SX3 Y-table travel extension

[Dingenman]

First of all I think this is a wonderful forum with lots of helpful (and patient..) people.
Although readiing many posts on several sites - also the one from Crevice Reamer - regarding preparing the SX3 for CNC, something is not really clear to me.
I have read many times that in order to extend the Y-axis travel you need to cut out a portion of the column to make way for the spindle. My SX3 is still unchanged from stock but when I look at the saddle there is about 1-1/4" space between the saddle and the column, and more important the leadscrew is another 1-1/2" further away from the column.

So it seems to me that you could gain some 2 inches of travel by just mounting a spacer of 1" at the front and have a ballscrew that is 2" longer then the stock leadscrew.
What am I missing in this story, I guess the ballnut is not that much longer then the acme one? I hope anyone can and will explain this to me - Thanks in advance!

[PriddyShiddy]

I thought the same thing.

think about it this way: to add an inch on the front moves the table toward the column another inch on a Y- move. to add an inch to the Y+ the screw has to hang an inch further towards the column also. add a little more for the ball screw and mount size which iirc are slightly larger than the acme brass nut, then add a little more for the cap head screw and washer to prevent over traveling, in a Y+ move. it all adds up. 2" extra travel means more then 2" extra space from the current screw.

I follows CR instructions exactly and have ~7.5" Y travel... which I use all of I will take some pics later of the travel extremes

here is my column fresh off my buddy's Bridgeport



and fresh ON the BP



my thread has a lot of info since I knew NOTHING about cnc when I started my conversion other than it meant I could use my handwheels for christmas tree ornaments. turns out they suck for that too

welcome to the obsession, ask away!

[cornbinder23]

On mine the ballscrew will hit the column before the saddle does, so there is also a pocket about 1" dia. for the ballscrew and snapring to ride into, as well as what you have milled off Priddyshiddy.
This gives me a bit more Y, cant remember exactly how much off the top of my head, I will try to measure exactly tomorrow.
Haven't heard from Creavice Reamer in a while, hope he is doing well and plugging away with his projects.

JTCUSTOMS

[PriddyShiddy]

I cut a hole for the ballscrew also. I did it after pre assembly in the machine to make sure it was correctly located.

tried to get pics last night but with my aluminum bracket and accordion chip guard I couldn't get anything useful.

checked my actual travels at 7.3" X and 19.25" Y. this is usable travel programmed in my limits. of course its really more but the limit switch eats up a little for homing and I left about .05" extra on each end just to make sure a bad move gets stopped befor hitting and loosing steps.





and yes... that IS a heavy duty zip-type bag on the column held with magnets to keep chips from sticking to the column and flying back into the Z pulley. amazing how many chips STILL sneak back there.

the magnets slide up and down on their own when the head comes really low to.

[Dingenman]

Thanks guys,

I took a better look at the pictures on the CNCFusion site and think to understand it. The problem must be the ball nut-to-column distance that is large enough with the standard acme nut but decreases with the new one which is quite a bit larger.

BTW: nice pictures!