# Clausing 8520 Retoration Questions



## Dbike199 (Dec 31, 2014)

I have had my Clausing 8520 mill since May. When I purchased it I intended to do a full restoration. Now that the "new to me" felling is over and I now have all the parts (mostly bearing) to do the project, its time to tear it down and get going on it. I'm looking for advice and had a few questions. I found most of my answers on the forum but needed a little clarity.

#1: Are there instructions anywhere that explains how to take the bed/screws apart? I'm sure I can get it apart but thought I would see if anyone had an actual procedure or a webpage with it.

#2: I was going to have the moving surfaces reground. It gets a little snug on the screws as you reach the limits which implies it has a slight wear and dish on it. I was thinking about taking 5-10 thousand off the top of the table too. My problem is I have been unable yet to locate a machine shop in central NC (Triad area) that has the equipment to regrind the ways. Does anyone know of anyone in NC that specializes in this type of work?

#3: I read a lot about scraping the ways and looked at possible doing it my self. I'm confident with the right tools I could do it. The problem I see is the cost of a beveled camel back straight edge. So now I'm looking for anyone in NC that might scrap the ways. Machine shops just look at me and say "that's a dying art, no ones does that anymore".

#4: I need to locate a knee handle, anyone have one they would like to sell? If all else fails, I plan to just make one.

Thanks for your help!

I have read many articles about the 8520, rebuilds and figured someone on here would be able to help with educating me a little further.


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## AR1911 (Dec 31, 2014)

If that is your mill, you have a very nice starting point!

Can't help you much, but it seems to me like there is a workaround to buying that big straightedge. For one thing, I think a 24" would be all you need.


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## Rbeckett (Dec 31, 2014)

Bill Gruby is the man to ask about the 8520 rebuild.  He rebuilt mine and his own to better than new condition and will know where to get the table ground as well as possibly even refer you to a scraper who can re-do your ways.  Bill is a Mod on this site and is around quite frequently, but you might want to reach out and contact him privately to discuss your needs and what you actually desire to do.  Bill is a #1 great guy who knows his stuff especially the 8520 series of machines and will not steer you wrong.  Give him a quick pm and you two can get all the answers worked out pretty quick and almost painlessly too.

Bob


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## RWL (Dec 31, 2014)

Dbike199 said:


> #3: I read a lot about scraping the ways and looked at possible doing it my self. I'm confident with the right tools I could do it. The problem I see is the cost of a beveled camel back straight edge.



Even if you buy a 36" straight edge it may not be straight.  Remember, you're talking about a few 10 thousandths of an inch when you're scraping.  Rich King taught us to check the straight edge on the surface plate and scrape the straight edge if necessary before starting a project.  Depending on how it was stored, a straight edge can twist or sag over time.  If you ever buy one, the proper way to store it is to hang it from an end, or rest it on 3 points.  Also, Yahoo has a Clausing group where there are some pretty experienced people who can give you advice.


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## Dbike199 (Dec 31, 2014)

AR1911 said:


> If that is your mill, you have a very nice starting point!
> 
> Can't help you much, but it seems to me like there is a workaround to buying that big straightedge. For one thing, I think a 24" would be all you need.



Yep, that's it! But I did add the DRO.


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## Dbike199 (Dec 31, 2014)

Rbeckett said:


> Bill Gruby is the man to ask about the 8520 rebuild.  He rebuilt mine and his own to better than new condition and will know where to get the table ground as well as possibly even refer you to a scraper who can re-do your ways.  Bill is a Mod on this site and is around quite frequently, but you might want to reach out and contact him privately to discuss your needs and what you actually desire to do.  Bill is a #1 great guy who knows his stuff especially the 8520 series of machines and will not steer you wrong.  Give him a quick pm and you two can get all the answers worked out pretty quick and almost painlessly too.
> 
> Bob



Thanks for the information Bob, I'll drop Bill a PM this weekend if he does not see this by then.


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## Terrywerm (Dec 31, 2014)

I cannot help you with all of your questions, but I will offer what I can.



Dbike199 said:


> #1: Are there instructions anywhere that explains how to take the bed/screws apart? I'm sure I can get it apart but thought I would see if anyone had an actual procedure or a webpage with it.



There are not, at least not that I know of. I had mine apart for a good cleaning when I first got it, and it was pretty simple. If you have a copy of the owner's manual with the parts list and exploded view, you should have no problem getting it all apart and back together again. The owner's manual is available for download in the downloads section.



> #4: I need to locate a knee handle, anyone have one they would like to sell? If all else fails, I plan to just make one.



Mine does not have the original knee crank handle either, and the one that is on there as a replacement has a straight handle, which has a tendency to strike the handle for the Y screw most of the time. There was an original on Ebay a few months back and it went for something like $80 if I remember correctly. I have been thinking about replacing mine with a handwheel, specifically this one:  http://www.ebay.com/itm/121524418091?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT      It should work without hitting the crank handle for the Y screw, and mine turns easy enough that a six inch handwheel should work okay. Of course the hard part will be to make the appropriate square hole in it to fit the knee on my 8520.  Before I order one, I do plan to check things over a little closer though, as it is possible that an 8" may work better.

Oh, and that Glacern 5" vise sitting on there looks just like mine!


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## caveBob (Jan 1, 2015)

terrywerm, dittos on that vender through eBay, I've purchased numerous things through them in the last couple years. Always good quality items & they were always shipped/delivered FAST!

The knee crank handle I got from them for my still apart Taiwanese knee mill, really looks cool:

Milling Machine Knee Crank Handle & Swivel Handle for Bridgeport, Acer & Others - $44.99 + FREE Expedited Shipping
http://www.ebay.com/itm/Milling-Mac...l-Handle-Bridgeport-Acer-Others-/111546645394

also ordered/recieved 4 of those 6" wheels terrywerm linked to but I'm partial to these knobs/handles...:

Chrome Plated Revolving Handle for Cast Iron Handwheel, Ball End 3/8" x16 Thread
http://www.ebay.com/itm/Chrome-Plat...ndwheel-Ball-End-3-8-x16-Thread-/121508554294

...they may not be exact "stock-appearing-equipment" but they sure are comfortable in the hand/use. (also have them on the lathe)

They have other stuff listed under "Handwheels" here:
http://stores.ebay.com/SCHWAIGER-WOODWORKS/Handwheels-/_i.html?_fsub=5555691015

...fwiw...


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## Dbike199 (Jan 1, 2015)

caveBob said:


> terrywerm, dittos on that vender through eBay, I've purchased numerous things through them in the last couple years. Always good quality items & they were always shipped/delivered FAST!
> 
> The knee crank handle I got from them for my still apart Taiwanese knee mill, really looks cool:
> 
> ...



WOW!! That's just what I have been looking for! I cant tell by the picture son the knee crank, doe sit have a square hole or does it need to be machined out for the shft on the clausing?

Thanks for the great links!


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## caveBob (Jan 1, 2015)

Dbike199 said:


> WOW!! That's just what I have been looking for! I cant tell by the picture son the knee crank, doe sit have a square hole or does it need to be machined out for the shft on the clausing?
> 
> Thanks for the great links!



You're welcome, excuse the rough quicky pic, kinda fuzzy but... it has a ~3/4" round hole. I'm sure you could come up with an insert/adapter for it, maybe locktite it in place?


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## AR1911 (Jan 1, 2015)

I used one of those to fit my Millrite, which has a 5/8" square drive. 
I bought mine at Grizzly, which was the best price at the time. I have seen them on ebay for $25 shipped, which is what I paid.
I bought a part from one of the hardware suppliers. It was a 5" steel tube about 3/4" diameter, with a 5/8" square hole for most of it's length. 1/2" of one end was threaded. I used a truck wheel stud that was the right thread to hold it to the handle. Works great.
   I recently discovered I could cut off about 1.5" of that to make a similar crank handle for the Clausing. IMO the BP crank would be too big for the Clausing. I may end up using a big handwheel.


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## Dbike199 (Jan 2, 2015)

Just a quick update on the tear-down:

#1: Are there instructions anywhere that explains how to take the bed/screws apart? I'm sure I can get it apart but thought I would see if anyone had an actual procedure or a webpage with it.
Almost completely taken apart: As recommended by terrywerm, it was pretty easy withe the Clausing exploded view of the manual.

#2: I was going to have the moving surfaces reground. It gets a little snug on the screws as you reach the limits which implies it has a slight wear and dish on it. I was thinking about taking 5-10 thousand off the top of the table too. My problem is I have been unable yet to locate a machine shop in central NC (Triad area) that has the equipment to regrind the ways. Does anyone know of anyone in NC that specializes in this type of work?
I'm still hoping someone in NC chimes in on this one.

#3: I read a lot about scraping the ways and looked at possible doing it my self. I'm confident with the right tools I could do it. The problem I see is the cost of a beveled camel back straight edge. So now I'm looking for anyone in NC that might scrap the ways. Machine shops just look at me and say "that's a dying art, no ones does that anymore".
Still looking into this. I plan on PMing Bill Gruby tonight when I get home for advice.

#4: I need to locate a knee handle, anyone have one they would like to sell? If all else fails, I plan to just make one.
caveBob shared some great links on eBay. If a original does not turn up in the next month or so, I'll order one of those and make it work.

*Thank you for all the great advice and help!!*


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## Rata222 (Feb 15, 2015)

Dbike199 said:


> #2: I was going to have the moving surfaces reground. It gets a little snug on the screws as you reach the limits which implies it has a slight wear and dish on it. I was thinking about taking 5-10 thousand off the top of the table too. My problem is I have been unable yet to locate a machine shop in central NC (Triad area) that has the equipment to regrind the ways. Does anyone know of anyone in NC that specializes in this type of work?
> 
> View attachment 91066


You may give a  company called Omni Mold in Winston - Salem a call.   My company  used them for some  precision work I couldn't get done  locally,about two years ago.  I was impressed with what they did for us and the people I dealt with.
 I do not know what they would charge (or even if they will do it)  - but they are who I am going to call first when/if my restoration reaches that point.  

Jim


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## janvanruth (Feb 17, 2015)

Before you started to tear it down how (in) accurate was it?


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## hdskip (May 8, 2015)

I just made an adapter for raising the z-axis on my 8520. I used a 3/4" deep well socket and made an adapter to fit my 1/2 drill. I've seen these for larger machines and it turned out and easy project. It works well for large moves with the drill. It would work pretty well with a ratchet I'd think. I'll give it a try and report back. I'll take a picture and post it later. As they say on TV ..... Pictures at 11:00.


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## hdskip (May 8, 2015)




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## astjp2 (May 8, 2015)

Don't grind the table, its the fastest way to warp it.  If you have it scraped, get it all scraped so it wont warp.  I ground a mill table and it warped .012" on a 26" table.  You may want to actually load the mill on a trailer and haul it to someone who has a facility large enough to lift your components and put them on a surface plate.  My plate is 4'x6'x8" and its barely large enough to scrape some items and get a good pattern.....my Chinese clone mill is about the same size and I have spent a lot of time trying to learn to scrap, the surface plate was my biggest expense besides the Biax I just won on ebay.  Tim


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## Splat (May 9, 2015)

*Here's* some info on the 8520. Maybe there's something there that may help you. God luck with the rebuild. They are great machines!


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