Motor speed controller for Kally 1SM?

[Ken S]

This novel has a happy ending. I had the wisdom to follow Rupert's suggestion and call Don. Don walked me through adjusting the potentiometers. After a few minutes, I now have the motor range from 600 to 2600 RPM. I don't think I will use the extremes, but the range seems very useful.

I will write up a more complete article. For the present, I want to express my gratitude to the forum members who helped make this possible. Without your help and encouragement, this would not have been possible.

Ken

[grepper]

Good job Mr. Ken!  After all that you have your grinder back better than ever! Please keep us posted!

Do you like one of your tach's better than the other?  Which one do you like?

[Ken S]

My favorite tachometer is: both. Either works well. I do not understand why the Cyber Tech seemed to act up initially; it works fine now. The Harbor Freight tach is larger and twice the cost, not what one would think for Harbor Freight.

I don't think most users need two tachs. I will just keep both for a "second opinion". I have often stated in posts, "there is no bad choice, just one choice which may fit your needs better".

Ken

[Jan]

Mr. Ken, referring our discussion concerning DC motors, I would like to mention, that I have just ordered an electrical construction set for my 8 years old grandson.

   
 
More than half century ago I was experimenting with exactly the same toy. I'm looking forward to return to it again.

[Rupert Lucius]

Mr. Ken, referring our discussion concerning DC motors, I would like to mention, that I have just ordered an electrical construction set for my 8 years old grandson.


 
More than half century ago I was experimenting with exactly the same toy. I'm looking forward to return to it again.

I, will follow you and order said set for my Grandson Ian who just turned 7.

Thanks
Rupert

[Mark Reich]

I've been using Kallys for many years, and have two methods of effectively "slowing down" the grinder.

This is going to sound simplistic, but the less pressure you use, the slower the machine works.  

When using a lightweight finishing belt, I run it on top of a worn out heavy belt so I have a flatter, more precise surface. It's easier to achieve precise pressure, especially on the edges of a lightweight finishing belt. I also use a heavy belt under leather, to eliminate "flutter". The more precisely the belt runs, the easier it is to use no pressure.

Even slower? I don't turn the machine on. I "strop" the blade on the stationary belt, just by drawing the blade from bottom to top. 

I finish edges using either method.

[grepper]

Even slower? I don't turn the machine on.

[pjwoolw]

I've been using Kallys for many years, and have two methods of effectively "slowing down" the grinder.

This is going to sound simplistic, but the less pressure you use, the slower the machine works.  

When using a lightweight finishing belt, I run it on top of a worn out heavy belt so I have a flatter, more precise surface. It's easier to achieve precise pressure, especially on the edges of a lightweight finishing belt. I also use a heavy belt under leather, to eliminate "flutter". The more precisely the belt runs, the easier it is to use no pressure.

Even slower? I don't turn the machine on. I "strop" the blade on the stationary belt, just by drawing the blade from bottom to top. 

I finish edges using either method.

Bingo!

I suppose all this variable speed stuff has advantages but I've never been able to talk myself into it. That much time and money, for me, would be better invested in a 2x72. I really don't need one of those either but it would be fun.

So what do you all gain be going variable speed on such a small unit? There isn't enough torque at low speeds to do anything heavy. Just trying to understand a little better what the goal / benefit is. Bang for the buck, etc.

[grepper]

I've felt no need to slow the Kally 1SM, but I thought it might be fun to play with if I could do it for very few $$$.  That however is apparently not the case, so for me the "bang for the buck" is a no-go show stopper.

I suppose it might be helpful for very small pocket knife blades and small scissors.  That kind of thing.

Even though the RPM is the same on the Viel as the Kally, 1725 RPM, the Viel grinder runs the belt faster because it uses a 6" drive wheel compared to the 4" on the Kally, so I suspect it quickly produces considerable heat.   I'm guessing that is why there is considerable interest in slowing down the Viel.  Another less expensive and involved way to go for the Viel would be to just use a smaller drive wheel.

[Jeremy]

Since I have been Frankensteining a 1"x42" grinder into something that hopefully I will be its own one day I thought the variable speed motor would be a good place to start. Not just for only for the mentioned feature but also its smaller size. I would like to have a contact wheel as some of you have with the Kalamazoo.

Mark realy seems to be on pint with lighter pressure and a "backing" belt. Genius!

The lighter pressure has been my answer when using finishing belts. I'm still not sure if slowing the speed of the motor down has any advantages or disadvantages even in the warmer seasonal temps. I do however like cranking it down when removing the final bur on toothy edges!

Other than the cost of the motor the only other necessary investment I see is paying someone to turn the inside diameter of the drive wheel to fit the new shaft. I swapped two wires in the control box to run the opposite direction, but at some point likely add another switch as Ken has done to run in both directions.

I believe it may have more advantages and uses with ability to change arbor size if the motor is mounted in way that Max has done.