Question about lathe speed for spindle turning (Nova Comet II)

[Guy Dotan]

I am a beginner. I recently purchased my first midi lathe: Nova Comet II (with extension.) It will be used almost solely for spindle turning. (Bowls - maybe in the future.) The lathe has variable speed, but I find that the ranges per belt are limiting. For this reason I am considering returning the Nova. I would love some help.

Details:

The lathe has the following speed ranges:

• Low Speed Pulley: 250 RPM – 680 RPM
• Middle Speed Pulley: 530 RPM – 1420 RPM
• High Speed Pulley: 1380 RPM – 4000 RPM

Nova claims that "The middle step usually provides enough range for most woodturning applications." However, for finishing, I think that going faster (2500?) is better. I am finding myself changing belts much more than I wanted... Am I wrong?

It seems that the Penn State Turncrafter TCLC12V, for example, has a more useful range of 950-3800

[Michael Mills]

I would use the high speed for spindle work. It should provide a very acceptable range. I purchased the Comet II about six years ago for my daughter but I do not know how often she changes ranges. I have the Nova 1624 (Belt) and do all of my spindle work at the 2200 or 2900 setting and never move the belt.
Is the PSI 950-3800 or 1950-3800? I saw one listing for the latter with a second slow speed setting being 500-1800.

[Guy Dotan]

I would use the high speed for spindle work.

It's probably a very reasonable compromise, but being a beginner I just don't know enough to determine if a slower speed for roughing is desirable. I can still return the lathe...

Is the PSI 950-3800 or 1950-3800? I saw one listing for the latter with a second slow speed setting being 500-1800.

The information online is confusing, but it is 950 - 3800. Here is an excerpt from one of the reviews on the PSI site. There also seems to be a mod that masked the range even more useful:

...the two speed ranges don't exactly match the ranges in the manual (500-1800 and 950-3800 but are close enough. BTW, PSI needs to change the specs in the on-line catalog, they show 1950 instead of 950. You can adjust the ranges if you are confident, competent and careful. Make friends with the PSI tech support engineers with an email or phone conversation - easy to do, they are quite friendly and helpful. There is a set of rheostats on the circuit board that control the motor speed. I have set mine to low-range 250-1600rpm and high range to 450-3500rpm with no load.

[John K Jordan]

I turn a lot of spindles. For most, I use something close to or at the maximum speed of my lathes, about 3000 rpm. I use the same speed for roughing, whether with a roughing gouge or a large skew chisel. (My PM lathe has a two-step pulley, the low speed goes from about 50-1500, the other from about 100-3000. I almost always leave it on the high speed pulley)

For very long or large diameter spindles I run slower.

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Turning a spindle fast is not the safety hazard of turning a typical bowl or platter. Turning faster gives a smoother cut for the same tool motion.

I do turn the speed way down when sanding spindles on the lathe, texturing, and for a few other applications.

The pulley steps you describe would be frustrating since I'm used to the PM, but then I remember turning on a non-VS lathe with stepped pulleys and I got pretty fast at changing the belt.

JKJ

[Richard Coers]

One major issue that hasn't be dealt with is reduced torque on a DC motor at low rpm. That's the reason they even have step pulleys, to keep the motor spinning faster to keep the torque up. Should you ever turn a small bowl, and try to turn on the highest pulley speed range, but turn down the speed with the potentiometer, you'll be able to stall it out very easily. It's my experience that changing pulley steps takes less than a minute, no big deal.

[Guy Dotan]

The pulley steps you describe would be frustrating

This is one detail I missed when I did my research. The ranges don't make much sense now that I've used it for a few weeks. (I also thought that the reverse option would be great for sanding, but I found that I don't want to use it...)

[Thomas Canfield]

I used a Nova Comet II for about 7 years along with a Powermatic 3520B. I almost always used the mid range for turning smaller bowls, lidded boxes, small hollow forms,and similar. I would use the high speed range for pens and spindles without any problem at the lower range since starting with fairly balanced material, but my stock was seldom square cut in preparation and pen blanks not center drilled. I very rarely used the slow speed range due to lack of power with the very small pulley at motor and narrow belt. I made a review shortly after getting my Comet II and was very critical of several features that I stand by today, but did find it to be a good lathe for smaller work, and travel. I did buff with Tripoli a lot of even larger bowls using 8" adapter and 8" wheel at the high end of the mid range without changing to the higher range.

I was going to replace it with the new Nova Comet 14, but had problems with the initial release unit and returned it. It had only 2 speed ranges, and I found the speed ranges did not fit my turning experience among other problems that I issued to Teknatool in review that was not to be made public.

Getting new lathe fever (like new car fever) I bought a Rikon 70-220 that had an initial problem (was demo at Woodcraft so not out of box) that Rikon was quick to address and I made the changes and now very satisfied. It is 3 speed range similar to the Comet II but mid range is a little slower and buffing slower making me want to go to the higher range at times. I have to always go to the higher speed range on the Powermatic 3520 to buff. Doesn't seem to be any real good solution but not that big a deal.

I have always firmly attached the midi lathes to bench without using the rubber feet. Also adding some additional height under the base greatly helps to clear shavings and dust from under motor.

[Guy Dotan]

It's a nice machine for the price for sure. The G3 chuck that came with the bundle is sweet. I had an issue with the extension bed and their customer service was absolutely amazing. If I could just lower the minimum speed of the high pulley....