Hello

Anybody own the sieg KX3 here?? I have found my one the head stock got a lot of flex (0.1mm) even push and pull with my hands side by side (I'm not a Muscle guy), I suspect it cause by the weak vertical column, it caused a lot of chatter when I tried use the 10mm endmill cutting with 6061 even only 3mm depth.

Kral

Are the gibs properly adjusted?

Joe

I'm pretty sure that's the same column as my SX3. Properly braced, the X3 column is VERY rigid.

CR.

yes, make sure the gibs are tightened and the ball screw bearings also tight. there will always be some degree of flex on every machine, but i think this one should be a bit better than .004" with just light hand force (30-40lbs).

for the gibs, youll have to pull up on the head somehow. an easy way is by resting the spindle nose on a block of wood. then youll find you can tighten them significantly better than if the spindle is just hanging normally.

I'm sure the gib is well adjusted, also I read some elder post talked about this issue, the back side of the head stock near the vertical column just got about 0.01mm when I push it, however it comes 0.1mm near the spindle (caused by the lever effect), it makes the cutter bounce a lot even with the shallow cut. Just not sure it caused by the gap from dovetail or flex of the column, will take more measurement tomorrow.

Kral

I'm sure the gib is well adjusted, also I read some elder post talked about this issue, the back side of the head stock near the vertical column just got about 0.01mm when I push it, however it comes 0.1mm near the spindle (caused by the lever effect), it makes the cutter brounce a lot even with the shallow cut. Just not sure it caused by the gap from dovetail or flex of the column, will take more measurement tomorrow.

Kral

that sounds alot like a loose gib. it could be flex, but its alot easier to rule everything "simple" out first.

I'm pretty sure that's the same column as my SX3. Properly braced, the X3 column is VERY rigid.

CR.

holy sh!t, your a master fabricator! :banana:

id like to see more picture of the brace if possible

id like to see more picture of the brace if possible

My goal with this was to have a lightweight yet very rigid CNC industrial-duty milling station. The braces are part of the flood cooling enclosure framework. The mill is easily accessable from all sides--including underneath the base.

CR.

Try and lower the head till it rest on a piece of stock and then tighten the gibs.
The weight of the head can jam the gibs.

ok....I did some more measurement on the vertical column yesterday, it's really flex, especially much more easy to lean forword/backward then the left/right, that's why the much more chatter when milling in Y direction rather then the X direction I have experienced before, however still don't know the root cause, most of the possibility is the column's base plate since it's only locked down by 4 bolts, it may twist or life up on the edge while the force applied on the column.

ok....I did some more measurement on the vertical column yesterday, it's really flex, especially much more easy to lean forword/backward then the left/right, that's why the much more chatter when milling in Y direction rather then the X direction I have experienced before, however still don't know the root cause, most of the possibility is the column's base plate since it's only locked down by 4 bolts, it may twist or life up on the edge while the force applied on the column.

have you tightened the Z gib yet? thats really where you need to start. without checking that 100% youll never be able to track down the issue.

the column will have a little flex for sure. so will the head. so will the tool, etc. there might be a little play in the Z ball screw breaing mounts.

you need to go systematically through each one to find out which is the biggest cause of flex, fixing them along the way if possible.


my little kx1 had loose z gibs, and play in the ball screw mount on both the z and y. when i tightened it all up, there was virtually no meaningful flex left without exerting more pressure than the machine sees while running.

Actually I measure on the column rather then the head stock, I think the problem comes with the loose gib at the most begining (hope so but not really), then I tigten it more and more and almost dead lock it but without the help, hence I have suspected the problem caused by the column. I am planing the simplest method to overcome it, bulid a brace fix at the top of column against the concrete wall just behide it, just don't know how well of the results :confused:...will keep the post.

I have fixed the bracket top of the column finally, without the bracket it easy lean to forword for 0.1mm with about 20-30lbs applied on the head stock, now it reduce to 0.05mm even with 70-80lbs and reduce a lot chatter. Also I found the column casting extermly soft when I drill the holes on it, much more softer then the mild steel, maybe the root cause of the problem, of cause I know what you pay then what you get, I may no more complain when I have plenty of money to get a haas... :idea:

I have fixed the bracket top of the column finally, without the bracket it easy lean to forword for 0.1mm with about 20-30lbs applied on the head stock, now it reduce to 0.05mm even with 70-80lbs and reduce a lot chatter. Also I found the column casting extermly soft when I drill the holes on it, much more softer then the mild steel, maybe the root cause of the problem, of cause I know what you pay then what you get, I may no more complain when I have plenty of money to get a haas... :idea:

where can i get mine :D

where can i get mine :D

Here:

http://www.haascnc.com/VMC_Main_default.asp

Bring lots of money. Better build a building to keep it in. :)

CR.

Here:

http://www.haascnc.com/VMC_Main_default.asp

Bring lots of money. Better build a building to keep it in. :)

CR.

"add to cart" :rolleyes:
looks to be a bit over my budget, better save up the lunch money :D

to contribute something useful instead of troll lol, at least with manual milling on the x3 i found a boring bar above off the top of my head (sorry didn't write it down) 500rpm to be unusable and very scary... the head would rock back and forth.

for those of you who have built a "cage" have you guys been able to take noticably deeper/faster passes with a good enough finish?