# Clausing 8520 Mill gears and other stuff on link, hope this is a help



## gregg (Dec 6, 2014)

[h=1]Gears  http://www.wentztech.com/metalworking/equipment/clausing-8520-mill/[/h]The gears in the quill can easily be broken. Here are some notes I collected on replacement gears:
One owner found one of the gears in his mill was marked Boston Gear S-3232.
 Their online catalog shows this to be a 32 DP 14.5 degree PA 32 tooth
The last pinion that drives the last gear that slides on the spline is 24 DP instead of 32 DP.
It turns out that the small spur gear portion of the 8520 compound gear (Clausing part 990-065 – cost $66) is a close match to McMaster-Carr part no. 6325 K31. Cost $7.79. A bit of cutting to get the hub thickness down to 1/4 inch, some finish sanding and reassembly using 1/4″ dia. cold rolled stock as a shaft and a broken length of 1/16″ drill bit as a pin to lock the two gears – and everything works. Whole job took about an hour and a half.
When I purchased my mill the gears seemed a little crunchy. It turned out that they were just dirty with dried grease. Here are some photos I found on the net that show the gear placements.




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## 34_40 (Dec 7, 2014)

That's good info Gregg!  And a great cost savings too!!  

I guess I was lucky and my fine gears were in great shape and after Terrywerm told me about these being "tender", I pulled the cover and removed them and cleaned / inspected / re-lubed / re-installed.  

So thanks for the info and the help to all of us here.


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## gregg (Dec 7, 2014)

34_40 said:


> That's good info Gregg!  And a great cost savings too!!
> 
> I guess I was lucky and my fine gears were in great shape and after Terrywerm told me about these being "tender", I pulled the cover and removed them and cleaned / inspected / re-lubed / re-installed.
> 
> So thanks for the info and the help to all of us here.



I was studying you post and that why when I found this information I was hoping it could help others. So thank you for a good thread.


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## Mrcushman (Dec 7, 2014)

gregg said:


> *Gears  http://www.wentztech.com/metalworking/equipment/clausing-8520-mill/*
> 
> The gears in the quill can easily be broken. Here are some notes I collected on replacement gears:
> One owner found one of the gears in his mill was marked Boston Gear S-3232.
> ...


 I purchased my 8520 and found out after getting home that all the gears are missing in the quill. Are you saying I can buy them, or do I need to make them? Are they available from Boston gear?


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## Mrcushman (Dec 7, 2014)

I am sorry this is my first try. Do I need to make these gears or are they available to buy. My machine is missing all of the quill gears. Thank you for posting the info. I believe you are saying that the 12 T can be made from pinion stock. Where would I purchase enough to do the gears? I do not have the shaft either, so can I make it from pinion stock as well?


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## 34_40 (Dec 8, 2014)

Mrcushman said:


> I am sorry this is my first try. Do I need to make these gears or are they available to buy. My machine is missing all of the quill gears. Thank you for posting the info. I believe you are saying that the 12 T can be made from pinion stock. Where would I purchase enough to do the gears? I do not have the shaft either, so can I make it from pinion stock as well?



Well at least one of the gears is from Boston Gear, and another is from McMaster Carr. With the picture that he provided and a phone call or e-mail to Boston Gear, maybe they would have more of them??  It's certainly worth a try, all they can say is no right?  It's my understanding that Clausing still has some of these available but very expensive.  

quote"_One owner found one of the gears in his mill was marked Boston Gear S-3232.
 Their online catalog shows this to be a 32 DP 14.5 degree PA 32 tooth_
 The last pinion that drives the last gear that slides on the spline is 24 DP instead of 32 DP.
 It turns out that the small spur gear portion of the 8520 compound gear (Clausing part 990-065 – cost $66) is a close match to McMaster-Carr part no. 6325 K31. Cost $7.79. A bit of cutting to get the hub thickness down to 1/4 inch, some finish sanding and reassembly using 1/4″ dia. cold rolled stock as a shaft and a broken length of 1/16″ drill bit as a pin to lock the two gears – and everything works"  end quote


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## Mrcushman (Dec 10, 2014)

gregg said:


> *Gears  http://www.wentztech.com/metalworking/equipment/clausing-8520-mill/*
> 
> The gears in the quill can easily be broken. Here are some notes I collected on replacement gears:
> One owner found one of the gears in his mill was marked Boston Gear S-3232.
> ...


I believe there is an error in the number of teeth in the larger 24DP gear. The calculation for the OD is not correct with 24 teeth. I also counted the teeth in the picture and it appears to be more than 24. What do you believe is the correct number and could it be explained to me as a novice. I will attempt to make the gears on my mill. Thank you.


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## Mrcushman (Dec 10, 2014)

I believe there may be an error in the picture for the larger 24DP gear for the numbers of teeth. The formula for the OD does not compute correctly for the OD for a 24DP gear with 24 teeth. Also, I count the teeth in the picture and it appears to be more than 24. Could someone explain to me as a novice if I am correct and if so what number is incorrect. I plan on making two sets of gears out of brass on my mill with indexer. Thank you.


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## gregg (Dec 10, 2014)

I'm glad your bring this up here. I don't have a Clausing mill. Going to go look at a 8530 if still there. Good luck to you. I know someone has a answer on this board. 




Mrcushman said:


> I believe there may be an error in the picture for the larger 24DP gear for the numbers of teeth. The formula for the OD does not compute correctly for the OD for a 24DP gear with 24 teeth. Also, I count the teeth in the picture and it appears to be more than 24. Could someone explain to me as a novice if I am correct and if so what number is incorrect. I plan on making two sets of gears out of brass on my mill with indexer. Thank you.


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## 34_40 (Dec 10, 2014)

Mrcushman said:


> I believe there may be an error in the picture for the larger 24DP gear for the numbers of teeth. The formula for the OD does not compute correctly for the OD for a 24DP gear with 24 teeth. Also, I count the teeth in the picture and it appears to be more than 24. Could someone explain to me as a novice if I am correct and if so what number is incorrect. I plan on making two sets of gears out of brass on my mill with indexer. Thank you.



I believe you are correct, if we are talking of the gear all the way to the right. It seems to have maybe 48 teeth.  Good catch


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## Mrcushman (Dec 10, 2014)

The way I calculate it using OD=(N+2)/DP or OD*DP= N+2 or (1.833*24)-2=41.992 (42) where N is number of teeth according to the formula in "Gears and Gear Cutting" book. Any problem with that if the OD is correct? So I believe the correct answer is 42 teeth for the larger 24DP gear.


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## gregg (Dec 10, 2014)

Just a thought you could go to the web site I posted this from. I put the address on the first post. He may be able to give you more complete answers? Terry here maybe your guy?  Here the wed site again I got the information from. Nice site.
*[url]http://www.wentztech.com/metalworkin...ing-8520-mill/*[/URL]



Mrcushman said:


> The way I calculate it using OD=(N+2)/DP or OD*DP= N+2 or (1.833*24)-2=41.992 (42) where N is number of teeth according to the formula in "Gears and Gear Cutting" book. Any problem with that if the OD is correct?


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## Mrcushman (Dec 13, 2014)

I found the gears required at MRO Supply. All gears are available. The gear in the picture labeled 24T with a 24 DP actually has 42 teeth.


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## 34_40 (Dec 13, 2014)

This is great information!   I've printed your post for future reference!  ( I hope a long time in the future!!!  LOL)

Thanks for all the help too.


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## Mrcushman (Dec 22, 2014)

I just purchased a direct replacement for the small 12 tooth DP32 gear that the fine feed wheel drives from Hub Hobby in Richfield, MN for 2.79! It is used on the Traxxas Radio Controlled car drive motor. It is part number TRA3942. Should save you some time and money. I also bought another with a larger hub that can be turned down to press into the 32 tooth gear, but it was 11.99.


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## Dbike199 (Jan 5, 2015)

I just ran across this post and was wondering what is recommended for a lubricant on the fine feed assembly?
Should I use any grease? If yes, what weight?
Or is it only oil, it has 4 oil buttons. And what weight oil is recommended?

By the way, great thread!


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## gregg (Jan 5, 2015)

my manual says 20 wt none detergent.. ???? I used synthetic car engine oil. Why? Cold out and don't want it to get thick?? Think going to way oil on ways after I get mill all cleaned up? Rest mill will get best oil I can find.


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## briarpit (Jan 8, 2015)

I purchased my 8520 back in September, and it was missing all of the quill fine feed gears.  I purchased and tonight just received gears from Stock Drive Products, sdp-si.com .  Here is what I purchased:

24DP12T, 3 inch long pinion wire stock, #A1C29-N23012, $20.44
32DP12T, 1 foot long pinion wire stock, #A1C 9-N321012, $19.42
32DP32T, 3/16 wide, 3/8" bore, #A1C1-N32032, $10.08
32DP48T, 3/16 wide, 5/16" bore, #A1C-N32048, $13.95

They may require some custom shafts to make it all work, but I think it's do-able.  I probably won't get to it for a few months, as I am quite busy on a remodel project at home and will be travelling quite a bit for work over the next couple of months.  Anyway, just wanted to share some info on this source for gears.


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