Accidently reversed my PM3520

[Bill Siler]

While my PM3520B was running in the forward direction, I accidentally toggled the reversing switch, without first turning off the lathe. The lathe simply came to a normal stop and then ramped up to the same speed in reverse. Is this a bad thing to do?

Bill Siler

 

[Mark Mandell]

Risk

Of spinning your mounted workpiece off the lathe at you, but it won't hurt the motor. Your VS drive is designed to do what it did.

 

[hockenbery]

You won't get a very good cut with it running backward.

Every once in a while a student will call me over. Their tool just won't cut and they just sharpened it. I announce they have met up with a common problem, switch the lathe to forward. we have a good laugh.

happy turning,
Al

 

[Steve Worcester]

The VSD (variable speed drive) is programmed to brake at a certain speed and then accelerate in the new, desired direction and speed.

It won't hurt anything, and if you have allen screws on the faceplate or chuck fastened down to the spindle, it won't even spin the piece off.

Lesson learned, go turn sommore!

 

[Ed_McDonnell]

After reading comments from other PM owners who have changed directions on the fly I decided to give it a try. Worked just like everyone said and it didn't seem to hurt anything. But it just didn't seem right to me. I can't bring myself to make a regular habit of switching on the fly. I still let the lathe spin down, flip the direction switch and then turn it back on.

I only run it in reverse for sanding difficult areas anyway, so stopping gives me a chance to check things out and see where work might be needed.

Ed

 

[Ron Sardo]

Ed, I'm with you, I would have to stop the lathe before spinning it in the other direction. Call it a neurosis.

Ok, here is another question for you 3520 owners.

Do you use the on/off switch every time you want to stop the lathe or do you just dial down the speed to zero?

 

[Martin Braun]

Depends on what I'm doing. If I am slowing down to sand, and just running a few 100 revs, then I'll just turn to '0' when I'm switching sanding disks. If I'm actually turning something, I'm more likely to use the on/off switch. I always make sure that the speed is set to zero & the switch off before I leave the lathe for any significant period of time - don't want any surprises later.

 

[Bill Hunt]

What Martin said.
Bill

 

[turner23]

PM Reverse

Ron,

I only use the 'on/off' switch when I begin and end working in the shop. I was told that the original 3520s had an issue with their switches and went bad on occasion, so on that model, the less you used it the longer it would last. I haven't heard anything about the switches (or buttons, I guess) on the 3520B, I assume there is no problem but I continue the habit. The other reason I always start and stop the lathe with the dial is that it COMPLETELY eliminates the chance of accidentally start the lathe in high speed possibly damaging the lathe, work-piece, or operator. I've heard too many stories about people turning spindles, switching to bowls and forgetting to check the speed before turning on the motor...My approach avoids the possibility altogether.

Cheers!

 

[Ed_McDonnell]

Well, how about this one. How many PM owners leave their machine powered up all the time. I don't have a switched outlet so I actually unplug the machine when I'm done using it. I started to do it during the summer because of the frequent lightning storms, now it's just a habit.

I'm trying to decide if powering the inverter up and down each day (sometimes a couple times a day) is more of a wear on it than leaving it on all the time?

Ed

 

[blackhorse]

Ed, I do what you do and have the same question. Have been meaning to put a switch between the plug and machine but...

BH

 

[Martin Braun]

Yeah, that is a very good tradeoff question. I have often thought about putting a switch between the lathe & the line, but we generally have so few lightning strikes by me that it just hasn't made my to-do list yet.

The other thing I was thinking of - I have not reprogrammed my inverter for faster startup/slowdown. I would imagine that if somebody has, than it would definitely be a good idea to use the speed control for on/off/ramping, instead of the on/off button.

By the way, when I first got my lathe I tried the forward/reverse switch while it was running, though I did not have a blank mounted, just the chuck. I remember thinking at the time, "wow that was not as eventful as I thought it was going to be! "

 

[Barbara Gill]

It will not hurt my Oneway to reverse without stopping but since it goes against everything I have been taught I stop it first. When I leave the shop I pull the breaker. When thunderstorms are a possibility I also unplug. We can have some fearsome storms. I am afraid that a direct hit on the lines might allow the surge to jump the open breaker.

 

[pfduffy]

switching my 3520

Ed, I'm with you, I would have to stop the lathe before spinning it in the other direction. Call it a neurosis.

Ok, here is another question for you 3520 owners.

Do you use the on/off switch every time you want to stop the lathe or do you just dial down the speed to zero?

Ron, I use my on/off switch all the time and it seems that I need to: the switch hangs up a bit with dust inside and I like to keep it crisp so I push it in and pull it out at every turning phase of work. The idea of using only the speed control as an off/on is a good idea and I may see if my brain will accept the change. I did switch the direction one time, like Barbara, and it made me very nervous but I did not accept the fact that it all worked like smooth butter. Phil

 

[Bill Pottorf]

Barbara is correct. I also use my Oneway reversing switch at slower rpms without using the on/off switch only for sanding and to remove or add buffer wheels. The key here is SLOWER RPM. It will not hurt the motor or controller. As for just switching off the power to the controller during lightning storms, ALWAYS UNPLUG THE LATHE. Power surges burning up the controller when jumping any switch is not worth the cost and is fairly long term down time to repair. Try it and find out. I always unplug my lathe EVERY TIME I AM QUITTING FOR THE DAY REGARDLESS. Just good practice.

 

[Ed_McDonnell]

I agree it's a good practice and I do it religiously. But in my experience, a computer that is turned off and on regulary is much more likely to fail than one that is never turned off. I would never leave the lathe plugged in unattended during our storm season, but the rest of the year the power supply is rock steady. I can't help but wonder if I'm shortening the life of the inverter / controller by plugging and unplugging when lightning isn't an issue.

Ed

 

[KurtB]

Pm3520

Ed,
When I bought mine from Osolnik Machinery, I asked them if it made any difference to the controller if it was left on all the time. They said they had one at their shop that had had full power to it from the day it was uncrated, going on 6 or 7 years. That said, I still wired a double pole, single throw switch in line on mine, and turn it off every time I leave the shop.
KurtB

 

[jdsilwones]

I'm not a linemen but I do not believe that a lightning hit would make it to the house system unless it was on the power-line between your house and the street transformer, but that section is insulated (code) and so the chance of a hit there is small.
I need to revise this. When I say the strike probably wont make it to the house I mean the high voltage spike, not the surge that normally kills electronics.
A disturbance in the line from most events will not make it across the open contacts of a switch. In my experience with electrical and electronic equipment in an industrial setting, we never had equipment damaged by power events unless it was on. Remember that most newer electronic equipment is on even when turned 'off' .
BTW, my Vicmarc has an on/off and forward/off/reverse switch. When sanding I'll often flip the direction switch, hit the stop and then start button, then be back sanding as the machine stops and then reverses. The drive computer ignores the reverse instruction until it sees a stop/start command.

 

[Gretch Flo]

turning power off

I unplug mine, just to be on the safe side. Just so I don't forget I plug it and turn the radio on right by each other.-even in non thunderstorm weather. By the way we could get thunderstorms monday 1/7/08 with 50 degree weather in Michigan!!!! So if I leave the shop and hear the radio, I know it isn't unplugged. Gretch

 

[Ron Sardo]

But in my experience, a computer that is turned off and on regulary is much more likely to fail than one that is never turned off.
Ed

I always turn off computers. Between my business and home I have at least a dozen computers. The oldest one is getting near 10 years old. Still going strong. I had a Dell die on me after 6 months of use. I think turning them off or leaving them on isn't really a issue.

I'm not a linemen but I do not believe that a lightning hit would make it to the house system unless it was on the power-line between your house and the street transformer, but that section is insulated (code) and so the chance of a hit there is small.

I had a lighting strike a few years back. It took out a TV, VCR and a well pump. We had surge protectors on our refrigerator and computers. The surge protectors where all fried but saved the appliances.

Are there surge 220v protectors?

 

[robo hippy]

As far as using the speed control for turning the lathe on and off, I like it. I never have to worry about starting up a bowl at 1500 rpm. Some times in the haze of production, I have forgotten to turn the speed down. However, I have found that the standard factory set braking time of 5 seconds will trip the reset button on the lathe for anything running at full speed (spindles or bowls) almost every time. I had the time set up to 8 seconds and no problems. I need to experiment with other braking times (6, and 7 seconds). I have had my 3520A model for about 8 years. I wore out one speed control knob at 7 years, and have almost worn out the on/off button (it is getting hard to push and pull, and there is a slight crack in the plastic housing. I do use my lathe a lot, I wore out one set of headstock bearings about 3 years ago.
robo hippy

 

[Ron Sardo]

Where do I find information on how to program the controller?


I was just thinking as i was turning... you know on a car radio there are presets that you can program for different stations. Wouldn't it be nice to have a few buttons to program a few different speeds?

 

[Jerry Hall]

For 4 years I have disciplined myself

to turn it off every day. I manage to do it about one day out of 30, maybe. No problems so far. I am better at powering off my shop when I go on a trip. One time I didn't my dust collector came on spontaneously and drove my neighbor crazy with worry. An email exchange gave him access to turn it off.

 

[robo hippy]

To program your converter, you have to call tech help through PM. They don't include that info in your tool manual because they are afraid that people will mess it up.

robo hippy

 

[Barbara Gill]

I'm not a linemen but I do not believe that a lightning hit would make it to the house system unless it was on the power-line between your house and the street transformer, but that section is insulated (code) and so the chance of a hit there is small.
I need to revise this. When I say the strike probably wont make it to the house I mean the high voltage spike, not the surge that normally kills electronics.
A disturbance in the line from most events will not make it across the open contacts of a switch. In my experience with electrical and electronic equipment in an industrial setting, we never had equipment damaged by power events unless it was on. Remember that most newer electronic equipment is on even when turned 'off' .

I had to chuckle (nicely and without malice) at your response because it is based on an urban assumption. I live on a large farm with lines that go across open fields. It is not unusual for lightning to cause a major surge. In may case with old lines and old wiring I think a major surge would have no problem at all jumping that little gap. Plus my shop is at the other end of the farm away from my house. I am not a lineman either which gives me a good idea. I will ask my local lineman if i should anticipate a possible problem. Yep, we are so rural I know the lineman.

 

[Jake Debski]

Like Barbara, I live in a rural area. We don't get what I would call excessive lighting but we get our share. Power surges during such storms are common, and I have some replacement bills to prove it. I switch(line feed) every evening and unplug during storm seasons. I don't know how much a 3520 controller costs but I have no desire to find out either.

 

[Bill Boehme]

........The other thing I was thinking of - I have not reprogrammed my inverter for faster startup/slowdown. I would imagine that if somebody has, than it would definitely be a good idea to use the speed control for on/off/ramping, instead of the on/off button.

By the way, when I first got my lathe I tried the forward/reverse switch while it was running, though I did not have a blank mounted, just the chuck. I remember thinking at the time, "wow that was not as eventful as I thought it was going to be! "

Where do I find information on how to program the controller?

If one of you gentlemen would provide me with the model number of your controller, I believe that I can provide you with a PDF version of the operating manual.

To program your converter, you have to call tech help through PM.

It depends on whether they have a lockout code set on the controller. If there is one, you can normally disable it, but it would also mean that the parameter settings would all revert to their default values.

If you are not a qualified technician or a controls system engineer or otherwise reasonably versed in this field, you could be creating a mess for yourself by diddling with something that you don't quite understand what you are doing.

These controllers usually have many control options available that are not being used. For instance, you might want to have a number of preset speeds available that could be accessed at the push of a button (OK, I know that this sounds a bit wonky -- you want to get away from the limitation of fixed speeds that you have on a stepped cone pulley lathe, so you buy a lathe with electronic variable speed control to get infinite control -- only to program in a set of fixed speeds -- go figure).

On a more practical note, you may want to change the ramp-up and ramp-down accelerations or even create a special speed profile.

 

[Rich L.]

3520B turned on

I tend to leave my lathe plugged in and turned on. No kids or strays in the shop and lightning is not a concern here.

 

[Sky]

I installed a wall switch to shut off my 3520A 6 1/2 years ago but rarely use it due to the very strong lightening storms here in South Florida. Unplug it every time when leaving.