# Comparison of the capabilities of the Clausing 8520 versus the 8530 ?



## Packard V8

On another forum, I saw someone desperately seeking a Clausing mill.  I have an extra 8520 in decent condition, so I offered it to him.  He was ecstatic and swore he'd buy it on the spot.  As it happened, I was away from the shop for a week and when I returned, he'd recanted.  Someone convinced him the machine he had to have was the much improved 8530.  Since this guy was only going to be working aluminum and plastics, is there really anything the 8520 couldn't do that would require an 8530?

Another thought, since they're many fewer 8530s around, how much more would one expect to pay for an 8530?

jack vines


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## Latinrascalrg1

Man if you weren't on the opposite side of the US I would jump on your offer, at the right price of course!


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## Packard V8

> Man if you weren't on the opposite side of the US I would jump on your offer, at the right price of course!


You're only a couple of thousand miles from this 8520.   FWIW, I rebuild engines and ship them dock-to-dock all the time.  The most difficult part is getting it crated and on the truck.  Once the wheels are rolling, a few more miles aren't prohibitively expensive. 

jack vines


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## Briney Eye

Packard V8 said:


> On another forum, I saw someone desperately seeking a Clausing mill.  I have an extra 8520 in decent condition, so I offered it to him.  He was ecstatic and swore he'd buy it on the spot.  As it happened, I was away from the shop for a week and when I returned, he'd recanted.  Someone convinced him the machine he had to have was the much improved 8530.  Since this guy was only going to be working aluminum and plastics, is there really anything the 8520 couldn't do that would require an 8530?
> 
> Another thought, since they're many fewer 8530s around, how much more would one expect to pay for an 8530?
> 
> jack vines


Depends on what he's doing. The 8530's have a beefed-up knee, more capacity over the table, and a two-speed gearbox on the X axis.

My 8520 had been fitted with the factory power feed (variac, universal motor and friction clutch) but, astonishingly, still had the original crank and dial in the cabinet. Since the power feed was no longer feeding and seemed pretty clunky anyway, I just reinstalled the original crank and dial after I had cleaned everything up and replaced the bearings. One of these days if I get tired of cranking maybe I'll drag the old power feed out and see if I can get it running again, but I think I'd be more inclined to buy and adapt a new "Servo-style" one.


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## Aaron_W

The most obvious difference is the manual feed, the 8530 has a 2 speed feed on the right side offering 1-1 or 4-1 travel speeds in the X axis. The same unit is found on some of the Clausing horizontal mills.

The added Z distance comes from a 4" taller column on the 8530, the 8520 could be fitted with a 4" spacer block giving it the same height. I'm not sure if the 8530 actually has a taller column or just got the spacer as a standard feature. Stock the 8520 stands 66" tall, the 8530 70", so if your 8520 stands 70" tall then it has the spacer.

Supposedly the knee is improved and heavier on the 8530, but can't say for sure how much difference it really makes as I've never actually seen an 8530 up close. The only 8530 I've seen listed for sale sold for $2500, the same price I've been seeing 8520s listed for.


Personally if in the situation of being able to choose I could see maybe paying a little more for an 8530, but I can't see the differences being enough to pass on a perfectly good 8520 in the hopes of eventually finding an 8530. There seem to be a lot more 8520s out in the wild, the 8530 came along later and were a more expensive machine so it makes sense that far fewer were sold.


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## Aaron_W

Following up on this as I looked into it more.

The 8530 has 15-3/8" spindle to table vs 11-3/8" on the 8520. There was a 4" spacer block available to the 8520 giving it the same spindle to table distance as the 8530.

This comes from a Clausing catalog identified as 1961 so would pre-date the 8530 by quite a few years as I think the 8530 came out in the late 1960s.





Examples of machines with the standard (short) column cap on the right, and one with the 4" riser (tall) on the left. The main identifying feature is the distance between the seam above the Clausing tag on the column and the head swivel mount. (photos from CL ads)





I've not seen an 8530 up close, and can not find any photos of a quality to determine whether or not the 8530 actually has an entirely new column or more likely just includes the riser as a standard feature. An entirely new column casting seems like an unnecessary expense. Of the 8530's improvements this riser seems to be the most useful, but not exclusive to the 8530.

Looking at the parts breakdown in the parts list for each, and photos of both the 8530 has a different knee design with a pronounced step. 8520 on the left (without riser block), 8530 on the right. These photos also show the 8530s 2 speed handle on the right side of the table. (merged from photos at lathes uk).


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## wa5cab

I see another difference that doesn't appear to be a consequence of merging two photos.  The table lift or jack screw visible in the 8520 photo has a nearly conical shaped lower support that sticks up from the base.  The one shown under the knee of the 8530 is apparently the same diameter all of the way down nearly to the base.


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## Rootpass

8530 from a completed eBay add.


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## Aaron_W

You can also see this in the parts lists. So the 8530 definitely has a different knee assembly, but it would take someone who has used both to say what improvements come from the change. More stability, more durable, ergonomics, easier to repair?

8520



8530


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## Rootpass

I don’t believe I’d turn around for the difference if you had the riser block for the 8520. I don’t really care for the power feed that came on the Clausings. It’s better than nothing but there are plenty of electric diy installs on the internet.


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## Packard V8

Rootpass said:


> I don’t believe I’d turn around for the difference if you had the riser block for the 8520.


Thanks for the confirmation.
1. Mine does not have the riser block.  How difficult id the riser block to find and how much should they cost?



Rootpass said:


> I don’t really care for the power feed that came on the Clausings. It’s better than nothing but there are plenty of electric diy installs on the internet.


2. What is the current cost for aftermarket power feed setups?

jack vines


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## Rootpass

Somewhere on the Internet is a write up where someone made one out of 4”square tube for an 8520. 
store bought power feeds are expensive (too me) several hundred dollars. But there are several videos of people making them out of 12v windshield wiper motors.


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## Rootpass




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## Rootpass

Here are the riser pictures but I can’t find the write up.






						Clausing 8520 Milling Machine
					

Mods and use of the machine




					imageevent.com


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## Aaron_W

I've run across a few posts about homemade risers, one person even made a wood form and sent it to a foundry to have it cast.

As far as finding a riser, the main problem seems to be that they are usually on a machine, and not many are going to sell it separately unless scrapping a mill for the parts. 


We are kind of bouncing between a couple posts here, but regarding price of an 8530 vs 8520 I suspect the 8520s are already pushing the limits of what people will pay, which is why regardless of features or model they seem to stick to that $2000-2500 range.

I know people like old US iron, but the reality is at $2500 you are already at the price of a new Chinese mill heavily influenced if not copied from the Clausings. These actually do offer some improvements, like an R-8 Spindle. Of course as new they offer a warranty, parts and readily available factory accessories like a power feed or DRO. How much of a premium is someone going to put on "vintage US iron" vs new Chinese?
I don't know when Clausing ended production of these mills but assume they had by the early 1980s which makes the youngest Clausings almost 40 years old and many are closer to 60.


A few examples of similar mills available currently. 

Harbor Freight 6x26" Mill $1899

Grizzly 6x26" Mill $2650

Grizzly 8x30" Mill $4095


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## Rootpass

I don’t disagree at all. Precision Matthews seems to sell a great product and good prices. In most ways I think you’d be way ahead with something just like what you are talking about.


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## Aaron_W

I did a lot of looking at options before finding an 8520, and really I just kind of fell into the one I got. I have a particular need for a mill no taller than 6 feet (basement shop with low ceiling), so at 70" the Clausing was the perfect mill for me, but I was looking at the others I listed, as well as some of the larger bench mills from PM and Grizzly. You can get a pretty big bench mill for $2000.

All of PM's knee mills use a Bridgeport type head which results in a much taller machine, so they wouldn't work for me, but their 835 is $4300 so again, once you get much past $2500 that starts to look pretty good, and is a lot more machine if you have the room.

At $2500 I think they are a good deal for a solid well kept machine, but there are a lot of other options at that price.


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## Aaron_W

Packard V8 said:


> Thanks for the confirmation.
> 1. Mine does not have the riser block.  How difficult is the riser block to find and how much should they cost?
> 
> 
> 2. What is the current cost for aftermarket power feed setups?
> 
> jack vines



There is a riser block on ebay right now, says it is new, $180. It is a little different than mine, just a spacer meant to be used with the original cap, where mine is a stand alone piece used in place of the standard cap. Don't know if this one is an aftermarket solution or Clausing may have altered the design at some point.

8520 riser block


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## Bobbycoke

I just purchased a Clausing 8512 mill which looks like the  8520 without the head [no quill] they sold them with a "fixed" head to be indivualized as to a particular need a lot got right angle heads for second operation use..........what I am looking for is the clausing head like in the second picture I am hoping one of our members  could lead me on the right track .......Thanks Bobbycoke
	

		
			
		

		
	




	

		
			
		

		
	
<<<< this is the head I need


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## Aaron_W

It is my understanding that Clausing sold this model so the end user could put their own preferred head on the mill. Bridgeport M heads were apparently a popular choice and may have even been an option from the factory. 

I'm not sure how much work is involved mounting an M head, but those are far more common than finding a Clausing head in decent shape that isn't attached to a good mill. I've seen M heads in working condition for $300-500 on ebay. The M heads seem to have been quite popular for converting horizontal mills to vertical mills as well. Not sure if it would be possible to mount a later Bridgeport J head, I've not seen that done on a Clausing or other mill. 

The one drawback is you lose the low overall height because of the top mounted motor if that matter to you, but you do get a shorter (depth) machine that can be mounted closer to a wall, since you don't have the motor overhanging at the back. 




There is a little bit of info on the 8512 with Bridgeport head here as well as links to manuals and other information on the 8520

http://www.wentztech.com/metalworking/equipment/clausing-8520-mill/


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## Briney Eye

Briney Eye said:


> My 8520 had been fitted with the factory power feed (variac, universal motor and friction clutch) but, astonishingly, still had the original crank and dial in the cabinet. Since the power feed was no longer feeding and seemed pretty clunky anyway, I just reinstalled the original crank and dial after I had cleaned everything up and replaced the bearings.



I had exactly the same experience with mine, and I couldn't believe that all of the original parts were still with it, either.   I've had the mill for a several years now, and just sold the original power feed a couple of months ago.

I bought the 8520 from a retiring machinist.  It was sitting next to a Bridgeport clone that I was actually there to look at, and he said he used it when he needed to hold closer tolerances.  Nice machine, among many nice machines that he had.  I wish I had had the money to buy the Hardinge HLV lathe from him as well.  He had bought it new, and said that it was the machine that really fed his family.

-Jon


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## boneyard51

Any body have any parts for a 8520? I need some dial and shafts for one, or would buy a parts machine. Bones


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