This post contains updates and corrections to information presented in my original Delta 46-756 lathe review.
The VFD controller information, in particular, is relevant to Powermatic and Jet EVS owners as well, since it turns out they all come from the same factory as the Delta units. Primary differences lie in the varying degrees of eloquence in implementing the units into the final product.
Don't care? Don't own one? Stop here... Otherwise, on with the show...
This has not been Block and Wrecker's week. It _has_ been faulty spreadsheet engineering/bean counter week. A combination of Router and Lathe failures have left me annoyed at the ongoing downward spiral of US manufacturing, engineering and support. It's mostly a mess useless marketing and bean-counting morons...
Since the PC890 series router was recalled due to shorting motor windings, and they resisted mailing a replacement, I had to drive 40 miles across a very crowded and unpleasant city to exchange the US assembled router body for a new "improved" Mexican assembled unit at a factory outlet. The replacement was new, and is an almost identical unit, with the same imported parts - Now with Imported Labor. Only the armature seems different. Let us hope that the words "pressure impregnated windings" were mentioned in a conference room somewhere along the way.
But the pièce de résistance was the failure of the new lathe, which prompted a long, twisted journey into the bowels of B&D customer service and various Tinglish VFD spec/programming manuals.
Turns out there exists in this lathe an intermittent condition which causes the lathe to go into runaway mode, whereby the spindle speed jumps to maximum programmed AC drive Master Frequency and the stop button refuses to respond. Only by flipping the BRS (Big Red Switch, a distant relative of the BOS which existed on the original IBM PCs) are you able to shut-off power and stop the unit. It is an interesting experience to have a 12" segmented vessel unexpectedly whiz up to 3000 RPM - especially when the stop button doesn't respond.
Did it consistently for two days, so I got online and discovered the wretched abortion known as ServiceNet. This has got to be the worst online ordering system I have ever used. Additionally, the newly converted PDF parts layouts suffered a severe loss of resolution. Glad I downloaded my older stuff before the Big Sellout. I then discover the needed part is on backorder until January 16, 2007.
And that the replacement sells for $772.39 !!! Holy Guano, Batman - I hope you get a reach-around with that!
So I call support and talk to the "engineer" who states that the mysterious "F" which is constantly displayed represents a fault condition, and that I need a new VFD controller due to the runaway condition - shucks, they saw this exact same problem just a few days ago. Their computer shows it to be backordered till, you guessed it, Jan 16, 2007. Bought a lathe to do Christmas gifts, but it won't work properly until after the New Year. Hmmm....
Being insatiably curious about such things, I asked who OEM'd the controller and got an evasive/unknowing answer to the effect that, "parts come from all over the world, and there is no one nameable manufacturer of the VFD." Wrong answer, dude. Been in the electronics business for many years, and I know that is utter BS.
Lest you fear that this is to digress into a spate of vendor bashing, there is actually some useful information contained below - at least for those who are interested in such things.
Spurred on by the conflicting/bogus information received, further research revealed that not only is there a nameable manufacturer of the VFD, but that it is the same company that produces a broad line of industrial controllers, as well as the VFD's installed on Powermatic and Jet lathes. And that company is Delta Electronics of Taiwan. Absolutely no relation to B&D/Delta Machinery, however.
I also learned that I can buy a non-DeltaWW OEM controller for $235. Or an almost identical Powermatic controller for $335. Not $772.39.
Of course, you'd have to spend 10 minutes programming the registers to match the Delta defaults and swap the plastic door. Damned, that works out to well over $500 an hour. Where do I sign up...
The Delta VFD controller, as well as the PM/Jet, are VFD-S series controllers. Mostly standard, off the shelf products. For example, the unit used on the Delta is based on the VFD015S21A/B controller. The OEM version has a custom plastic door and a few pre-programmed registers which make it non-standard - Unfortunately. The controller is much more capable than it is allowed to be by the Delta register settings. (For those who are unaware, the VFD is a microprocessor controlled power switch, and contains non-volatile memory locations which can be programmed with static values to enable/disable certain built in functions of the basic unit. Among these features are frequency/current/voltage readouts, and externally mounted speed/start/stop/fwd/rev controls.
Jet and PM utilize these functions, Delta does not. If these functions had not been locked out, an add-on box with heavy duty switches & controls, a digital speed readout and mode indicators, etc. could be built and retrofitted DIY for about $20. As it is, you would have to connect the controller to a computer with an RS-485 port and appropriate software, and rewrite the relevant registers. And that naively assumes that they have not set a passcode to protect the registers from being written to. Admittedly, the unenlightened could really make a mess in there, but I consider it a loss (for me) to not have easy access to the registers and various mode displays available. Unfortunately, any attempt to do this would most assuredly void the warranty, and this I can relate to. Motor damage, controller damage, and personal injury could result from improper settings. However, the minute the warranty expires, that sucker's getting modded for external switches - unless I get fed up waiting 3 months for a VFD and dump the whole thing back in the original vendor's lap.
It also turns out that the mysterious "F" display represents the Frequency of the AC Drive Master Clock, which is then used to set the ultimate speed of the motor. It does not represent a Fault condition. Strangely enough, however, the runaway speed flaw has not presented a fault code. Go figure...
There is a programmable divisor that may be used to present alternate readouts based upon the AC Drive Master Frequency, but I am hazarding a guess that the speed indicator on the panel does not represent an accurate spindle RPM reading - which probably explains why PM and General use a separate RPM display and pickup module.
In conclusion, it is amazing how much more acceptable this lathe would have been in the market had Delta chosen to spend another $20-$50 in materials. I'm beginning to think these guys aren't particularly bright - particularly in the electronics arena.
Heavier machined toolrest/head/tail stock clamps, better controls (or the ability to add them), a Zero Phase reactor coil to the VFD output, and a TEFC motor would have rescued a product that is seemingly out of favor with vendors and customers alike. Comparing this unit against the Jet/General/PM is like night and day - but at a price. Since I paid far less than retail, the sum comes to just about $500, but had I been asked to pay $1800 - or more - I would have most likely passed it over in favor of the Jet 16" EVS w/ 2HP 3phase TEFC motor. As it is, I've only got a slight case of buyer's remorse - and that may diminish once the waranty expires and the shortcomings are corrected, at least in my tiny part of the world - courtesy of DIY.
FWIW