More Questions - Emco Compact5 CNC

Well, that EMCO 8.6 I was asking about left my possession Sunday. Local machinist wanted spares for his, and mine had some headstock issues, so it went to a better home.

Now I'm looking at a EMCO COmpact5 CNC mill/lathe. It's not the F1, but I have not determined what generation it is.

What I'd want it for is to learn basic CNC programming, and to make things like firing pins for pistols. It looks like a fun toy.

It seems to be complete, powers up, DRO shows on the screen and the numbers move when you bump the servos via the manual controls. Has a chuck, maybe some collets, includes the milling head. Also a steady rest. The machine was in use by a recently deceased benchrest rifle builder. He also has a much larger CNC machine that looked to be his workhorse. This little one is pretty clean. Asking price is $700

I've searched the web and found surprisingly little about these machines. I did find this

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is most useful.

Does anyone here own and use one?

Suggestion of things to look for / at to evaluate it?

Things to watch out for?

Overall usability for the intended purpose?

Does the price seem right based on what I've mentioned?

Thanks in advance for any help.

Rex

Reply to
RB
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I'll be trimming out a lot of the quoted text to keep this from growing above the 30K limit for incoming e-mail (designed to keep viruses out of a couple of small mailing lists which I host).

O.K. The cross-slide should have a steel plate held on by four screws in the corners, and have two fairly large threaded holes (alternate positions for the toolpost -- one for small diameters, and one for larger ones -- the cross slide does not have enough range to cover both at one setting. The turret bolts down to the cross slide in place of the steel plate, and has a motor sticking out through a cutaway in the chip shield. There are two chip shields -- one for the turret cross slide, and one for the QC toolpost. The turret has a vaguely triangular shaped plate facing the chuck with three radial slots and three holes. It has to be connected to the back of the panel after feeding through a notch in the front of the chip pan. I wound up mounting a connector to the front of the chip pan to make it easier to convert between turret and QC toolpost, since each has its own strong points. The turret is better for a lot of tool changes per part, but it can't handle large diameter workpieces so the programs can select "tool

0" to cause the machine to pause while you change tools on the quick-change toolpost. Note that one of the nuisances of the turret is that it has no absolute addressing. The commands only involve "move forward 'N' stations, so you have to remember which station it is on at the moment to figure out how to move it to the one which you want. And, you have to remember to end your program by returning it to a known starting point, or the next run will be using wildly inappropriate tools. :-) [ ... ]

Second -- or perhaps third.

[ ... ]

Well ... it is one of two different styles of such micro-tapes, the one less readily found.

O.K. I have two styles.

Philips LDB4401 certified digital Mini-Cassette (8920 440 10101

Realistic Mini 30 Cassette (Cat No 44-633) Radio Shack. (Probably long out of production.)

They can be identified by a hole through each of the back corners, into which snaps a plug to enable writing. (That was one of the first things which I made on the lathe. :-) The hole is counterbored from both sides. And the plug has a recess in its head to keep from pushing the pin down too hard and far.

Multiple programs can be saved on a single cassette, but deleting a single program is difficult. And -- it is *slow*.

:-)

I've never used the floppy drive in my Sun Blade 1000. I usually copy things from other systems via the net -- or sometimes via CD-ROM. Floppies just aren't big enough any more. :-)

[ ... ]

Well ... the QC toolpost was the low-budget version of the machine. The turret was the more expensive version. You really *can't* use a CNC machine without either a turret or a quick-change toolpost, because something like a lantern style toolpost would not repeat when you changed the tools in the middle of a program. For a simple example, you use one tool to turn a shaft down to the proper diameter, the next tool to thread it, and finally a parting tool to cut it off from the main bar of stock. Each tool has to be in the right position for the program (or the program has to be edited to correct the tool position, which is a problem since you can't stop the program in the middle of a run, edit it, and continue from where you were -- it always goes back to the start.

There is a microscope with cross-hairs which is on a base which fits the ways and is used to define the position of each tool tip relative to the others. The tool change command has:

1) how far to move the turret ahead to the next tool (or 0 for a quick-change toolpost), 2) The X-offset from the first tool's position. 3) The Z-offset from the first tool's position.

so the commands move the tools to the right place relative to the workpiece. Without this, you may thread in air above the workpiece instead of actually threading the diameter just cut.

Wrong for this machine. The spindle is a Morse Taper 2, and the collet adaptor bolts to the nose of the spindle in place of the chucks. It accepts ER style collets. The adaptor without the nosepiece looks sort of like a steel wine glass with a hole through the stem. :-) Looks like the ER-25 series is what it uses.

Now -- it is possible to make an adaptor to use the D series of collets with a drawbar. (The D series are the next size up from the WW series of watchmaker's collets.) And those would probably be more rigid than the ER-25 ones in the "wineglass" adaptor.

Hmm ... do you have the manual for the lathe? If it is the latest, then you will probably have this already (or should be able to find it in the shop), but just in case:

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it is large, and slow because it is scanned to PDF format at a fairly high resolution -- but print it once and then you can go through it quickly.

I just went though it and discover that it does not have what I was remembering -- drawings of the accessories. Among other things, there is a weird looking thing which has a bunch of grooves which is used as a reference for setting the tools, and a metal plate which is used with it as a reference for setting the toolpost location.

Those must have been in the technical reference manual, which I never got around to scanning.

Hmmm ... let me look on eBay to see if any photos will be helpful.

1) 270255813367 Milling head. You say that you have this. It uses the same collets as the lathe spindle in the proper adaptor.

I have the column and head with a separate manual milling base, but the bolt-on adaptor does not fit the lathe's mounting point, so I can't use it as a CNC mill.

2) 270256127147 Aha -- the tool setting parts which I was mentioning above. This tells you what to look for in the shop. You should have these. (or eBay this set if you can't find them.) 3) 270256128354 Steady rest. Check for one of these. It will be useful in turning long slender workpieces. The price on this auction is (so far) not bad. 4) 270256158230 Hmm ... the milling table. I don't have this, though it looks very much like the milling table for the ancient Unimat SL-1000 which I have (same maker, anyway.) 5) 310053252950 Lathe parts manual. Might be worth while having. 6) 330202900069 Complete lathe -- look at the price. :-)

The fourth photo shows the turret, so you know what to look for. It might have the red paint shown, or the yellow/orange paint. (Hmm ... what color is your machine? Red is later, orange is earlier.

7) 280246555008 A set of proper collets. 8) 280246556226 *Not* the standard quick-change for the Compact 5, and only has one station. Not a good choice.

And that's it for the moment. What were the auction numbers for the two which you found? They may still have useful images, even if they are closed already.

The correct chuck will have a recess on the back of 40mm diameter (1.575"), and three counterbored holes for a 3-jaw, or four counterbored holes for a 4-jaw.

Well ... since you apparently both posted and e-mailed, I see the e-mail first, and a reply there will get to you much sooner than one in the newsgroup. Hmm ... maybe I'll save a copy to send out to the list as well.

Enjoy, DoN.

Reply to
DoN. Nichols

I picked up the machine last night, along with all the accessories I could find. It appears to be a 3rd gen machine, with milling attachment, turret toolpost. It came with Milling table and vise, indexer, 3-jaw chuck, and two collets. No sign of a collet closer. It came with a user/student manual.

Overall in nice shape, apparently used and properly cared for.

Many thanks to Don Nichols for helping me know what to look for, and in identifying the accessories. He took a lot of time emailing me about the nuances of this system.

In the process of gathering this stuff, I talked to the seller, who was liquidating the estate of his brother, Shelley Davidson. If you have an interesting benchrest shooting you will know the name. Here's a good article about him and what he used his machine tools for:

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Neat guy, and a respected craftsman. I regret I did not know him.

RB wrote:

Reply to
RB

Good deal at that price with all of that.

I've owned and used one for quite a while, collecting accessories over time, so I've learned what to look for.

Interesting indeed.

Enjoy, DoN.

Reply to
DoN. Nichols

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