A cool "Gizmo" I just got

[Kmot]

Harbor Freight had a 25% off coupon for today, New Years, only. I went there and found what I think will be a very useful gizmo to have for my lathe.

It is a contact tachometer. Nothing new in that. But, this one also has a switch to select "Surface Feet Per Minute".

I used it already to compare the calculated RPM for each drive belt setting on my 9x20 lathe and every belt position showed a higher RPM on the digital tachometer than the belt chart said it would be, and that is good information to have.



http://www.harborfreight.com/digital-contact-tachometer-66400.html

 

[rake60]

Cool toy!

I'd seen the claim of SFM readings but never understood how that could be possible
since it depends on the diameter of the material.

After reading the manual on the link, it makes perfect sense.

Another gadget added to my next Harbor Freight visit shopping list.

Rick

 

[Troutsqueezer]

That could be a handy device to have around. I think though, that after a short while, you'll be spinning up the lathe to a speed that your gut tells you is about right.

 

[AR1911]

I'll have to have one too. I wanted to figure cutting speed yesterday for 3/8" cutter in cast iron.
After looking up some specs, I realized the best info was on my PC, which I would need to boot up...

So I just set it to 2750 and winged it. Cut fine.


I wonder how this tool would hold up over time. Pressing that wheel against a fast-spinning shaft has to impart some shock loads.
Does it feel like it would last?

 

[Kmot]

Well, I barely had to apply any pressure for the wheel to spin away and take a recording. How long will it last is a very subjective question. Some guys can make things last a lifetime, some guys break things in a very short time. :big: