Lead Screw

KHK · Jun 12, 2017

Howdy. I am new to the forum, and look forward to getting to know you all. :cheers:

I am retired, and I have gotten in building a LSR (Land Speed Racer). As part of my quest, I acquired a Clausing 1500 14" x 4' with a bad lead screw. I called Clausing and got a horrible shock when told the price of a new one. Does anyone know a source for used ones? I also see ads for lead screws )generic) which I assume can be machined to fit my application. The prices are reasonable. My issue right now is time. I have to be at BSF in 8-weeks. I also realize time may not be on my side, but I had to try. :cryin:

Anyone got one for sale?

Cole2534 · Jun 12, 2017

Bad how? Like worn or snapped in half?

Since you have a lathe you could attempt to cut a new one. It would probably take several iterations to arrive at reasonable accuracy, and would never be as accurate as a well ground screw, but stressproof round bar is pretty reasonably priced, you'd probably have a hundred bucks in enough material to make 2 screws.

Sent from my SM-G930R4 using Tapatalk

iwananew10K · Jun 12, 2017

Giving the diameter and thread will help your cause.

Bruce Nelson · Jun 12, 2017

If part of the lead screw is good, you could machine a new one on the same lathe. If the bore of the spindle is large enough to accept the stock that you are going to make the new screw out of, and if you have a steady rest and a follower rest; you can machine the thread in two or more setups by using the undamaged part of the lead screw. When re-positioning the screw to take cuts where you left off on the previously finished portion, you will have to adjust the longitudinal position of the tool to pick up the previously machine thread.

I was able to finish my lead screw in two setups. I can't tell where the threads match up by eye. I made the screw out of stress-proof steel. You will also have access to a vertical milling machine to mill the keyway. If you don't think you have the skills for this project, look for an experienced journeyman machinist to help you.

L Vanice · Jun 12, 2017

KHK said:
Howdy. I am new to the forum, and look forward to getting to know you all.

I am retired, and I have gotten in building a LSR (Land Speed Racer). As part of my quest, I acquired a Clausing 1500 14" x 4' with a bad lead screw. I called Clausing and got a horrible shock when told the price of a new one. Does anyone know a source for used ones? I also see ads for lead screws )generic) which I assume can be machined to fit my application. The prices are reasonable. My issue right now is time. I have to be at BSF in 8-weeks. I also realize time may not be on my side, but I had to try.

Anyone got one for sale?

So what is the land speed record for an engine lathe?

If it helps to say no to Clausing and their replacement parts prices, I bought a used Clausing in 1984 and thought it would be a good idea to get spare cross feed screw. This was not so long after the lathe was out of production and the prices were not terrible back then. But the screw arrived and the thread surface finish was incredibly rough, nothing like a ground finish or even a good lathe turned finish. I live about 55 miles from the Clausing parts warehouse, so I went there with the reject part, having made an appointment to exchange it for a good one. They brought out a steel bin with their entire stock. I looked at every one and they were all junk. The guy I talked to said he thought they cut the threads with a die head. If so, they had dull chasers and left the coolant shut off. I got a refund.

Later I found an unused and well-made screw from some other brand of lathe with the correct thread. I cut the threads off the new and old screws and brazed the new threads on the gear and bearing end of the Clausing screw. It was better than new when I finished, and did not cost much.

So yes, the best solution is to get a length of good screw with the correct thread and make the ends fit the lathe. There is probably a joint and aluminum shear pin just to the right side of the quick change gear box.

Larry

KHK · Jun 12, 2017

I get it. Buy a threaded shaft and attach my ends on it. I can do that, and feel kinda stupid for not thinking of it.

Land Speed record for a lathe? Hmmmmm. I am running a 1956 blown fuel Harley KHK (think of a side valve, flathead Harley Sportster). Talk about stressing 62-year old parts. My engine was in broken bits when I started. Please come out and watch a 70-year old man blow the doors off the young kids. Oh yeah, drive your neighbor's car and bring lots of sun blocker.

kensmachine · Jun 12, 2017

you could try these guys http://www.dcmorrison.com/SCREWS.html

traditional-tools · Jun 12, 2017

If your current screw is bent, you could try to straighten it, or have someone straighten it for you.

I don't see where you've said what it actually wrong with it yet.

Ebay is probably your best bet to find a used one.

I hope you make it to BSF in 8 weeks, whatever that is...

mach2 · Jun 12, 2017

And if it is the threads are worn but have enough left you can recut them. I did this as a quick fix for a mill screw that was worn .020" in the middle and gave that much dial error over half the screw length. Single point rethreaded it removing .020 off the full length. This results in backlash but restores the accuracy.

Sometimes with a little modification the screw can be reversed placing the good length near the headstock.

Still the best way is to replace.

JRIowa · Jun 13, 2017

The screw is the easy part. Lots of places sell threaded Acme shaft. The hard part is the half nut. Check the price on that. You'll wish you'd have bought a different lathe. BTW, I've got a 1500.
JR

gbent · Jun 13, 2017

traditional-tools said:
I hope you make it to BSF in 8 weeks, whatever that is...

BSF Bonneville Salt Flats. One of the best reasons in the world for a rental car.

mmarquette · Jun 13, 2017

I found a 1.250-6 acme which is not standard from greenbay manufacturing. There site showed a lot of different sizes and grades. sold by the foot so you don't have to buy 10' and only need 4.

hanermo · Jun 13, 2017

Anyone on this list with a modernish CNC lathe can cut you a new one, of exceptional accuracy and finish, in 15 min setup and 10 min time -
with bonus of start and finish ends made so size for you perfectly accurately, at exactly the right spot.

Anyone doing you a favour might charge as little as 100-200$ for the work, that should not take them even an hour.

Likewise, any machine tool brands rep. might do it, or know which of their customer might do it, as a customer-relations exercise.

WHHJR · Jun 13, 2017

I have a 1400 and a 1500. I have cut new cross feed and compound screws along with one new compound nut. It is really quite easy. The main lead screw is a fairly fine thread, but shouldn't be to difficult to do in 2 setups.

Mark Wendt · Jun 13, 2017

gbent said:
BSF Bonneville Salt Flats. One of the best reasons in the world for a rental car.

Well, that and deer hunting.

Newman109 · Jun 13, 2017

KHK said:
I get it. Buy a threaded shaft and attach my ends on it. I can do that, and feel kinda stupid for not thinking of it.

Land Speed record for a lathe? Hmmmmm. I am running a 1956 blown fuel Harley KHK (think of a side valve, flathead Harley Sportster). Talk about stressing 62-year old parts. My engine was in broken bits when I started. Please come out and watch a 70-year old man blow the doors off the young kids. Oh yeah, drive your neighbor's car and bring lots of sun blocker.

Above posters are giving good advice on repairing your Clausen lathe and, FYI McMaster-Carr has all the lead screw stock a man could ever want.

McMaster-Carr

BTW, I once owned the Uncle of your '55 KHK. It was a 1953 Harley KK. (45 cu. in. racer flathead). It was well used and had been raced at Daytona by one of the many previous owners. Shortly after I bought it, I was racing in a Scrambles race and managed to take a tooth off of the main drive gear, then a $10 part. Because Harley had not yet added the trap door in the left crankcase, I was forced to split the crankcases to replace the gear. Working alone in my basement in Chicago, it took me 4 days to do the repair. In 1954 and later until 2003, they had the trap door. They got rid of it when they changed to a rubber-mounted engine in the Sportster so that anyone who damages a transmission nowadays will probably have to go back to the dealer if they aren't handy.

Good luck on the Land Speed. Hope you don't damage the cylinders, there aren't any more. LOL.

gwilson · Jun 13, 2017

Manhattan Supply Co. sells 3 grades of threaded Acme screw rod. Their highest one is quite accurate. You could buy a length of it and weld on whatever you need to the ends. Needless to say,weld it on ACCURATELY,and machine to suit. It will be plenty accurate for anything you'll be threading.

KHK · Jun 13, 2017

BSF - Bonneville Salt Flats

I acquired the lathe from a hurricane damaged shop. It is rusty from exposure to rain. The lead screw has begun to flake, and from all appearances, is unusable. The internals are pristine, but the outer has a mild layer of surface rust - like dust. No holes, etc. The lathe was seldom used for reasons I know not. Loads of cutting tools still in boxes with it.

The 7.5 hp 3-phase motor was an issue until I built a static phase converter for it (220, 240, 240). It runs great with no noise, etc. It came with a 12" four jaw and a 6" 3-jaw, steady rest, and boxes of various cutting tools and components, a couple of which I am not familiar. There must be 20 dial indicators of all sizes, a dial-bore gauge, a set of drill bits from 3" on down, a Dumore tool post grinder, a set of micrometers from 12" down to 1", and a host of other stuff. There was also a Powermatic drill press and a Jet milling machine included. I could have gotten more stuff, but we ran out of room on the trailer and our pickups. I only had one shot at loading at the site. We hauled off 22K pounds of stuff. :cheers:

KHK · Jun 13, 2017

Newman109 said:
Above posters are giving good advice on repairing your Clausen lathe and, FYI McMaster-Carr has all the lead screw stock a man could ever want

Thanks for the lead.

BTW, I once owned the Uncle of your '55 KHK. It was a 1953 Harley KK. Good luck on the Land Speed. Hope you don't damage the cylinders, there aren't any more. LOL.

I think the KK's started it all down to the KRTT.

My cylinders are the stock bore honed for a little extra clearance for BSF. I mounted a Aisin 500 blower and a Morris magneto with a fuel adapted Super B (modified by Don Roswell). It is going to be one spooky ride as I will be operating at the very limit of my equipment. I have dreamed of running BSF since I was a kid, but job, wife, kids, educations, mortgages, etc kept me on a more sane path.

If it ain't blown, it sucks!!

KHK · Jun 13, 2017

gwilson said:
Manhattan Supply Co. sells 3 grades of threaded Acme screw rod. Their highest one is quite accurate. You could buy a length of it and weld on whatever you need to the ends. Needless to say,weld it on ACCURATELY,and machine to suit. It will be plenty accurate for anything you'll be threading.

I will attach the two shaft ends by counterboring and stub sweated on. I do need accuracy, as one of my more fun hobbies is building hunting rifles.

Thanks.

Lead Screw

Plastic

Diamond

Diamond

Stainless

Diamond

Plastic

Cast Iron

Diamond

Stainless

Diamond

Diamond

Cast Iron

Titanium

Stainless

Aluminum

Diamond

Diamond

Plastic

Plastic

Plastic

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