New PM3520A, 2 questions.....

================================== The larger option is the way to go. You're paying a substantial amount to get a lathe that will handle a large piece of wood. Why would you want to reduce the capability by a large percent? Remember that the strength of the steel is roughly prpportional to the square of the diameter. 4/4 vs 5/4 inch, or 16 vs 25. There are other factors to consider in determining strength, but why do it that way? The adapter won't be much additional weight on the nose of the Mini, plus it will already be well balanced, so it would be like adding a Super Nova chuck where you originally had an older Nova chuck. YMMV

Ken Moon Webberville, TX

amp is plenty. What do you say?<

The PM tech doesn't know what he's talking about. Your electrician friend does.

Steve Sarasohn

There are three kinds of people, those who can count and those who can't.

That's what I did. I bought a Jet 1442 last year and wanted to buy a chuck and some other accessories. I also plan to upgrade to a Woodfast, PM, or similar lathe in the not-too-distant future, so I chose to purchase a chuck and faceplates with 1 1/4" threads. I bought an adaptor from Jet to allow this to be used on my 1" spindle. Works like a charm. The adaptor was $65, but I'm guessing that one could be had for less.

Max

1. 20 amps is plenty - I run a 5 hp air compressor on a 20 amp (220)circuit and that is a heck of a lot heavier load than any normal wood lathe - maybe some behemouth that turns a 96 inch slab might need more, but nothing in the

According to the electrical guide, "Wiring Simplified", which is a comprehensive overview of residential wiring requirements, guidelines and methods, your 2 hp, 240V motor should pull about 12 amps. That means a 20 amp, 240V circuit using 12 gage running 70 feet total should be just fine.

When I wired my 240V circuit, I used 10 gage wire with a 30 amp breaker running less than 75 feet. Remember the breaker is there to only protect the wiring and not the appliance - in other words, size the breaker to the wire gage and length and not what's plugged into it. I chose to go larger than needed for my 3hp Unisaw so that I could also plug in my dust collector if I ever choose to convert that to 240V or a larger planer or jointer if my ship ever comes in.

(Also, the extra cost to go with 10 gage and a 30amp breaker was minimal when compared with needing to upgrade or add a second circuit if using

Owen Lowe wrote in news:onlnlowe- snipped-for-privacy@corp.supernews.com:

Ron, The PM tech may know PM lathes, but he doesn't understand electricity that well. Motors may burn out on a circuit that can supply too much current if the motor has a problem (bind, super catch, etc.) before it trips the breaker (blows a fuse). A motor will not burn out (or start) on a protected circuit that is rated too low for the motor (the breaker trips). 20 A is fine for your lathe. Regards, Hank

one correction to Henry's remarks - low voltage, caused by excessive drop in the feed lines for example, can in fact cause a motor to burn out, especially if it drops the speed low enough that the centrifugal switch engages the starting windings. However, I agree that you don't need to worry about it.

Not owning one, merely drooling, does it try to maintain a constant speed under load? I which case, might it increase and hold its current draw past the time tolerance of the breaker?

That is possible in a simple circuit but the variable-frequency drives (which do try to maintain constant speed) are very sophisticated and will sense such a condition and shut-down well before the motor would cook. This is probably built-into the circuit to protect the drive electronics more than the motor since they would be more likely to blow first. Also, while Noble is correct about the start windings in single-phase motors, in the AC variable-frequency case the power supplied from the VF converter is 3-phase so there is no start winding to my knowledge. Billh

One more correction. What you say is correct if we are talking about a single phase motor.

This lathe comes with a VFD and a 3 phase motor. So, there is no centrifugal switch because there is no start winding. One of the many advantages of 3 phase motors driven by a VFD

Bill R

aaah, didn't realize it has vfd. Given that, you really don't have to worry - every VFD I have seen has both a soft start (controlled acelleration) feature and a max current limit - These are user adjustable,though few wood turners mess with the parameters. I have a Delta VFD-B series drive on my Logan metal lathe - it's a 3 HP drive running a 2 hp motor - so I set the current limit to a lower value suitable for my motor. I also turned off the deceleration profile on "stop", so it would coast to a stop (that way the emergency brake would work), and I changed the accel profile to 15 sec from 30 because I'm impatient. On the other hand, I haven't messed with the parameters on my Stubby wood lathe.

single phase motor.

centrifugal switch because

snip-------

Thanks to all for your responses. I'm contiually amazed at the wealth of info and expertise on this board, and on the web in general. What did we do for research before having the internet? Probably went out and actually talked to people. LOL.

Ron

. . . or just blundered blindly into the abyss, whilst waiting for snail mail to arrive.

Max