KO-Lee Cutter/Grinder Revamp

Ray C

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Made good progress this morning (Oh, how I love having the day off work)...

Here's the first final draft. The parts have been sourced and if this thing works, I'll post all the links to the materials.

With luck, all ABEC-5 bearings were sourced on sale. Taper bearing was $20 and the two radial bearings were $20 each (not bad for ceramic). Two radials were used because the cost of a single wider one, tripled the cost of all the bearings combined. The thrust bearing was $7. Two O-rings were $5. Two oil seals were $5. The automotive valve spring was $6. Total cost is $83.00 and that includes shipping on everything. The metal is all shop drops and it will be a combo of 4140, 1045 -and the tube in the middle (not shown yet) will be aluminum. Automotive transmission fluid will be used for a lubricant. Pretty sure there is a bottle or two in the garage.

There's only one part that refuses to be found easily... A small breather cap with a filter is needed. Just need enough ventilation to let pressure equalize when temps change. -Don't want to suck grinding dust in thru the oil seals. It will get in there over time. Let me know if anyone has leads on a small screw-in, filtered breather element. It can have a tube if needed.

Anyhow, to get good prices, the design was switched to metric bearings. Also, I found (and enclosed) a really handy automotive valve spring ID chart that has full dimensions and compression specs. The compression specs will be needed so a proper shim can be inserted to set the preload on the taper bearing. I've used valve springs for all kinds of stuff and finding this chart was like finding the Rosetta Stone.

Question: To save me some time, does anyone out there have any info about taper bearing pre-load pressures? If you do, let's talk!

The 3D spindle animation and valve chart PDFs are enclosed as attachments.

FirstCompleteDraft.JPG


Regard

Ray C
 

Attachments

  • SGSpindleAssembly.pdf
    814.3 KB · Views: 7
  • Valve Spring ID chart.pdf
    34.7 KB · Views: 11

Ray C

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Thanks... While looking into the ones you suggested, these showed-up as a product suggestion and kinda what I had in mind. I might make some kind of hex that covers this and has a cotton/fiber filter too.

https://www.amazon.com/gp/product/B0195UXY6M/ref=ox_sc_act_title_2?smid=A158LRHTFH4QLV&psc=1

Anyhow, I'm going to have some kind of breather and filter element in there because grit inside the spindle is what killed the bearings in my old surface grinder.

Ray
 

Ray C

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Getting a little closer... I think the dimensions are about right except the tapered end needs to be about 1/2 - 3/4" shorter. The taper is a 2 degree so I'll have to make my own hubs for this. The shaft diameter is not large enough to support a standard 3 TPF hub dimension. On the positive side, shallow tapers are easier to cut.

DraftII.JPG

3D PDF also enclosed...

Ray C.
 

Attachments

  • SGSpindleAssembly.pdf
    949.8 KB · Views: 9

Ray C

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Whoah baby, the bearings and oil seals showed-up today. The only thing I'm waiting on now is the O-rings and the vent plugs but those are not show-stoppers. I mic'd out the bearings to verify size then, plugged the values and tolerances into the CAD (FYI: Alibre). All the bearings were ABEC 5. They mic'd dead-on to spec and feel really nice. What is it about bearings that just seems so cool for some reason?

Friday, I hope to cut most pieces to rough size leaving plenty for the chucks to hold on to. I'm going to heat treat all the metal to RC 38 which is really nice to work with. Not too hard, not too soft, gives nice surface finish that is durable enough for these purposes. The center tube will not be heat treated because it's just a chunk of 2" dia, schedule 80 pipe -not enough carbon in it to bother with. FYI: The diameter of the device was chosen based on sched 80 dimensions.

If all goes well, we'll be in doing lathe work on Saturday. What piece do you want to start with? The choices are: the spindle-end cap, the pulley-end cap or, the spring retainer? (We can't do the shaft or center-tube yet because I'm still deciding on the overall length).

Let me know where you want to start... It's your call. Before we do each piece, I'll post-up the part diagram and profile. We can go step-by-step on how the cuts are executed.


IMG_20180118_214406.jpg

Ray
 

Ray C

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... Didn't get moving on time and am a little behind where I wanted to be. Family matters rule though... The TV cable to the family room went on the blink and I got to spend my Friday night resolving that little issue. Personally, I'd like to cut that cable with snippers but that wouldn't go over very well with everyone else.

The plan is to get all the pieces to rough size then, heat treat the ones that need it. Except for the shaft, all the pieces are trimmed-down.

This is one back-break'n hunk of stock. 4" diameter and about 3' long. Haven't weighed it but, I'll guess it's around 80lbs or so.
IMG_20180119_165539.jpg

I'm not too happy with the current blade in the bandsaw and cutting though a 4" log is taking even longer than expected. All the main pieces were carved off of this. The two end-caps and the two flange plates for the center cylinder piece.
IMG_20180119_172936.jpg

Here's an obligatory action shot... I didn't take pictures while carving things to rough size. I also carved-up some thinner stock -and you'll see why later.
IMG_20180119_181247.jpg IMG_20180120_125631.jpg

And I do believe this accounts for all the basic pieces along with the pieces for a grinding wheel hub. I did my best to size the pieces and orchestrate the assembly steps as not to create a workholding nightmare when the part need to come down to final size. Pretty sure it's all going to work-out w/o too much hassle. You'll see as we get rolling -and if I screwed-up, you'll see that too.
IMG_20180120_143359.jpg

Here's a little hub being made from two pieces. In an earlier post, I misspoke and said it will have a 2degree taper... It's actually 3 degrees and to be specific, it's 3 degrees per side. NOTE: It is not 3" TPF (which is a fairly common hub taper).
IMG_20180120_145532.jpg


The welding Ju-Ju was hit'n on all 8 cylinders today. Yes indeed, this is a gratuitous welding porn photo. It's perfectly fine to ask me what filler wire I used on 1045 -and the answer will be: The piece that happened to be laying on the welding table for the last couple weeks. It was probably 70 or 80S B or D2, possibly 6. Whatever... it will work fine.
IMG_20180120_150132.jpg

So... Hopefully sometime today, I'll fire-up the heat treat oven then, temper these down to about 35 RC which is really nice to work with yet still is a durable surface finish.

Ray
 

Ray C

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Ughhh... ! TIG welding, standing up, working on a round part, elbows up in the air and no hand support. I really didn't want to bother putting the chuck on the welding table so this got welded "cave-man" style. I guess no need for fancy because it's going to be taken down on the lathe. Yes, the weld is recessed a good bit. The outside surfaces of the "donuts" needs to be a precise distance which will be addressed on the lathe; thus, the weld was sunk way below the flat surface of the donut.

Well anyhow, the shaft is 4140 and the donuts are 1045. Do you know what kind of filler rod you're supposed to use with that combination of metal? You guessed it... the rod that's been laying on the table all week. (Turns out it was an ER70S6). I'm sure it will be fine after it's heat treated and tempered. The donuts had to be heated since they were a tight press fit. I'll bring the oven up to 1650 to normalize all the metals. That will remove all stresses, let the metal relax and also allow the weld caps to "meld" with the other base metals. When it drops to 1550, it will get quenched. I have a cylindrical quench tube for just these applications.
IMG_20180120_202150.jpg

And here's the shaft. Currently, it's a good bit longer than it needs to be.

So... those bigger disk-shaped pieces will be welded in similar fashion to a piece of schedule 80 pipe. All the work-holding will be done easily on the lathe. Also, on this project, I'll get a chance to use the bullnose live center that was made not long ago.
IMG_20180120_205943.jpg


I think that's it for now...


Ray
 
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Darn Ray, if I knew you were going to do this, I have almost a full complete head assembly less motor from a K O Lee T & C grinder I bought surplus. All you had to do was mount it on top of the round vertical column, add motor and sheaves and belt. The spindle runs smooth, with the mandrel that accepts the common wheel adapters. Oh well. Don't let me stop you from progress. Looking good!
 

Ray C

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Darn Ray, if I knew you were going to do this, I have almost a full complete head assembly less motor from a K O Lee T & C grinder I bought surplus. All you had to do was mount it on top of the round vertical column, add motor and sheaves and belt. The spindle runs smooth, with the mandrel that accepts the common wheel adapters. Oh well. Don't let me stop you from progress. Looking good!

Thanks Ken but building a spindle like this has been in the back of my mind for a couple years. I pretty-much need to get it out of my system now so, that's what we're going to do. I do appreciate you keeping me in mind though.

And by the way, you know our creed: Never buy something when you can make it for 3 times as much and take 6 times longer to get.

Ray
 
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