Laguna Revo 1836 Electronics Problems

[Richard Coers]

Not sure of your intended target for "That's" in the horse pucky statement. Laguna's statement relayed from the drive manufacturer?

Electromagnetic interference through the air made one of my digital calipers unusable near my Powermatic lathe. I traced it to one of the LED task light bulbs at the lathe. The numbers on the caliper display would go crazy if it came within about 3' of the light.

JKJ

If that offending light was on your Powermatic lathe, why didn't that EMI shut down your lathe? You participate in a lot of forums John, when is the last time someone had a VFD controlled machine shut down due to EMI? A lot of praise for Laguna's new line of lathes, but poor Edward is the only one in the forums to have this issue at his residence. I'm very skeptical about that answer and that diagnosis from the manufacturer is horse pucky in my opinion. Now I know that the VFD can cause EMI issues with other electronics, but the manufacturer said it was EMI in his residence. A friend had to remotely locate his VFD that controlled a CNC spindle, because the manufacture of the CNC machine claimed there was interference creating lost steps in the stepper motor controllers. Shielded cable should resolve that issue, so don't know if the machine manufacturer failed to do that, or didn't ground the shielded cable properly. Now if they tell Edward to remotely locate his VFD, then I would understand and have faith that could be an issue. But no one else has reported issues on the Laguna lathes.

[John K Jordan]

If that offending light was on your Powermatic lathe, why didn't that EMI shut down your lathe?
...
... no one else has reported issues on the Laguna lathes.

Richard,

Bob Abernathy started this thread describing a problem with his Laguna 1836, - is the problem with his Revo resolved now?
Edward Weingarden reported a problem with his Revo 24-36 in this same thread - is his problem now resolved?
Joe Frank Porter also reported a problem with his 18-36 and told how he resolved it.
Don Davis on another forum described electrical problem on his Laguna 24-36 and how he resolved it - he sold his lathe.
Now Edward Wargo tells about his experience and the attempts to resolve it, and what Laguna relayed to him about possible electromagnetic interference.
(Maybe Laguna will share any other owner-reported problems, you think? )


This is what I know about electrical/electromagnetic interference from my own experience:
- Electrical interference can result from external magnetic fields, EMI.
- Electrical interference can come through the power supply line in the form of noise (irregular and often higher frequency voltage fluctuation).

Electrical devices can be affected by both types of interference due to a design or manufacturing weakness, or component or connection failure - even something as simple as a poor or intermittent ground connection on some component or the entire device.

None of us know any specifics about the environment Edward's lathe is in (or Bob's, or the other Edward's for that matter).

I also know nothing about the electronics, wiring, and shielding on the Laguna. Does it have a Delta VFD identical to those in the Powermatic, Jet, and some other lathes I am familiar with? (One hint that the electronics may be different is the comment about the relay.) If not identical, exactly what VFD does it use, how is it wired and controlled, and what are the weaknesses in the entire system? Don Davis said the electrician he sold his problematic Lagua to "re-wired the VFD" and that Laguna had used a low end VFD. But even the fact that other identical Laguna lathes do not have problems does NOT eliminate the possibility of electrical interference causing a problem with Edward's lathe.

My background experience is strong in debugging, in software, electronics, and mechanical hardware. There are severral ways to approach debugging a problem and somme are easy with a consistently repeatable problem, but an intermittent problem is the hardest. An easy approach with electronics is to substitute known good components - apparently already tried in this case.

Another way is to temporarily relocate the device in a known good environment. However it's difficult to locate another shop with the same model lathe, and move the lathe there for a suitable time. Better would be to temporarily swap lathes and see if the second one showed the same problem in the suspect environment - might be possible if Edward had a brother across town with the same lathe.

Another way is to postulate, to think of a possible reason for the problem - done in this case by the lathe electronics manufacturer with the guess of electromagnetic interference. A good starting point to prove or disprove EMI is to identify the type and strength. Discovering the type (frequency, noise, etc) can provide clues to locate the source.

There are instruments that will measure and locate EMI from external sources, both in close proximity and more distant. Since we don't have those instruments one approach is to test by adding additional shielding. If that works, then a permanent solution can be devised.

It is usually far easier to detect electrical noise on a power line, although it does require a common oscilloscope. If discovered, the best next step is to locate the source of the noise and eliminate it. Noise can come from anywhere, for example from a neighbor on the same transformer. If the noise is coming onto the property from the utility service they should be able to fix it. If the source cannot be found or fixed, a reasonable second approach is to filter the noise before it gets to the device.

If this were my lathe, with my background in electronics I would first test for electrical interference and if none found, disassemble as needed and examine the electronics carefully for component and connection issues. You never know - I once fixed a high-end computer system with one finger by reseating an IC that had worked it's way part way out of the socket. Three guys had been working on it most of the day by the time I got there but nobody noticed or even thought to look for that.

BTW, comparing the effect of the LED lamp interference on my digital caliper and my Powermatic lathe is not useful - think apples and oranges.

JKJ

[Roger Chandler]

The Laguna uses the Delta S-1 inverter, same as the Powermatic 3520b and Jet 1642 evs.

[Dick Strauss]

VFD manufacturers do suggest using shielded cabling if the runs are more than 25' or so because unshielded cables can pick up EMI over long distances. This can cause false low voltage triggering of the low voltage circuits and might lead to starting/stopping at random times. However, this should not be an issue in a shop because of the short cable runs unless you live near a radio transmitter or high voltage power lines, etc.

I once had a top of the line Alpine CD player refuse to play when I got within a mile or so of a broadcast tower on a mountain because of high level of RF levels.

[John K Jordan]

The Laguna uses the Delta S-1 inverter, same as the Powermatic 3520b and Jet 1642 evs.

That's great information, Roger, thanks! That's a healthy VFD. Does it have a cooling fan? Powermatic and Jet opted to not spring for the fan on the three lathes I have with the S1.

I forgot, do you have a Laguna? Our club is helping to buy a lathe for the turning program at a local children's ranch and I think they decided to get a Laguna.

JKJ

[Roger Chandler]

That's great information, Roger, thanks! That's a healthy VFD. Does it have a cooling fan? Powermatic and Jet opted to not spring for the fan on the three lathes I have with the S1.

I forgot, do you have a Laguna? Our club is helping to buy a lathe for the turning program at a local children's ranch and I think they decided to get a Laguna.

JKJ

John, I have a Delta midi, a Grizzly G0766, 3 hp, which uses the Delta “M” series inverter which is more advanced than the S-1, and also have the largest Grizzly G0800, 3 hp. which is made by Harvey, the same manufacturer of the Powermatics, and is comparrible in class to the PM 4224b...very heavy duty. The G0800 uses the Delta “EL-220 inverter” series. Premium features all the way.

[Edward Weingarden]

JKJ:
The issue with my lathe has not been resolved yet. I am now awaiting a second headstock replacement.

[tom lucas]

Rephrasing some of what john has already posted: EMI comes in two forms: radiated (through the air) and conducted. It would take a pretty powerful and close-to-the-lathe source for radiated EMI to cause an issue. On the other hand conducted interference could easily occur, caused by some other machinery or appliance, or even the neighbors', if they are on the same side of the transformer.

I suggest trying an isolation transformer at the tool. This should remove most conducted EMI. And also use a ferite bead on the power cord. That will remove high frequency noise and is a dirt cheap added layer of protection.

[Chris Hachet]

John, I have a Delta midi, a Grizzly G0766, 3 hp, which uses the Delta “M” series inverter which is more advanced than the S-1, and also have the largest Grizzly G0800, 3 hp. which is made by Harvey, the same manufacturer of the Powermatics, and is comparrible in class to the PM 4224b...very heavy duty. The G0800 uses the Delta “EL-220 inverter” series. Premium features all the way.

That seems like one heck of a nice heavy duty lathe.

[Roger Chandler]

That seems like one heck of a nice heavy duty lathe.

It Is indeed!

[Edward Wargo]

Today I had the opportunity to do some turning and decided to follow the advice offered in one of the posts following this blog. I taped over the red and green on/off switch and used the speed control knob to set the speed of the lathe. I did not have a single occurrence of digital readout failure and the motor never shut off. I know this is not a thorough test of the problem, but I can say that it was nice to use the lathe for about six hours without a failure.

[Edward Wargo]

Today I had the opportunity to do some turning and decided to follow the advice offered in one of the posts following this blog. I taped over the red and green on/off switch and used the speed control knob to set the speed of the lathe. I did not have a single occurrence of digital readout failure and the motor never shut off. I know this is not a thorough test of the problem, but I can say that it was nice to use the lathe for about six hours without a failure

[Edward Wargo]

William,
Thank you for sharing your experience. I have been following your suggestion for three days now and have not had a single episode of an erroneous digital reading, nor has the motor has stopped.

[tom lucas]

For what it cost you'd think they'd make it work as intended. Pity one has to tape over the switch to use the thing.

[William C Rogers]

William,
Thank you for sharing your experience. I have been following your suggestion for three days now and have not had a single episode of an erroneous digital reading, nor has the motor has stopped.

I have been operating this way also and now getting use to using the speed dial to stop the lathe.
john Keeton first posted this as how he uses his lathe

For what it cost you'd think they'd make it work as intended. Pity one has to tape over the switch to use the thing.

It is a much safer way to operate any lathe IMO. You are not starting at a high speed. The tape is only a reminder to use the speed dial to stop the lathe