by a screwdriver slot at the end of the motor, they appear to be free from any restriction.

Ken,

Do you know if all their stores carry out repairs? I live in Surrey my nearest would either be Hampshire or Kent. If this is the case it would only be an hour or 2 by car and I could take it there myself.

I will keep you all updated

 

[AES]

Dave, I did know about POETS day, I was "trying" to make a funny, sorry! = FAIL

Good luck with the saw.

AES

 

[Claymore]

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