converting a Kalamazoo 1SM

[Ken S]

I have been posting about "Gen III", converting a Viel belt grinder to variable speed (Gen II) and switching to a smaller Viel drive pulley (Gen III). I am happy to report that I am most pleased with Gen III, and will post full conversion instructions. soon.

Along the way, I became curious about the Kalamazoo 1SM belt grinder. I had no intention of purchasing a second belt grinder; I was just curious. Several bessex friends shared their thoughts with me. I acquired a 1SM "skeleton". A previous owner has purchased it for its legendary Baldor motor. I installed the fixed speed motor I originally used on Gen I with my Viel. The combination worked nicely for a very brief time until my motor shorted out.

I had a second Penn State Industries motor I was planning to use for a sevond Viel conversion. I decided convert my 1SM to variable speed. I probably would not have done this if the original Baldor was still attached to the skeleton. With a dead motor and a spare variable speed motor on hand, it became a no brainer.

I will describe both what I did and what I would do differently. The constraint with the 1SM is the round shaft for the idler pulley. It is welded onto the frame where the PSI motor would ideally be mounted. This means that the motor must either be mounted with spacers to clear the hump or lowered. I intended to mount the motor lowered and butting up against the frame. In a senior moment I decided to try using spacer bushings. These worked, however, I ended up lowering the motor somewhat to clear the platen mounting.

Next time, which will probably never happen for me, I would lower the motor mounting holes and pull the motor up directly against the frame. Using a square, I scribed a vertical line  through the center of the existing shaft hole. The hole is one inch; placing the vertical line half an in from the edge is accurate enough. EDIT: Lowering will not work without modifying the round shaft. The shaft has a milled groove to accept the locking screw of the collar. The groove does not extend high enough to lower the motor enough to directly abutt the frame. The groove could be milled to be longer, however, just using the three standoffs seems the practical course. Sorry that I have been too occupied to return to this. I hope to complete the thread soon. The Kally is working very well.



Sorry, this post is incomplete. I can not get the photos to post. I will keep trying.

EDIT: The first attached photo shows how I used the lever which came with the Penn State Industries motor as a drill pattern for the three radial motor mounting bolts. It also shows how I lowered the motor slightly to clear the platen mounting. The lower shaft hole was drilled with a hole saw.

The second attached photo show the hardware I used. The bolts (stainless, although regular bolts would work M6x30) and the heavy steel bushings which hold the motor securely clearing the round shaft.

The third attached photo shows two of the bushings.

The fourth attached photo shows the heads of the three radial motor bolts.

The fifth attached photo shows the motor portion of the Kally.

No mounting plate is required. If someone should ever want to convert back to a fixed speed motor, the conversion places no hinderences.

Ken

[grepper]

Let me know if there is anything I can do to help getting your images posted Mr. Ken.

[Ken S]

Thanks, Grepper. They are the same images I sent to you. I would be most appreciative if you would post them. I will do a follow up post with captions.
Thanks muchly,

Ken

[EOU]

This is going to be a great topic Ken and we are very happy to see that you are going to share the details with the Exchange. Almost every day we receive a call or email from people who are going to enter the sharpening game, either for fun or profit, but are lost with regard to the type and model of equipment and supplies they should buy. Experienced sharpeners like you are far better qualified to give advice in this regard than we are. Your thread is going to provide some very interesting perspective to issues that the novice may not even be considering.  In that vein, we would encourage you to explain your modifications in the sense of not only "what you did" but "why you did it" for the benefit of those who don't have as many used-up abrasive belts tucked under their suspenders as you do. We should all give Ken a round of applause. He's invested significant amounts of time and treasure in developing these tools. Thanks for putting in  the effort on these projects Ken and thanks, in advance, for sharing with the BESS Exchange.

[Ken S]

Sorry about the photos. I will have to redo them. As a fifty year film and darkroom person, this is frustrating.

Ken

[Ken S]

I just completed the first post and added five photos. Please do not hesitate to post questions or comments.

Ken

[grepper]

So, what do you think of your new child Mr. Ken? How's it panning out? Do you know the min/max belt SFPM?

[Ken S]

How is my new child, Grepper? So far, so good, however, I have spent more time disassembling and reassembling both the Viel and the Kally than actually sharpening with them. I have two tachometers and do plan some testing. Preliminary (unverified) tests indicate that my original PSI motor (which I adjusted for speed range) reads approximately a 600 RPM minimum speed. Since I have not verified this reading, I will use only rudimentary math. A four inch drive pulley is one third of a foot. That roughly cancels out multiplying the diameter by pi. Therefore, the surface feet per minute is around one times the rpm, or 600 sfm. That is around one third of the unmodified Kally's sfm, and even lower than the unmodified Viel with the six inch drive pulley.

On the high end, the PSI variable speed motor's top speed is about 2600 rpm, substantially higher than the unmodified Kally.

I have a piece of plate aluminum I cut off of an earlier Viel plate. I have been flattening and smoothing the bandsawn edge. When I had my Kally working with my 1/4hp fixed speed motor, I could only hold it against the grinding belt for a few seconds before it became too hot to hold. With the lowest speed, I can hold it perhaps twelve seconds. That is not Tormek, however, it is noticeably better.

Knowing what I now know, I will not try to adjust the factory settings on this second motor. The factory range is quite satisfactory.

Ken

[grepper]

"I could only hold it against the grinding belt for a few seconds before it became too hot to hold. With the lowest speed, I can hold it perhaps twelve seconds."

Did it take 4X as long to remove the same amount of metal using the slower speed than faster? 

Aluminum is pretty sticky stuff.  I suspect that it heats faster than steel due to increased friction.  Does anybody know if that's correct?

[Ken S]

Grepper,

Your questions are well chosen. I consider my last post as initial observation, with any remote resemblence to good science being purely coincidental.

When I get caught up with some other projects, I will do better. I will take minimum and maximum RPM readings with both of my tachometers and use proper math to compute the SFP.

I keep a digital timer in my sharpening area. I will make up three identically sized pieces of flat steel. I will hold each in my fingers and grind for an identical length of time. One piece will be at minimum, one at maximum, and the third at middle speed. I will take before and after dial caliper readings to show the amount of steel removed. My gut feeling is that with the cooling time included, the slower RPM will actually remove more that 1/4 of the metal that the faster speed removes. I will let the tests tell the tale. I have always been more concerned with temperature than time.

I agree with your thoughts about aluminum. It was a poor choice for my ad hoc grinding. It just happened to be sitting on the bench next to the Kally.  

Ken