Well thanks everyone. Much appreciated. This was a fun project and a labor of love. I started off thinking I'd get a 24" bed length version of this 1340, Matt gave me a quote for it, and I was close to pulling the trigger, but everyone here said "longer is better." Who am I to argue with THAT !!?!?!?!
The lathe was not in stock when I ordered it, and came about three months later which was fine. Then it sat in my garage for a few months while I learned to weld, converted a bench to a welding table (
https://www.flickr.com/photos/davidpbest/albums/72157672375283855), built a welding cart (
https://www.flickr.com/photos/davidpbest/albums/72157671235486470), then tackled the stand construction (
https://www.flickr.com/photos/davidpbest/albums/72157672474119185), and then decided to prove I was a REAL MAN capable of moving the lathe into the basement working along (
https://www.flickr.com/photos/davidpbest/albums/72157671928399283). And I only lost a single finger in the process (
http://www.hobby-machinist.com/thre...-bad-accident-end-mill-defeated-finger.56337/). In all seriousness, the finger loss was not related to any of the lathe work - just a stupid, stupid accident on the milling machine.
- you have a different top-side handle for the carriage lock. I didn't quite get if that was ratcheted or just swings from loose to lock?
- did you modify the stock carriage locking mechanism in any way? (I'm talking about the underside foot or clamp part)
The carriage lock on the stock machine is an M8 socket-head cap screw pulling up on a threaded steel plate that locks against the bottom of the front bed way. Several others here have posted about converting this to some kind of lever locking mechanism, and I decided to do the same. I'm a big fan of Kipp adjustable lever handles, so that's what I employed. If you look at this photo (
https://www.flickr.com/photos/davidpbest/32194862321/in/album-72157672547607804/) and the next few, you'll see what I did. I didn't have to make any modification to the clamping plate under the carriage, I just bought a low profile Kipp lever with male 50mm long M8 threaded stud (
http://estore.jwwinco.com/default.aspx?page=item detail&itemcode=8N50A32/D), turned a replacement stainless steel handle for it that matched the other handles I made (purely cosmetic), then turned a stainless cover for the body of the lever mechanism (ultra cosmetic).
- did you see anything worth upgrading or modifying in terms of the power feed assembly? (ie. the worm gear assembly, the slotted power bar & related mechanism). I suspect my older gen lathe is different with a cast iron C bracket that the power bar loosely threads through. But there are no bushings or contact surfaces to accept thrust load while power feeding or anything to replace with wear. Maybe that's all fixed up with the PM, but I would love to see some pics of your lathe if you happen to have any handy from the rebuild. The PM parts manual PDF wasn't too clear on this & I'm looking for good ideas.
Well, I definitely discovered some quirks. Probably worth noting here, but Matt at QMT was quick to get things resolved. Here are the quirks - all probably unique to my machine:
The power feed for the carriage is driven through the QC gearbox. Photo:
Where that feed drive gear shaft exits the QC gearbox housing, it runs through a bronze bearing pressed into the housing that's lubed from the drip oil system above (just under the switch panel). Photo once shaft and gear train was removed and the bushing cleaned and polished - you can see the oil drip hole in the bushing (fed by a tiny copper tube from above) and spiral grooves to distribute the oil:
From the other side:
On my machine, the bushing was bound up with what looked like black tar, and was probably paint or filler overspray that got into that mechanism at the factory, heated up and froze the drive shaft. The result was that any kind of power feed would start for a few seconds, then stall as speed increased, and the change/treading gears would grind. In the process of diagnosing the problem, I pretty much stripped/chipped all the the available change gears - the large combo, and the four smaller gears. Once I figured out that the gear shaft coming through the bushing in the housing was the problem, it was about 3 hours work to pull that shaft, get the bushing cleaned out, reassemble the shaft and the gear train on it, get it lubed, and running again. Matt had the factory direct-ship me replacement change (threading) gears which came in a few days and all was fine after that.
If I have any criticism here, it's that the oil for that bronze bushing is fed from a drip point above that's easy to miss. That's what drove me to put in a new single point oil pump and distribution system for the QC gear box. That stock QC gearbox oil drip system is pretty lame IMO, especially when the power feed shaft really depends on lube from above to not over heat and freeze up. Of course, if I were designing this lathe, that shaft would be on a precision permanently lubed titanium bearing. But this is not NASA.
That power feed shaft coming out of the QC gearbox drives a hub clutch with two balls on springs on one side, and a drive plate with dimpled recesses on the other. Drive plate photo:
Drive hub with balls and springs:
It took a while to get that dialed in so the carriage wouldn't start stuttering as the clutch slipped during heavy roughing operation on stainless steel. The ball bearings are tensioned with set screws, so dialing in the clutch tension is not a big deal - just trial and error.
The shaft that articulates the forward/reverse switches in the box below the power feed shaft, has a steel paddle secured to the shaft that triggers the two switches. That whole mechanism inside that box is like working on a wristwatch - fussy tolerances, tiny screws (4-40 BTW, not metric), spacers, washers, opposing nuts, etc holding the switches in precise position, etc. If you take it apart, take a bunch of photos first to know how to put it back together.
The cross slide on my lathe came with a really strange distance ring that wasn't just metric, it really belonged on some other kind of machine entirely. The cross slide screw was imperial, worked like you'd expect, but the ring with the mm and inch markings had no correspondence to the distance moved when turning the handle. Again, an email to Matt got this quickly resolved with a direct ship replacement of the threaded shaft, dials and bronze nut - complete assembly - in a couple of days.
Hope this helps.
