SIEG X2 Y Axis Stock Screw Dimensional Drawing?

That’s interesting about the leadscrew. I thought it was ACME but I guess thats why I was never able to find much information about it.

I am also using the 2” column riser block and have not noticed any difference in rigidity but I am only using 1 spacer. I think you are the first person I have heard to of ever used 2 spacers. Your mill must have a ton of travel! I have been contemplating upgrading the studs as I feel they are not adequate. I cant remember what size hardware I got to replace them with. I have not gotten around to doing it yet but I will soon because I need to re-tram the column. When I trammed it I used LMS’s plastic shim stock. I know, it was stupid but it was all that I had at the time. I now have Steel shim stock to replace it with and I am hoping it makes it a little more rigid although I think its rigid enough for even 1/2” end mills and slightly larger.

I've not had any problems using a pair of the 2" lift blocks. I did add another piece of rack gear onto the bottom of the stock length used on the solid column, so I can lower the head way down closer to the table. My original thinking was that, since I use as 3" screwless vise most of the time, or a rotary table, I really didn't need the head as close to the table as you get without using spacers. Originally I had left the Z axis scale as it was, because of this (moved from my original tilting column) on the DRO 350 I had been using. But when I got the new DRO with glass scales I ordered the Z axis scale long enough to allow for the extra 4 inch lift. So at that time I also extended the rack gear. It is so nice to be able to work on taller things!

These machines, if properly modified, strengthened where needed, etc., are capable of far more than their printed rating. Admittedly, I work mostly with aluminum and plastics. I try to avoid steel unless it is a necessity. But I do work with steel when needed, and just keep the depth of cut down to 60 mils or less. With 6061 aluminum or plastics, cutting 0.1" passes is easy. That said, I routinely use milling cutters up to 1 1/2" diameter, and a fly cutter that is about 3" diameter. I have also cut T slots across a 6 inch diameter disc of 6061 on my original rotary table. I think that was one of the hardest jobs this mill has done so far, but it did it without complaining.

For tramming, I finally ended my frustration and bought an Edge Tool dual indicator tramming tool. That makes life a lot simpler.
 
The issue of the Y axis nut shifting and binding appears to be a relatively rare problem -- this is the first time I've heard the complaint. It's possible there's a manufacturing defect in there. Maybe the pocket for the nut is poorly machined, the nut itself is defective in some way, or ??? (fill in the blank).
 
delete post.

Thanks! In the interim, I was reading a lot of forum posts looking specifically to see if anyone had ever added a rear support bearing on their Y axis screw. I didn't find anything about that, except that many feel this is an acceptable way to do it, supporting the screw only at the crank end. My personal opinion disagrees. But I did find mention of the axis screws being 5/8-20 (on the ones with inch conversion screws).

Here is a link to a slew of information on threads, including where I discovered that there were no 20 TPI listed under standard ACME sizes, but several 20 TPI across the range of UNS thread. Thus, knowing we have 5/8 screws now, I concluded they are UNS 5/8-20. A tap for that thread is available on McMaster-Carr if anyone needs one. Also the 37/64 drill bit required for it.

https://www.gewinde-normen.de/en/20-un-thread.html
The issue of the Y axis nut shifting and binding appears to be a relatively rare problem -- this is the first time I've heard the complaint. It's possible there's a manufacturing defect in there. Maybe the pocket for the nut is poorly machined, the nut itself is defective in some way, or ??? (fill in the blank).
 
I have heard many complaints about the same issue. I’ve had the same issue but was able to adjust It to decrese the binding but it still gets tight at the extent of it’s travel toward the operator
The issue of the Y axis nut shifting and binding appears to be a relatively rare problem -- this is the first time I've heard the complaint. It's possible there's a manufacturing defect in there. Maybe the pocket for the nut is poorly machined, the nut itself is defective in some way, or ??? (fill in the blank).
 
The issue of the Y axis nut shifting and binding appears to be a relatively rare problem -- this is the first time I've heard the complaint. It's possible there's a manufacturing defect in there. Maybe the pocket for the nut is poorly machined, the nut itself is defective in some way, or ??? (fill in the blank).

(All of the above). ;)

The first Y Axis nut I originally found inside this mill, back in 2004 shortly after buying it, had incredibly bad looking threads. The best way to describe them would be a comparison to how Play Dough will crack and separate when extruded if it is too dry. That is literally how the threads looked. I replaced it with a new nut from LMS, which was in much better shape. But Y axis binding has always been a problem on this mill, and I've seen it mentioned several times over the years in forums. Likely one reason people developed the thrust bearing modifications available for the Y axis.

Still, now that I think about it, the X axis on the stock X2 table, lacking any addition of a power feed, also has its tail end unsupported. But the length of that axis is so much longer that probably helps prevent the nut jamming in its slot. The biggest problem I ever had with the X axis was very poorly machined gib strips. Eventually I lapped and polished both axis gib strips, which helped smooth things a lot. They looked pretty rough from the factory, and it made trying to get uniform tension across the X axis range impossible. I had an ammeter mounted on my first X axis power feed, which liked to die if the load got too high. The power draw would vary by double the lowest amount (.2 to .4A) as the entire axis was traveled under no load at all, until I lapped the strip.
 
What I was saying (apparently unclearly) is that the issue of the nut shifting is unusual in my experience. It is very common for the feed screw/nut to get tight when the table is close to the end of its travel, but then it loosens back up when you move the table back. This is an alignment issue -- the nut doesn't line up exactly with the mounting block.

That's why it is recommended to loosen/retighten both the feed screw nut and mounting block so they can get closer in alignment. Manufacturing tolerances could be such that this is only partially successful for a given machine.
 
I have heard many complaints about the same issue. I’ve had the same issue but was able to adjust It to decrese the binding but it still gets tight at the extent of it’s travel toward the operator
My current magic formula for setting those 3 screws involves working between them, as well as adjusting the angle up and down on the screw shaft, while trying to hold the nut centered. But it never seems to stay as I adjust it, even if I tighten the nut retainer screw rather tight. Over time, and moving the table fore and back, the nut manages to start moving, and then gets a mind of it's own. I've thought about trying boring a detent on one side of the nut for the screw to sit in. If that didn't work I could flip the nut around and undo it. One thing I haven't done is, when the nut binds up, pull the table off the carriage and see exactly what the nut did. I'm usually in the middle of a job and want to finish it, so I readjust the nut and continue on. I should probably take the time to do that once. It might help me see a means of prevention.
 
Agreed, this is when mine binds, in the middle of a job but it’s only when the Y-axis is almost at its end. Speaking of, can you post a picture of your spacer ?
My current magic formula for setting those 3 screws involves working between them, as well as adjusting the angle up and down on the screw shaft, while trying to hold the nut centered. But it never seems to stay as I adjust it, even if I tighten the nut retainer screw rather tight. Over time, and moving the table fore and back, the nut manages to start moving, and then gets a mind of it's own. I've thought about trying boring a detent on one side of the nut for the screw to sit in. If that didn't work I could flip the nut around and undo it. One thing I haven't done is, when the nut binds up, pull the table off the carriage and see exactly what the nut did. I'm usually in the middle of a job and want to finish it, so I readjust the nut and continue on. I should probably take the time to do that once. It might help me see a means of prevention.
 
Back
Top