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Table Saw Fault

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AbbeyRd

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My Rexon table saw starts up ok but when you start cutting a piece of wood, it switches itself off. :(

Has the NVR switch failed or is it ikely to be someting else.
Thanks
 

Mike.C

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Hi AbbeyRd welcome to the forum.

When it switches off can you turn it on again straight away, or do you have to wait awhile?

Cheers

Mike
 

Benchwayze

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I had this problem a few years ago. In my case I could restart, but as soon as I loaded the blade, the motor stopped again.

It was something amiss in the MECHANICAL part of the NVR switch. I.e., the switch-prod inside wasn't lined up properly with the switch pad, and consequently the switch wasn't being held properly in the ON position. Soon as I applied load, the switch flicked itself off.
I'm afraid I forget what I did to correct it, but I think it had something to do with the spring.
My advice tho' is to seek pro advice and have the switch tested for electrical fault first .

John
 

AbbeyRd

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Hi fellas.
Thanks Noel for moving to correct forum.

Mike.C":389fluax said:
When it switches off can you turn it on again straight away, or do you have to wait awhile?

i have to wait a few secs and then it will start again but pressing the red off switch seems to reset it for immediate restart.

Will not stop on though when I try to cut anything.i
 

9fingers

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Simple (aka Cheap) NVRs do not have any load current sensing ability but are often plagued by dust ingress.

It could well be that mechanical vibration is causing it to drop out. A good clean out with an airline or as a recent "patient" found, blowing down a drinking straw, dislodged the dust and got him running again.

If this is a brush motor and especially if it has soft start, there maybe manufacturer specific electronics that could well have current sensing built in and giving trouble. Rexon do not have a good record of providing design information.
The motors are usually special to type due to integral gearboxes and unobtainable/expensive so lets hope it is not that causing trouble.

Good luck

Bob
 

AbbeyRd

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I phoned the Rexon helpline and the technician seemed to think that it could be a circuit board problem.
He is going to talk me through bypassing the NVR switch to see if the board does need replacing at a cost of £39.

Wish I had a compressor to give the motor a good blow out as there did seem to be a lot of sawdust around

Keep you posted :D .
 

marcros

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AbbeyRd":1c37a5c8 said:
Wish I had a compressor to give the motor a good blow out as there did seem to be a lot of sawdust around

Keep you posted :D .
what about a can of compressed air (usually for cleaning computer keyboards), or even a drinks straw.
 

andersonec

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AbbeyRd":2vfz98p9 said:
I phoned the Rexon helpline and the technician seemed to think that it could be a circuit board problem.
He is going to talk me through bypassing the NVR switch to see if the board does need replacing at a cost of £39.Keep you posted :D .
Had a similar problem with a Rexon thicknesser a couple of years go, had to bypass the the little control board which governed the slow startup, no problems after that.

I got a Henry type vacuum cleaner from Wickes a couple of months ago which had two connections, suck and blow, quite powerful and enough to move dust,,,,under £40,,,

Andy
 

AbbeyRd

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andersonec":3v629ojn said:
I got a Henry type vacuum cleaner from Wickes a couple of months ago which had two connections, suck and blow, quite powerful and enough to move dust,
I bought one of those and have been impressed with it but blowing it out made no difference.

Going to bypass the board tomorrow and will let you know.

My money is on the NVR switch #-o
 

AbbeyRd

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I have bypassed the circuit board and .................................drum roll..............it works. =D>

So it was a circuit board problem after all. I have spoken to a local engineer who thinks that the board is only to control the brake and that I can run it without the board.

Think I will get a board if anyone knows who sells them cheaper than £38

Thanks to everyone for their interest. :D
 

9fingers

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As well as the brake, you might lose any soft start feature.

There are a worrying number of small saws coming on the market with bespoke circuit boards built in and often very little knowledge outside of the manufacturer of how to repair them and indeed exactly what they do.

Glad to hear you are up and running.

Bob
 

Dibs-h

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A Rexxon table saw with a brake? I didn't think that end of the market had an induction motor, let alone an electronic brake.

Or have times changed?

Dibs
 

9fingers

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Times have changed Dibs. The advent of cheap electronics enables soft start (to prevent lightweight machines leaping in the air and popping fuses) and braking comes almost free.
I don't think they are using induction motors (?) but still rely on Satanic-spawn brush motors

Bob
 

kirkpoore1

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9fingers":3uta920b said:
As well as the brake, you might lose any soft start feature.

There are a worrying number of small saws coming on the market with bespoke circuit boards built in and often very little knowledge outside of the manufacturer of how to repair them and indeed exactly what they do.

Glad to hear you are up and running.

Bob
Man, I hate those circuit boards. 20-odd years ago I bought a variable speed grinder. One month after the warranty ran out, the circuit board burned up. It was a $50 grinder, and the replacement board was $35. I pulled the wheels off the grinder, threw the rest away, and bought a real, single-speed grinder for $75. 20 years later it still runs great.

Kirk
 

Digit

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coming on the market with bespoke circuit boards built in and often very little knowledge outside of the manufacturer of how to repair them and indeed exactly what they do
Looked at any speed control units lately Bob? Every manufacturer seems to produce his own variation that is non-interchangable with any body elses or even their own product a few months later.

Roy.
 

9fingers

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Yes indeed Roy,

I had a jet wetstone grinder in for repair with one in. In the end I found the data sheet for the chip but even with that I could not find the fault which was an intermittent. Even tried the old favourite of re-heating every joint. I scrounged a replacement board from Axi in the end.
Different circuit but mercifully it fitted!

One of these days I will carry out my threat of refusing to work on anything with a brush motor in it - just to keep my sanity!!

Bob
 

Digit

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Half the time the damn components don't even seem to have recogised codes do they.
As for heating, I've done that numerous times on old valved stuff but now a days you end up heating the entire board unless you can mask it.
Not everything seems to be progress.

Roy.
 

AbbeyRd

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UPDATE

I purchased a new circuit board from RexonSpares at a cost of £38.60 :cry: :cry: and it works perfectly. =D>

The blade starts up slowly and brakes when it turns off so the board is useful and is worth having if only to stop me being scared out of my wits turning the saw on.

Hope this thread helps someone in the future.

Thanks to all who have replied. :D
 
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