High and Low

[Sean Hughto]

So I'm a bit slow. I have Jet 1642 (1.5 HP). I've had it for coming on 2 years. I turn lots of bowls at near its maximum capicity (13" to 15" range - you can never really get the full 16, at least over the bed). The lathe came with the belt on the high set of pulleys I believe (or at least I put the belt on those pulleys when I set it up). I've never thought much about low (I know, duuuhh, right?) until the other day when the motor got warm enough that it decided to take a break to cool itself off. It then occurred to me that I never spin the big bowls that fast, and some extra torque might be helpful, so after she cooled down and was ready to go again, I changed the belt to the low pulleys (took less than 1 minute). The clouds broke and the angels sang! Turning that blank was much more pleasurable with that extra torque and the motor was happier and cooler too. Anyway, I'm probably the only doofus who never thought much about the high and low configurations - happy with what seemed to be good enough in la la land - but just in case, I heartily recommend others keep it in mind for heavy work.

Happy Easter.

[Steve Schlumpf]

The majority of the time I have mine set in the high range position but when I have a heavy blank (like today!) I change it over to the low range. Like you mentioned - more torque but I also like the increased braking capability when dealing with large blanks!

[Dan Forman]

Thanks for the reminder, I haven't used the low range on my PM yet, - haven't done any large heavy ones yet, but do have a big blank waiting.

Dan

[Tim Thiebaut]

I am just the opposite to this, when I got my lathe in Dec I set my belt on the middle pully, and although I have dropped down to the low pully once for a large blank I turned, my lathe has never run on the 3rd...fast pully...at all yet, my lathe is a VS and high speed on the middle pully has seemed more then fast enough, I really cant imagine how fast it goes on the 3rd pully, I guess I should try it out one of these days just to see.

[John Hart]

That's funny, Sean!! At least you didn't burn up the motor before you figured it out. :)

[John Keeton]

I guess this whole issue takes one back to one's roots. Back "in the days" one only used overdrive, or high gear/high range, for highway cruising. So, when I got the Jet, I left it in "low range" for the torque issue, and would only consider using "high range" for cruising - i.e., finials, delicate finish work, etc. I didn't know I was "doing it right" - just was doing it because that is the way it had always been done!?!?!:confused: Kinda lucked into that one!:)

[Rich Aldrich]

I started out on the Jet 1642 and kept it on low out of beginners fear of speed. I never really consider changing the speed range unless I turn a spindle like a tool handle, then change the speed back to low range for the bigger diameter stuff like bowls.

[bob svoboda]

I like to finish turn green bowls. The low range on my 3520b is essential for sanding the warped surface.

[Greg Just]

Sean - there is no such thing as a doofus. This feature is easily overlooked. Since I have had my Jet 1642, about a month, I have left it on the low setting. I have been taking advantage being able to turn larger bowls so I have wanted the extra torque. I have not done much spindle work lately and that I have has worked fine at 1200 rpm.

[David Gilbert]

I also have a Jet 1642 and I use the low range almost all the time. I like the fact that I can just crank the speed knob all the way over and I don't have to worry about the speed going over 1250 rpm or so. Since most of my bowls are in the 6 - 8 inch diameter that works nicely for the maximum speed recommendations. It's also nice for roughing down my bowls. I also routinely sand my green bowls at 50 rpm so the low range works fine for me.

Cheers,
David

[Reed Gray]

When I got my PM (over 10 years ago) it was on the high speed range. I had problems with bowls tripping the over load button whenever I turned it off. I called them and we adjusted the braking time. Later I figured out that it did that because I was on the high speed range. I recently did a Saw Dust session for the Willamette Valley Woodturners, the host's lathe was on the high speed range. Since the session was on bowl coring, I set the speed range down to the low range.

Now I have a Robust, which has 3 speed ranges. Most of the time it is on the middle speed range. Problem with the low range was that it was too slow for smaller bowls (max rpm about 800 or so). Brent helped me adjust the speed ranges by tweaking the phase converter. Now slow speed range is up to 1200 or so. Most of the time, except for really big pieces, I go on the mid range, which tops out at 2200 rpm. Perfect for me and smaller pieces, and adequate for coring. I only use the low speed range for sanding, and it will shut off at about 15 rpm. Any faster, and I can't keep the abrasives on my warped bowls. The high end speed of the mid range is perfect for most of my spindle work which is rolling pins, potato mashers, and the occasional kraut pounder. I almost never use the high speed range.

The newer PM shuts off at 50 rpm, and the high speed on the slow speed range is 1200 which is too slow for my tastes. They are very reluctant to help you adjust the parameters on your converters.

robo hippy

robo hippy

[Roger Chandler]

I use the low belt setting on my Grizzly G0698 for larger blanks, especially when out of round and unbalanced. The extra torque is demonstrable, and makes a difference. My low setting goes up to 1260 rpm, and the high setting goes to around 3250 rpm, which is flying, but it does make for some smooth cuts. I like to change over to the high setting when I am making the last couple of finish cuts, especially shear scraping or shear cutting with a gouge.......almost no sanding needed!

[Chip Sutherland]

DUH...my 3520B has high belt? Never used it. Guess if I did pens on the MM, I might change it....but that's what my Jet Mini is for. I rarely turn anything over a 1000rpm regardless of size. I guess I turn in a 'comfort zone' not paying much attention to the RPMs.