# 8520 Knee Bevel Gears



## Zertsman (Dec 21, 2021)

Just brought home an 8520 that needs a bit of love and care.  I can see the teeth on the bevel gears for the knee are just reaching and really look worn.  There is gap between the teeth and the individual teeth are more triangular shape and pointed on the ends.    Is there a place to purchase these gears, or something close that can be modified to fit?   Maybe blanks that can be bored out to fit the existing shafts?

I have a lathe and can modify gears, but do not have the equipment or expertise to make a matching set of bevel gears.

Any help is appreciated.


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## Flyinfool (Dec 21, 2021)

Need more info.
At least close dimensions of each gear, tooth count, shaft size. Some pics would help to.
There are places that you can buy gears, but we need a lot more info to try to find a close enough match.


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## Zertsman (Dec 21, 2021)

I just got it home today..   Wanting to replace my round column mill with a knee mill.  I'll need to take it apart.  I think I'll have to take the whole knee off to get the shafts out and the gears off.  Was hoping for a cleanup and lubricate.    I guess for such an old machine, some wear is inevitable.

With tooth count of each gear and some overalls, I'm assuming it's possible to order a set.  Correct?


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## Alcap (Dec 22, 2021)

I’ve heard that Clausing has parts for our older machines . Have you looked up the part numbers yet ?


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## jcp (Dec 22, 2021)

Clausing part numbers are 341-019 and 341-018.


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## Zertsman (Dec 22, 2021)

I had read that here.   had doubts they'd have parts for something so old, but called and they are on their way.  

good advice here as usual.  Thanks for everything.


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## Janderso (Dec 22, 2021)

Zertsman said:


> I had read that here.   had doubts they'd have parts for something so old, but called and they are on their way.
> 
> good advice here as usual.  Thanks for everything.


Parts for the 8520 should be a viable business, they made a bunch of them.


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## woodchucker (Dec 22, 2021)

Zertsman said:


> I had read that here.   had doubts they'd have parts for something so old, but called and they are on their way.
> 
> good advice here as usual.  Thanks for everything.


how much did you pay? just curious. Every thing from them seems to require you to give your arm and leg... sometimes both legs.


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## markba633csi (Dec 22, 2021)

I'm guessing 225 for the pair


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## Zertsman (Dec 22, 2021)

The gear on top of the screw was 140ish and the gear on the knee handle shaft was almost 50.    since one was cheap, I got the both, because they'll fit each other.  Had they both been expensive, I'd be following the advice above.   It's all about the ratio of the 2 gears and how they fit the shafts.  It's a fiddly process, but fully doable.

I just wanted to clean it up and have a mill with a knee.  I think the capacity of this mill is below the round column one I have, but it's round column mill.  I get tired of re-setting up after moving the head.  Also the R8 collets are nice.  This little thing has smaller collets.  I'll need to get new arbors for my chuck and boring head.

I'm missing the fine feed handwheel as well..   they want 85 dollars for it..     guess I'll make one.


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## woodchucker (Dec 22, 2021)

I made one ... took an old wheel and just put a pin in and it's done.
BTW, since you already have a mill, you might want to change the quill lock like I just did. It will improve your experience greatly.  You need to offset the hole from the existing hole, and with a real mill, you would have the capabilities, and it will be short work.. I didn't have a second mill, so it was more involved.








						[How-To] - Clausing 8520, 8530 New Quill lock like a BP
					

I kept calling this a brake in the POTD.. sorry. brain fart. I wanted a tool less lock. It originally came with a hex cap bolt. I created a new one with a tool less design, but it required an enormous amount of torque to pull the casting tight. A horrible desing. I always noticed in Utube videos...




					www.hobby-machinist.com


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## woodchucker (Dec 22, 2021)

This was an old wheel from my Southbend that was broken... welded it up and drilled, bushed, and pinned...
you don't need much


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## Zertsman (Dec 22, 2021)

I saw the lock..  really slick.  do you have dimensions on modifications to the head?
How far you moved the hole and what diameter?
Dimensions for the brass sluggs?

my round column mill has good functioning quill lock which i think is identical to the one you have devised.  quill has never dropped while machining as long as this is tight.


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## Zertsman (Dec 22, 2021)

about what diameter wheel did you use?   prolly doesn't matter much I guess.


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## woodchucker (Dec 22, 2021)

mostly 7" My go to was 7" now about 5  sorry, I confused threads.  that was for the surface grinder..
I'll have to measure.

The slug was 3/4 but turned down to I think .741..
I moved the hole but don't know how much. I didn't have a way to measure it.


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## Zertsman (Dec 22, 2021)

slick and simple..    just have to dismantle the head and get it on the other mill..   prolly a good idea to scatter it and inspect things though.


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## woodchucker (Dec 22, 2021)

just don't blow out the back of the hole. It's important the keep that structure there.
see pics of the back end.


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## Zertsman (Dec 22, 2021)

I'll take out the lock from my round column and steal some dimensions.


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## woodchucker (Dec 22, 2021)

Zertsman said:


> I'll take out the lock from my round column and steal some dimensions.


I doubt they are the same.
You will have to engineer it on the fly.


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## woodchucker (Dec 22, 2021)

My wheel is 4.5 inches.


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## Zertsman (Dec 25, 2021)

Ok..  Got my new gears in hand and started into tearing it down.  I thought I could do it all from the bottom but can't get good purchase on the lead screw to loosen the nut on top of the gear.

So I took off the table and cross slide and lead screws to get a socket on top of the gear.  This is what I see.  It has been thoroughly peened.  What is the best way to hold the OD of the leadscrew and use an impact or rachet to loosen the nut?

The knee is still on the mill.  I'd really rather not take it off.  I don't have a lot of that kind of help to get it all back on.

I thought of milling some grooves in wood blocks and clamp it that way, sort of like a rifle action in a vice.  It's pretty smooth and I doubt my strap wrench will hold it.

Is there a trick?

Thanks


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## woodchucker (Dec 25, 2021)

wow, what kind of moron does that?
If I remember the gear is keyed, why would someone need to peen over the shaft like that?

I think you might need to grind the top of the shaft and nut using a die grinder.
Or maybe take a drill bit that would drill the top of the shaft out.. same size.. I would grind the tip so it stays in the center already drilled, and a very flat grind you don't want to take much of the shaft off, so you want it taken off quickly.

Or I might just turn the nut off and hope that the shaft does not twist.
Or hit it with a torch and turn the nut off.. losing the nut is not a big deal, hurting the shaft is.  That peening is not a little peening, it is heavy and excessive.

That's what I would do... hopefully someone else has another idea.
Good luck


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## Flyinfool (Dec 25, 2021)

What about using a nut splitter to get the nut off? That will let you get the nut off then you can clean up the threads on the shaft with a thread file. You may need to grind the top of the gear teeth a bit to make room for the splitter, but you do have a new gear in hand. You will then need a new nut that is likely available at the hardware store, even if you have to cut the nut a bit thinner.


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## Zertsman (Dec 25, 2021)

was wanting to leave the screw installed.  I'm going to try and clamp it with all my clampy devices and see if my impact will just spin it off.

If I damage the end of the shaft, I guess I can turn the shoulder down a little, but then I'll have to disassemble it.  maybe.


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## Flyinfool (Dec 25, 2021)

With the nut splitter you can leave it assembled.


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## jcp (Dec 26, 2021)

I took mine completely apart….knee and all but I can see why you would rather not. Since the gear is toast, can you get to it enough to grind a couple of flats on the gear sides for a wrench or any sort of clamp? If you can’t get to it with a grinder, the barrel type wood clamp on the shaft should get it off.


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## Zertsman (Dec 26, 2021)

Barrel clamp..   that's what it's called..   I'll throw one together and see what happens..   Need to get some things.


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## tq60 (Dec 26, 2021)

Get a small pneumatic 90 geared die grinder and small carbide cutter.

Carefully remove area where damaged.

Cut nut away from shaft.

Carbide will make it a short job. 

Sent from my SM-G781V using Tapatalk


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## woodchucker (Dec 26, 2021)

Zertsman said:


> Barrel clamp..   that's what it's called..   I'll throw one together and see what happens..   Need to get some things.


So one thing you may not have thought about, is tightening all the gib screws (not hard, you don't want to damage the gib) with the right pressure the knee won't move and you might be able to in effect lock the screw.

just be careful.


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## Zertsman (Dec 27, 2021)

barrel clamp worked.   Drilled an undersized hole in the wood, split it, clamped it on and held the lead screw quite well.   Was able to back off that nut with a rachet easily enough.  Chased it with a tap and reused it.  That part is done.   Found new issues, will create a new thread if I can't find solutions.


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## wa5cab (Dec 28, 2021)

In general, Clausing has a lot of parts still available for machines that they or Atlas Press once made.  However, AFAIK all such parts are US made and made in relatively small quantities.  So parts for machines made back in the early or mid 20th century are going to seem expensive if you are like most Americans only used to the lower end of Chinese-made equipment.  In any case, $83 sounds OK.  

As far as the spindle nose goes, it would be nice if Johansson had used R8 when they designed the mill but they didn't.  Fortunately 2MT collet sets are still available and will work fine.


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## Zertsman (Dec 29, 2021)

I got it with a keyless chuck, but only up to 1/4"

Having trouble finding a budget friendly 1/2" keyless chuck and a 2mt arbor with a drawbar already drilled.  LMS has an arbor on Amazon but the chuck end is 2JT.  All the cheap chucks are J33.  Last arbor I tried to modify was difficult.  This one being tapered on both ends, will have to be pressed into the chuck and the chuck either directly in the lathe jaws or tighened onto a piece of bar stock.  I know the position of the drawbar threads doesn't have to be precise, but there are alot of variables.

Am I worrying for nothing?

I'm not that worried for the 2MT vs R8..   I have some fly cutters I'll need turn arbors down for, but most things will be fine.  I have endmill holders for larger cutters.


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## woodchucker (Dec 29, 2021)

Zertsman said:


> I got it with a keyless chuck, but only up to 1/4"
> 
> Having trouble finding a budget friendly 1/2" keyless chuck and a 2mt arbor with a drawbar already drilled.  LMS has an arbor on Amazon but the chuck end is 2JT.  All the cheap chucks are J33.  Last arbor I tried to modify was difficult.  This one being tapered on both ends, will have to be pressed into the chuck and the chuck either directly in the lathe jaws or tighened onto a piece of bar stock.  I know the position of the drawbar threads doesn't have to be precise, but there are alot of variables.
> 
> ...


I saw that AllIndustrial had one.
I was thinking of getting. I have one for for my drill press from a company no longer avail... The chuck is great, but the more I used it, the more I appreciated how fast I can do a keyed chuck.


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