Jet 1642 or Nova DVR 3000

Hi Gotwood,

My first choice and only choice right now is the NOVA DVR 3000. I used one for a week in a workshop with Ernie Conover and the machine is great. No pulleys or v- belts. Nice digital control for speed. Can pivot the headstock for turning outboard. You can extend the base for longer spindle turning. You can easily index with the 3000. It was just a joy to work with. Good luck in your search, and get the machine that you determine is right for you. Only you can make that decision. We can only give our opinions of what is right for us.

Dan

Hi Anne, I try to follow posts on the DVR fairly closely and haven't encountered any reports of this. I know there were some very early teething pains, but I don't recall becoming aware of this happening even in the earliest versions.

I'm going to be doing an update of my review of the DVR in a few months and would appreciate any specifics you can give me about the people involved so that I can contact them, or at least the specifics of the problem and under what conditions it actually ocurred.

My experience, having lived with a DVR for several years now, and not known for being particularly gentle with a lathe, is that the DVR may warm up, but I have never had it shut down from heat.

Thanks in advance for any followup you might be able to provide.

Lyn

anne wrote:

The DVR is designed to shut it self down if the temperature limit is exceeded.

It is better to have the lathe shut down then damage the motor or other components.

Last year I noticed my DVR seemed to be runn> Don't know anything about the Jet, but know of a few people who have had

Another thaing that the DVR is designed to do is to shut down with a heavy catch. This is a protective measure for the operator. It will shut down for only a few seconds and then resume operation. I've mostly noticed this occurring at speeds below 500 rpm.

In my opinion, the DVR is a wonderful machine for the money. I don't believe I could ever go back to my NOVA 3000 after nearly three years of using a DVR. It is a good idea to vacuum the headstock breathing areas periodically. I do so every time I clean up the lathe after a turning job.

Fred Holder

Lyn, Fred and anyone who has used both N3Ks and DVRs _in some depth_.

From my armchair and not just for thrift, I have not yet been able to justify changing (upgrading?) from a N3K to a DVR, considered strictly as a lathe for turning wood. I understand the more convenient size of the headstock & drive design and the small footprint and better tailstock etc. It is the motor and its controls that are different and interest me. Although my wife often calls me "Spurtle", always stirring up trouble, I do want some informed pro/con opinions and my questions are not meant to be a sly indictment of the DVR.

If I didn't own a N3K, which seems to be just right for me, I would probably buy a DVR. I know y'all are thinking that Arch would look for a bargain in a used N3K. :) ....but seriously, why not?

Some say that the DVR runs 'smoother'. If true has the reason been determined? Are the motor bearings better? Does the belt and pulley system produce a 'rougher' rotation? Would better belt & pulleys help? Why haven't other quality manufacturers changed to DVR?

Overall, is the speed and torque control on the DVR superior to the control on my VS N3K? How & why?

Has anyone had to replace a DVR motor? Why? Was the cost, time & and hassle really significantly higher than would be the case for the belted system?

In summary then; cost and pride of lathe not being objectives, what are the turning utility reasons for buying a DVR instead of keeping or finding a good used N3K? TIA.

Turn to Safety, Arch Fortiter

Yes, it does, most noticably at higher speeds

I don't think there has been an independent scientific comparative analysis, but there are several things to speculate about. Most prominently the lack of belts that prevent stretching and rebound, pulley misalignment and climbing,the tendency to develop a set, perhaps slight variations in thickness, etc.

There is also some speculation about the inertial effects of the motor itself with its direct, inline coupling to the work piece.

Perhaps it is the "improved" bearing system, or the speed control, or the smoother torque curve.

I really can't say for sure, but it is one of the things most prominent about the DVR, even when compared to much higher priced lathes.

Are the motor bearings better?

Well the bearing system is slightly different. As you know, the 3000 uses a pair of bearings right at the nose, a system that several mechanical engineering types have informed me is quite sound.

The DVR has the same nose pair and adds a third at the far end of the motor.

Interestingly, belt drive record turntables were once in demand (and even preferred over direct drive units) because it was believed the belt helped isolate the platter from motor pulsations and vibration.

I'm sure a high quality belt would help, but could not remove all the inherent problems of stretch, etc, inherent in the typical belt.

Why haven't others changed to the DVR. I suspect one reason is that Teknatool has some patents, etc. Another probably has to do with the cost of designing and manufacturing the headstock/motor assembly. This is not inconsiderable, and I suspect a lot of manufacturers can go the traditional route a lot more cheaply. Then there is the matter of the power and expense demands of developing a motor that will perform well at very low speeds below 100. Finally, I suspect that a lot are still waiting to see how the public accepts the DVR approach.

I had a 1.5 hp Leeson (which is now on my Drill Press) on my 3000, coupled to a Minarik controller. The DVR has more Torque and HP, a smoother power curve, has more precise and stable speed control, and has future electronic capabilities that can be implemented that aren't likely to be found on the typical DC controller.

How this is accomplished has to deal with the nature of the DVR motor itself (covered here and at their website in detail).

Well the "motor" can include several things. The drive core and headstock poles themselves, the electronics internal to the headstock,and the outer drive controls. Most of the past "problems" were in the internal electronics which all exist on one board. Lots of people have exchanged, upgraded the internal boards. It is made easier if you pull the headstock, but you can avoid this if you take your time and have nimble fingers. The internal electronics are meant to be upgradable, and I suspect we will eventually see a lot of DVR's being upgraded to newer and more spectacular performance standards by swapping out this board. It offers a way to upgrade the "motor's" performance relatively cheaply, certainly more cheaply than buying an all new motor. I haven't swapped boards out yet, but I did pull the boards on my brand new DVR just so I could take photos to show folks. I imaging it took about a half an hour to remove and replace.

The reasons to go with the DVR are more power, smoother power, variable power to meet demand, more precise control of power, a more compact headstock (not to be dismissed, hanging the Lesson off the end of the 3k was no small thing), no shafts to possible break, not belts to change, maintain, ability to interrupt on a catch or excessive load, and some future enhancements I can't talk about right now.

Reasons not to go with the DVR are its lack of extreme low end speed (below 100) and weaker power at the very low end (below 250) which is nice to have for very heavy, out of balance blanks, eccentric work, some hollowing tools, and for finishing and sanding. I still miss these things, but wouldn't give up the other features of the DVR to get them back.

Then off course there are the other factors of a better tailstock, etc, that do come with the DVR.

There's probably some important issues I've completely forgotten, but these are some things the come to me off the top of my head.

Lyn

Good answers always, Lyn. Thanks.

Turn to Safety, Arch Fortiter