bugger.

[frobzwiththingz]

It's 12:30am, and I'm currently in the middle of completely disassembling the cross-slides of my Bridgeport, so as to figure out why it just decided to ignore any turning of the X-axis handwheels and just sit there, motionless, taunting me. This is one of the three main machines I now make most of my living with, and I cannot afford any serious downtime. Gonna be a long night.

Update: 2:42 am: Machine is back to working order.

frotz, you owe me a donut. I like donuts. Split-nut adjustment screw was fine, though it was really hard to see anything in the X saddle until I unscrewed the leadscrew all the way out and could then get some damned light in there. This is what I saw on the right hand side:



See that funny rectangular prism hanging there? it seems that the split-nut is keyed, and that is the key piece. a 2-inch long square key, that had seemingly completely vibrated out of its place, leaving the acme split-nut free to rotate along with the leadscrew. I had to tear down the whole thing in order to take out the split-nut adjusting screw, then the split-nut itself, re-align everything with the key in place, and shove it all back in:



The odd thing is, I see nothing in the cross-nut assembly that would be designed to prevent this from happening again; no little holding screw or clip or pin or anything. Is this just something that needs to be checked every once in a while, or every decade or so it randomly hoses you at a bad time again?

Other than that, everything in there seems in good shape, the x axis is now back to near no backlash after reassembling, and I was surprised to still be able to see original wayscraping marks on the saddle ways. not bad for a machine made in 1946.

Now I'm going to have some tea, and maybe a chili dog, and go to sleep.

Comments

[frotz.livejournal.com]

I bet you a donut that stupid split nut adjustment screw is busticated.

...though you should be able to poke at it underneath from the left to maybe confirm or deny that without stipping it, so maybe you did?

[frobzwiththingz.livejournal.com]

you owe me a donut. Maybe a munchkin; the actual problem was only about an inch away. Where's a good donut place these days? entry upated with actual problem and result

[scliff.livejournal.com]

Verna's in North Cambridge is still the bestest evah.

[tamidon.livejournal.com]

really?

[rmd.livejournal.com]

I'm not sure about evah, but they're pretty darned good.

[tamidon.livejournal.com]

personally I go for cider donuts out at the orchards in autumn, but that would mean delayed gratification

[tb]

Cake or raised? Kane's in Saugus is really good for the latter. For cake donuts we're fond of Heav'nly, especially now that there's one in N. Reading. Their raised & filled aren't bad either.

[oneagain.livejournal.com]

Ooh! I have had donuts from there! I have to agree on the nom factor.

[bikergeek.livejournal.com]

Ouch. Hope you get it fixed soon.

[whitebird.livejournal.com]

Huh. Interesting residuals you've got depicted there. What have you been machining?

I've used a big Bridgeport drill press, and maybe a big Bridgeport surface grinder, although I'm not sure of the brand on that machine. But I was machining interesting ceramics between '83 and '87. (Beryllium Oxide, and Alumina Oxide, mostly.)

[frobzwiththingz.livejournal.com]

The white stuff there doesn't really exist; it's an artifact of macro mode, flash, and cheap P&S camera. That surface is actually dull greenish grey. I mostly machine aluminum and steel, with occasional brass, pvc, HDPE. who knows what this beast has worked on before I got it; as said, it was manufactured in 1946.

[whitebird.livejournal.com]

Ah okay. It's amazing just how tough good machinery is.

[blk]

MMmmmmmm, donut.

[(Anonymous)]

yay, go you

am here trying to fix things myself, is taking many all-nighters

and a keyboard i cannot seem,to figure out

smiles
--v