Digital RPM readout for my lathe

[rbertalotto]

Now that I've converted my lathe to DC Variable speed, I needed some way to measure spindle speed. I bought a hand held tachometer from EBay for $35 that works great...

But it is a bit of a pain to use on the fly......
I remembered I had a bicycle digital speedometer hanging around so I dug it out and installed it on the lathe. This unit consists of a magnetic sender unit and the display. All battery powered so no electrical hook up is required.....
The pick up need a magnet super glued to the spindle and the pickup located nearby...

The display unit was simply mounted on a wag of two part plumbers putty......A bit of finagling with the set up calibration and it reads KPH at +/- 10 RPMs of the handheld tach...Close enough for government work!

 

[JDJones]

Great idea, are you going to make some sort of conversion chart so you can tell what RPM's = KMH?
We have some VFD drive lathes where I work and they realy help whaen you waant perfect cut threads as most manual lathes only go down to 45 RPM's being able to slow them down a little bit more is nice

 

[rbertalotto]

Hi JD,

No need for a conversion chart, when calibrated properly it reads
"XXX KPH" which is the actual spindal RPM,disregard the KPH). It is accurate to within 10 rpms from 90 to 400. I rarely turn at more than 400 RPMs.

,BTW, Great barrels...my 6.5 on my TC has accounted for its fair share of venison ...............)