The cutting tool is to the left of the carriage. Most of the stock I turn is between 1/2" and 2-1/2"; seldom anything larger other than fitting back plates to chucks. I have to say that I do not yet understand the dynamics of what is happening but if I make a heavy cut I can see the tool dip and it "appears" that the front right of the carriage is lifting ever so slightly. Right now I'm making some more of the rods I mentioned above but when those are finished I can chuck up something and try to video what's happening. I like HSS tools and cut my teeth on them, so to speak, when I started machining but this lathe has enough power that I'm using mostly carbide so no sharpening is involved. I've started locking the carriage for cutoff operations and find that it goes much more smoothly. Sometimes I lock it for facing but only on larger pieces of if flatness of the end surface is important. If the end is "just there" as with the end of a bolt and doesn't do anything, I usually don't lock the carriage. I'll follow up.
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Repairing Cross Slide Screw, Need Suggestions
- Thread starter David2011
- Start date
Thank you! Your description is what I had INTENDED to do; joining the new lead screw material to the old hand wheel end. I got over confident and thought I had a good enough fit to do a heat shrink joint. I heated the hand wheel end socket until it started turning yellow/brown and attempted to insert the lead screw. About 1/2" in it stopped and nothing I could do at that point was going to make it go deeper. I sawed the lead screw off at the end of the hand wheel piece and broke a carbide stubby drill trying to remove the remainder of the lead screw's pin so I doomed that job.
There was no choice but to make a new hand wheel end. This time I used a file and a Sharpie to get a perfect slip fit. A brazed carbide boring tools was used to scratch up the inside of the socket and a file was used on the pin of the lead screw. Yes, it is just held on by the Loctite 603 and no pin. I've machined ten shoulders and threads on 9/16" 416 stainless so far and have six to go. The real test will be making the nuts for the shafts since they're 1" round brass and have to be knurled.
Here are some pictures of previously completed rods and nuts and a picture that shows them in use holding the gunsight to the 20mm Oerlikon mount. The rods are just to the right of the shoulder braces and the nuts have been blackened. Not especially related to this discussion other than to demonstrate what the repair has to accomplish. If it completes the next knurling job, I'll feel like it was a 100% success using just Loctite 603.
Kind of a funny story about the rods for the gun sights. The employee with the Battleship Texas Foundation wanted to know if I could machine shafts to fit the odd diameters of the holes in the gun sights and mounts. That didn't make sense to me. I've been making parts for the guns for a year and working on the guns for almost 2-1/2 years. One thing that has stood out is how consistent the engineers and designers were in the early 1900s with using standard fractional sizes for almost all materials. They didn't use measurements like 0.483"; it was almost always 3/8", 7/16", 7/8" and so on, even if expressed in decimals, so it made no sense that the rods to fix the sights on the mounts would be some in-between size. I told him that maybe we should clean the paint out of the holes and check the measurements before making odd sized shafts. There are about 20 of these guns on the ship so having to make 40 odd sized shafts was not appealing. Well, son of a gun! Once the paint was removed a standard 9/16" rod fit perfectly.
Carriage lifting/tool diving update
While using a boring bar the tool diving/carriage lifting problem happened again. The good news is that I was boring threads out of the stock so the dip/lift was cyclic and gave me some time to troubleshoot. The motion was the greatest at the right rear corner of the carriage. After locating the fasteners that hold the “strip” (that’s the technical term for it according to the manual) on among the caked on oil and chips I pulled in off and gave all of the parts a good cleaning.
Sorry; no photos since my hands were way too grungy to touch a camera or phone. I’ll try to give a good description in case anyone else needs to attempt this. As nasty as it was with foul smelling old oil/coolant and thick caked on chips in places that seemed inaccessible to chips, it didn’t take too long to clean it up. The gibs had obvious wear. I didn’t measure it but would guess it was around .010” judging by the unworn ridge.
The strip holds two flat gibs, each about 3” long and each gib has two adjusting screws and locknuts. The gibs are located by drilled dimples for the set screws. With the gibs sitting in place on the strip they got a good dose of way oil and the strip was bolted back onto the carriage. I moved the carriage well away from the chuck end of the bed to get it to an area w minimal wear, tightened the gib set screws and snugged the lock nuts.
Moving the carriage took just a little bit more force on the carriage hand wheel than before at the unworn right end of the bed and as it moved left the slight drag disappeared. Another pass or two with the boring bar revealed that almost all of the tool diving and carriage lifting was gone. Before the adjustment there was a strong pulsing in the cross slide hand wheel. After, I could barely feel it. By placing a finger on the juncture of the bew and the carriage I could feel a very tiny bit of motion but nothing like before the adjustment. I’m calling it a 90%-95% improvement. I think the only way to make it perfect is to have the bed reground. It’s very workable as is now.
While using a boring bar the tool diving/carriage lifting problem happened again. The good news is that I was boring threads out of the stock so the dip/lift was cyclic and gave me some time to troubleshoot. The motion was the greatest at the right rear corner of the carriage. After locating the fasteners that hold the “strip” (that’s the technical term for it according to the manual) on among the caked on oil and chips I pulled in off and gave all of the parts a good cleaning.
Sorry; no photos since my hands were way too grungy to touch a camera or phone. I’ll try to give a good description in case anyone else needs to attempt this. As nasty as it was with foul smelling old oil/coolant and thick caked on chips in places that seemed inaccessible to chips, it didn’t take too long to clean it up. The gibs had obvious wear. I didn’t measure it but would guess it was around .010” judging by the unworn ridge.
The strip holds two flat gibs, each about 3” long and each gib has two adjusting screws and locknuts. The gibs are located by drilled dimples for the set screws. With the gibs sitting in place on the strip they got a good dose of way oil and the strip was bolted back onto the carriage. I moved the carriage well away from the chuck end of the bed to get it to an area w minimal wear, tightened the gib set screws and snugged the lock nuts.
Moving the carriage took just a little bit more force on the carriage hand wheel than before at the unworn right end of the bed and as it moved left the slight drag disappeared. Another pass or two with the boring bar revealed that almost all of the tool diving and carriage lifting was gone. Before the adjustment there was a strong pulsing in the cross slide hand wheel. After, I could barely feel it. By placing a finger on the juncture of the bew and the carriage I could feel a very tiny bit of motion but nothing like before the adjustment. I’m calling it a 90%-95% improvement. I think the only way to make it perfect is to have the bed reground. It’s very workable as is now.
Last edited:
- Joined
- Aug 29, 2019
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- 1,164
Sounds like you found the source of the problem. I am currently working on the same issue on my Clausing 5913 lathe. If you follow my thread you will see how I am removing material and am going to replace it with Moglice. On these old machines they tend to have harden bed ways and the saddle ways are not hardened. So I'll bet you if you take the saddle off your lathe and turn it upside down you will see where most of the wear on the saddle ways is on the chuck side /front. Or in simple terms the front left side of the saddle. The guy I bought the lathe from was a total idiot. He had taken the shims out between the "Strips" (I call them Gibs) and the under side of the saddle. Had the saddle so damn tight you could not force it right or left and the banjo was broken and one of the gears on the banjo had stripped teeth and It only had 1/2 of the Half Nut and it was stripped smooth as a chicken's butt. He was going through his 4th divorce, I hope his wife divorced him for lathe abuse.
Posting a link to your Moglice thread because it’s an ambitious undertaking. https://www.hobby-machinist.com/threads/anyone-here-actually-used-moglice-on-a-lathe-saddle.108654/
One of these day I’ll further investigate where the wear really is in my lathe and how difficult it might be to fix it. I usually only machine 1”-3” areas on a part and since the Victor has a spindle bore of 1-1/2”. I can usually work close to the chuck. Since I rarely work on the entire length of a piece the wear isn’t a big concern.
One of these day I’ll further investigate where the wear really is in my lathe and how difficult it might be to fix it. I usually only machine 1”-3” areas on a part and since the Victor has a spindle bore of 1-1/2”. I can usually work close to the chuck. Since I rarely work on the entire length of a piece the wear isn’t a big concern.