Lathe repair advice needed

[Richard King 2]

I you have a good Bridgeport take the saddle off and indicate the top of saddle cross-slide ways. Flats co-planor then indicate the dove- tails. then do the same to the bottom of the cross-slide ways. I suspect you will figure it out then. It sounds as if your sharp and can do it your-self. I can teach you how on here I think. If you have a dovetail cutter or a good fly cutter we can do it.

 

[thebeebe5]

I you have a good Bridgeport take the saddle off and indicate the top of saddle cross-slide ways. Flats co-planor then indicate the dove- tails. then do the same to the bottom of the cross-slide ways. I suspect you will figure it out then. It sounds as if your sharp and can do it your-self. I can teach you how on here I think. If you have a dovetail cutter or a good fly cutter we can do it.

Sounds really scary...
The measurements you mention are foreign to me. I’m not sure I can get Brian’s permission to take his lathe apart. Maybe when he’s not looking!
But i’ve dived into worse I suppose. I did watch the video. I don’t have any precision pins, but I could make a pair at the shop tomorrow and then I can make some measurements.
Here are some photos for what good they are. I always feel a bit lost when looking at lathe parts photos. Lack of familiarity I suppose. The gib looks a bit beat up.
The worn screw also makes sense and I’m wondering if that can be replaced on this machine.

 

[markba633csi]

So who's Brian? Aren't you the owner of this lathe? I'm a bit confused
Anyhow, it does sound like the cross slide is badly worn and if Rich can re-scrape it for you for a reasonable price I would do that rather than trying to fix it yourself and making it worse
-Mark

 

[SLK001]

The cross slide doesn't look all that worn at all. You can still see the original scraping marks on it. I suspect that your bronze nut is worn. Your nut does have an anti-backlash adjuster built in to it. Just reassemble the slide and tighten the screw a bit.

 

[Richard King 2]

I was using the video as an example on "how to do it". A easy way to check it is in a Bridgeport. It might not be Jig Bore precision, but should get you in the ball park. If it wiggles .010 or what ever. You can figure it out with-out a lot of rebuilding experience. It would be real handy if your milling machine vise swiveled. It would be be easy to indicate the flats co-planer and tap the vise around while indicating the dovetails. do one side and move the indicator to the other side and it should indicate .001" or less. middle 1/3 low. If it is more then that it needs to be machined or scrapped. I don't do you tube shows but my students do. This shows some examples.
Check it out and lets figure it out. Here is another couple showing how to.

 

[jwmay]

Probably neither here nor there, whats with this perfectly straight line across the saddle ways? Looks like an almost perfect joint between two pieces of metal. It's NOT a crack, right? I also noticed what could be a crack in the gib. Idk... it's what it looks like from here.

 

[Richard King 2]

That looks like a crack, clean up the inside and get a flash light and look in there and under the dovetail. It could be something the builder scribed on to show you the slide travel limit....hard to say. A quick way to check backlash in the screw and nut is to assemble it and push and pull the slide at different sections of the screw. You can put a dial indicator against the slide and push and pull with your hands. Or just read the lost motion of the feed crank. The scraping looks pretty dismal. What brand lathe is it? Made in China I suspect. No oil groves either. Use a stiff paint brush and clean the screw. Look at it all along the the screw and see if the pitch or threads all look the same thiickness. Look at the gib screw too and see how the head fits in the slot. The cross side is probably high in the middle and rocks like a rocking chair because there are no wipers, no lube holes and grooves. The scratch looks bad too on the top slide is a sure sign chips got drug under there with no wipers. Also lack of lube can cause scratches. . Measure it up like Keith Rucker does in his show, dowel pins, etc.

 

[Richard King 2]

For the crack, buy some brake cleaner in a spray can, wear safety goggle... and see if it penetrates into the crack..

 

[SLK001]

And, can you post pictures with a little less detail? Those ultra sharp photos just make things too easy.

 

[Richard King 2]

As SL said, I usually download them at 10% pixel as the higher setting take for ever for me to download and come across as a close up sometimes. It's a learning curve figuring out al the things on these sites.