Smoked my new (to me) NSK Presto :(

[Scott Hackler]

Not literally but I did screw it up. I bought a used NSK Presto setup for carving on my next "big" turning project. This one must have come from a lab or something because the regulator gauge reads .1 to .4 mpa (???) Well I turned it up to .4, maxing it out and it has worked great ....for a while...

So fast forward and I start noticing that the handpiece is spit and sputtering once in a while. Then without warning it seemed to slow down to 1/8 speed with the same spit and sputtering. Just will not do the job that it is supposed to do...... SO... I ordered a 0-60 psi gauge and after receiving it today I went out and traded the gauges. The company states "not to exceed 35 psi), I pressured it up and SHAZAM it pegged out the 0-60 gauge. OOOOPS! :( Stinks but I am now sure that the turbine cartridge is shot and I am going to have ot spend $139 for a new one. Dang that was an expensive goof.

What really stinks in that since returning to the shop I have been working on this new sculpture/turning and now I am shut down until the new part. :(

Lessons learned.........

[Steve Vaughan]

Never used one of those, but that right there does not sound cool at all. Good luck with it all!

[Dan Hintz]

0.4 MPa is roughly 60 psi, so it juuuust pegged it... but it was still way too powerful.

[Scott Hackler]

Dan, where were you a few weeks ago? :) I figured that the top scale of the MPa would surely be max for the tool it was meant for! Guess not. But it was awesome for a while...... :)

Really stinks because I also was working on a little walnut turned box that I am turning into lace, with piercing.... at least I WAS...

[Doug Wolf]

Scott,
Sorry you smoked your turbine, but that brings up a few questions you could answer.

I just acquired a used Midwest "Quiet-air" hi-speed dental hand-piece along with hoses, control and foot pedal. It didn't come with any instructions and I've read about keeping the air pressure under 35 psi, but can't find any info on oiling maintenance.

Should I use oil? If so, how much? What weight of oil? How often? Etc. I also wondered if you used oil on your hand-piece, or doesn't it require it?

Thank for any help you can give me.

Doug

[Scott Hackler]

Doug, I don't know about your particular brand/model.... but the NSK Presto is a sealed turbine unit (no oiling). Also if you dont have a 0-60ish regulator and gauge, I would highly recommend getting one. I would assume that your unit was pre-regulated to the proper PSI prior to the dental chair, so you will need to have the proper PSI going into the handpiece or you might end up doing what I did. :( I did run it a little last night with the proper PSI and it does run a bit but its pretty rough. I am thinking my over pressure blew the oil/lube out of the bearings.

Gonna order a new turbine cartridge today, so I can be working on my project(s) possibly this weekend.

[David DeCristoforo]

Ow... ow ow ow! That's a bummer. I know just how you feel. That's a pretty expensive hand piece to hose on the maiden voyage. In all my years, I have never even heard of a "Megapascal Pressure Unit", much less seen a gauge that measures them! Scheeech!

[Dan Hintz]

David,

I see it most often in tensile strength measurements, but Wiki says it's often used for barometric pressure.

[Bob Bergstrom]

The guy who gave me a dental drill ( he sells them) gave me a can of lub that says use once a day. Max on the pressure is 40psi.