acme rod/nut refurbish?

I'm considering renewing the crossfeed screw and nut on my new/old shaper. I'm considering using Errol Groff's method for renewing the screw. He purchased ACME threaded rod and cut it to the length of the threaded portion of the feed screw, then bored and reamed one end to a 3/16x1" hole. Then he cut off the worn threaded section of the feed screw, leaving 1" of the threads, then turned down the threads for a press fit and pressed on the new threads. This for a 16" South Bend, seems hard to believe it would hold up but if it didn't a little brazing would cure it.

The shaper's cross-feed nut looks somewhat like this one:

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I'm thinking of purchasing a cylindrical nut and turning it down to make a bushing threaded on the ID. I'd then bore out the worn threads on my cross-feed nut for a slip fit over the nut, then silver solder the new threads in.

I'm planning to buy the parts from Green Bay Manufacturing Co. but they have multiple parts that would work for what I'm planning. For example, they carry rolled 5/8-10 LH ACME rod in both 4140 and 1018, and they carry 5/8-10 LH ACME nuts in bronze, gray iron, and 12L14 steel.

Is this a good way to go, and which material should I use?

In case I decide to make it, does anyone have a 5/8-10 LH ACME tap they might be willing to loan me?

Grant Erwin

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Grant Erwin
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Press fit is nice. But I would bore a hole perpendicular through the two parts (new thread and old shaft) and drive a pin through it. 3mm sound small, but do a lot. I did this recently when I modified a vice. If you are paranoid enough, you still can add Locktite.

Don't silver solder it, the nut will get soft. Locktite, and so no press-fit. Locktite isn't very good on brass, but you have a lot of surface. Depending on size & shape of the parts, there might be a clever solution with modifying the old and new nut and joining them with screws or pins.

HTH, Nick

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Nick Müller

As Nick says, I would tend to use a 600 series Loctite or similar. I would also go for the 4140 and bronze combination. If lubrication was extremely rare I might tend towards the cast iron nut, But if you oil the screw with something like way oil once a day the bronze would probably hold up better.

I need to do a similar job on mine at some point, but need to do the vertical screw and nut. That one is also going to need a pair of crossed helical gears since the existing bronze ones have eaten too much swarf other the years and don't have a very good tooth profile any more.

Mark Rand RTFM

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Mark Rand

======================== Some of the older machining books indicate that you can cast a babbitt nut in place around the thread. This seems to have been common on lathe half-nuts at one time, both because of easy shop repair [most shops probably had a pot of hot babbitt standing by when the books were written ...] and claimed much less wear in that the oil from a brass/bronze half-nut would shortly turn black showing leadscrew wear, while it would not with babbit half nuts.

Any one tried this?

If you are interested Lindsay's has reprints of these techniques see

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have all three books and they are worth the money just to read, even if you don't babbitt anything.

How about using the newer moglice compounds?

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F. George McDuffee

Pull off the backhoe. Acquire a good, heavy box blade - the biggest your unit can handle. Get 2 hydraulic cylinders. one to control side tilt and one to control the forward/backward angle of the box and the auxiliary controls to go with them. They also make one to pivot the ripper bar on larger units, though I find it unnecessary. Look up Gannon or LandPride to see the best. A good box blade and operator can move more dirt than a front bucket ever thought about.

Ford 340 with an 84" high-backed 1100# Land Pride box. Needed to add 500 pounds to the front to keep it down some of the time. Liquid filled tires. If you get the teeth set right, just control the rip by the tilt of the bucket. ______________________________ Keep the whole world singing . . . . DanG (remove the sevens)

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Seems kind of like overkill for working on his shaper.

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Just a brief followup: Errol wrote me that in fact the press fit did not hold up, that the splice had to be TIG welded (makes more sense to me). Also, when I removed all the broken and jammed gib screws from the apron (not the part behind the clapper, the part the table bolts to that slides sideways) and replaced them with new ones with just a little drag, the cross-feed now works perfectly again.

As I posted elsewhere today:

To summarize, to deal with a shaper that's having trouble ratcheting:

  1. try adjusting the nuts on the left end of the cross-feed screw to add a little rotational drag to the screw

  1. can also try putting in some kind of frictional washer in there, e.g. a fiber washer or spring washer

  2. try slightly tightening the gibs on the cross-slide (apron)

  1. try disassembling the ratchet mechanism and cleaning out gunky oil and relubricating with light oil, possibly reconditioning the point of the pawl for a more definite engagement.


Mark Rand wrote:

Reply to
Grant Erwin

I may indeed have one. Ill check this weekend when I go home. I dont know if its left or right hand.


"If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around."

"Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion).

-Buddy Jordan 2001

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