Help, my bandsaw just stopped working

[heatherw]

This evening I was busily engaged in making bandsaw boxes when I had to stop the saw for a minute to talk to someone. When I tried to start it again it wouldn't start.

I tried moving the plug to another socket, blowing all the dust out of the microswitches, turning the electricity off at the mains and then turning it on again.

The saw is a SIP 01489 14" heavy duty, it's 8 to 10 years old but i only started to use it about 2 years ago, it's had very little use, still looks brand new.

The only 2 things left to do which I actually know how to do is to take the switch apart and see whether there's dust in it, and take the plug off and see whether a cable's come loose. Then we start to get in to the mysterious realms of electricity and motors and suchlike.

There was no warning whatsoever, it was running just fine and I'd turned it off and on several times in the past hour it didn't heat up, there was no burning smell, the plug and motor look fine. Can anyone give me guidelines as to what to do next? I really need it to work, there's something I need to finish before next week.

 

[CHJ]

Suspect dust in the NVR switch assembly. Assuming you checked the plug fuse that is.
Despite sealing every hole I could find in the column, it was not till I turned the NVR upside down so that the holes in the Perspex cover were on the bottom that the dust stopped getting in.

 

[heatherw]

Thanks Chas, I'll take it apart first thing tomorrow morning. I hope it is the switch, there was a lot of dust around.

 

[blackrodd]

Thanks Chas, I'll take it apart first thing tomorrow morning. I hope it is the switch, there was a lot of dust around.

I had a similar problem and was advised to get some switch cleaner from maplins after the dust was blown out!
I've had no problems since. Regards Rodders

 

[Noggsy]

My bandsaw (a very reliable Kity 613) stopped working last week in between cuts. I think it was the cold in the workshop tightening the blade slightly which threw all the settings out and meant that the blade was tight against the back of the wooden plate in the table and also the thrust-bearing. Having faffed a bit, I took the blade off, re-set everything and it ran perfectly again. I'm not saying that's what has happened to yours, because I could hear the motor trying to turn (and I presume you cannot or it wouldn't be the NVR), but mention it in case it useful to you or anyone else. Good luck in sorting it.

 

[heatherw]

Well, I took the switch apart and it was full of sawdust. I blew it all out and cleaned everything up, but the saw still doesn't work. The plug looks fine, and they don't have fuses here. Can sawdust ingress break switches?

I have an Axminster grinder which has what seems to be an identical switch on it and I was wondering about changing it over to test whether it's the switch or not. but wouldn't this be rated lower than the bandsaw switch? Should it say something on it?

 

[SteveF]

is it possible to bypass the switch ...just for testing purposes?

 

[heatherw]

I'm sure it would be, Steve, (why didn't I think of that?) but there are a lot of cables in there and I'm not sure which ones to use. A friend of mine might have time to come round this afternoon and look at it.

 

[SteveF]

ok good luck

i was guessing u had machine......>>>>>2 wires (no earth)>>>>>>>>NVR.....>>>>>plug
i thought just go new wire from saw to plug

 

[CHJ]

Switch should be fine once any bits between contacts are removed and it looks as though mechanism is clicking over.

Next step I'm afraid is do what should have been the first option if you had the tools.

Get someone with a mains voltmeter to determine how far the supply is getting, taking on board that if there are any door safety switches these will only be made if door is shutting and depressing them correctly or you make them by hand whilst making sure your hands are well clear of any wheels or blades.
Any Door switches will be wired between the incoming mains supply and your NVR switch, so if no supply at NVR then it's likely safety switch is not made

A mains light bulb wired up to some insulated probes could do the job but anyone with this in their kit probably has a suitable mains voltmeter anyway.
And you will more than likely need a second pair of hands to measure and check switches.

Do not rely on a something like a small neon (mains tester) screwdriver, it may glow from leakage currents without having a true supply present.

 

[SteveF]

apologies if I gave false advice and I never considered the door safety switches

 

[heatherw]

Switch should be fine once any bits between contacts are removed and it looks as though mechanism is clicking over.

What does this mean Chas? The switch doesn't make a noise when I try to switch on. It's kind of rubbery, not positive, no click. There are only the two big silver contactsoperated by the green button, right?

 

[CHJ]

Switch should be fine once any bits between contacts are removed and it looks as though mechanism is clicking over.

What does this mean Chas? The switch doesn't make a noise when I try to switch on. It's kind of rubbery, not positive, no click. There are only the two big silver contactsoperated by the green button, right?

You do have an NVR switch I take it, A start and stop button in the same case? By clicking over I was referring to the electro mechanical contact latches moving over.


The green button closes the main contacts and should electro mechanically latch a set of contacts , or the contacts your green button closed at least, until such time as the red button is pushed or power fails.
Even if the NVR switch is not latching your motor should run until you take your finger off the green button if power is present.

If you do not have an NVR switch, then most of the above advice may well be erroneous.

 

[heatherw]

Yes there is a NVR switch, but there's no power anywhere and I assumed this was responsible for the rubbery feel to the switch mechanism. There is no attempt by the machine to start, no noise from the motor or anywhere. It's just like a tall metalic bandsaw-shaped ornament. If you see what I mean.

 

[heatherw]

The switch is very similar if not identical to this one

http://i.ebayimg.com/t/Woodturning-...0X/$(KGrHqZ,!qYFEy1YLcwQBRkm0(gzcQ~~60_12.JPG

 

[MARK.B.]

Just a thought so please dont shoot the messenger , but are your other sockets working ok with other power tools ?,could you have a fault in the fuse box ?

 

[CHJ]

Then get your friend to help trace the supply from the incoming lead via the safety switches (if fitted) to the NVR.

Some sorting to do in the birdsnest of wires you mentioned to trace those leading around the saw frame to any safety switches I'm afraid.

Find the junction of the incoming power cable and check for supply there first.

 

[heatherw]

We fixed it!

Ok,well, Pat fixed it, and I helped.

It was one of the microswitches and we've bridged it till I can get a new one. Soooooooo pleased, and thanks for all the help everyone.

 

[Kevan14]

The advise was great my 12" SIP Bandsaw just stopped, a quick blow one the door micro switches saved the day, my neighbour installs new floors, he was replacing a beautiful solid oak 1/4" depth by 18" wide with some of the most impressive knots I have seen in a long time with a modern slate effect tile, he dropped the boards off so I could use them in our wood burner.

Had I not been on 38 tablets a day including 120ml of Morphine to control my pain, the wood would be used for making furniture, but the best I can manage nowdays is to turn the odd pan handle. My wife loves it when I get some oak for the wood burner, a bit of oak and her washings dry, I normally get a delivery from the coffin makers you get a 6'6" by 2'6" with the lid shape cut out, my last delivery had 30 temporary Crosses used to mark the grave until a stone is placed they were great for cutting up, I don't feel guilty with those but I truly hate wasting such rich old oak on a wood burner. I joined just to say thanks for the advise I have a happy odd job man toiling away in my workshop.

I will enjoy reading the forum if I can no longer indulge myself.