I just added a Clausing 8540 horizonal mill to my shop. It seems to be in good condition. The lead screws have about 15 thou backlash and everything seems to run ok. The table has lots of dings and some coolent stains but nothing serious.
I also have a Rockwell combo horizontal/vertical mill that I have been using for awhile. I have used the horizonal a small amount. I have mostly used it with an endmill to machine from the back instead of the top. It is also great for cutting keyways; The #30 spindle is very rigid and runs woodruff cutters well. I have used it with the arbor and a thin milling cutter like a saw to cut some 3/16 brass plate. (yea, I need a bigger bandsaw).
Its interesting to compare the rockwell and clausing horizontal mills.
I really like the power feed on the clausing. Its quiet, runs off the main motor so it stops when the machine stops. The limit buttons are simple and there are no cables hanging around. My rockwell does not have any power feed but they did offer an electric one that seemed to be "ok". I have used electic power feeds and they do the job but keep going when the machine is shut off. Also the stock rockwell power feed removes the right handwheel. That would annoy me!
The rockwell has 6.75 inchs of Y travel and the clausing only has 5. MAJOR difference. I think the rockwell has a bit more knee travel as well but I don't know yet if that will be significant.
The clausing runs smoothly and the variable speed is nice. No belt changing like the rockwell. The clausing back gears are also very quiet while the rockwell back gears are pretty loud. (I checked them and they are in good shape). The downside is that the clausing variable speed system is somewhat problematic and can be VERY expensive to repair if problems are not promptly discovered and repaired.
The clausing arbor is about 2 inchs shorter than a standard arbor and finding a used one is tough. Too bad, because Bison sells standard #30 arbors for about 100 bucks via (penntool).
Optional vertical head for the rockwell is great! My only complaint is the lack of a quill spring. It works well but changing from horizontal mode to vertical is a royal PIA. You have to remove the horizontal overarm (3 diameter rod) and install the vertical head which is even heavier than the horizontal ram.
I have seen bridgeport heads added to machines and that seems like an interesting project for the clausing. They I could use the power feed in vertical mode too. Only downside is the correct size bridgeport head would have MT2 taper and all my tooling is R8.
Both machines are too short and I think they need to be lifted up a about 4-6 inchs to get a comfortable working position (I'm tall).
Rockwell has 200 thou/rev leadscrews where the clausing has 100 thou per reveloution leadscrews. If you are use to bridgeports you will like the rockwell, but I think 100 thou/rev is better.
Any other opinions? chuck