JH,
The x axis is a tough one since it is short travel. So every thing needs to be able to float some to make the initial adjustments and then it gets locked in.
You may want to consider drilling  small holes ( tap also so you can plug the holes ) so you can adjust the ball nut mounting screws since they are hidden when everthing is put together.
They would be located when the axis is nearest and farthest from the bearing. A little thought now on how you will adjust everything will save a lot of fooling around later.

From a design point of view, one could go in and analyze the axis and use calculations to guide ones decision on what to do or being done. 
Not as easy as one would think since the calc's are subjective. Sometimes just easier to make and modify as needed.

BTW, you want to preload the two bearings as that may be a greater source of backlash than the nut. I just assume you'll do that with a nut on the shaft. Would be nice to be able to measure the torque
differences due to preloading. I am lucky as i have a good torque gauge.

Just a few thoughts,
RICH

I'm with Rich on the preloading.
On my 2nd lathe, I used 2 Premium motor bearings, not the super expensive matched set.
I adjusted the preload by inserting shims between the outer races until I had a bit of torque interference with the nut fully torqued to spec.
No gauge (Rich has all the cool toys).
Think I ended up with 0.004" shim.
Backlash ended up in the neighborhood of 0.00015".

The X screw on my SuperMax has dual tapered roller bearings back to back and shimmed. I was surprised, very tuneable.

Hey Russ, when i bought that $600 gauge for $40  and my friend asked what in the world i wanted it for.
I told him it was part of my "collection" of stuff to gather dust from the air. It has  really come in handy.
It can give you definitive info on binding that would otherwise be very hard to pinpoint.
Keep the eyes open for that useless stuff if one can rationalize buying it. Sure does beat a stick with a rock on the end.

Another one is the small adjustable torque screw drivers ( they allow nice adjustment of set screws so you tighten the gibs just so ).
The set i have is from Utica, are calibrated, and cover 1 to 100 in oz. Like new for the cost of a can of beer.......

Sorry JH, but hopefully the tools used here relate to the retrofit adjustment,

RICH

A lot of good advice here guys, clearance is the biggest issue with this part of the build, the lathe is really small to begin with so that really impacts a lot on my decisions. I want to beef up what ever parts i can along the way ie. the x ball screw was 12mm it is now 16mm, the bearings were 8mm id 20mm od hey are now 12 x 32.

I think the point of failure on this part of the build is going to be the way I have mounted the nut, I forget how small the clearance was but from memory the nut could be no bigger than 28x28mm and for a 16mm ball screw thats tough.

I'm having a good time in the mean time and i can always do it again if im not happy, I really just need my lathe up an running again.
 

Yes im still alive, i've been called out of town for work till the end of the month so have not been able to work on my machine.

Cheers.

the nut could be no bigger than 28x28mm and for a 16mm ball screw thats tough.

Have a look at
http://www.linearbearings.com.au/Portals/0/BNT%20Platform%20Nut.pdf
It might fit; it might not.

Some other good stuff at that web site. I have used the THK stuff before - not cheap, but very nice and probably worth the money imho.

Cheers

I took the day off today (from my normal job) to do more work! good news is i have made progress on the machine.

The 4th draw did not fit, it was just to tight i got a new front cut and got all of the draws to fit and got em all sliding without hitting each other.



I was never happy with the way the control panel fit on the machine so i decided to make I new one I thought id add a few more buttons as well.
Also in this picture you can see one of the air rams that will open the door once the job is done, wont know if this was a good or bad idea until ive run the machine for a few months, in the mean time i get to play with pneumatics.



Finally I have finished the bearing block and motor mount, I need one more part cut for the inside and still have to size and order the belt but the milling is all done!



Another shot from the front:



I pleased with how everything fits, not a bad days work.

Cheers.

Pressurised oil on the bed of an AL54B?
I'll bet that has never been done before!

Hum ... doesn't look quite like the original any more, does it?

Are you going to cover the main axis leadscrew?

Cheers

Are you going to cover the main axis leadscrew?

I would like to but I'm out of ideas as to how.

Bellows:
http://www.kellysearch.com/qz-product-7917.html

Closer to home:
http://www.linearbearings.com.au/Products/BellowsDustBoots/tabid/138/Default.aspx

http://www.oreca.com.au/

Alternately, buy some suitable fabric, cut out disks, and either sew together (tricky) or just STAPLE together.
PVC-coated fabric will do fine, and is cheap.

Cheers