mill/drill vs knee mill

[Fasttrack]

I'm kinda stealing this from the "HSM essential machinery/tools" thread, but i noticed that MikeyD suggested buying a mill drill before a mill.

That got me wondering...what are the disadvantages/advantages of a mill drill vs a knee mill? What are the major differences? The biggest difference i noticed was in the column (square vs round) but surely theres alot more to it...

[MickeyD]

The reason I suggested a mill/drill is that they are cheap, easier to move than a full sized mill, and if you buy it half way right, you will not lose any money on it. Another plus is that you can usually use the tooling that you get for them on a "real" mill later on.

[wierdscience]

Yup,but look for a mill drill with a dovetail column.Round columns have problems with rigidity and repeatability like losing your center if you need to move the head between operations.

[BadDog]

I dunno. My experience was the opposite.

I started with a lathe, and I can't imagine doing it otherwise. It's the main machine of any general purpose home shop. And even now, I make more "round things" (particularly bushings and rods/shafts) than anything else. The initial manifestation of my ongoing illness was a Griz 9x20 lathe I found only barely out of the crate and for less than half new price with several upgrades and a tool cabinet included. We had great times learning to do what needed to be done. When we finished the project, I wiped her down with oiled rags, caressed it lovingly, spoke of it tenderly, and for a while, we were happy.

After a while I was hooked and looking for new thrills. I’m ashamed to say, the little Griz just couldn’t keep my wandering hands at home. And so, I began looking for a drill to complement the little lathe.

First plan, find a used Bridgeport. I kept hearing about all these great machines, loaded with tooling, and often fully equipped. These stories fueled my fantasies, for a time... After looking a while, I realized that this aint the rust belt or the East Coast iron surplus, and the prices I kept seeing out here just were beyond what I was willing to pay!

Next target, the HF 2hp model. Seemed it would really do anything I would want, or at least 98%+ anyway. Then I started researching and found out about HF quality issues vs. RF originals, and then there were the Jets and Griz offerings among others. And next I learned about "round column" problems, tramming issues, loosing your zero switching tools, etc.

So then I started to looking at square columns, but they are much more expensive and have their own issues. And now you’re getting into the mini-Bridgeport and Clausing knock-off range at that point. I then realized that used machines of this type were not really common and often did demand a significant portion of new, though you sometimes got some tooling (most also of questionable ChiCom heritage).

After a bit on this road, I realized the sticker shock had worn off and I was again looking at $2k-$3k machines either way I sliced it. And I further realized (remembered) that I could get a very decent full size Bridgeport DRO and power feed for that price range. I had come full circle, but now paying the full size price seemed fully justified based on what I had learned, what I felt I would want/need, and what I would get as alternative in that price range.

Considering all the alternatives, I’m very happy to say that’s exactly what I did shortly there after. It wasn’t too long before I found a Bridgeport 2J 1.5hp Vari-Speed with less than a year on a professionally “remanufactured” head and motor. It also had Accurite DRO and power feed on the x-axis. I’ve got less in that than I would have had to pay for ANY square column mill drill (and the DRO + power feed is just gravy!), and even though it does have some slight wear on the longitudinal (x) way (though almost no back lash for what that matters) and some divots in the table (that do bug me a bit) it’s still several times the machine that any of the smaller machines will ever be.

Now things felt a little odd in the shop. My first love, the little Griz, sat there quietly beside the enormous interloper only a few feet away. It still did as much as it could of the jobs I asked, but increasingly, it could not keep up with the jobs I could do on the newcomer. Finally the day came, as I’m sure she new it would, when she was moved aside into the ever diminishing free floor space of my shop, to make room for a new lathe. It was an 11x37 Rockwell. A lathe much more aptly matched with the Bridgeport. And in what must have been a final crushing blow, the Griz spent it’s final days at my hands making new bushings and shafts to refit the new Rockwell.

Finally, she was cleaned and oiled one last time, her cord unplugged and neatly coiled, her tools wiped down and put a way one last time. I would love to keep her, just for the occasional small job and fond reminder of the days before the iron sickness was fully manifest. But the sickness calls to me in my dreams, and I must make room for more tools, so soon she must leave my shop forever. Will it be a small shaper? A surface or tool grinder perhaps? Or maybe a modest sized Horizontal Mill. And still my fevered dreams burn on...

She sits quietly now, on the other side of my shop, under a non-descript tarp, awaiting a new master to once again oil her ways and caress her dials as I once did...

[J Tiers]

That got me wondering...what are the disadvantages/advantages of a mill drill vs a knee mill? What are the major differences? The biggest difference i noticed was in the column (square vs round) but surely theres alot more to it...

OK....

You want to do a particular bit of work. You get set up, maybe do part of the job, and THEN you realize that you will need more space between the head and the table due to some detail, like getting the cutter out of the pocket you need to mill. We'll assume that the quill movement isn't enough to do it for you.

So, with a knee mill, you note the setting on the dial, unlock and crank down the knee, do what you need to, and crank it back up to same setting and lock. You are back in business.

With the round column mill-drill, you measure the head height, loosen the clamp, crank up the head, do what you have to, let it back down to your measurement and re-clamp it, trying not to let it rotate so much that it gets out of rotational position for you.

If position is critical you have to devise some means of returning the head to the same rotational position......

OK, which one is easier to use?

[torker]

I deal with the "round column" issue everyday. Returning the head is no big deal if you have a laser mounted on it as I do.
I have it landmarked on the wall 20 feet away and can plop an endmill right back in the same hole. Takes about 10 seconds to bump it over or whatever.
I've done a ton of work with mine. Aint no BP but it CUTS METAL and it was cheap. I'd buy one all over again instead of doing without.
You guys holding out for the killer BP deal...you all have fun with that hacksaw
Russ

[speedy]

20 feet?

I like that laser set up Torker. If I don`t have 20 foot of workshop space do you suppose I could bounce that laser off mirrors?
DTIs are handy also.

[japcas]

A friend of mine drilled and tapped the rack on his round column so that it was stationary and run parallel with the column. This way when he raised the head, he just made sure to push the head over against the rack solidly before locking it in place. He has had real good luck with the alignment using this setup and turns out some real impressive model engines. I have a square column mill and like it a lot but if you could get a decent deal on a round column then the alignment issue really isn't an issue. Good luck with your search.

[rws]

J Tiers has it right. I do gunstock work mostly with my knee mill. I tried at first with a friends round column mill, and it worked fine until you need to change tools! You loose your place and have to take the time to get back. Plus, I doubt the laser trick would be very accurate, close, but not perfect.

So I bought a knee mill from Grizzly, it aint a Bridgeport, but it does the light duty stuff I need just fine.

When I do a barrel in my lathe, I take great pains in the set-up, indicating in. I would never take the barrel out, or disturb the set-up, until I finish the work. You just can't get it back perfect. Same with a mill, once I get things where I want them, I ca crank down, do whatever, and come back where I was without loosing accuracy.

That's my $.10 worth.

[John R]

I lived with a round column mill/drill for years...had to re center every time I had to change the head space and had to stay with light cuts but it worked and it was all I could afford at the time. It was a matter of mill/drill or nothing. I now have a big knee mill and am in hog heaven. As long as you are willing to put up with its shortcomings there is nothing wrong with a mill/drill.
John R

[J Tiers]

You guys holding out for the killer BP deal...you all have fun with that hacksaw
Russ

You ain't got NUTHIN to say to me about make-do.......... I used a Craftsman 109 as my only lathe for quite a while.....

Yep, I know all about make-do......

Oh, yeah, and I still do vertical mill work on a horizontal mill...........

[bob308]

from what i have seen and used a mill-drill does neither well. a knee mill does both very good.

like i learned years ago if you want to play the game right step up and buy the right tools.

enco has a knock off of a clusing 8520 that would be a good start way ahead of a mill-drill. you can do better work on a wore out b-p then on a mill-drill.

[japcas]

enco has a knock off of a clusing 8520 that would be a good start way ahead of a mill-drill. you can do better work on a wore out b-p then on a mill-drill.

I disagree with this statement. You can give a new Monarch 10EE to a new guy and he probably can't make jack. Even if he can he probably will not be able to work to the machines ability. I've seen good machinists turn out work you wouldn't believe on machines that most would consider junk. The man operating the machine dictates the quality of the parts more than the machine he is operating. In most machine shops, the machinist doesn't have the luxury of always using a brand new machine to turn out the work. Most likelly the machine could very well be 20 to 100 years old. Just like golfing, just going out and buying the most expensive and best golf clubs doesn't make you a professional. It takes practice and so does machining. That is why it is considered a skilled trade.

What machine you buy should also be determined by what you want to do on it. You don't buy a lamborghini if all you are going to do is go down the road to the grocery store. If you are planning on opening up your own shop then by all means buy good equipment. But if you have never laid eyes on a Bridgeport then don't think that is the only way to go just because others tell you that you must have one. Bridgeports have there place and so do mill drills. As I stated in my other post, I have a friend who has built some very high quality model hit and miss engines and he uses a round column mill drill. Mill drills have allowed a lot of people to get into the machining hobby who otherwise may have never started. Some of the people may have upgraded to a bigger machine, others may very well be using the same machine they started with.

[JCHannum]

Any machine tool is better than no machine tool.

From that point, there are some tools that are definitely better than others, and a knee mill is definitely better than a mill drill. The benefits of a knee over a moveable head have been amply described.

The selection of shop equipment will depend to a large degree on budget and space constraints. Selection of equipment that will satisfy these constraints is the key.

A milling machine is capable of several functions. The efficiency and accuracy in performing these functions should be the deciding factors in the selection of the machine. As price and size increase, so does the efficiency.

If the budget and space are available, a Bridgeport class mill is probably the best choice for an HSM. The next choice down from that is one of the smaller knee mills. Next step a square column mill drill, last choice a round column mill drill.

[cmiller231]

I agree with everything negnative said about the round column mill - drills. I picked one up because it was at a right price (1978 Jet $250 with collets and vise). I would never buy one new .
Another issue that needs to be said is that i've seen a lot of knee mills with a short quill travel ,like 3-3-1/2 ". This would be a major PITA because you would constantly be cranking the knee up and down.So IMHO the knee mill dosen't solve all the problems unless it's got 6" quill travel.. Although the square column might very well work out better because I think most of them if not all have a 6" quill travel.
All in all the mill drill is a good drill press IMHO. Although i've done a fair amount of mill work on it.And it has done a good job.But I still swear at it a lot because of the round column.
Torker :Have you ever checked to see just how close that laser repeats?In other words like bore a hole -move the head ,re adjust head with laser and then ind. hole .
Chris