LatheHamster

[john lucas]

Does anyone own one of these. If so what do you think. Looks interesting.
http://www.lathehamster.com/

 

[Rob Wallace]

Bill Rubenstein was showing this unit at the AAW Symposium in Tampa - it seemed really cool, and appears to be quite accurate for setting speed. My main concern was the size of the controls being a bit small, particularly when you are repeatedly turning the lathe on and off. I'd have to look at it more closely to see if it is any better than other commercially available controllers, but for VFD motor retrofits, it seems great. I like the screen and speed setting features.

I'm also interested if anyone has one that could give a brief review and opinion about it...

Rob

 

[Bill Boehme]

Last year (2012) at SWAT, Bill Rubenstein showed me his design for this device. I believe that that it may have been more like an engineering brass-board at the time (meaning basically a prototype), and I gathered that he was interested in my thoughts about the design. I was impressed by its features as well as his fabrication skills.

 

[Ian Thorn]

How does it work on the screen showing the rpm if you have a lathe with 8 speed pully set up does it read the shaft speed. As my setup changes 3phase power to single phase with vari speed I have had to log the speed Max & min for each belt setting .

 

[Bill Boehme]

Some woodturners have used a magnet on the spindle and a magnetic sensor to count revolutions per time interval. The disadvantage is that at very slow speeds this becomes somewhat slow to update and a bit erratic in the readings. A more sophisticated solution (also quite a bit more expensive) uses an optical encoder on the spindle to sense both speed and angular position.

Something that one might discover with many of the simpler VFD drives is that the readings that may appear to be erratic actually are a true reading of the speed. The simple volts/Hz VFD's really do start to lose speed regulation at around 200 - 300 RPM and slower.

Some of the really good sensorless vector VFD's (such as the Toshiba Tosvert line) provide good regulation for motor speeds down to 60 RPM or even slower.

A vector drive provides speed regulation better than 1% down to zero speed.

 

[Sergio Villa]

My Vicmarc Vl 300 has a Fuji with a RPM reader of the motor. I installed a RPM Reader on the spindle (Tachulator) and double checked (just fur curiosity) with a cheap laser reader. At the speed of 1:1, i.e. same motor shaft and spindle RPM, all three readers show practically the same RPM, less than 1% differences. The tachulator is permanently installed, easy to install and read. The spindle can go at less than 10 RPM with the motor at 30 RPM.

 

[Bill Boehme]

My Vicmarc Vl 300 has a Fuji with a RPM reader of the motor. I installed a RPM Reader on the spindle (Tachulator) and double checked (just fur curiosity) with a cheap laser reader. At the speed of 1:1, i.e. same motor shaft and spindle RPM, all three readers show practically the same RPM, less than 1% differences. The tachulator is permanently installed, easy to install and read. The spindle can go at less than 10 RPM with the motor at 30 RPM.

Is it the Trexon Tachulator tachometer? (try saying that really fast) 😀

 

[Mark Mandell]

My Vicmarc Vl 300 has a Fuji with a RPM reader of the motor. I installed a RPM Reader on the spindle (Tachulator) and double checked (just fur curiosity) with a cheap laser reader. At the speed of 1:1, i.e. same motor shaft and spindle RPM, all three readers show practically the same RPM, less than 1% differences. The tachulator is permanently installed, easy to install and read. The spindle can go at less than 10 RPM with the motor at 30 RPM.

If you want/need to go that slow, consider some supplemental cooling for your motor. At those rpm's a tefc motor can easily overheat.

 

[Ed Jarvis]

rpm

Bill,
I have a optical sensor a Seeka GS5n that I got off ebay with a red lion Paxr display unit for my lathe, have I missed something?

,
Thanks
Ed Jarvis

 

[Sergio Villa]

If you want/need to go that slow, consider some supplemental cooling for your motor. At those rpm's a tefc motor can easily overheat.

I know what you mean but I never had a problem, just use common sense, and checked the motor more than ones. I use it for some sanding and perhaps there is not enough stress to the motor. By the way, when the spindle goes at 10 RPM the motor runs at 30 RPM.

 

[Bill Boehme]

Sanding is OK since there is hardly any load on the motor. If you were doing something that was putting a significant load on the motor, that would be a different story. If you can put your hand on the motor ... and keep it there ... without the need for steak sauce -- then things are OK.

As most of us know, the thing that makes electrical and electronic gadgets work is magic smoke. If you let the magic smoke out, then the device will no longer work. And, forget about trying to put the magic smoke back in -- it can't be done. Magic smoke has a distinct ozone aroma. If you smell it, then something has given up the ghost.

 

[Mark Mandell]

I know what you mean but I never had a problem, just use common sense, and checked the motor more than ones. I use it for some sanding and perhaps there is not enough stress to the motor. By the way, when the spindle goes at 10 RPM the motor runs at 30 RPM.

My lathe is in the garage, and when I've got it dialed down for sanding I have a 20" box fan blowing the dust out the door which keeps the big 3hp motor cool as well. When the beast lived in the basement I had a 6" HVAC duct-helper fan hooked up on the end of the TEFC housing. Did just fine at keeping the Magic Smoke contained.