Atlas 12x36 model 3986

[Stan20]

I’m looking at buying a Atlas 12x36. Model 3986.

it has a 3 and 4 jaw chuck.
QCGB
steady rest
Taper attachment
Milling attachment
various tooling
drill chucks

asking price is $900.

I mainly want to use it for odd end jobs around the farm and with making parts restoring tractors. Any thoughts or insight would be greatly appreciated.

 

[markba633csi]

Buy it, taper attachment never seen usually. Same with steady although not as rare
-Mark
Twirl the spindle and see if it has a nice smooth feel and sound. No notchy-ness or roaring noise. Check the carriage carefully for damage/problems with the handwheel feed and the half-nut mech and the cross-feed mech

 

[BGHansen]

To me the biggest thing to consider is the condition of the bed ways. Run your fingernails across the headstock area. If there's significant wear, that's a toughie to fix properly.

Move the carriage to the headstock and jog the longitudinal handwheel back and forth. Lightly tighten the carriage lock until you start feeling resistance. Then try to crank to the tail stock end. It'll probably get tight as most work is done at the headstock. Repeat starting at the tail stock and move to the headstock and it'll be loose. I believe the Atlas lathes use shims on the bottom of the carriage to adjust fit to the bed.

Very nice price for what's there. I wouldn't worry about broken gears or worn feed nuts too much as all of those parts are readily available and just bolt in.

Bruce

 

[markba633csi]

Thanks Bruce, you filled in the checklist that I started. The ways are most important since they define the ultimate accuracy of the machine.
-Mark

 

[wa5cab]

As the other respondents have said, that is an excellent price for a 3986, and especially with that many of the accessories, which tend to be scarce and pricey if purchased individually. Average going price for them is about $150 +/- each, including the chucks. So if you add them all up, you could say that the lathe is free! Normal asking price for that model (a 12x36 bench model) is about $1200 to $1500 without most of the listed accessories.

However, you should check the bed for wear. The best way to do that is to carry along with you a 0.0"-1.0" and a 1.0" to 2.0" Micrometer. The nominal thickness of the ways is 1/2" and the width is 1-1/2", but that does not mean that the original or new way thickness and width were 0.500" and 1.500". The actual tolerance on the base dimension was about +/- 0.005" or maybe even a little more. But once established, the tolerance between any two spots is +/- 0.0005".

Anyway, establish the original thicknesses and widths at the right end of both ways. Before measuring them clean the areas thoroughly as the lathe was made between 1966 and the Summer of 1974. So there could be more than half a century's varnish buildup. Then measure and record the thickness and width about every 6" from the headstock to the right end of the bed. Note that wiping off with only a clean rag is adequate to make a decision so if it isn't practical to clean down to bare metal, if you do buy it, then make the more accurate test later.

One other thing to check, although it won't enter into the buy or don't buy decision is whether it has steel or plastic compound and cross slide gibs. Judging from the relatively few 3985 and 3986 that we have in the database, the switchover started around the time that those two models were discontinued, so we do not know whether any of those two models were shipped with plastic gibs or not.

Anyway, regardless of whether you buy it or not, try to get the serial number. and whether it has steel or plastic gibs. It will be on an Atlas nameplate on the right end of the bed. The model number is also stamped on that plate.