Bandsaw NVR Switch

[paulm]

Do NVR switches fail ?

Went to do a quick cut on my Startrite bandsaw yesterday afternoon and it didn't really start running, now neither the red nor the green buttons seem to do anything, no positive action to either of them when pressed.

Are they serviceable at all or should I take the internal bit to my local electrical factors and try and get it matched up ?

Suspect it needs a new one but thought I might ask here before trying to track one down.

Cheers, Paul

 

[sooty]

I have had this happen a couple of times on my perform lathe.

It's usually a build up of fine wood dust on the contacts of the switch and its quite a simple job to clean them, the contacts are usually protected by a plastic cover,with a little care you can slide this out of the way and clean the contacts.
I just reverse the vac and give them a blow of fresh air does the trick nicely.
Please if you do this be shure to make a drawing of the wiring at the back of the switch for re-assembly.
Good Luck
Phil

 

[paulm]

Good tip Phil.

The inside of the switch casing and the contacts etc looked pretty clean so I don't think it is likely to have been that, but will give it a blast with the airline anyway tonight to be sure.

Cheers, Paul.

 

[Timmo]

I have found this on my Record BS250 bandsaw a few times and tracked it back to a slightly dodgy buzz bar (extension lead) that I was using where the contacts were not being made correctly..I wiggled the plug and then it worked fine...
You have probably checked this but but it might be worth checking for a dodgy connection in the plug or a blown fuse...
Sorry if you have already checked these..but from experience of the problem this was the cause for me...
Cheers
Timmo

 

[misterfish]

Do you use the foot brake? On my 352 I find that after using the foot brake it takes several attempts to get the motor to run - I think the mechanical interlinks between the pedal and the switch need cleaning/lubricating but have not yet 'got around' to sorting it out; I just don't use the foot pedal.

I'm also not sure if you get any reaction at all when you press the green button - I know it's obvious but have you checked the fuse to make sure power is actually getting to the saw?

Misterfish

 

[dickm]

Do NVR switches fail ?

Are they serviceable at all or should I take the internal bit to my local electrical factors and try and get it matched up ?

I've not yet had an NVR fail, but they certainly can, if the solenoid goes open circuit or, possibly, the contacts burn over time. But as others have suggested, dust (especially on a bandsaw) can be a b***er. Certainly worth giving everything round the switch a good cleanup. But if it's a fault internal to the NVR, then replacement is almost certainly the only answer.
One difficulty then may be the age/make of the NVR. It's only in the last 10 years or so that there seems to have been much standardisation/interchangeability with NVR components, and if it's older than that, you will probably find that direct replacements are hard to source.
What saw is it, BTW? On the old Startrite 352s, the NVR was pretty much naked inside the column, so was almost bound to get dusty. But at least there was space to play about with alternative switches, and if it has the mechanical brake interlock like mine, you don't get microswitch interlock problems

 

[paulm]

Thanks for the advice and ideas guys.

Can't get to it tonight but will first of all cheque the fuse which thinking about it I didn't actually do

Don't think dust will be the problem as the nvr is mounted on the outside of the column in a sealed dustproof box, and it looks clean enough as far as I can see.

Hope it isn't the fuse as then I will be really embarrassed, but at least I wouldn't need to splash on a new switch !

Cheers, Paul

 

[Nigel]

Paul
some bandsaws like mine have an interlock switch connected to the door which can play up and give the same symptoms,

Cheers Nigel

 

[Digit]

I've had two fail, both on TSs. One failed on the brake ciruit, probably from age, and the second from new on my SIP TS.
It didn't always turn off! Nasty.

Roy.

 

[paulm]

Now sorted

Having taken some time to think about it properly and do some proper basic checks, I'm embarrassed to admit that all that was wrong was a fuse in a plug

But it wasn't that obvious, honestly :roll:

Turned out it wasn't the bandsaw plug, it was the extension piece I had run to the saw that had it's own plug that had blown it's fuse.

So all fine and working again now and I am also now more familiar with the switchgear and stuff in case it ever does need replacing in the future, so it was a good thing really, honestly :roll:

Thanks to all for the suggestions.

Cheers, Paul

 

[davegw]

I've had two fail, both on TSs. One failed on the brake ciruit, probably from age, and the second from new on my SIP TS.
It didn't always turn off! Nasty.

Roy.

Roy

I'm curious - having just bought an SIP lathe - what was the customer service like? did they replace?

Dave