Mill/Drill

[cworth60]

I am planning to buy a Mill/Drill with power feeds and have shopped the catalogs, which would be the best but, Rong Fu, Jet, or Grizzly. I will be using machine mostly for cast aluminum but may use on steel or alloys.
I would appreciate information from anyone who has either of these machines.

[Ron LaDow]

C60,
I looked at 'em for a long time, finally bought the knee mill that most suppliers offer for not a whole lot more.
One thing that was obvious is that there isn't a lot of room twixt the head and the table on the D/Ms; by the time there's a chuck and a vice in there, I'm not sure there's room left for a drill.

[bdarin]

I have a Jet mill/drill. Of those mentioned, the Jet was the most "ready to go right out of the box" of them all. Didn't need any tweaking or cleaning or adjusting. However, If I had to do it again, I'd go for the knee machine, probably by Jet, definitely a floor model. But, I got a good deal on the mill/drill, so.................

[SGW]

I'd go with the Jet, myself.

I also agree with the other replies; if you can possibly manage it, get the small Jet knee mill (JTM-830 or JVM-836). You'll be happier in the long run, and amotized over 20 years or more, the extra cost really isn't that much.

[cworth60]

<font face="Verdana, Arial" size="2">Originally posted by SGW:
I'd go with the Jet, myself.

I also agree with the other replies; if you can possibly manage it, get the small Jet knee mill (JTM-830 or JVM-836). You'll be happier in the long run, and amotized over 20 years or more, the extra cost really isn't that much. </font>

Thanks for the reply, I will definately go with the knee model, That is why I wanted imput from others who have mills. Thanks again,

Curtis

[cworth60]

<font face="Verdana, Arial" size="2">Originally posted by Ron LaDow:
C60,
I looked at 'em for a long time, finally bought the knee mill that most suppliers offer for not a whole lot more.
One thing that was obvious is that there isn't a lot of room twixt the head and the table on the D/Ms; by the time there's a chuck and a vice in there, I'm not sure there's room left for a drill.</font>

I appreciate the reply, I was indoubt as to whether I should get a knee model and due to the replies I will go get the knee mode.
Thanks again for your imput.

Curtis

[cworth60]

<font face="Verdana, Arial" size="2">Originally posted by SGW:
I'd go with the Jet, myself.

I also agree with the other replies; if you can possibly manage it, get the small Jet knee mill (JTM-830 or JVM-836). You'll be happier in the long run, and amotized over 20 years or more, the extra cost really isn't that much. </font>

Thanks for your input, I am definately going with the Jet knee model.

Thanks again,

Curtis

[SGW]

Of course, it would be *really* nice to get something bigger.... ;-) It seems as though no matter how big the table is, a job comes along when it's not *quite* big enough, and you might be able to find a "good used" larger machine for about the same money. But for normal sorts of model/home work, I think either of the small Jet knee mills ought to make you happy.

I strongly urge you to look at both machines, in person, if you possibly can, before you actually buy one. The descriptions are okay, up to a point, but there's nothing like actually seeing something.

[cworth60]

<font face="Verdana, Arial" size="2">Originally posted by SGW:
Of course, it would be *really* nice to get something bigger.... ;-) It seems as though no matter how big the table is, a job comes along when it's not *quite* big enough, and you might be able to find a "good used" larger machine for about the same money. But for normal sorts of model/home work, I think either of the small Jet knee mills ought to make you happy.

I strongly urge you to look at both machines, in person, if you possibly can, before you actually buy one. The descriptions are okay, up to a point, but there's nothing like actually seeing something.</font>

I agree, I am going to look before I buy, When I bought my lathe I didn't look at it before buying and wish I had. I bought the Grizzly G4007, Have had a few problems with it, like bolts stripping threads, they are just too soft, I replaced them with 10.5 grade (Metric)

Thanks, for the input.

Curtis

[Phil B]

Aside from the physical size difference, what does a knee mill have to offer over the mill / drill machines?

PMB
http://benchmark.20m.com

[bdarin]

With a knee machine you can raise and lower the work relative to the quill without changing the alignment. With a mill/drill, you raise and lower the whole head, which is on a column (like a drill press table), that can rotate around the column. This can mess up a carefully made alignment of the tool to the work.

[sch]

<font face="Verdana, Arial" size="2">Originally posted by Ron LaDow:
C60,
I looked at 'em for a long time, finally bought the knee mill that most suppliers offer for not a whole lot more.
One thing that was obvious is that there isn't a lot of room twixt the head and the table on the D/Ms; by the time there's a chuck and a vice in there, I'm not sure there's room left for a drill.</font>

Actually a careful reading of the specs shows that all the mills and mill drills have within 1" of each other the clearance between the quill and the table. This really surprised me as I thought there would be more variance. The average runs 17-17.5" with a couple at 18" and a few at 16.5". The advantage with the mill drill is its compact size and wgt. The disadvantages have been listed. It is also a pain in the rear to
change speeds. This applies to the largest of the mill drills (RF 30/45 equivalent) Steve


[This message has been edited by sch (edited 09-26-2001).]

[Thrud]

I would buy the biggest machine you can sneak into your workshop that you can justify spending the money for. Everybody was the same problem - the machine is always "a wee too small" than you would like it.

The Z axis (height) is important because you need room for workholding (vices, chucks, rotary tables, etc.) and tooling (boring heads, tapping heads, drill chucks, drill bits, mills, etc.).

SGW is right - check it out in person first if you can - they always look good in ads.

The R-8 Bridgeport spindle is what you should make sure you get (lots of tooling available). A 40 or 50 Taper spindle would be better (on bigger machines). MT3 spindles are sometimes sold on mill/drills - avoid them.

Get a Spin-L-Mate (or the like) tool for cleaning the spindle socket (every time you use it). They get the socket cleaner than you can with a rag.

[SGW]

I wouldn't necessarily avoid a mill with a M3 spindle if it was otherwise attractive. M3 collets are readily available, and you can get M3 shanks for boring heads and such, which will probably take care of most home shop needs. You can easily get a drill chuck with a straight shank to fit a collet (that's what I do), so that isn't a problem. But Thrud is right -- R8 is "the standard" and certainly the one to prefer if you want the widest selection of tooling options.

And also on the Z axis -- yes. By the time you pile up a rotary table and maybe a small vise on the rotary table and have a drill chuck and a reamer in the drill chuck...it eats up the vertical space pretty fast. My mill has a maximum Z clearance of about 12.5", and there have been occasions when that has been REALLY tight. A riser block about 3" thick for the mill column is on my "to do" list, but somehow it hasn't happened yet.

[Thrud]

SGW is right, MT spindles are usable. I have one myself.

But they are far, far easier to damage. In a drilling machine the MT shank drills have a positive drive tang on the end to allow transmissinon of power. As you know, these can twist off under load - then the drill spins free and damages the socket. Other tooling for the MT spindle such as face mills, or boring heads do not have this tang. Power transmission is wholly reliant on the frictional forces between the shank and socket. The only thing effectively holding these two surfaces together is the drawbar.

Consider carefully a Morse Taper spindle - pay to upgrade to an R-8 if available.

The Bridgeport R-8 spindle is keyed and has a greater angle on the taper allowing greater torque transfer.

Always make sure the tool & socket are clean & dry and the drawbar is torqued properly!

Dave