Shaper problem

[Rik Shaw]

I have just acquired an ALBA 1A and am in the process of cleaning it up etc. I have a problem though. Yesterday, for the first time I wound the table sideways toward me (that's to the right if you were facing the front of the machine) until it reached its limit then tried to wind it back. It would not move. I can wind the handle either way but it has no effect, the table remains where it is - stuck.

The only thing I can think of is that the cross slide nut threads have stripped or its location button has sheared of though I am puzzled as I never used any undue force.

To clarify, when I refer to "cross slide nut" I do not mean the securing nut/locknuts at the end of the cross traverse feed screw. We are talking here about the concealed nut which rides along the screw transferring its sideways motion to the cross slide/table.
Because the machine had been standing idle for many years and despite my attempts at cleaning and lubing, the table was quite tight - but movable - on the cross slide. I have tried pushing it while winding to get it back on the thread but it is far to tight for that. (I tried this thinking that the end of the shaft might be relieved as a safety feature).
I have loosened the bottom cross slide jib and one of the screws on the top jib (the other two are masked by the main casting) and tried to give it another push but it won't budge. I have even tried putting a vertical bar in the central T slot nut and using a loop of rope and three foot length of timber coming of the main casting attempted to lever the cross slide and nut back onto the thread while wife wound the handle but to no avail.
Has anyone got any brilliant ideas how I get out of this one?
Rik

[awemawson]

It is 25 years since I sold my Alba #1 so my memory isn't crystal clear, however:

If you remove the nut and lock nut from both ends of the cross screw, is there any play in the screw - can you push / pull it sideways or even totally withdraw it? The number of possibilities of what is broken is severely limited. If the nut has stripped you'd expect a fair amount of end play on the screw. If the engaging pin on the nut that locks it to the carriage has sheered, when turning the handle to one end it should come up solid against the casting. You've slackened the gibs, are they actually loose? Can you totally with draw them to create more free movement.

Post some pictures of the gib / carriage / screw area so we can cogitate 

[Manxmodder]

Rik, I am also currently restoring an Alba 1A,mine is now stripped down to component form.

Later todayI'll have a good look at the leadscrew and nut component parts assembly and see if I can figure out what might have gone wrong with yours.......OZ.

[Manxmodder]

Rik, I'll also take some photos of the dissasembled leadscrew assembly and associated components and post them here later,in the meantime don't do anything rash I'm sure there will be a simple answer....OZ.

[mcostello]

End of lead screw turned down to prevent damage. Check back to MEM BBS, explanation there.

[Joules]

Yep you have run the nut off the leadscrew.  To protect the table from crashing and stripping/wrecking the nut.   Simply push the table at the opposite end and wind the nut back on the leadscrew, this how my Elliot 10M behaves.

[Chrispy]

AMMCO shapers have the same setup. The threads stop just before you would have a part breaking bind up. Made for folks just like me. 

[Joules]

Get yourself a soviet wife....  One who has done some weight lifting 

Actually you could try putting some studding down the centre T slot with a steel plate on the end of the studding then fashion a lever to contact the shaper some where you can lever the studding without damage.  That will put a heck of a load on the table.  Spray as much lube as you can into the slideways.  Take it steady as you go, if things start bending STOP, don't take them to breaking point.  Gentle tapping with a copper hammer won't harm either.  If its as tight as you say, you could well have stopped the nut.

              Joules

[nrml]

Sorry for resurrecting a dormant thread, but I'll add my 2 pence worth for anyone trying to sort out a similar problem in future. mcostello and Joules are spot on with their explanation. To solve the problem, my first approach is to place a block of wood against the side of the table and whack it with a hammer to bring it up to the lead screw. If that doesn't work, I dismantle the lead screw and move the table just enough to re-engage when reassembled.

More importantly, I find that if it dis-engages while on auto feed, simply reversing the direction re-engages it as long as you don't move it manually beforehand. I have purchased one of these http://www.igaging.com/page21.html to use as a DRO so that I never have to use manual feed on the table again.