Photo Tachometers & Spindle RPM

E

elecbob

Active User
Registered
Joined
Feb 2, 2011
Messages
25
I am wondering what opinions the membership has about the many photo tachometers that are available. Also if there is a quick cross index of spindle RPM versus Cutting Speeds in FPM? I know that it depends on diameter of the work piece and of the material being turned. I have a South Bend 9 lathe. Once I get the various RPM's I think it should be easy to develop a chart for cutting speeds. Like to hear some input. This forum is such a vast knowledge base. Thanks,
Bob
 
Hey Bob

Here is the array of RPM measuring tools I have gone through.

All worked, but I am now using the tool on the left is the most useful now, the Monarch Pocket Tach 100.
I got that on Craigslist for $25. Snap! Uses this special reflective tape, $3.00 a roll. Little 3/8 inch square pieces on any spindle, in an pit of the way place.

The second is the Westward mechanical tach which has a rubber tip that you just stick onto a rotating shaft. I made a brass fitting to stick into a chuck or collet and measure from there. I got this for $40 on EBay once, like new.

http://www.grainger.com/Grainger/WESTWARD-Dial-Tachometer-3BY11?Pid=search

The last is a Starrett 104 "Tach", really a counter. It counts turns, and you watch your second hand on your watch. These can go for $5 to $50 on EBay, depending on what tips come in it, and who is watching!

The digital tach is nice because one little piece of the $3 roll of tape on every spindle in the shop and I am all set to take a two second reading!

Bernie



yva2esyz.jpg



redy3ema.jpg
 
Wow Paul

That Tachulator looks pretty cool! SFM too?


Bernie
 
Bernie,
where do you get the reflective tape for the optical tachometers from?
Have a tacho but no tape.
thanks
Frank
 
There's another electronic tach/SFM calculator similar to the Tachulator. It's the MachTach.
http://www.machtach.com

There are two disadvantages to the MachTach. First off, it's only available as a kit. (-BUT- there's an offsetting advantage. The kit is only $56 (less power supply and enclosure), with free shipping to the US, $14 international. Tachulator is ~$120, assembled) Secondly, it's a one-man show, and there have been times when the kits have been unavailable.

The Mach Tach allows using/entering any number of "slots" (light/dark transitions) on the shaft between 1 and 60, allows entering diameters from .01" to 99.99" (or 1 to 000mm), displays RPM from 0 to 9999, displays SFM from 0-9999 (or surface meters/minute from 0 to 9999). You specify inch or metric mode when you order.

Several sensors are available form MachTach - IR reflective, slot-type optical sensor, and Hall effect sensor.

For further info, check their website or the MachTach Yahoo group.

Bottom line: The MachTach has pretty much the same specs as the Tachulator, and you can save some money if you DIY.


Disclaimer: Other than having bought one, I have no connection to MachTach.

Best wishes!
 
Bernie, you lost me with this comment "The second is the Westward mechanical tach which has a rubber tip that you just stick onto a rotating shaft. I made a brass fitting to stick into a chuck or collet and measure from there. I got this for $40 on EBay once, like new."
The Westward comment lost me. I have a tach just like that one. Yours just like mine has the SW logo on it's face. Those tachs were made by Stewart Warner. I have no knowledge of any link to a Westward???
 
I have three MachTachs on two mills (one of them CNC) and on the shared VFD installation on the third mill and lathe. When you switch between machines, the tach shifts to the active machine. I really like these tachs.
 
You must log in or register to reply here.
Back
Top