Thread: Opinions on Clausing 8520 Knee Mill?

I've long known that the lack of a knee and a rotating head on my Jet JMD 15 has been holding me back. As I've not got a huge amount of space I been looking for a small mill with a knee that might fit the bill (pun intended!) . I've got a lead on a clausing 8520 which is fairly small, and has all the feature I'm looking for...

The only draw back I can see on the outset is that the spindle is Morse Taper #2... which is not going to fit with any of my current R-8 tooling and seems to be sort of odd ball... for example, I have yet to find a face mill that I'd be able to use on the machine.

But never having seen one of these machines up close and personal... much less run one, I'd like to find out what others think of these machines.

http://www.lathes.co.uk/clausing%20vertical/

B

The Clausing mills get a lot of interest from home shop guys wanting to upgrade to a bigger machine. It can be broken down into manageable chunks of iron and carried into a basement. Get the power table feed. You might want to look at the Rockwell mills, one model has a convertable head, allowing you to use it as a horizontal mill as well.

As the owner of a Bridgeport M-head mill with a B&S #7 taper spindle, my advice would be to hold off for somthing with an R8 spindle.

I have been looking for an affordable J-head to mount on the backside of my mill since I got it just for the R8 capability.

I have not been held back from performing any milling operations with my m-head yet, I've just had to modify a bit of tooling to fit in a 1/2" collet. There is still quite a lot of MT2 tooling available though, so if you can work around the 1/2" restriction you'll be OK. -Mike

I've had one of these for six years, with a MT2 spindle. Works great so long as you stay within its limits. You won't likely run a proper face mill in one of these because of power restrictions. They are usually equipped with 3/4 or 1 horse motors and weigh about 700-800 pounds.

That said, I won't be willing to part with mine anytime soon. I've been very happy with it. They're about 1/2 the size of a Bridgeport and fit nicely in a garage workshop. No power downfeed, but neither that nor the spindle taper has been a problem. They're well-made and worth buying, IMO.

If you don't like MT2, I'd suggest making or buying an MT2 to ER32 or similar adapter. That way it would be better than the R8.

Chris P

Hey Bill (nice name)

I looked at, and considered strongly, the 8520, wanting badly to stay with some old iron, but, alas amd alack, living in the south there just aint no machines!! Found a couple up north, but frt chgs put them out of sight.

Like you, the MT taper was a turnoff, as I already had a pile of R-8 stuff,... but I wanted to alert you to another feature (downside?) that you didnt mention and is a pretty important---the distance between spindle and table, is (I think) 12-13".

Now, having discussed the cons, I went ahead and got one anyway,--- a Chinese clone that is. I got a WT 6x26, it has the R-8 spindle, but also retains the 12" clearance, but, I added a 4" riser right away and solved that problem. and I,ve fallen in love with the thing.

If you want some sure-nuf insight into the Clausing, theres a Yahoo group (of course, isnt there a Yahoo group for everything)......

http://groups.yahoo.com/group/clausi...guid=160370336

And, a Yahoo group for the Chinese 6x26.....

http://groups.yahoo.com/group/6x26millingmachines/

Good luck,
Bill Pace

I have an 8520 and so far have not found the MT2 spindle to be too much of a drawback. It came with an Indian vise that works well and a set of MT2 collets and some rudimentary hold downs for the table. It also came with a jacobs chuck with a cutoff bolt for a shank (terrible runout). I modified a J33 to MT2 adapter by cutting off the tang and drilling and tapping for the 3/8-16 drawbar for use with a Rohm keyless chuck. I like the idea someone else had about an adapter for ER series collets. I would like to do the same for my SB 9A one day.

Another drawback is the lack of a return spring for the quill. However there is someone on the Yahoo 8520 group making an aftermarket spring. I just haven't done it yet.

I have used a flycutter in place of a face mill. As another writer said, the machine might be a little light in HP for a face mill. I've never used a real face mill though so I can't compare. I have used full sized milling machine (Trak, I think) at my work in our model shop and the 8520 can't compare for rigidity but then that's an apples to oranges comparison as the 8520 only weighs about 800#.

I'd like to find a small shaper or older horizontal mill for tasks that require more ability to move metal though. I think I could squeeze one into the shop. [img]smile.gif[/img]

All in all for a home hobbiest I find the Clausing to be just right for me and hope to get more out of it as I go along. As a point of reference I paid $1600 to a local machinery dealer here in San Diego for it a couple years ago.

Bill

3MT ER32 collet chuck - from Little Machine Shop. I'm also interested in this for my South Bend 9A. Anyone tried it?

Jeff Greenblatt

Yes,

It has proven to be a good match for the 8520.
Well built and nicely finished.

PK

Make sure you confirm the brand of spindle...whether it's an MT2 or B&S #7...the tapers look nearly identical laying side by side but there's a huge difference when you go to fit the parts together. Completely incompatible.

Also, the MT#2 tooling must have a drawbar for milling...fine to use a standard arbor for drilling, but the side forces of milling will loosen and crash the cutter in short order.

If you have a mill-drill I'm not sure you wouldn't be better off looking for a Bridgeport or clone thereof. I used a mill-drill exactly once...but comparing the two mentally I don't think you're going to get any improvement in rigidity, mass, etc. That said, the Z-knee is a nice feature.

The main gain in the Clausing (wonderful machine BTW, my Dad has one) is as stated, small footprint and easily moved into the basement without cutting the house apart.

-Matt

You might consider changing the spindle to accept R8 tools. If you have a considerable amount of tooling, it may be cheaper to do so.

Everyone seems to like the Clausing. My only hesitation would be the cost compared to something larger, heavier and with power feeds.-Jerald

Yeah, I thought of that too... not entirely sure what that would involve... and whether I could do the spindle swap accuartely enough to make it worth while... what would this take?

B

There is an 8530, which is a little beefier in the knee area. Think it also carries the B&S taper.

Almost cross-posted, Billy. An integral R8 conversion might be possible. Minimum OD of an R8 taper is 24mm (.9448"), versus a 7/8" OD on an MT2 spindle. Would probably involve boring the quill body, changing out the bearings, boring and re-cutting the splines in the upper carrier, above the pulley.

You're trading rigidity and mass for versatility. The closest I've gotten to a face mill for steel plate is a shop-made, 1.25" cutter that holds two carbide inserts. Works a treat at high rpms, fast feeds and light depths of cut (.030" or less). In steel, the limit with a .5" cobalt rougher is about .100 DOC at 600 rpm per pass. It'll get there, but takes time.

If you foresee needing to do any regular amount of heavy slab milling or face milling in steel, one of these is probably not for you. Such work on a regular basis is for a horizontal or shaper. Otherwise, no problem. I've had a hard time finding faults.

Bill Pace, if you need a contact in the southeast, let me know (central FL).

The 8520/8530 are MT2 spindle mills, whereas the 8525/8535 are B&S taper spindles.

I've been quite pleased with my 8520, especially with a Shooting Star DRO and Servo 140 power feed on it, though the work envelope has been a problem lately. The Rockwell mill provides 6" cross travel (vs 5" for the 8520) but parts for it are just about impossible to find. Clausing still provides quite a few parts for the 85## series mills.

Mike

"Yeah, I thought of that too... not entirely sure what that would involve... and whether I could do the spindle swap accuartely enough to make it worth while... what would this take?"

I talked to a shop in Grand Rapids Mi. about recutting my spindle to R8 and as I remember they wanted about $300 to do the job. As I understand it, they have had good success with the procedure.

I think........I'd want it bored and then ground. I'd require some type of certification relating to runout afterwards, to insure accuracy. I suspect they'd have to ID grind the hole.

I saw an article on making an R8 collet assembly in Machinist Workshop magazine this month although I have not read it, there may be some info there for you.

If you need the name of the shop, I can most likely get you in touch with the guy who gave it to me. Most any good local shop should be able to do the job.-Jerald

Several companies made little vertical mills that were a little beefier than the Clausings. Wells Index used to make one. One was on ebay recently:

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7589868534

Jimbo

new guy here.
i have had a 8520 for over 10 years it was my frist mill. the only drawback to the #2m-t is you already have the r-8. now the mill is light it is now a bridgeport but it is way ahead of any mill-drill made.

hey i hope this is in the right place but i have the older johannson version of this mill and i need some parts are there any sources you folks can recommend?