Two speed gearbox

[belongtotom]

Would somebody have idea for a two speed gearbox which could be adapted onto a lathe drive motor which in turn would reduce the driven speed of the lathe by 1/2 .Seen such a creation years ago and it was planetery in princple , however it was fitted onto a 10H.P. electric motor .The reason for reducing the spindle speed is to make threading into a shoulder easier Any thoughts

 

[Mac1]

I thought about adding a separate motor with the proper pulleys to give the slower speed. It would use the existing motor as a jackshaft. You would only use the extra motor when you need the slow speed.
In the end I just built a handcrank to fit the left end of the headstock spindle. When I need to thread to a shoulder, I just stick the handcrank in the spindle and turn it as slow as I need. In addition, I don't have a threading dial on my lathe so I don't have to disengage the feedscrew at the shoulder. I just turn in the opposite direction. For my infrequent threading jobs, its adequate.

 

[OlCatBob]

B"Tom,

I have a 4 speed "Drive-All" that would be perfect for you, but shipping would kill you. Already set up for a flat belt on one end, and a double v-belt on the other end. Look up Drive-all on e-Bay for an idea; be warned that they weigh in at about a 100 lbs.

Like this,

http://www.ebay.com/itm/DRIVE-ALL-U...ltDomain_0&hash=item485ad11080#ht_1026wt_1050

Bob

 

[rdhem2]

Good Sir:
A plant I worked at for a good while had on old Monarch lathe that was fitted with a Model "T" Ford three speed tranny. 5 hp motor to Vee belts to tranny input. Tranny out to flat pulley four step. Lots of gears and speeds to choose from. Rather simple arrangement actually and a Model "T" is a puny thing anyway. And the real bonus is you do not need a reverse pushbutton!

 

[John Hasler]

Would somebody have idea for a two speed gearbox which could be adapted onto a lathe drive motor which in turn would reduce the driven speed of the lathe by 1/2 .Seen such a creation years ago and it was planetery in princple , however it was fitted onto a 10H.P. electric motor .The reason for reducing the spindle speed is to make threading into a shoulder easier Any thoughts

How about a transmission off a dead riding lawnmower?

 

[Rbeckett]

+1 on the gearbox from a riding mower. If you get the right one you will even have reverse. Changing the input pulley size will definitely speed up the output, but there are certain limits you need to stay within to prevent overspeeding the box and causing a lack of lubrication related failure on the input shaft. Changing the lube to a high pressure gear oil would probably be a good idea, but that requires undamaged grease and oil seals or new ones installed. Just my .02

Bob