Record Power BS350 Bandsaw - NVR Switch Problems

[Routermonster]

Hi All

I am having problems with the NVR switch on my bandsaw. It normally takes a couple of seconds for the start button to 'latch' when I press it. Yesterday, having been working OK for a while, it suddenly refused to do so when I restarted it. Now I have to hold the button down for the motor to run; as soon as I release it the motor stops, even if it's been running for a several seconds. It's still under its 5-year warranty, so I'll contact Record Power tomorrow. But, in the meantime, does anyone have any ideas what could be wrong?

Thanks

Les

 

[paulm]

Hi Les, might be worth dismantling it a bit and blowing out any accumulated dust/crud, having first unplugged from the mains of course !

Might need a new switch but no harm in trying the easy stuff first I guess ?

Cheers, Paul

 

[9fingers]

There is no reason I can think of for an NVR of any type to require holding for any length of time. It should be instant.
So perhaps there is a build up of dust in the electromagnet gap which initially you were compressing to make it work and now is too thick for it to work at all.
If you can get inside, then a good clean out with compressed air, might do the trick. I would still try and get one under warranty - useful as a spare especially if it is one of the simple/crude ones** as they do have a habit of failing - but not progressively as you describe.

Bob

** see figs 18, 19 here http://homepage.ntlworld.com/bob.minchi ... Issue2.pdf

 

[Routermonster]

Bob and Paul

Your diagnosis was correct! Thanks for the link to your induction motor article.

I removed the switch from the bandsaw and unscrewed the yellow plastic surround to the 'emergency stop' button and black cover plate - and found that the coil and switch contacts were covered in fine dust. After blowing out the dust (I used a drinking straw) and reassembling, I hit the start button and it fired up instantly.

The above yellow surround is disintegrating, so I'll contact Record Power about a replacement.

I note that Axminster sell an equivalent switch (ref KJD12).

Thanks for your help.

Les

 

[9fingers]

I'm glad to hear that you are up and running once more!

Bob