Installing a Tachometer on a Lathe

Morning guys,I have a lathe that came with a rotary phase converter which I will be able to run other machines with it so that a plus.My problem now is telling how fast my lathe is running since it has the reeves pulley setup,which I use a crank handle to change speeds.So last night I got on Youtube and watch some that those owners installed a tach on their lathe for rpm reference.What I am wondering if someone here has done that to their lathe or mill would like to hear how you like that setup?Or if you solve this problem dealing with it another way please let me know cause I don't have a clue.Either way,where or who did you purchase your parts from,I did look at the auction site and there must be a million tachs.How can a person tell which one is better than the other

I picked up one of these Amazon.com: tachometer laser
and spent a few minutes taking readings at different settings and recording them. Not the most elegant, but the cheapest, and accurate enough for my purposes

Look on eBay under digital tachometer, there are several that use hall effect and cost about$20.00.
Karl

On a South Bend with a 72 tooth back gear, I mounted a magnetic pickup reading the teeth and fed it to a Red Lion electric tach. These are set up for a 60 tooth gear so a 1 second count reads RPM directly. Since the gear had 72 teeth, I told the counter it was running on 50 cycle AC, making it read correctly.

I used a slotted optical switch mounted on a mill as shown which is connected to a small microcontroller circuit that just counts the pulses and does a simple operation to display rpm. I was going to take a picture of the rest of the gizmo but I am lazy tonight. That was years ago and you might suspect that I am really thrilled with it. Not because it doesn't work, with more experience I find that all that kind of jazz is not very helpful. With experience you don't need it. If you don't know what a optical switch is, the one in the pic is a OPB 829D.

http://datasheetz.com/data/Sensors,...e - Transistor Output/OPB829D-datasheetz.html

9100 said:

On a South Bend with a 72 tooth back gear, I mounted a magnetic pickup reading the teeth and fed it to a Red Lion electric tach. These are set up for a 60 tooth gear so a 1 second count reads RPM directly. Since the gear had 72 teeth, I told the counter it was running on 50 cycle AC, making it read correctly.

Click to expand...

Sorry for the zombie thread bump, but I want to do the exact same thing. Do you have a part number on the mag pickup and tachometer display you used?

I installed it probably 30 years ago and the counter I used is out of print.
Here is a link to a distributor. Scroll down to the data sheets. I recently bought several meters for a similar application and had to buy a whole computer in a panel meter to get the one function I needed. There are probably better options.

http://stevenengineering.com/Tech_Support/PDFs/38_PANEL-METERS.pdf

Here is a link for magnetic pickups.

http://www.farnell.com/datasheets/2058061.pdf

They have pretty much stayed the same except for being more versions.

Bill

YouTube

Measure the speed, mark the speed handle at each end. Interpolate appropriately.