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KO LEE B250 Cutter Grinder with B923 Motor - no spindle?

uchip

Plastic
Joined
Jan 25, 2023
Hi all, first post here.
I recently purchased the above cutter grinder at a decent price in what seems to be in good condition. This model however does not use a spindle; the grinding discs mount directly on the motor.
Now since I coudn't find much information on the web I wonder if this B250 model is a "starter" grinder intended to be used as is or if some/all of the many options KO Lee offered can be added. I would be interested in adding a spindle if possible. My main application is grinding rubber rollers so I would be using it as a small cylindrical grinder with let's say 6 inch wheels (I think 8 inch wheels would be pushing it). By adding a spindle with its smaller core when compared to the motor would extend my reach when I grind between centers. This is what I think anyway. Now my questions:

1) If I can't add a spindle to this unit then this will be the end of this chapter and I will use it as is.
2) If I can add a spindle, how the heck is the B923 motor removed from its column so I can add the appropriate saddle and accomodate the extra hardware for the spindle? The head rotates freely 360 degrees and goes up and down very smoothly using the handle but I see absolutely no screws or anything letting me remove this thing. Is this done by underneath? Even if this is a small unit when compared to its brothers it is still quite heave to reach out under and fiddle with bolts.

Some photos attached. Any help would be appreciated.
 

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There are a number of K.O. Lee cutter grinder manuals on the Vintage Machinery website.
There is a model in the PDF that is a close match to your grinder.


The short answer is that the grinder is not designed to accept a add on spindle. (See page 9 for a version that did accept a spindle)
You may find that the 1/2 HP motor is adequate for grinding hard rubber with a silicon carbide 8" wheel.
 
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In fact that attachment on page 9 would be ideal. And an 8" wheel would give me enough reach to grind between centers, cylindrical style. The issue here is the surface speed which would most likely be too high for our application at around 86K in/min (8" wheel, 3450 rpm motor). We currently grind at around 25K in/min so either I reduce the speed of the motor which is not ideal with a single phase or add a gear reducer which is also not ideal to implement or I do a ~3:1 pulley ratio with a spindle; unless there are other solutions I'm not aware of. So if there is a way to remove that motor from its column and see what can be done I would look into implementing a spindle; it might be doable even if it wasn't designed for it. It seems like a nice machine, I would hate not being able to use it.
 
I suspect there are two nuts under the plate where the motor spindle is mounted. Theybloosnt to rotate and with the nuts off the motor can lift off.
*Still if the motor runs smooth there is no reason to take it off
looks like a scraped oil way travel for long and cross, and the is very accurate..
spindle nose extentions are common for that type grinder.
To get the wheel a distanc out one can turn the motor spindle to an angle, and then dress the outward portion of the wheel with s dresser mounted to the table travel.
turn/swing the wheel head in the direction that allows the wheel holding nut to tighten when in use.

Agree it is a shame they dont show the wheel head turned at angle in tha manual. That is a very common practice for OD grinding.
I would likely use a 7" wheel.
 
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Another option I have used is to add a motor plate and an extra motor so using the motor-spindle just as a spindle. That way one can change RPM with changing pulley size.
Turning slowley a 8 or 10 inch wheel wotld be ok. looks like
a 10" wheel @ 800RPM would be about right
 
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"Grinding rubber" would be a great thread topic

Adding that here would not have a good search topic so to start a new thread would be great.
Sfpm, wheel choice, wet or dry othe aspectsyou migh include toget the thread started.
Buck
 
Using a spindle nose extension could be worth a try so I could mount smaller grinding wheels, ID grinding style and adjust surface speed that way. Just wondering how accurate these extension arbours are; would need about 4 inches pass motor body in length. In this case I would use the machine in a surface grinder configuration instead of cylindrical grinding. My motor shaft is 5/8" with both an outside and inside thread. Wonder what the inside thread is used for? And what type of arbour would be suggested here if I use let's say a 2 or 3 inch wheel? I apologize for my ignorance with these machines.
 
My KO lee Id thread is for holding a flat ended mount, that has a 5/8 straight wheel mount diameter. It is not a taper nose spindle like a normal surface grinder or Tc grinder has.

I was thinking that you might the motor spindle 30 or 45* so the part is still facing the wheel Od but at an angle...Then you dress the wheel Od to be parallel with the long travel.

I would make a motor mount plate to mount an aditional motor behind the the motor/spindle, then run a belt to drive at the correct SFPM. The existibg motor would just be driven as if it was just a spindle.
That way you could do your rubber work..and still use the3450 RPM wnen needed.

You could pull the motor and in its place mount a tool post grinder.
 
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