KO-Lee Cutter/Grinder Revamp

Ray C

Registered
Registered
Joined
Nov 16, 2012
Messages
5,586
Perhaps you've seen this from other photos... It's a KO-Lee cutter grinder. It's a good platform and the table and all mechanisms are in excellent condition. I don't think this machine was used much in it's lifetime as there are very few signs of wear (hardly any at all really).

IMG_20180102_193146.jpg

The motor is the weak link. The bearings are going bad and vibration can be felt in the short shaft. The long shaft is OK. The seller told me about this when I got it. I'm guessing someone bumped a wheel really hard and damaged the bearing on that side.

Anyhow, I once had a B&S #2 surface grinder but, sold it a few years ago. It needed too much work. It took up too much space, and I rarely worked on parts more than a few inches in size. Also, the things I make do not need sub-ten-thou tolerances. I've used the KO a couple times to do some grinding on small parts within a half-thou and it works out fine. My plan when I sold the B&S was to modify the KO-Lee to handle the simple grinding tasks that come my way.

The time as come...

I'm tackling this in a couple ways and doing the work simultaneously as I go. The plan is to address a travel issue with the KO. It's got about a 12" horizontal travel which stays true the whole way. The vertical travel is about 4" and falls-off at the extremes. I'll see what I can do about that. The other idea, is to remove the old motor and replace it with a small 3 phase and design a new spindle. The spindle design will just be a larger version of the tool post spindle I dreamed-up and posted here several years ago. It's proven to be a very good design but I want to improve a couple things to handle heavier grinding wheels possessing more rotational energy.

This will be an ongoing project that I hope to finish by spring.

The drawing for the spindle is being recreated from the ground up. Here's a sneak preview. The design is still in my head and no dimensions are shown because I'm still making rough measurements of the KO-Lee platform and also, I have not settled on a convenient way to terminate the business end of the grinder shaft. Kicking about 3-4 ideas around. Here's what we have so far. You can upload the .pdf and see it in 3D.


SpindleConcept.JPG

As with the last project (https://www.hobby-machinist.com/threads/bull-nose-live-center.64859/) all the machining shots along the way will be shown and described (so you can butcher-up metal just like me).

Regards

Ray C.
 

Attachments

  • SGSpindleAssembly.pdf
    161.2 KB · Views: 25

benmychree

John York
H-M Supporter Gold Member
Joined
Jun 7, 2013
Messages
6,092
What would be wrong with simply replacing the bearings in the original motor?
 

Ray C

Registered
Registered
Joined
Nov 16, 2012
Messages
5,586
What would be wrong with simply replacing the bearings in the original motor?

For the sake of preserving this machine, I'll probably do that too. I'm trying to get a little extra use out of it. The motor shaft is longer on one end than the other but even the long end won't extend far over the centerline, even with the motor fully rotated. That motor attaches with two bolts and sits on a heavy rotating platform attached to a 3.5" dia cast iron pole that can elevate up/down precisely. It's the perfect assembly to make a table-top grinder. The whole frame is about 100 times more rugged than the flimsy 1/2" diameter shafts coming out of the motor.

If you're concerned about preservation of the machine, don't worry; I like old equipment too (as long as it's not totally clapped-out). The motor comes off with two bolts, it will be put in storage with other treasures and a new modular assembly will go on the existing pivot atop the pole.

Regards

Ray C.
 

Ray C

Registered
Registered
Joined
Nov 16, 2012
Messages
5,586
When this was purchased about 5 years ago, it was disassembled, cleaned and lubed. FWIW, the scraping is about 80% good condition. Since buying, it was only used about a dozen times and only needed to make horizontal (+/- X) passes. In that direction, it stays within a thou until the last inch of travel. I can live with that. In the Y direction, it was varying on a constant slope as the bed was moved toward the front.

I just did a quick disassembly and re-cleaning of the ways and gears. (I'll wipe-down the outside soon. When I was taking it out of storage, a bag of polishing rouge spilled on it....) Anyhow, upon indicating the table, things are looking up. The X direction still looks good and the Y direction can be fixed without modifications.

The arm (I'm pointing to) supports the table and it apparently has a slight slope upward (wrt to the motor pedestal). That arm is totally fixed and the Y ways and gibs are fixed too. The only apparent way to fix the slope is to scrape the ways or bend the arm... I'm not going there. Simple solution... With a sine plate atop the milled circle where the adjustable angle bed sits, I could get the Y direction to run perfectly true with a 1.5 thou shim under the sine leg.

IMG_20180114_153337.jpg IMG_20180114_153423.jpg

I had a hunch this was how things were going to work out. End of story... I'll make a little fixture to hold a small mag vise I happen to have and make sure it's shimmed accordingly. With that shim under the sine plate, the 4" of travel did not move outside of 1 to 2 tenths. I'm good to go. I'll finish cleaning it, build a proper stand (with storage underneath) and continue the motor/spindle module.

Ray C.
 

benmychree

John York
H-M Supporter Gold Member
Joined
Jun 7, 2013
Messages
6,092
It may be a problem to find a replacement motor for the job that is well balanced enough to perform satisfactorily for grinding.
 

Ray C

Registered
Registered
Joined
Nov 16, 2012
Messages
5,586
It may be a problem to find a replacement motor for the job that is well balanced enough to perform satisfactorily for grinding.

Naaaah... I'll toss a 3 phase on it. Maybe a 1/2 or 3/4 HP. I've got a couple 1HPs around but I'll look for a smaller frame unit.


Ray
 

Ray C

Registered
Registered
Joined
Nov 16, 2012
Messages
5,586
So here's all the basic parts except the tube/housing in the middle. The ends of the shaft are not designed yet but all the pieces are positioned. A couple things need some minor tweaking after all the components arrive and are measured. The final length needs to be decided upon as well. If you have questions, let me know. Perhaps tomorrow I can post an exploded diagram.

So far, the only significant difference between this and the old post grinder design, is a heavier tensioning spring and beefed-up rear bearings. Those were changed from needle bearings to two radial bearings. For the spring, I'll probably use an automotive cylinder head valve spring.

Once again, the PDF can be uploaded and viewed in 3D.

SpindleBasicParts.JPG
Regards

Ray C.
 

Attachments

  • SGSpindleAssembly.pdf
    744.4 KB · Views: 16
It can take up to an hour for ads to appear on the page. See our code implementation guide for more details. If you already have Auto ad code on your pages there's no need to replace it with this code
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock