Tachometer for VFD driven lathe

[JWD]

Hello folks

Just a quick question to see if anyone who has done their own VFD conversion has some advice on a tachometer that i can position on the spindle

Many thanks
JD

 

[Yojevol]

I take it that you want to check the shaft speed. The easiest way is with a hand held digital laser tachometer. You just have to stick a bit of reflective tape on the shaft and point the laser at it. The're very cheap and work well. At least mine does. Search on ebay for it and several will come up.
Brian

 

[CHJ]

Not a ready made solution but this article may provide some answers.

I find that a control potentiometer marked with divisions at the cardinal speeds is more to my liking than a digital display.
I use the Speed Discs to calibrate against 50hz mains lamp.

Wood lathe speed is not critical and I find that with those fitted with push button speed-up/speed-down controls I spend too much effort watching the readout rather than an instinctive quick twist of the potentiometer.

 

[katellwood]

does the VFD have the facility to do it for you. my experience is that there are so many parameters the VFD can be setup to do it for you.

My second hand Mitsubishi couuld be setup

 

[JWD]

its an invertek e3 - id imagine there is some way to do it, however there are 3 spindle positions so not sure that would work!

 

[TFrench]

I fitted a 12v hall effect sensor to the pulley on my graduate. Unfortunately the power source was in the same box as the inverter and the interference made the display very unhappy! By the time I worked out what was wrong with it I realised that like Chas says, you just get a feel for what speed you need and don't actually need to know the exact number. Never have bothered to get it working properly! I believe farmer giles on here fitted one to his viceroy, I'm sure there's something about it in his build thread.

 

[Farmer Giles]

I did

Here's a link

post1228741.html#p1228741

Cheers
Andy