The begining of my z axis table project
You might want to look at a scissors jack for inspiration. That way you only need enough room under the table for the scissors mechanism and there’s nothing above the table. Using the simple screw method you’re using leaves you with the tall screws extending over the bed.
The screw action works well if you can move the screws to the back or both ends and mount the screws into the machine case bottom & top. Then the table will ride up & down like 3D printer beds do.
@Jim_Hatch As you only really want to travel up a certain distance (i.e. no closer than focal length of the lens) you could do the whole setup in reverse, so the z-axis table actually goes down instead of up.
where did you get the gt2 closed loop drive belt???
@Norman_Kirby If you look closely, I don’t think it is a closed loop, cos it slips oddly as it goes over where it has been joined.
well spotted Yuusuf
@Yuusuf_Sallahuddin_Y you’re correct. At the 0:02 mark you can see the overlapped joined part in the lower left as it gets ready to go over the roller.
What would be the best way to join that belt?
@Ariel_Yahni_UniKpty I’m not familiar with this myself, however a quick google suggests it is not wise to do so unless absolutely necessary, but you are introducing a planned failure point.
See this link for discussion on this same topic:
http://bbs.homeshopmachinist.net/archive/index.php/t-60510.html
I’ve often thought about trying to figure that out, but never got around to it. Figure you could glue the ends then a piece glued to the back over the seam if the belt was going to be very tight. I have seen a tool that melts round hose together and was wondering if you could do something like that with belts too.
I tested some with glue for bike tyres, when you fix holes in the tubes on your bike. and put the patch on the back of the belt.
And after that sand it slightly to still allow it to bend around the pulleys.
I have a 3D printer with a broken belt, i used that method until my new belt arrived. But it still works so the new belt is unused yet 
If you set the ratio of the stepper pulley to the corner pulleys high enough, you can get the fill travel without a join going over a pulley.