SIEG
Super X2PLUS mill CNC conversion
X AXIS
After finishing Z axis I started the X conversion that I initially thought it would be a straightforward procedure. I could not have been more wrong on that matter!
As I stated in the beginning of this presentation my mill has the X1 extra long table that, for some reason unknown to me leaves too small space between the table and it’s base.
I started measurements by making an “oil printout” on paper to record all measurements. That works like this: you apply used oil on the (flat) surface you wish to print and then you touch the surface with a clean white paper. Next you measure and write all measurements on the paper and if you want to transfer it to the computer you either scan or photograph the printout. As simple as that!
The “oil printout” of the left side of my mill table.
In my mill the printout revealed a problem that took a lot of head scratching to solve it.
The distance between the underside of the table and its base (the top of the Y moving part,
is there a name for that?) was just 19.5 mm (that’s 0.768 inches)!
A photo of the left side of the table (stock nut is 45x18mm)
A photo of the right side of the table
Removing the table to investigate what modifications are needed
Left side without the table
Right side without the table.
All drawings of X & Y to seek possible solutions on the drawing table.
FACTS
I could not find a ballscrew with a nut that small without braking the bank! The matter needed a different approach! I did not like to machine the base (I did not have access to another mill either) so I was looking and looking for solutions to similar problems in the internet.
Stock screw is 12 mm thick
X stock screw
For some reason there are very few CNC conversions of X1 mills published and most of the conversions I found use the stock screws for X and Y. There was no light from this source!
Finally I decided to tackle the problem in a non conventional way:
If there is no space for the ball nut under the table, kick it out of there.
After Transferring all measures to the drawing board I figured out the solution details:
The idea: place X ballnut at the edge of Y moving part
Naturally putting the ballnut there was not a straightforward task. Some modification was needed.
The easy part was to cut the ballnut top using my disk grinder.
As right side is machined 3mm to make some space for the screw I could do the same on the left side in a way that the ball nut fits.
The difficult part was to grind the surface under the ballnut (the red area, see next sketch) to make space for the ballnut.
So material from the area marked in red at the above sketch was removed. That was not an easy task using just hand tools (I managed mainly with help from my little dremel).
The ballnut under the table bolted at the edge of Y moving plate
The result: The ball nut fits in the gap and has a clearance of 0.5 mm from (as you can see it almost touches) the underside of the table.
... to be continued...