Kasco carriage drive modification, thoughts needed.

Celeriac · June 30, 2012, 11:55:51 AM

In my normal manner I've been dragging out the process of rehabbing a Kasco mill that was donated to the camp. The mill as originally built had 12v gearmotors to drive the carriage and for the raise/lower. The mill was converted to electric drive so there is not particular need to stay with the 12v system. To that end I have replaced the raise/lower with a 180vdc gearmotor which doesn't struggle like the old 12v system. I was going to leave the 12v system on the travel but it the power supply and rheostat system seems rather questionable. During my procrastination I acquired a ½hp three phase gearmotor and a VFD which I hope will be more functional in the long run.

The question at hand is applying the new motor to the mill. The original setup uses a #35 roller chain, with a sprocket on the 12v gearmotor and is setup as follows.

The new gearmotor is a bit slower and the shaft is larger, so the old chain sprocket is not going to work. My thought, even before the motor swap, was to possibly change over to using wire rope instead of the roller chain. My thought is that it would be smoother and more efficient to not make three direction changes. My idea is as follows...

Thoughts? Am I on the right track, or should I stick with the chain drive and a larger sprocket?

Cutting Edge · June 30, 2012, 12:37:58 PM

I too have been kickin ideas around about either leaving my chain drive or switching to cable. Both have their pros/cons. The biggest benefit I see of using chain is repairs. If the cable breaks, you either have to long splice it or replace it all....with chain, all you need is a master/repair link.

Celeriac · June 30, 2012, 02:45:21 PM

The more I think about the cable idea the more confused I get. In essence the cable needs to slip laterally on the pulley as it rotates, so there has to be a fine line between too much and too little tension. Perhaps it's time to buy a bigger chain sprocket and keep on moving.

Indiana Robinson · June 30, 2012, 07:15:28 PM

The Kasco mill I use to have (bought new) came new with cable drive. The cable tension was controlled by a spring at one end of the cable. It has been too long to be sure but I think it was on the left end so that the capstan winch action was pulling toward the spring.
The cable was only about 1/8" (again I forget for sure). The cost of just replacing it was quite low but I think I only replaced it once. About all that wore much was the aluminum pulley. I believe it was aluminum so that the cable would grip it better. I was quite happy with how it worked for me. It also served as a bit of a slip clutch if the pull was too heavy. As I recall I had two opposing wing nuts on the spring end eye bolt that held the cable so I could adjust the tension without tools.

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bandmiller2 · July 03, 2012, 07:52:25 AM

Of course a fella could go hydraulic very durable and easy to control. Frank C.

Celeriac · July 03, 2012, 06:15:36 PM

Quote from: bandmiller2 on July 03, 2012, 07:52:25 AM
Of course a fella could go hydraulic very durable and easy to control. Frank C.

True, but what electrician would want a hydraulic drive? In all seriousness I did contemplate something involving a power steering pump but abandoned the idea after some consideration and pricing of parts.

kelLOGg · July 03, 2012, 08:10:58 PM

I put a chain drive on my Cook MP32 and the advice Cook gave at the time was to drive it from both sides. Driving only one side can make the other side play "catch up" when sawing a big log bcause it requires more force. I put a one side drive on first and the very first log I sawed I observed just what Cook described so I added a 2nd chain on the other side and have never since had a problem. The "catch up effect" produces a cut with a pronounced washboard appearence. Look in my gallery for pics if you like of the drive mech.

bob

Hilltop366 · July 03, 2012, 08:24:41 PM

I wonder if you off set the ends of the cable and have a bit wider flat bottom pulley the cable would not rub on itself and wear as quickly or have to slip sideways, could also put more than one wrap on the pulley for added traction if needed.

Larry · July 03, 2012, 08:51:00 PM

With my old Kasco I found out I could go WOT in reverse and hit forward if I wanted to break the chain. :-[ :-[ I only did that a few times...about the same number of times as I tried too saw off a log stop. :D

The optimum solution is to put a chain on both sides. As good as the feed works from the factory, I don't know if it would be worth the effort to re-design.