Leave your inverter alone.

[Chris Rauber]

The previous owner of my Robust had turned the lathe down by altering the parameters in the VFD. I knew this when I bought it but it didn’t bother me until I tried to turn small spindles and the lack of speed drove me crazy. I contacted Brent and got their settings sheet and printed off the Toshiba manual and altered the parameters…this was a week ago. Brent and I have exchanged 10 emails since then and I’ve spent 15-20 hours trying to diagnose and fix why I can’t use my lathe controls but can use the on board inverter start and stop and speed dial. It’s looking like I’m going to be sending my inverter in and having them reset it and going from there. Learn from my mistakes and just leave your VFD alone.

 

[Joe Kaufman]

Good advise. Reminds me of a neighbor. His business sells inverters (VFD's) and his position is not to sell to individuals for personal use because it requires too much after sale "hand holding". The profit margin is not there for a single unit sale. It's nice of Brent to continue the support when the inverter "seal was broken" so to speak. I hope you get it running correctly w/o too much additional trouble.

 

[Bob Brown]

The previous owner of my Robust had turned the lathe down by altering the parameters in the VFD. I knew this when I bought it but it didn’t bother me until I tried to turn small spindles and the lack of speed drove me crazy. I contacted Brent and got their settings sheet and printed off the Toshiba manual and altered the parameters…this was a week ago. Brent and I have exchanged 10 emails since then and I’ve spent 15-20 hours trying to diagnose and fix why I can’t use my lathe controls but can use the on board inverter start and stop and speed dial. It’s looking like I’m going to be sending my inverter in and having them reset it and going from there. Learn from my mistakes and just leave your VFD alone.

Did you ask the former owner if he made notes.

 

[Mike Johnson]

A list of factory parameters can be easily compared to the existing parameters set up on the VFD.
If the VFD has a display and keypad you can manually scroll through the parameters and write each one down on paper.
If the VFD does not have a display, a computer, software and interconnecting cable is required to view and change parameters.
You can also save the VFD settings file to your computer and review the parameters on the computer using the factory software
which is quicker and easier then scrolling through the VFD display using the keypad.
There should only be a dozen or less parameters to mess with on a typical lathe application.
All of the other parameters would be the factory default.

 

[Dean Center]

One of the parameters tells the VFD what controls to respond to. One setting is the VFD and another is the lathe controls. (I think there are a couple of other options, depending on the VFD) Your VFD manual should say which parameter and setting to use.

 

[Richard Coers]

Better subject title would be don't change it if you don't know what you are doing. They are made to be changed.

 

[Don Wattenhofer]

Better subject title would be don't change it if you don't know what you are doing. They are made to be changed.

Good call Richard. It is very easy to customize most VFD's via the built in key pad and there is no reason that you shouldn't unless you don't understand what the parameters mean.

 

[Tom De Winter]

I agree with Don & Richard. I've replaced and programmed VFD's on lathes. However I would discourage making changes unless there's a good reason to change something.
I'd like for my Jet 1840 to run a little slower but I'll trust the design engineers to know and program the minimum rpm that's safe for the system.

 

[robo hippy]

I have one of the early AB's from Brent, and it has 3 speed ranges. I had Brent help me adjust the parameters so that minimum speed was much lower than the 50 rpm that some manufacturers seemed to think was appropriate. Their concern was that the motor would over heat being run at slow speeds. Brent urged caution when using the slow speeds. I checked temps by putting my hand on the motor as I sanded, which is the only use I have for 10 to 15 rpm, though some use it for thicker finishes. It runs cooler than when I am roughing bowls. That was the 'reason' that PM gave to me when I asked them why they bumped the turn off speed to 50 rpm minimum. As far as I can tell, since the lathe is in idle speed, over heating is a total non issue.

robo hippy

 

[Bill Boehme]

I have one of the early AB's from Brent, and it has 3 speed ranges. I had Brent help me adjust the parameters so that minimum speed was much lower than the 50 rpm that some manufacturers seemed to think was appropriate. Their concern was that the motor would over heat being run at slow speeds. Brent urged caution when using the slow speeds. I checked temps by putting my hand on the motor as I sanded, which is the only use I have for 10 to 15 rpm, though some use it for thicker finishes. It runs cooler than when I am roughing bowls. That was the 'reason' that PM gave to me when I asked them why they bumped the turn off speed to 50 rpm minimum. As far as I can tell, since the lathe is in idle speed, over heating is a total non issue.

robo hippy

When the motor speed gets really slow, the effiency gets really low which means that most of the electrical energy is converted to heat. To make matters worse, the ducted fan at the back of the motor isn't able to do any meaningful cooling at thirty RPM. This would be a concern if you were coring or roughing bowls at such a slow speed, but for sanding it shouldn't be an issue.

The other issue with running at extremely low speed is that the latency in feedback data causes closed-loop speed control to become erratic. It's not too bad for a light-load condition like sanding, but for medium to heavy loads the speed would become unstable which would probably trip a fault flag and cause the inverter to shut down.

The manufacturer doesn't know what the end user will be doing with the lathe so it would be foolish and irresponsible of them to intentionally design an in-warranty failure mode.

 

[Tom De Winter]

I've noticed that at minimum rpm the motor runs cool but the cooling fan on the inverter turns on and runs for 5 or 10 minutes after turning the lathe off.
Sanding or finishing is the only thing I do at slow speed.

 

[Marvin Jones]

I recently replaced the old Delta in my 3520B, the manufacture date was October, 2005 and I bought it March 2006. I have replaced the spindle and motor bearings so have been in every opening in the headstock. I have always disliked the way Powermatic used electrical tape to isolate the wires. When I reinstalled the motor, I bundled the wires a little tighter then put everything back together. Yesterday I was roughing in some bowls and the lathe would not stop rotating at zero potentiometer setting. It was rotating about 1 RPM or less. I could hit the shutoff switch, wait a minute and pull it back on and it would stop turning until I moved the potentiometer again. I grabbed the tiny but thick manual to the new LaPond VFD and went through the trouble shooting section and found nothing. Then I thought maybe the potentiometer was failing but it would ramp up and down smooth as glass forward and backward. Then I thought maybe I messed up the wires when I tightened them up so I removed what I installed and the lathe acted perfectly normal. I finished roughing in the bowl I had on the lathe with no further issues. TICKY TICKY Powermatic potentiometer, I'm guessing.

 

[robo hippy]

I did notice that my AB, when turned down to lowest possible speed for sanding my warped bowls can be a little jumpy for constant speed. My Vic 240 is not, and it will go slower than the AB.

robo hippy

 

[Marvin Jones]

On the original drive, my lathe's lowest speed was about 30-50 RPMs, on the new drive, it will slow to barely turning, no torque but perfect for wiping on poly. Smooth turning though. Powermatic may have set the Delta up to protect the motor, guessing...

 

[Don Wattenhofer]

I did notice that my AB, when turned down to lowest possible speed for sanding my warped bowls can be a little jumpy for constant speed. My Vic 240 is not, and it will go slower than the AB.

robo hippy

That may be due to the quality of the motor, I have a similar problem with a 2 HP Chinese motor that saved me about $100.00 over a Baldor when repowering a lathe that had a stepper motor originally. The motor that I used to upgrade my Powermatic 90 is a Baldor with a TECO VFD and that will operate smoothly down to 50 RPM.

 

[R Henrickson]

That may be due to the quality of the motor, I have a similar problem with a 2 HP Chinese motor that saved me about $100.00 over a Baldor when repowering a lathe that had a stepper motor originally. The motor that I used to upgrade my Powermatic 90 is a Baldor with a TECO VFD and that will operate smoothly down to 50 RPM.

My AB has a Baldor motor

 

[robo hippy]

My AB has a Leeson motor on it. Not sure if it is as good as the Baldor or not. I do know Brent 'upgraded' his motors, but not sure if all of them are Baldor or not any more. Mine is one of the very early ones. It didn't have handles for the sliding headstock, but 2 nuts that you had to use a wrench on. Had that set up replaced. I do prefer the 3 speeds to 2. The mid range is 'not to slow, not too fast, just right' for almost all of the turning I do. Low range for sanding.

robo hippy

 

[Jim Woods]

The previous owner of my Robust had turned the lathe down by altering the parameters in the VFD. I knew this when I bought it but it didn’t bother me until I tried to turn small spindles and the lack of speed drove me crazy. I contacted Brent and got their settings sheet and printed off the Toshiba manual and altered the parameters…this was a week ago. Brent and I have exchanged 10 emails since then and I’ve spent 15-20 hours trying to diagnose and fix why I can’t use my lathe controls but can use the on board inverter start and stop and speed dial. It’s looking like I’m going to be sending my inverter in and having them reset it and going from there. Learn from my mistakes and just leave your VFD alone.

When I converted my Nova 1642 to VFD, I realized the value of making changes one at a time after initial set-up so they could be reversed if I had unexpected results. Mine runs from 6hz to 90hz (10% to 150%)

 

[Emiliano Achaval]

For very large pieces I change the braking speed. I have installed about 3 VFD's so far. They are programmable for a reason, LOL

 

[robo hippy]

Hmm, don't want to attempt that. I do remember with my 3520A when I first got it, when turning bowls in the high speed range, it would trip the breaker when I turned it off with a larger bowl blank on. Started turning in the low range and the problem went away. This is another reason why I like the 3 speed ranges on lathes. Low range is too slow, high range is too fast, and mid range is just right.

How many speed ranges/pulleys does the Stubby have?

robo hippy

 

[Don Wattenhofer]

For very large pieces I change the braking speed.

That would be the deceleration parameter time. Rapid deceleration of a heavy load can cause an overload, but most VFD's have a provision for connecting breaking resistors to absorb that overload current during deceleration.

I do remember with my 3520A when I first got it, when turning bowls in the high speed range, it would trip the breaker when I turned it off with a larger bowl blank on.

The overload is a function of the VFD sensing an overload and shutting itself down which results in the load coasting to a stop
I am not sure but I thought that the Powermatic's had the breaking resisters.
The use of braking resisters on a wood turning lathe I would think could possibly cause the chuck to unscrew so you might want to get out of the range of fire when shutting down a heavy load.