Help-Powermatic Lathe 3520B proximity sensor

Re: Help-Powermatic Lathe 3520B proximity sensor

John K Jordan

Did you check for position and wiring? I read where someone had that problem and found the sensor had moved away from the spindle shaft somehow and it worked again when he pushed it back into place.

JKJ

Re: Help-Powermatic Lathe 3520B proximity sensor

Julian

Position and wiring all good. Checked all the wire connections and ensured the sensor was in position to pick up the corners of the locking collar.

Call Powermatic

Re: Call Powermatic

Julian

I have called Powermatic and all the guy in the technical dept. suggested was to check all the wiring. Not much help. They seem to want to sell parts more than help.

Re: Call Powermatic

john lucas

But it sounded like you need a part. I do agree it would be nice if they would help trouble shoot the problem.

Re: Help-Powermatic Lathe 3520B proximity sensor

Dale Gillaspy

OK, what exactly does the proximity sensor do? Is that what relays the speed of the spindle to the little LED display? If that is all it does, you could just as easily let it go. I have had my MM for 5 years, and mine only works intermittently now, I think. I say I think, because after about15 minutes of owning it, the novelty wore off, and I haven't looked at it since.

I get wanting everything to work right, and if you truly use it, OK. I go by the piece, not the number, so it is not a big deal to me.

Re: Help-Powermatic Lathe 3520B proximity sensor

gary jarvis

Last year I had the same problem. Powermatic said there is no adjustment just an assembly replacement. After taking the inspection plate loose I found by loosening the screws that hold the sensor in place it is possible to move it. The second time I moved it everything started working again and no problems since. Evidently a very small movement can make a difference.

Re: Help-Powermatic Lathe 3520B proximity sensor

Dick Hines

You mean people really look at the display. The only speed I ever paid any attention to was when buffing. I now have that marked on the speed control knob.

Re: Help-Powermatic Lathe 3520B proximity sensor

John C Lucas

I have the A series and the display is just mumbo jumbo on the back of the lathe so I never look at it. Never had a lathe with a speed display so I just adjust buy feel.

Re: Help-Powermatic Lathe 3520B proximity sensor

John K Jordan

The biggest value is at demos when someone asks what speed are you turning. "Ah, let me... 2837. Just be careful not to crank it to 2838."

JKJ

Re: Help-Powermatic Lathe 3520B proximity sensor

Julian

I did not have an RPM display on my old Delta lathe and managed to turn several projects over the years. Perhaps it more of a personal challenge. If I do manage to fix it, I will post my solution. Thanks for the feedback.

All of the....

Brian Roberts

"ya don't need it" remarks aren't much help....IMHO.

If it's on MY machine it needs to work.

Re: Help-Powermatic Lathe 3520B proximity sensor *LINK*

Bob Entwisle in NJ

I looked at an online 3520B manual and in that manual, the part number for the sensor is JWL1642-130S

Here is a link to the part on the Powermatic parts web site about 40 bucks.

https://parts.powermatic.com/SearchResults.aspx?s=JWL1642-130S

Hope this helps

Bob in NJ


https://parts.powermatic.com/SearchResults.aspx?s=JWL1642-130S

Re: Help-Powermatic Lathe 3520B proximity sensor

Josh Bowman

Here's an option. I've put a few of these on my machines.

http://www.ebay.com/itm/291122353744?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Re: Help-Powermatic Lathe 3520B proximity sensor

Julian

Bob, thanks for the info. That was helpful. I'll order the part.

Re: Help-Powermatic Lathe 3520B proximity sensor

Julian

Josh; Did you put one of these sensors on a PM3520B lathe? This is surprisingly cheap.

The length of the sensor looks like it might be a challenge to fit inside the small area where the current sensor is mounted. Thanks for the info.

Re: Help-Powermatic Lathe 3520B proximity sensor

Josh Bowman

No I have not, but the 1953 metal lathe and the Walker Turner drill press were far more of a challenge. There's actual a lot of room inside the PM 3520, but tight to access. But the sensor is not limited to inside, it could be mounted on the hand wheel. BTW, it comes from China and will take a few weeks to get here. If you go this way, let me know and I can give you more wiring info. I'd also order a wall wart power supply for it as well. Since it will work with a 9 volt battery, but that would be inconvenient to connect and disconnect and change. If your pretty handy, you might be able to find the power that the old one used.

Re: Help-Powermatic Lathe 3520B proximity sensor

Julian

Big thanks to Josh; for your suggestion to look on Ebay. I found several sensors that would work with the PM3520B and they only cost about $5. Have to order from China but with PayPal I felt it was safe and could wait the 2-3 weeks for delivery. But before I ordered it I decided to check the wiring and the sensor again. With the lathe plugged in I check the sensor. Touched a screwdriver on the sensor and it worked. Tapped the sensor lightly several times and the RPM display showed a number. I was determined to make this work. My mistake was I did not take a photo of the sensor attached to the small bracket. It took me several assemblies before I got the configuration correct and now the RPM display works as it should.

Re: Help-Powermatic Lathe 3520B proximity sensor

John K Jordan



>Touched a screwdriver on the sensor and it worked. Tapped the sensor lightly

>several times and the RPM display showed a number. I was determined to

>make this work. ... It took me several assemblies before I got the

>configuration correct and now the RPM display works as it should.

I am so glad you got it working. I considered suggesting you tap into the wires and check the actual voltage/signals but I didn't know your level of electrical expertise and what equipment you have, and I've never looked at that part of the circuit, what type of sensor it uses, and whether it could be debugged with a simple multimeter or needed a scope. If the sensor is a simple hall probe they almost never fail - the failure is usually in a connection or power or interface circuitry. The fact you had a zero on the display was a good sign.

JKJ