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Thoughts on Vintage (1978) Mill/Drill from Enco [GL-30B]

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IHateMayonnaise

Aluminum
Joined
Jul 17, 2016
Location
Albuquerque
Hi folks,

An interesting machine came up in the local classifieds that caught my eye, and I wanted to see if any of yall have seen/worked with/owned it and could answer some brief questions. I currently own a 2001 RF-25 from Rutland that I've rebuilt that I am medium-happy with. My largest concern seems to be with run-out (getting ~4 10ths on the R8 taper), which I have been unable to mitigate in a cost-effective way (nobody will dust the taper for less than $500k that I've found). I've tried different spindles, tapers, bearings, preloads etc etc etc and it appears as though this is what I am able to do with this machine.

The machine itself is being sold for $500, but I think I can get them down a little bit. It is a solid machine (seems to be comperable to an RF-30), and everything seems to be much more robust than my RF-25 (especially like the large handwheels). It comes with a custom metal stand with tray underneath to catch some chips that seems to be very sturdy. On the machine itself, everything seems to work fine and it appears to be complete as far as I can tell. Both axes on the table seem to be tight, and not too much wear on the lead screw nuts. The spindle is badly, BADLY in need of being cleaned/repacked with fresh bearings, and probably the drive sleeve bearings as well as I'm sure they are original. The taper on the spindle seems to be "well-loved," in that it has some serious scratch marks/pits, however inserting an R8 collet seems to be nice and tight, mostly around the straight portion on the rear of the collet. Other than this, there is minimal noise when the system is under power at the maximum speed, and the run-out that I can feel with my finger on the taper seems to be not egregious. I'm going to bring a 1/2x6" gage pin and measure the TIR of the spindle through a 1/2" collet and see what that says. I'll do this with their collet (not in the best shape), as I don't want to bring one of my brand new hardinge collets in case it gets dinged up on some rough spots in the spindle. My largest concern here is that if there is run-out that I cannot minimize by cleaning/repacking/replacing bearings, that I am basically screwed because I'm sure there is no way I can get a replacement quill/spindle/drive sleeve. My question for the audience is: with these older machines, were the tolerences better/worse generally than they have been lately? Has anyone had any luck in refurbing these old spindles and minimizing the run-out to an acceptable degree?

One interesting thing that I noticed is that the mill appears to be painted AFTER the column was joined to the base, meaning that there is no discernable interface between these two components. I take this to mean that either the mill hasn't been trammed (even at the factory), as the seam is transitionless on all sides. I've shimmed mill bases before and I'm familiar with this process, but one thing that I don't have a feel for is: how well were these older machines built in order to minimize the need to tram (as much as is possible)? My RF-25 interface between the column/base looks like it was milled with a cheese grater, and it took a lot of effort to flatten/increase the contact area, let alone tram the soomb*tch (something like .020" was shimmed on one corner alone). Obviously, the proof is in the proverbial pudding, in that I will bring a DTI and measure the tram from the spindle on the table directly, The fact that they painted over the seam between the base and the column seems concerning, though.

The one thing that I cannot figure out is how to engage the fine-feed assembly. In my machine (and all Rong Fu type machines that I've seen) achieve this with a clutch that can be achieved by screwing in the giant screw on the course-feed assembly, which shifts the outer worm-wheel inwards to engage with the worm gear on the fine-feed assembly. This part of the machine appears to be unmodified, I just appear to be missing something. Anyone have some insight? If I can't figure it out next time I go over there tomorrow afternoon then I'm likely to take the thing apart to see what the deal is.

Any other thoughts or comments are welcome.

Cheers,
IHateMayonnaise
 

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