Checking RPM

[pennview]

I just turned the speed dial until it stopped turning and didn't pay any attention to where that was. Perhaps it's in need of the high speed adjustment. Whatever the case, it's a fun item for someone who likes to tinker.

[JPG]

I also received the tach from vxb yesterday and was surprised to see similarly high readings. I merely used a piece of masking tape on the spindle flat while in drill press mode. I have not had an opportunity to try it further(my attention is elsewhere).

[dusty]

I too ordered a tach but I am getting mine for $2.77 plus shipping. In the end, I will have spent about three dollars less that you who bought from VXB.

The cost that I have to swallow hard and accept is that this $3 savings cost me about three weeks in waiting. Mine has been shipped direct from the factory.

[mountainbreeze]

Reading this thread inspired me to get the Tach from VBX. I checked out my old Mark 5 and here are some results. I put a piece of the reflective tape on the drill chuck for my test.

Slow - 923
A - 1018
D - 1375
G - 1818
J - 2384
M- 3004
P - 3786
S - 4820
W - 5940
Fast - 6040

[JPG]

Reading this thread inspired me to get the Tach from VBX. I checked out my old Mark 5 and here are some results. I put a piece of the reflective tape on the drill chuck for my test.

Slow - 923
A - 1018
D - 1375
G - 1818
J - 2384
M- 3004
P - 3786
S - 4820
W - 5940
Fast - 6040

IIRC, that is about what I got at fast and slow?????????

[billmayo]

I find that I can get around 6500-6600 RPM with the Control Sheave just clearing the Speed Control bracket leg with a used motor belt (27" length). I adjust the high speed adjustment for a maximum range of 5200-5400 RPM for customer's headstocks.

I find using my "Poor Man's Speed Reducer" reversed for increasing speed (1 1/2" pulley on upper Drive Sleeve shaft, 8" pulley on Idler shaft. link belt between the 2 pulleys, no Gilmer belt) I can operate the quill shaft at 10,000 - 12,000 RPM for short periods of time. I find the quill bearings tend to overheat and tried to seize once I am past 12,000 RPM. The idler shaft bearings did not present any noticeable problems after these high speeds (18,000 - 20,000 RPM) runs. The quill bearings only lasted for short periods of time past 12,000 RPM. Quite a high level of noise and vibration at these speeds. These were all old Gilmer quill bearings as I never tried using new higher rated (ABEC3) quill bearings when doing this testing to see the maximum speed I could use for making DC motor conversions a few years ago.

[allsas]

Seemed to me that the 9V battery is drawn down if left in the Tachometer. Battery is dead after a month / month and half. Taking the battery out gives you a better chance of bring it back on line.

I have a multiple voltage power supply where one of the jacks is the 2 post 9 V jack. I would check the voltage on the jack to confirm the voltage. Mine is set on the 7V setting because the 9V was about 10V.

It's very constraining, having a cord into the tachometer and a power cord to the power supply. But it's ready, after long storage intervals.

[dusty]

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.

I hope that you will post those speeds. I plan to do that as well. In fact, I made an excel spreadsheet to record the advertised (charted) speeds and plan to calculate deviation from those numbers for all of the info I can collect.

I am curious about just how much speed varies from machine to machine.

Hmmm Do I remember how to determine standard deviation for a collection of numbers like this? No problem. My oldest grand daughter will know how?

[pennview]

Here are the spindle speeds for my 510 that I recorded using the tach from VBX. It should be noted that my dial is off a bit in that on the low end I'm able to turn it past slow to just about the FAST setting and on the high end it stops at the W setting, so it needs a bit of adjusting. Overall, it runs from 810 to 5835, with the highest speed reached at the V setting. It dropped down to 5800 at the W setting and at that point the dial wouldn't turn any farther. The values were rounded to the nearest 5.

- 810
- 900
SLOW 1005
A 1085
B 1175
C 1320
D 1445
E 1575
F 1715
G 1905
H 2050
I 2220
J 2425
K 2635
L 2830
M 3065
N 3355
O 3595
P 3880
Q 4215
R 4580
S 4885
T 5290
U 5705
V 5835
W 5800
FAST -

[dusty]

Today I received a package; one of two that I have been waiting for. One was coming from China and the other from San Jose, CA. The two items were both online requisitions and were placed just two days apart.

One item is my tachometer from China and was ordered on Mar 27. The other is an antenna for my wireless network which was ordered on Mar 29.

The item from China, with a two day head start today won the race. I received the VXB tachometer in today's mail.

Now I can measure the headstock rpm but I am not sure I want to. I fear what I am going to find.

A quick check at the LOW and HIGH speed settings yielded numbers I did not expect and don't know if they are normal (though not per the manual) or do I now have work to do with the headstock.

My headstock runs faster than expected at both ends.

LOW = 1000 rpm (SB 700) while the HIGH = 6650 rpm (SB 5200)

Hmmmm...Could it be that the tach is wrong? Will the speed change when I attach a saw blade and arbor?