Laguna 1216 Speed is changing by itself

[KMCloonan]

Has anyone had any issues with the Laguna 1216 lathe speed control? This morning I set up the lathe to turn a pen - when I turned the speed to the desired RPM it sped up, then slowed down, then sped up, without me touching the lathe. I switched the belt to the medium pulleys, and turned it on - typically the slowest speed on the medium pulleys is 324 rpm - mine went down to about 50 rpm, then sped up again, with the Digital readout showing 648, then 324...etc.

I called Laguna since my lathe is still under warranty until early October, but they were not available, so I left a message.

I thought I would check to see if anyone here has had any similar issues with their Laguna 1216.

Thanks

 

[Hippie3180]

Our Jet sometimes varies just a bit, but we think it's the extension cord and I know it jumps around a bit when sanding etc.

 

[KMCloonan]

Our Jet sometimes varies just a bit, but we think it's the extension cord and I know it jumps around a bit when sanding etc.

Mine is not varying by a bit - it's slowing almost to a stop, then speeding up. Also, when it seems to level off on RPM, the digital readout keeps changing up and down with nothing touching the lathe.

 

[Hippie3180]

Mine is not varying by a bit - it's slowing almost to a stop, then speeding up. Also, when it seems to level off on RPM, the digital readout keeps changing up and down with nothing touching the lathe.

I am by far an expert but seems I've heard something about the control box on variable speeds being a issue.

 

[Edgar]

I don't know anything about your lathe, but I sometimes have a similar problem with my NOVA DVR. Dust can get inside the lathe and interfere with the optical speed sensors. When it happens, I have to take the rear plate off the headstock and blow compressed air into & vacuum the inside of the control box.

 

[KMCloonan]

I don't know anything about your lathe, but I sometimes have a similar problem with my NOVA DVR. Dust can get inside the lathe and interfere with the optical speed sensors. When it happens, I have to take the rear plate off the headstock and blow compressed air into & vacuum the inside of the control box.

Thanks Edgar - I wondered about that - I looked inside the headstock and it is a bit dusty. I will blow it out and see if that helps.

 

[jttheclockman]

Blowing dust out of control box is always first target. But sounds like a control board problem.

 

[Sataro]

I've had no issues like that with my Laguna 12/16. Had those issues with my Delta lathe. Shot of air blowing dust out & all back to normal.

 

[randyrls]

Kevin; I do NOT have this lathe, but it appears to have a DC motor. Two sources of issues are the optical speed sensor, and the speed control potentiometer. I'd wait and see what Laguna has to say. Keep us posted.

Least Likely is the optical sensor. I'm not sure if the Laguna has one.

Most likely, The speed control isn't sealed and can get sanding dust inside the control.

 

[greenacres2]

Had those symptoms on my little Delta (46-460) started a few months after the speed control was replaced under warranty--the speed control issue was random up & down, but never got crazy slow. The second time were almost exactly the same as you describe, and turned out to be a broken potentiometer. I was a few months out of warranty, did a little reading and u-tubing--learned how to tell what "pot" to get and for about $5.00 was back in business. The factory knob didn't fit the new pot, but it was just numbers 1-9 anyway. Little knob that came with the pot is fine, and is less likely to get hit since it is smaller--less likely to break another pot.

Good luck!!

 

[egnald]

Of course, go with whatever the manufacturer has to say, but if I were to let my 1970's electronic tech kick in, I would try taking the knob off and spraying some contact cleaner in the potentiometer, especially if it was more stable at different speeds. - Dave

 

[KMCloonan]

Thanks everyone for your input. I started up the lathe last night, and it seemed to work ok. It accelerated and decelerated acceptably, and held a constant speed. I plan to blow out the headstock anyway, and I like the idea of cleaning out the potentiometer as well.

I looked at the operations manual, and for the RPM sensor it says "Works very similar to a Laser Tachometer to relay the ACTUAL rpm of the spindle", so dust or crud can definitely mess things up.

I also hope to hear back from Laguna tomorrow when they return to the office.

 

[KMCloonan]

Laguna did call me back yesterday - Nice fellow - Rick. I described the symptoms, and how the symptoms went away when I took Edgar's advice and blew compressed air into the headstock pulley chamber. Rick commented that that would have been his first suggestion. He seemed glad to hear the lathe is now working properly, but he left me his direct phone # in case the lathe starts acting up again. I would call that decent customer service.

Thanks again to everyone here for your advice - thanks to Edgar for leading the pack.

 

[KMCloonan]

Well, it happened again. This time the Digital Readout jumped around, but the actual RPMs seemed consistent, so I was trying to finish a pen I had started, when the lathe shut down. I unplugged it. plugged it back in, turned it on, turned the potentiometer knob up & down and after about 5 seconds, the Digital Readout started jumping around, then an "ERR3" code, and shut down.

I contacted Rich from Laguna, got his voicemail, so I described what the lathe was doing, and asked for next steps. He sent an email the next morning, apologizing for not answering my call, as he was on Holiday. He told me he was shipping me a new RPM Sensor which is on its way to me.

The only downside is I need to remove the faceplate from the control panel to get at the sensor, and also remove the control board from underneath the lathe to unplug the sensor and reinstall everything once I have plugged in the new sensor into the control board. The pictures Rich sent showed a 1216 lathe lying on its side to get at the control board from the underside. This sort of implies I need to detach my lathe from the stand, and lay it on my workbench. This sucker weighs about 100lbs, so that's not a lot of fun. I may try removing the control board while still on the stand, if it's feasible.

I think I will also go ahead and swap out the bearings while I have it torn apart - I posted last year about the REVO 1216 headstock bearings getting pretty hot - I have not yet replaced them, they are not making noise, so I just let them get hot (very warm). The do weep a little lubricant over time.

Wish me luck!