Thanks Harold.
I liked the RF-30 I used (it belongs to a good friend of mine) and it was plenty capable for what I was using it for. Sometimes it is best to remember that a chalk line and a cutting torch may be the metal cutting tool best suited. :-)
Cheers Trevor Jones
You casting aspersions on my design and fabrication skills? ;)
Peter
Peter Grey wrote: (snippage)
Off the top of my head, it was either 8 or 10 inches. The dealer that I talked to at that time said that they sold them mainly to small machine shops for use as drill presses. The extra colunm height allowed them to use full length taper shank drills and still have reasonable work capacity.
It is quite small. It is nice quality. They stopped building them in in the 60's. The table size and the lack of space under the tool are it's real limitations. Whithin those limits, it's a great bit of kit, and I have not regretted it's purchase. I will have to find something VERY nice to motivate me to pass it on.
The price range you are looking at is far less of a spread than around here. Here a RF-30 (or -31) is around $1400 CDN. The RF-45 runs about $3500. Those are both Tiawanese made machines (slightly better reputation than the chinese made machines) The dealer that had the taller column machines was charging about $150 CDN more for the tall ones. Looking at a Tiawan built machine next to a China built machine makes a pretty good case for the Tiawanese product.
Cheers Trevor Jones
No, I'm saying that a guy that has a tolerance of plus or minus a 1/16 inch, has little need of a jig borer that is capable of holding a tolerance in the millionths range.
Lot's of guys get lost in the "more accuracy" argument and dont't see the 'accurate enough" side of things.
Not aimed at anyone in particular. :-)
Cheers Trevor Jones
it
You SHOULD be casting aspersions on my design and fabrication skills....
Peter
I'll stick to the premise that "He who has not sinned, shall cast the first aspersion"
Or something to that effect. :-)
Cheers Trevor Jones
it
That's the chief reason I found myself in agreement with your post. I still wouldn't own a mill drill, but my way of working isn't the same. I don't do layouts, I use the screws, so my method would not lend itself to a machine without a knee. That's the way my generation was taught the trade, not even with DRO's. The point about working to a layout line was very convincing, and it's highly unlikely new guys in the hobby will take the time and gain enough experience to work with the screws. It takes years of experience to work that way and do it without making scrap.
Harold
This is probably a good time for me to speak up since my shop is almost the embodiment of Trevor's advice.
About 9 years ago I bought a used 1979 RF-30 (Jet) for $750 that had spent it's life in a camera repair shop. It's in good shape and I have done a few fairly inticate milling projects with it. But mostly I've drilled holes, hundreds if not thousands of holes. The truth about the RF-30 is that it's a nice heavy drill press that can also do some milling.
Most of my work is making brackets and adapters and repairing small parts. This is almost entirely work on Mini Coopers, so the machine is used in support of the cars. I also do the usual repair work for friends and neighbors. I have yet to have had to use any of the Bridgeports in my friends' shops that they have kindly offered.
My mill/drill has a #3 Morse taper spindle. I thought that this was going to be limitation since mill tooling is expensive and sometimes hard to find for this taper. R8 is much cheaper. However, Morse taper drill bits are fairly cheap, used, and I have had good luck finding larger sizes at estate sales and Boeing Surplus. The expense of 4 or 5 #3 MT endmill holders is more than made up for by the fact that I can drill 1 inch (plus) holes in steel without having to worry about drill bits slipping in a chuck.
That's my experience. I'd still like to have a vertical mill and the RF-45 looks good. But so far I haven't needed it and I've used the extra money and space in the shop for a small shaper.
I'll just add one more thing. A lot of people say that the mill/drills are pretty worthless. If this was the case there should be a lot of these things for sale used. I think the truth is that they make such good drill presses that people seldom sell them even when they upgrade to a larger mill.
Cheers,
Kelley
Given that I'll be scribing and machining to a line, is there an advantage to going with a dovetail unit as opposed to a mill with a round column?
Sometimes
Hi Peter,
Having used a G1006 (RF31) for 6+ years, I'll weigh in that they are good machines for the money. A dovetailed column machine will be more rigid, a big plus. You don't lose center raising the head, another big plus. Losing center usually isn't that big a deal, you just pick it back up with spuds, indicators, or use screw machine length drills and avoid having to move the head too often on a single part.
The big minus of round columns is not being able to use the dials / DRO without rezeroing after a head move, at least if the work is at all picky. If you intend to work to layout lines this may not be a big deal, you just pick up one scribe line and zero the axis, shift and pick up the other scribe line, zero that axis, then come to 0,0 which should be the intersection of the lines within a few thou. Just learn to cross over your backlash or you'll be poking holes somewhere other than planned!
Cheers, Stan
Peter Grey wrote:
Wow - the very first time I've ever disagreed with Harold. I would certainly own a mill-drill. I'd put it on the end of my bench and I would use it exclusively for drilling holes and mixing paint. They make really wonderful drill presses if you don't have very tall workpieces. (If you need to drill a hole into the end of a broomstick you're up the proverbial creek ..)
Grant Erw> .. I still wouldn't own a mill drill ..
I think that most of the folks here *do* work with the lead screws, because that's all they have. The machine with the used lead screws isn't fast (doesn't have to be for the hobby metalworker) and it's certainly less accurate than one with new leadscrews, aside from one with a dro.
But typically it's what we have, and so we use it until the money arrives for new lead screws or a dro setup. Personally I would rather have the first, under most conditions.
Most folks in a *production* environment would not have the slightest clue about how to run a machine with manual leadscrews, most shops like that are all NC and those use ball screws. The carriage simply *is* where the number on the screen says it is. If they were given a manual machine, the first thing the new crop of machine operators would say is "Hey. This thing's broken!"
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Yes. Suppose you are drilling a hole. You lay out your part, centerpunch your hole, carefully clamp the part, locate the centerpunch right under the spindle, clamp the X and Y axes, put in a center drill (maybe 2 1/2" long) and start the hole. Then you open it out to maybe 1/4". Then you get out your 1/2" drill bit and dang it you can't get it into the chuck - the head's too low. So you loosen the head and raise it up a little. Uh oh, now your spindle isn't above the hole anymore. So now you have to fuss around lining up the hole again.
It is this keeping-spindle-while-raising-head feature that is why you pay the extra bucks for a dovetailed column. It isn't just while drilling holes. You could start milling something with a longish end mill and then switch to a real squat fly cutter. Mill tooling varies a lot in effective length.
The best way is to have a knee mill - that's why the small Clausing knee mills are so sought after. They have the rare combination of small footprint, light weight, and knee.
Grant
Peter Grey wrote:
Big snip---
Yep, I agree. Actually, Grant has me wrong, although my last post clearly stated that I wouldn't own a mill drill. In an earlier post I did suggest them make a good heavy duty drill press, and I would gladly welcome one for that function. I'm spoiled in that I already own a knee mill, so it's for that reason I made my last bold statement, obviously not a clear and full statement about my real meaning. I also agree that if one has no others choices in life, a mill drill is far better than a file.
Excellent report on the real world, Kelley.
Harold
So here's a question. Penn Tool has an inexpensive knee mill (see
Peter
I'm of the opinion that you'd still be better served with a knee mill, in spite of the limited quill travel. You'll still be able to do some serious drilling with it, even relatively deep holes. What you do is raise and lower the knee if you run out of travel with the quill, and with the knee you don't lose orientation so long as the head is dialed true to the table. That's not true of mill drills, which come with the round column.
In the real world, you're not likely to encounter the scenario of drilling through three inches often, though, so it's not as bad as it may sound. Regardless of frequency, it is far and away more convenient that constantly trying to re-establish orientation each time you move the head on a mill drill. In reality, that's my one and only serious gripe about them. If they'd key the column such that they didn't turn when moved, I'd likely have nothing negative to say about them.
When using a knee type mill, there's no real advantage to running the machine with the knee in any particular position. It's engineered and built such that it should be as useful at the top as at the bottom, the only exception being if you were taking some extremely serious cuts, the knee might resist flexing slightly better at the bottom, near the base, there the column length has been reduced to a minimum, and is slightly heavier in section than it is higher up, due to the slight taper that is generally a part of the design of that type of machine. For the most part, it's a point not worthy of discussion.
Harold
On Tue, 11 Nov 2003 05:03:58 GMT, "Peter Grey" brought forth from the murky depths:
Check out Grizzly's offerings. They have several better at similar or lower prices and G3102 which is nearly identical except for weight.
Ask yourself: "How often do I have to drill deep holes?" Be honest with yourself. "What am I making? What WILL I be making?" Buy machinery which will allow you to do that.
Why would you? It's adjustable for different height workpieces. (Guessing here. I haven't worked on a real mill since 8th Grade metal shop.)
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That's where the round column comes into its own. Simply swing the head around *behind* the machine, and drill the tall object which is sitting on the floor.
Gary
I was asking since the spindle to table distance seemed so short (11.2") on the Penn Tool mill. I had figured that one could always just lower the knee if one needed more clearance, and I figured that doing that would get more than 11 inches, so I wondered if there was some "rule" against operating the mill with the knee not elevated fully.
Peter
So what about this one?
Peter
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