# Green mill



## blackelim (Dec 1, 2013)

I am a new member here and I just drug home a Clausing 8520 mill that I could use some help with.  
My mill has a very "cool" all thread draw bar I need to replace A.S.A.P.  I tried to search the web and internet and it seems there might be 2 different types of drawbars.  One is back turn to release and the other is strike to release, I would like to make a back turn to realease but I can find a picture or drawing of how it works.  Can someone post a picture so I can make one?  Maybe a quick discription on how it works?
It is and original 3 phase motor so I need to make a decision on change the motor or inverter drive it, I have read most posts about this but am still undecided.  So a quick positive and negitive review might help.  If I buy a new single phase motor should I get one with a capacitor start?  What size would be recommended?
I need new belts, is the correct size 22" and 48?  
Sorry for the shotgun volume of questions,
Thanks


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## Hawkeye (Dec 1, 2013)

Welcome to the crew. Good bunch of questions. First, the drawbar. I don't have a turn-to-release type, but it seems to me they can only work if the releasing nut can push up against something immovable. As far as an easy freplacement, i made one for my Victoria U2 mill out of a piece of Grade 8 threaded rod. I drilled and pinned the top nut to turn the drawbar.

I have two machines running off a VFD. I love it. Really good speed control. I also had to buy a single-phase 3 HP motor for the Victoria. Cost about $15 more than I paid for the mill ... really. 

Hope this helps.


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## Terrywerm (Dec 2, 2013)

I have a Clausing 8520 but it's drawbar is not original. In its place was a long 3/8" hex head cap screw. It works just fine, but it is the smack it to release type. I am not sure how the back off to release type worked, but I wish I knew for sure also as I would consider making that type. 

My mill has a 110/220V single phase motor on it, currently wired for 110V operation. It works just fine, though I can see where having a three phase motor on it and a VFD would be ideal. As for belt size, I will have to do some digging for that answer, but be aware that the belt size can change with the motor used, depending on it's physical size and mounting. My mill originally had a 1/2 HP motor on it, but has a 1 HP motor on it now. Plenty of power that way.

Welcome aboard, by the way.


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## Bill C. (Dec 2, 2013)

blackelim said:


> I am a new member here and I just drug home a Clausing 8520 mill that I could use some help with.
> My mill has a very "cool" all thread draw bar I need to replace A.S.A.P.  I tried to search the web and internet and it seems there might be 2 different types of drawbars.  One is back turn to release and the other is strike to release, I would like to make a back turn to realease but I can find a picture or drawing of how it works.  Can someone post a picture so I can make one?  Maybe a quick discription on how it works?
> It is and original 3 phase motor so I need to make a decision on change the motor or inverter drive it, I have read most posts about this but am still undecided.  So a quick positive and negitive review might help.  If I buy a new single phase motor should I get one with a capacitor start?  What size would be recommended?
> I need new belts, is the correct size 22" and 48?
> ...



I found this manuel during a Google search, http://wentztech.com/WebDisk/Metalworking/Clausing/Clausing 8520 Instructions Parts.pdf


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## davidh (Dec 2, 2013)

if you have a few bucks to spend, get the link type belt. the vibrations will drop to near zero.  they are a bit more expensive than good quality industrial ones but in my humble opinion they are well worth it. . . . .


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## blackelim (Dec 2, 2013)

I think I will try the VFD and see how it runs.  
I have the link belt on my band saw so I think I will try some on the mill also, kind of takes care of the belt lenght question.
How about how old is the machine?  The serial number is 002728.


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## blackelim (Dec 15, 2013)

Here's a picture of the green Clausing I bought. It needs some work and it didn't come with much tooling but it seems to be a good start.
I had a permanent magnet D.C. motor and control that I mounted to get it under power, I still have to complete the drive connections.


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## Terrywerm (Dec 15, 2013)

I see that someone adapted a power feed to the table on your machine, something that I have been wanting to do, but haven't had the nerve to spend the money and take a chance that it may or may not work. If you ever get to taking that portion of the machine apart, it would really be nice to have photos!!


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## blackelim (Dec 15, 2013)

terrywerm said:


> I see that someone adapted a power feed to the table on your machine, something that I have been wanting to do, but haven't had the nerve to spend the money and take a chance that it may or may not work. If you ever get to taking that portion of the machine apart, it would really be nice to have photos!!



I will be taking apart as it ether needs the pinion gap shimmed or a new set of gears.  The gears run a little noisy. When I do I will take some pictures for you.


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## Terrywerm (Dec 15, 2013)

That would be wonderful!!  I much prefer the standard type of power feed such as you have on yours, but did not know if one could be adapted properly to this type of mill. I looked at the ones that are designed for mill/drill machines, but don't care for losing the handwheel on that end. Using the type that is designed for the Bridgeports is a better option in my book, but mounting might be an issue, thus the desire to see how yours is done.


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## 34_40 (Dec 16, 2013)

I'll have to admit that I've never seen a mill like that! I really like the size too.
Thanks for the pics and love the Cougar also! LOL...:rofl:


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## blackelim (Dec 20, 2013)

34_40 said:


> I'll have to admit that I've never seen a mill like that! I really like the size too.
> Thanks for the pics and love the Cougar also! LOL...:rofl:



I kind of surprised someone recognized that it was a Mercury Cougar!


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## SEK_22Hornet (Dec 20, 2013)

While this is not related directly to the Clausing mill being discussed, I can describe how the back off to release drawbar on my Grizzly G0704 mill works which might give someone some ideas on building one. There is a cap that screws into the top of the spindle.  It has a hole in the top that allows the top end of the drawbar to stick out. There is a shoulder on the drawbar that won't allow the drawbar to come out through the hole, so when you turn the drawbar counter clockwise, the shoulder hits the cap and pushes down on the collet, releasing it very smoothly. You can see the cap with the drawbar (square head) sticking out top in this photo.


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## Rbeckett (Dec 20, 2013)

Me too, me too on the power feed.  I am still waiting for my machine to arrive from rebuild but I would love to start working on gathering all of the right components to add that type of drive to my machine.  CDCO has brand new sets for pretty low prices, but they don't know if it will fit a clausing or not.  And I am like Wormy.  I don't want to  spend a bunch of cash and not be able to return it if I cannot adapt it to fit...

Bob


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## Terrywerm (Dec 21, 2013)

SEK_22Hornet said:


> While this is not related directly to the Clausing mill being discussed, I can describe how the back off to release drawbar on my Grizzly G0704 mill works which might give someone some ideas on building one. There is a cap that screws into the top of the spindle.  It has a hole in the top that allows the top end of the drawbar to stick out. There is a shoulder on the drawbar that won't allow the drawbar to come out through the hole, so when you turn the drawbar counter clockwise, the shoulder hits the cap and pushes down on the collet, releasing it very smoothly. You can see the cap with the drawbar (square head) sticking out top in this photo.




Dan, thank you so much for the description and photo of the top of your spindle. This has been quite helpful, and now I can design something for the Clausing.  The Clausing spindle has threads on the outside near the top, I should be able to make something to work with that. Once done, I will have to post pics and plans, too.


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## SEK_22Hornet (Dec 21, 2013)

You are very welcome! Glad it was helpful. The cap on mine is just hand tight, so if you need any more photos, just let me know and I'll be happy to take them. Pretty simple design.


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## 34_40 (Dec 22, 2013)

blackelim said:


> I kind of surprised someone recognized that it was a Mercury Cougar!



I loved my 69 model..  Yours is wearing Eliminator paint/striping.. correct?

Can I ask what the value of such a mill is?  I really like the size of that one and will try to keep an eye open for one, but what do they bring dollar wise?


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## Terrywerm (Dec 22, 2013)

SEK_22Hornet said:


> You are very welcome! Glad it was helpful. The cap on mine is just hand tight, so if you need any more photos, just let me know and I'll be happy to take them. Pretty simple design.



Thanks Dan, but I have already started on the design and drawings for such a cap to fit on the Clausing mills. It's pretty straight forward. I just never ever sat down to give any thought to how a person could set this up before.





34_40 said:


> Can I ask what the value of such a mill is?  I really like the size of that one and will try to keep an eye open for one, but what do they bring dollar wise?



Prices for Clausing 8520 mills vary quite a bit. A good one will usually run somewhere around $1000 or more, depending on condition. These machines do have some things to watch out for, and there were four different models:
8520: Most common model, has a #2 Morse Taper in the spindle
8525: Same as the 8520 except that the spindle has a B&S #7 taper in the spindle.  
8530: New and improved version of the 8520 but with a heavier knee and a two speed crank drive for the X feed on the table, as well as end caps on the table that would catch coolant running out of the T-slots. It also has a slightly taller column. Uses MT2 taper. Not nearly as common as the 8520, but a great prize if you can find one.

The 8520 was originally sold by Johannson, and those machines are found for sale from time to time. They are every bit as good as the ones with the Clausing badges on them. Clausing bought out Johannson at some point.

These mills do have a weak spot:  The gears for the fine quill feed. They are made of brass and are often damaged with a number of teeth missing. Some parts are still available for these machines, but I do not know about the fine feed gears. If I recall correctly they are not available any longer.

The Clausing mills also perform much better with a 1HP motor on them in place of the smaller 1/2 or 3/4 HP motors. 

You can find more photos and details about them here:  http://www.lathes.co.uk/clausing vertical/index.html

A similar mill was offered by Rockwell, though I forget the model number. From what I understand they were just as good as the Clausing, but I think the Rockwells are a little harder to find. There are differences between the two brands of machine, so don't assume that they are the same under the skin. More info on the Rockwell is available here: http://www.lathes.co.uk/rockwellmillers/

ON EDIT:  I found a good listing of small milling machines and who sells them here: http://bridgeport.askmisterscience.com/smallmills.htm    Definitely worth a good look!


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## SEK_22Hornet (Dec 22, 2013)

Grizzly, Harbor Freight, and Wholesale Tool all sell a similar sized Chinese mill, with WT and HF being the least expensive.  Grizzly has several versions in the same size range, including at least one that is listed as being Taiwan made. Here is a link to the WT version.

http://www.wttool.com/index/page/pr...Milling+Machine&update_continue_shopping=true


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## 34_40 (Dec 23, 2013)

Thanks for all the information!!  I would love to find one of these for my shop! I'll have to keep my eyes open!


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## blackelim (Dec 24, 2013)

34_40 said:


> I loved my 69 model.. Yours is wearing Eliminator paint/striping.. correct?
> 
> Can I ask what the value of such a mill is? I really like the size of that one and will try to keep an eye open for one, but what do they bring dollar wise?



It is my daughters car, 1970 XR7 original color repaint with the Eliminator stripe kit and hood scoop.  I recently sold my 1970 Eliminator though.


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## 34_40 (Dec 25, 2013)

blackelim said:


> It is my daughters car, 1970 XR7 original color repaint with the Eliminator stripe kit and hood scoop. I recently sold my 1970 Eliminator though.



I drag raced a 69 model back in the late 70's.. had a 351 Boss clone w\ a 4 speed.  Lotsa fun and now memories! )

Thanks for sharing pics of your mill.. I hadn't realized they made such a mill..  who knew? LOL..


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## blackelim (Dec 30, 2013)

I got around to taking the table drive off to get some pictures for you guy's.




Bolted straight to the table with no adaptor



Looks like original bearing fits in drive housing





Don't know if the holes are original 



And the gear that slides onto the original lead screw
It is a very old servo unit, I called and they didn't even have new brushes for it. I do need some new ones.


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## Terrywerm (Dec 31, 2013)

Interesting!!!  Thanks for taking that apart and posting the photos, too!!  I suspected that everything must just happen to be the right size. Not sure if those are extra holes or not, I will have to take one end of mine apart and do a quick comparison.


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