CAN THIS BE DONE?

[emtmike]

I am very new to this pen turning and have a question about my lathe I can change the speed by moving to belt. What would happen if I put an inline dimmer switch on the electrical cord. I could slow it down and speed it up like that. Would that hurt the lathe.

 

[JimGo]

Mike, search the archives and you'll see that the motor you (probably) have on your lathe won't tolerate the change in voltage particularly well. It might work for a few minutes, but that's about it.
Edit: http://www.penturners.org/forum/topic.asp?ARCHIVE=true&TOPIC_ID=6324&SearchTerms=dimmer

 

[KenV]

If you really want to do that, get a DC motor and a speed controller -- lots more bucks but nice.

 

[Randy_]

Originally posted by KenV<br />If you really want to do that, get a DC motor and a speed controller -- lots more bucks but nice.

Agreed.....Best solution; but expensive. Sell the manual model and by a VS unit. Considering the loss you would incur from the sale of your current lathe and the extra you would pay for a VS model, the conversion might be economically feasible. I'm sure someone will come along with cost of converting a lathe. One very nice feature of converted lathes is the will run from 0 rpms to max. The store bought VS units usually has a low speed of around 500 RPMs and that is a little high for boring, sanding and finishing.

P.S. What kind of lathe do you have? Some are easier than others to convert.

 

[TomServo]

I converted my taig lathe to VS - got a 2.25HP treadmill motor from www.surpluscenter.com - $10 + $10 shipping - and i bought a pair of KB Electronics DC speed controllers for $50 shipped off ebay - I've got an extra motor and controller I don't know what I want to do with yet.

here's one rated to 1/2 HP without a heatsink: http://cgi.ebay.com/KBIC-PENTA-KB-POWER-DC-MOTOR-SPEED-CONTROL-KBIC-120-NEW_W0QQitemZ7585267787QQcategoryZ97187QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The units I purchased output 130V DC instead of 90V DC - if you look around a bit you can do it pretty cheaply. That unit I linked would work very well - you could easily put a 3/4HP motor on it with no heatsink, as long as you don't try to use the full output continuously. The other thing this brand of controller requires is a "plug in resistor" it sets the controller for the size motor you want - surplus center sells these, fortunately - they're like $3.

 

[TomServo]

mike: there's a sort of dimmer made for ceiling fans that will sort of work on regular induction motors (i give no guarantees as to efficacy or relative safety) but they're really made for split pole motors - and usually only rated to 5 amps. You probably couldn't even get a 1/4HP motor to start on one

 

[lafrilot]

I had that same wanting, and I purchased a Wood's E-Trac AC converter and a 3 phase motor(same size and hp as existing motor) both off of ebay. The E-Trac is a 110v model that converts the electric signal to 230v 3 phase. Now I have forward and backwards rotation as well as dialing in any frequency from 30hz to 100hz for speed control. Plugged it in and never looked back. I have a Craftsman model and also hated to change belt positions for different speeds. The beauty is, when you have a bowl blank mounted and it is not "true", I can dial in frequencies at .05hz increments to eliminate table vibration. Also, I can turn pens at normal rpm's and attain friction polishing speeds at the touch of a button. WOW!!!!!

 

[Randy_]

Originally posted by lafrilot<br />.....I purchased a Wood's E-Trac AC converter and a 3 phase motor(same size and hp as existing motor) both off of ebay.....

Leo: That sounds like a nice set-up; but a little pricey. What did that conversion cost you, if I may ask??

 

[lafrilot]

As I recall, it cost me about $200, because I got it all on ebay. If you would like I can get you the model number but it might not be rated for the same motor. If brand new, probably around $500.

 

[Randy_]

Thanks for the info, Leo. I was just looking for a ballpark number as I thought others reading this thread would be interested. I'm happy with my 6 speed(bicycle and lathe!!); but if I ever feel the need of a VS, I will probably go the treadmill motor route. That alternative would fit into my budget a little easier.

 

[ryannmphs]

check out surplus center. That where I got my motor (have since sold it due a funding problem). You can just email them what you are looking for and what you want to do and they will give you some recomendation.

Great service and I will order from them again.

Ryan

 

[Randy_]

Thanks, Ryan. I just sent for their free catalog!!