Just Bought An Emco Compact 8

Paul_O

Paul_O

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I'm now looking to get collets and a 3 jaw self centering chuck. Problem is, I'm not sure what type of spindle taper is has (I assume 2 Morse taper, but need to verify). I'm also unsure what type of chuck will fit this guy. I just bought this guy yesterday for $1200, it included 2x 4 jaw chucks, drill chuck, plenty of HSS cutting tools, live center, metric an english gearing, and some misc. drills, original manual, ect. Not sure if it was a good deal, but it is in good condition, so I'm pleased. Any help is greatly appreciated!
 
Google is wonderful :)
Seems to be MT3
http://www.lathesonline.com.au/estore/docs/emcocompact8brochure.pdf

Looks like it has one of those bolt through the back spindle noses like the smaller Chinese lathes.
My lathe also has a similar set up, and Sieg does not publish the specs. I turned a rod down to just fit into the bolt hole on the spindle nose, and turned it to a point. I then mounted the dead center in the head stock, mounted the turned rod in the tool holder (I just jammed it in the boring head holder), and backed off the cross slide until I could just get the rod into the bolt hole. I measured the distance with a 2" indicator since I have a metric screw with imperial markings :(

Mine has a 2 1/8" nose with a 75mm bolt circle (boggle)
I just buy 1 7/8" threaded adaptors and mill them out.
 
Paul_O said:
I'm now looking to get collets and a 3 jaw self centering chuck. Problem is, I'm not sure what type of spindle taper is has (I assume 2 Morse taper, but need to verify). I'm also unsure what type of chuck will fit this guy. I just bought this guy yesterday for $1200, it included 2x 4 jaw chucks, drill chuck, plenty of HSS cutting tools, live center, metric an english gearing, and some misc. drills, original manual, ect. Not sure if it was a good deal, but it is in good condition, so I'm pleased. Any help is greatly appreciated!
Click to expand...

Paul, according to the Lathes.uk site (http://www.lathes.co.uk/emco/page2.html), Emco used a proprietary chuck mount, which makes it harder to find a chuck to fit; ebay may be a good place to look for used Emco stuff. It is possible that other Compact 8 users know of better alternatives and I would suggest you join the Emco Larger Lathes group (https://groups.yahoo.com/neo/groups/emcoV10lathe/info) and check their stored files and perhaps ask the group directly. I belong to the Emco Super 11 Yahoo group and just checked - nothing on the Compact 8 there.

I'm not sure about the spindle taper, sorry.

It appears that this lathe was copied by Asian makers so it is possible that chucks made for those lathes, the ubiquitous 9X18-20, might fit. You might ask the Yahoo group about this first.

I see Compact 8 parts on ebay from time to time, usually when someone parts a lathe out. If you can, try to find a decent steady and follow rest and carriage stop. It will cost you as these parts are no longer produced; I would be prepared to bid aggressively if you do find something you need. Sears once sold this lathe so they may have some parts still available on their Parts Direct site.

Like all Austrian-made Emco lathes the Compact 8 was apparently built to high standards. While it appears to have some limitations it is capable of good work. I recall reading some threads long ago about the precision some guys were able to turn to so you have a good lathe in your hands. Now you need to outfit it properly - good luck!
 
Collets: Joshua said your lathe has an MT3 spindle. You can can go to Little Machine Shop. Check their part number 2728 (universal collet closer, $100), which includes an MT3-to-C3 adapter and draw tube. C3 collet set - part number 1991 (⅛" to ½", $110). I have both and use them on my Grizzly 9x20. You'll need to cut the draw tube to length, but that's easy to do. It's not as pretty or elegant as a lever-type collet closer, and won't have quite as much range as a collet chuck and a set of ER collets, but it will definitely do for work up to ½".
 
The problem with a draw bar and collet thing with the mt3 taper(maybe more the drawbar size) is that the size of the thread dosn't allow for much stock diamitor to go through the end if using a holow draw bar, (about 6-7 mm if I remember corectly)
I've seen a german companie that makes collet chucks and other emco 8 accessories a front closing one will allow bigger stock through.

just found an example for sale says it's compatable with a couple of lathes so maybe they used the same taper on a few.

http://www.ebay.co.uk/itm/ESX25-Col...hash=item419899221e:m:mVvST6a5TS2j1rr7-eFG7BQ


Stuart
 
Thanks all for your responses!

I found a few of my answers (thanks to you guys and the nice folks at the yahoo users group), and I'd like to run a few of them by you:

For a backplate, http://www.emcomachinetools.co.uk/125mm-dia-backplate-for-compact-8-lathe . I'm in the USA, but it looks like they ship international. ~$85

Collet adapter: ESX25 Collet chuck for Emco Compact 8 Lathe ~$100


s-l1000.jpg

http://www.ebay.co.uk/itm/ESX25-Col...hash=item419899221e:m:mVvST6a5TS2j1rr7-eFG7BQ
He doesn't list the runout, but it looks like it may be an original Emco. I assume ESX25 and ER25 collets are interchangable?



What kind of runout should I be looking for on a self centering 3 jaw chuck?



I'm noticing quite a bit of backlash on the main carriage (turn the handle maybe 20 degrees before the carriage starts to move) Is that normal? Is it worth taking apart to investigate?



Thanks again everyone!
 
lots of back lash on the carriage is normal for most lathes, can't say for sure about yours. It is just because the you are driving a rack and pinion rather than a lead screw. For really fine adjustment, you can either bump the hand wheel with your palm, bump the carriage with a mallet, or use the compound - use whatever method is best for the moment. You can get adjustment much finer than the lathe will actually cut by using the compound. Just set the compound to 60 degrees from the z-axis and you get 0.0005" advance on the z-axis for each 0.001" advance on the compound. Makes it easy to dial in that last 2 or 3 thou off a facing cut.

For a 3jaw, anything under 0.005" is fine. Most of use are happy if we get to 0.003", some of use live with something closer to 0.010". If you need better, use a 4jaw, spend huge money on a set true chuck, or loosen the chuck to adaptor screws and knock it around with a mallet. Best to just assume that anything in the 3jaw needs to start over size and will be off center. The same goes for a collet BTW on your machine, it will run better than a 3jaw, but not as well as a 4jaw.

The collet style you have pictured is far preferable to a draw bar style imo.
They are simple to make, buy a collet nut, and machine the rest from semi-hard steel. Unless you are planning to really use it hard, it can be made from semi-hard and not require hardening/grinding. It is an excellent project to practice turning to size, cutting threads, and setting up and turning tapers. Your shop made tool will actually be better than a commercial tool since it will fit the spindle to a higher tolerance and allow you to remove the work in the chuck for milling, and put it back on the lathe for finishing with better repeatability. All you need is a dial indicator and some marking fluid or transfer dye to test the fit.
Check out Myfordboy and Tomstechniques on YouTube, they both have excellent videos on setting up the compound for a taper. The $ is better spend on something else, put the cash in a jar for your new mill fund :)

-Josh
 
I'm thinking that machining my own collet chuck will be the way to go. Do you guys have any recommendation on what grade of steel to get and where to get it from? I usually get my raw material either from my works scrap bin, but they mostly carry plastic and aluminum, or from mcmaster which is spendy.

For a collet set, I'm looking at this one from Shars, anyone have good/bad experiences here?
http://www.shars.com/3-20mm-by-1mm-er32-collet-18-pcs-set
 
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