Clausing 1509 cross slide nut assembly

I don't know about the 1500-series lathes, but on the Clausing 5900-series, the cross slide nut is retained in the saddle with a flat point set screw with the tapped hole on the HS side of the saddle.

Mike

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The same is true with the Clausing 5400 series, which is what I have.

When you put it back (or its replacement), you should leave the setscrew loose until you have the crossfeed leadscrew cranked to pull the nut as far towards the crank handle as possible. This will ensure that the nut is at the right height, so it won't bind in service.

Enjoy, DoN.

I misspoke myself (miswrote myself?) on the model number. The lathe is a

5914.

Thanks Mike, Don, exactly what I was looking for. I guess I needed to look a little harder at the saddle. I'm going to look into part availability today.

Regards,

Adam Smith, Midland ON

If you are talking about replacing the nut, I did that myself a couple of years ago. The nut was around $50 as I recall. Unfortunately it made only a modest improvement in the backlash so it looks like I'll need another screw as well. Those run around $250, though so I'll live with the backlash for now.

DoN. had good advice on not tightening the set screw until the cross slide screw is installed and the cross slide is moved toward the operator as far as possible. Besides adjusting the nut for the right height, it also ensures that it is algned along the axis of the screw.

The replacement nut has a ball oiler on the top to permit lubrication of the cross slide screw, something that my original lacked and that would have made it hard to lube the screw, which may partially explain the wear on my cross slide screw. I'm sure that the 30+ years of service the lathe saw before it came to me also took its toll.

Mike

I had a chat with Clausing Service Center a bit earlier, and the nut is currently $48.40, the screw and nut assembly is $266.20. I'm now chewing on what I'm going to do, but I did want to correct my post in an earlier thread stating that the parts were unavailable. I must have been thinking about another parts inquiry, there doesn't seem to be any problem getting these (other than the price that is). $325 Canadian, ... gulp.

BTW, my concern is not so much backlash, as indeterminancy in how much I'm advancing the tool when working to a set figure. I hate wanting to take 10 thou, dialing 10 thou, and getting 7 thou off. Tricky in some materials getting that last 3 thou off without enough there to give the tool something to chew on.

Thanks once again, both, for the prompt answers.

Adam Smith Midland ON

FWIW, I have around 30 thou of backlash, going by feel not actual measurement, and can generally hit the dimension I want to within 0.001" if I'm careful. A DRO would fix your problem at somewhat more cost than the nut & screw. A cheaper option would be to mount a plunger-type indicator to indicate displacement.

Mike

Hmm ... back when I replaced them, the nut (part # 990-069) was $43.65, and there were two choices for the leadscrew:

Q-551 $31.26 (Screw)

or

Q-551S $94.40 (Screw Assy)

The difference is that the second one has the gear pressed onto the shaft and pinned in place.

I got the first option, and found myself wishing that I had gotten the second one instead, as pulling that gear from the screw, and then pressing it onto the replacement was a bit of a pain. (The pinning was no problem, IIRC, but the pressing bent the new leadscrew slightly. Getting it straight again was a bit of work.

Note that the part numbers above are for the 5418, but I believe that they apply to the 5900 series as well.

For pricing, a gear which I have had to buy twice, was $94.01 several years ago, and is now in the $186.00 range. They had to have more made between my first purchase and the second, and the price reflects the cost of production in modern times, I fear.

Check whether you can get the screw without the gear -- if you are set up to press the gear off the old leadscrew and onto the new one.

O.K. My Clausing had been fitted with a work-around (and the leadscrew and nut were sufficiently worn so the backlash was about

0.070"). To the right of the cross-slide at the back was an aluminum mount screwed to the carriage to accept a 1" travel dial indicator. On the right side of the cross-slide near the operator was an aluminum bracket with a hole for 1/8" drill rod, and a thumbscrew for clamping that in position. It was arranged so the end of the drill rod would meet the point of the dial indicator, so you could roughly zero it by sliding and clamping the drill rod, and then fine zero it by rotating the dial on the indicator. This is fine for work within a 1" radius range (2" diameter).

An alternative (not cheap) would be to get one of the Shooting Star DROs and mount it to the lathe to read off your position precisely, independent of the accuracy of the leadscrew. It might work out to be more economical for you than the leadscrew.

I have one, which I have not yet gotten around to installing, so I occasionally use the dial indicator just for backup, even though my leadscrew is in good shape at the moment.

Enjoy, DoN.

The P/N's for these parts on the 5900 are 5900-88 for the screw (with gear) and 5900-37 for the nut according to my manual and last year's Clausing parts list. I don't know if the parts are intergangeable or not between

5400 and 5900 series lathes, but suspect not as the same parts list has the P/Ns you quote above. The nut was $44 even and the screws were $64.87 and $88.67.

If you want real sticker shock, try pricing the X-axis leadscrew for the

8540 mill - $1300+, as I recall.

A potential problem with the Shooting Star, good as they are, is that the resolution is 0.0005", which is doubled to 0.001" for diameter measurements. That's probably good enough for most work, but makes it hard to sneak up on a really tight tolerance. The dial indicator would still work of course. For the longitudinal axis I've been finding a Trav-a-dial really handy, especially when turning or threading to a shoulder. It's muc easier for me to track an analog dial by eye than a digital display.

The P/N's for these parts on the 5900 are 5900-88 for the screw (with gear) and 5900-37 for the nut according to my manual and last year's Clausing parts list. I don't know if the parts are intergangeable or not between

5400 and 5900 series lathes, but suspect not as the same parts list has the P/Ns you quote above. The nut was $44 even and the screws were $64.87 and $88.67.

If you want real sticker shock, try pricing the X-axis leadscrew for the

8540 mill - $1300+, as I recall.

A potential problem with the Shooting Star, good as they are, is that the resolution is 0.0005", which is doubled to 0.001" for diameter measurements. That's probably good enough for most work, but makes it hard to sneak up on a really tight tolerance. The dial indicator would still work of course. For the longitudinal axis I've been finding a Trav-a-dial really handy, especially when turning or threading to a shoulder. It's muc easier for me to track an analog dial by eye than a digital display.

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Hmm ... as long as you aren't turning to a shoulder at the same time, try using the compound. Set it as close as you can to 5 degrees

44 minutes 21 seconds (5.7392 degrees decimal), and for every 1.000" you crank in on the compound, you will move in only 0.100", so you can easily crank in 0.0001" real diameter (with 0.001" on the compound dial.)

Note that is 5.7392 degrees from parallel to the axis of the lathe. Some compounds are marked in degrees from parallel, others in degrees from at right angles to the axis.

Another benefit from most DROs is that they have a button to read out diameter removed instead of radius removed, while the longitudinal feed continues to read directly in length.

Enjoy, DoN.

I've used that technique before with good results. It doesn't help much with power feed or threading though and that's where I like the Trav-a-dial.

The Shooting Star has that feature, but the resolution of the encoder/electronics is still the same - 0.0005". Switch the display to diameter and the Y-axis display increments by 0.001" instead of 0.0005". The compound trick above will get you to tenths, but then the DRO is not reflecting the turned dimension. It's possible to keep track manually, of course, but the more things I have to keep track of the more mistakes I make. That's just me, though.

Mike

Well, I seem to have convinced myself to have a shot at making the parts. I've been blowing a bunch on bits of tooling and so forth lately, think I'd rather spend the time than the money. We'll see how it goes, though, I may be back to purchasing before I'm done.

Interesting points about the use of the dial indicator as "poor man's DRO". I'll give that a whirl, seems like a good technique. It doesn't get me out of the repair though: this is all in the context of a pretty major repair on the lathe, the cross feed screw (among other things) is completely unuseable, not just worn.

Regards,

Adam

My 5914 had about 2.25 INCHES of backlash in the center of the lead screw when I bought it. I think the machine was only being used to cut off parts (not using the middle part of the lead screw) at the end of its commercial life. I bought the new nut for about $50, cut the screw thread off of the lead screw asm and silver soldered a new length of acme screw stock onto the remaining stub of the lead screw. Alignment was not perfect so I ended up laying the asm on a steel table and giving it a few loving taps w/ a copper or brass mallet. I got the idea for only replacing the threaded portion her on this news group about 3 years ago (just as I was beginning to repair this machine). I still had my mid 1920's vintage South Bend lathe to turn the ends of the acme threaded stock and the stub end of the original lead screw. I bought a 3 or 6 ft long stick of precision acme screw stock from McMaster Carr.

Don't feel bad, this is a pretty demanding job. You need to be very accurate when you bore and turn the pieces to fit, and you need to have a couple of spots that are nearly press-fit in assembly. But you also need some regions with a thou of clearance for the sliver solder.

Jim

Hmm ... mine (a Clausing 5418 -- 12x24") had pretty bad wear in the middle of the leadscrew, though not quite that bad.

My machine came with a bed turret, instead of a tailstock. (I had to chase down one to fit it later. I sometimes do batches of parts with the turret mounted, and a typical example would be (using rod stock fed through the spindle in collets):

1) Set workpiece length against stop/center drill

2) Center drill the end using the same tool, with center drill extended.

3) Knurl OD to length with a T-bar knurler.

4) Turn part of length to smaller diameter with roller box tool in a single pass.

5) Thread that length to shoulder in a single pass with Geometric die head.

6) Drill center through length to tap drill size with bit in a Jacobs chuck

7) Tap to depth with tap in releasing tap holder.

To this point, nothing has used the carriage or cross-slide.

8) Use parting tool in cross-slide to undercut the end of the threads against the shoulder. Carriage is positioned with a turret bed stop.

9) Use parting tool to part off workpiece with carriage positioned using another station on the turret bed stop.

10) While steps (8) and (9) are being done, belvel selected points with a hand-held file.

11) Catch rather warm workpiece in a wire basket.

12) If there is sufficient stock length, Go back to step (1) above and repeat.

So -- note that there is no wear on the longitudinal leadscrew for threading, as that is done with the Geometric die head (and much more quickly, FWIW. ) And the cross-feed is powered from a sliding worm gear keyed to the leadscrew's key.

This is the kind of work which the lathe had been used for most of its life. The threading dial was still in one of the drawers -- never mounted. (It is now mounted, of course, and gets regular use.)

As a result, the cross-feed leadscrew was nearly worn out (V-points on the threads, with lots of width between threads), and the threading (longitudinal) leadscrew was pretty much unused. I have no idea how many cross-feed leadscrews and nuts that machine had been through, but very little carriage motion (it was probably left in one spot for the parting off), so the bed was in excellent condition. All things considered, that was very good for me, as the cross-feed leadscrew and nut were a *lot* cheaper to replace than the longitudinal leadscrew and the half-nuts.

I suspect that your 5914 had seen a similar life, and there may be somewhere around a bed turret for it with a matching serial number (as mine was).

I've still got the old leadscrew, and I will probably use it as a guide to cut a new leadscrew for the future. I've got the acme threading tooling for 10 TPI ACME LH, and the follower rest, so I should be able to do it.

And -- I have the 10 TPI Acme LH tap for making a spare nut.

I should make both before I need them again. :-)

Enjoy, DoN.