Power cross feed question
Umm, how does it work?
I recently picked up a nice 10K and while I can get the power feed to work longitudinally I can't figure out the power cross feed. I assumed that the three position lever behind the power feed engagement lever was it but if the lever is in either the top or bottom the power feed engagement doesn't move. In the center I get power feed longitudinally but nothing otherwise.
I'm guessing I'm missing something obvious but a couple of machinist friends weren't able to figure it out either (spoiled Hardinge owners) since none of us has ever used a South Bend. Either something is broken (which I'm doubting since the machine is in really nice shape) or I'm missing something.
Oh, not sure if it matters but it has a taper attachment. Here's a photo:
Last edited by Paula; 02-12-2011 at 09:56 AM.
Reason: Oversize image -- see guidelines
on mine, down is crossfeed, and up is carraige feed, center is neutal, you did tighten the clutch I assume...also mine takes a couple seconds to start moving, wear I guess....Nice find by the way!
I'll bet it's the clutch he's missing! That's the starwheel at the bottom center. Just a fingertip tightness is all you need.
It is beautiful. Just like mine - only a LOT cleaner!
Yes. When it is in the center the half nut leaver can be engaged for screwcutting. Up or down then you use the star wheel to tighten the clutch for feed. The feed amount per rev is beside the threads per inch on the thread chart on the quick change gear box. Nice condition, wish mine looked that good, Peter
"...three position lever behind the power feed engagement lever was it but if the lever is in either the top or bottom the power feed engagement doesn't move. In the center I get power feed longitudinally but nothing otherwise."
The thing you are calling the "power feed engagement lever" is the half nuts lever.
It is ONLY used when the machine is set up for threading.
The reason you cannot move that lever to engage what you think is the longitudinal
feed, when the feed selector lever (three position, up-middle-down) is in the center
is because of a deliberate lockout mechanism built into the apron.
So to recap:
1) Set the halfnuts lever in the open position, you will be sure this is so because
the carriage will shift back and forth then.
2) put the feed selector lever in the UP position to get longitudinal feed, and
3) put the feed selector lever in the DOWN position to get power crossfeeds.
4) To actually engage the feeds, as mentioned, turn the star wheel clutch gently
to the right, or tight. To stop the feed, turn it left or loose.
5) the halfnuts lever ONLY when you doing threading with the leadscrew.
Download a copy of the South Bend "How to run a lathe" book from Steve Wells' site. All this and other SB stuff will be explained.
Hmm, that's the best explanation I've heard. I'll give it a whirl tomorrow when I machine a backplate for a chuck. Thanks much Jim and everyone else.
Originally Posted by jim rozen
I've read the "How to Run a Lathe" and while it's a nice 15 minute read it leaves more not explained than explained. Like cross feed for instance. Not mentioned once.
Which version of HTRL do you have?
The 1942 edition; in chapter 2 has a paragraph, "Power Carriage Feeds" that covers this subject.
I don't think the earlier editions do, I'm not sure about the 1930 edition, it may have it.
If you can find a 1942 online some where or check the auction sites, it would be worth running down.
Wow! That is a good looking lathe! You got a good one. I'm sure the feeds will work when you do like Jim R. said. The chart on your gearbox tells you where to put the levers to get different feed rates, how many thousands of an inch it will advance for every revolution of the spindle.
Yes, very nice lathe indeed!
Too bad about the british motorbikes though.
I think that's a twin-carb 650 BSA in the background there???
I guess that's my bad on the HTRAL recommendation. I've got a paper copy from 1969, which is about the same age as my lathe. I didn't look at the older copies, just posted the easy link.
Glad you got it worked out in spite of my misdirection.
Dual plugged. Very nice. Don't suck those tennis balls into those mikunis!
Not dual plugged:
Neither is the earls fork bike done that way, in the background. Nor is this one:
You may notice a slight swelling of the pilot. Also a subtle shift in hair/beard
color. I assure you this is just a trick of the light.
Were the drum brakes stock on that single swing arm BMW?
Nice! I thought you had the detailed personality of an airhead owner. You have some cool bikes for sure. I've wanted an older one but until the current projects are done I'm limiting my losses. I see a dirt bike back there too.
My boxer started as an r90S that I crashed - here's a link from the original build which is what set me on the path to my own lathe (and mill now). The frame was redone, the rear end from a GSPD and the front is a Ducati donor. I'd like to upgrade the suspension this year. Hoping to get it reworked in time for the National in Pa this summer.
You crashed an original R90S??
Well I guess the wreckage turned out OK in the end!
If after all this explanation it still does not move then you may have lost the key in the slot of the feed screw that engages the cross feed. Could have happened during the rebuild.