Checking RPM

tomsalwasser · Post by **tomsalwasser** » Fri Mar 25, 2011 5:05 pm

dusty wrote: Have you pulled the cover off the power station so that you can watch the variator at work while you change the speed dial.

Thanks Dusty I just pulled the cover and I am getting action on the variator so that's good. It sure makes a racket as I work the variator but it quiets up, smooth and solid when I lock the handle down. Is that to be expected?

Thanks,
Tom

dusty · Post by **dusty** » Fri Mar 25, 2011 5:20 pm

tomsalwasser wrote:Thanks Dusty I just pulled the cover and I am getting action on the variator so that's good. It sure makes a racket as I work the variator but it quiets up, smooth and solid when I lock the handle down. Is that to be expected?

Thanks,
Tom

I can not confirm that it is universal but mine is the same way. There might be a bearing to change that would quiet it some but I don't remember it ever being quiet. Now back when it was quiet (if it ever was) is too long ago for me to remember.

Isn't that neat. It was so long ago that my equipment was new and fully functional that I don't even remember when.

:):):)

JPG · Post by **JPG** » Fri Mar 25, 2011 5:30 pm

tomsalwasser wrote:Thanks Dusty I just pulled the cover and I am getting action on the variator so that's good. It sure makes a racket as I work the variator but it quiets up, smooth and solid when I lock the handle down. Is that to be expected?

Thanks,
Tom

You will notice the speed is changed by rotating the lever which rotates a spur gear that moves a rack/platform that the variator is attached to(shaft). As the rack is moved up/down, the belts move in/out. The slides for the platform are very loose and the platform will wobble causing the shaft to wobble and the belts to flop in and out. All that makes a rattling sound.

I got new slides in an effort to 'fix' that, but the new ones were no better than the 'original'. SS CS(Dave) says they ARE sloppy fit. I measured the 'slop' to be about 0.010". So I shimmed the slides and 'improved' matters, but at certain loads/speeds it still is noisey.

I did not realize I was the Pope;), but I do agree with Dusty's speed numbers. I assume he is reading them from the same source as I!

Yes it is worse with the lock nut 'loosened'. That lets the spur gear and square shaft slop to get in the act.

tomsalwasser · Post by **tomsalwasser** » Fri Mar 25, 2011 7:40 pm

pennview wrote:No, I haven't used it. I just ordered one after seeing you reference to a tach. I've been thinking about one for a while, and for $7.77 I figure I can't lose much. All you need to make them work is something reflective, so I figure some reflective tape from Home Depot or the like is all that's needed.

Here is the tachometer in action:
http://www.youtube.com/watch?v=hA0ANrX8 ... ature=fvwp

cincinnati · Post by **cincinnati** » Sat Mar 26, 2011 12:13 am

Keep us up to date on how good the Tach works.

Harbor Freight has one for $39.99. 20% off coupon would make it a local option to buy.

http://www.harborfreight.com/digital-ph ... 66632.html

pennview · Post by **pennview** » Sat Mar 26, 2011 2:18 pm

I received the tach from VBX today, loaded the 9V battery, and tested the speed of my 510. I got speeds from 810 to 5707 RPM, using a 3/8" x 3/8" square of reflective tape placed on the rim of a small cast iron faceplate. You get three 8-10" strips of the reflective tape with the unit, as well as a pouch to keep it in. The tach has a memory feature that stores the last, highest and lowest speeds observed during the test and the speeds are shown on the display as you change speeds on the Shopsmith or whatever you're testing.

The instruction booklet says it will not read speeds off of something that has a reflective surface unless you blacken that surface, and that smaller surfaces may need a couple of reflective strips and then you would divide the test results by the number of strips you used. All in all it's a nice gizmo for under $14.

dusty · Post by **dusty** » Sat Mar 26, 2011 5:42 pm

pennview wrote:I received the tach from VBX today, loaded the 9V battery, and tested the speed of my 510. I got speeds from 810 to 5707 RPM, using a 3/8" x 3/8" square of reflective tape placed on the rim of a small cast iron faceplate. You get three 8-10" strips of the reflective tape with the unit, as well as a pouch to keep it in. The tach has a memory feature that stores the last, highest and lowest speeds observed during the test and the speeds are shown on the display as you change speeds on the Shopsmith or whatever you're testing.

The instruction booklet says it will not read speeds off of something that has a reflective surface unless you blacken that surface, and that smaller surfaces may need a couple of reflective strips and then you would divide the test results by the number of strips you used. All in all it's a nice gizmo for under $14.

Thanks for this info. Might be worth having in the shop.

I wonder - would it work the same if you put the tape on the sanding disk or a blade? I also wonder if the tape would work on the band saw blade.

pennview · Post by **pennview** » Sat Mar 26, 2011 8:17 pm

Dusty, I expect it would work on the steel sanding disk (black) as the contrast between it and the reflecting tape (silver) is significant, but I'm not sure how it would handle the bright steel of a saw blade. I'll give it a try tomorrow.

pennview · Post by **pennview** » Sun Mar 27, 2011 10:33 am

Dusty, It read speeds off of both the steel sanding disk and the saw blade. I though it would have a problem reading off of the blade but that was not the case. All of the reading were taken at the same speed setting, but they varied by a few RPM depending on which reference I was using -- disk, blade or faceplate.

One of the things I'll likely use the tach for is to chart the various spindle speeds around the speed dial.

dusty · Post by **dusty** » Sun Mar 27, 2011 11:25 am

pennview wrote:Dusty, It read speeds off of both the steel sanding disk and the saw blade. I though it would have a problem reading off of the blade but that was not the case. All of the reading were taken at the same speed setting, but they varied by a few RPM depending on which reference I was using -- disk, blade or faceplate.

One of the things I'll likely use the tach for is to chart the various spindle speeds around the speed dial.

That will be interesting information and much more accurate (for you) than what is written on the various speed chart.

What everyone must realize is that speeds are generalization based on the design. Wear and tear will make all of them deviate some (over time and from machine to machine).

Yoy said your top speed was 5707 with the speed dial set where (5200)?