Hey guys. I finally got my x3 setup and ready to go, but the z-axis is killing me. I have a fairly new one without the gas strut and the 2:1 gear ratio. I'm not sure what in heck Sieg was thinking when they changed it. A couple more inches of travel certainly isn't worth it, especially since you could just extend the quill if you had to.

It not just the fact that it's heavy, but moving the thing takes twice as many turns to get there. Maybe I have my gib a little too tight, but I still would like to make it easier. It's on a bench against a wall, so there's no way to do a counterbalance type thing.

If anyone has one lying around from a cnc conversion or some other project I would love to buy it off you. Or if anyone knows where I could order one... Grizzly probably carries it if no one has one they can part with.

Thanks for any help! :)

cnc fusion sells them

you can also piece mill one from mcmaster.com

About $20 at www.mcmaster.com

quick service, I use them

yea mcmaster rocks.. all kinds of bits and widgets... i was wondering tho.. i would think that if you had one, you'd keep it on if you did a cnc conversion.. just to relieve some of the load on the z screw...
or am i missing something?

I'm putting a gas shock on my cnc conversion.

I'm not sure if it would be better to use a shock or a counter weight system.

well the benifit i see with the shock is that your not adding moving mass to the equasion.. well not as much...

Thanks for the help guys. I think I'll get one from McMaster since I usually have an order for them every couple weeks or so. However, I'm not sure which to get. You can see there struts on catalog page 1137 or just search "gas struts".

http://www.mcmaster.com/

Does anyone which one is the correct size? From another thread I learned that the upper thread is M8 on the mill head, but I guess at the moment they only have M8 struts in the expensive stainless form. Drilling and tapping for 5/16-18 shouldn't be too hard though.

If someone who knows the dimensions could take a quick look and tell me which one, I would greatly appreciate it. I'm also thinking a 90 pound rating would be best?

Thanks :)

Did you ever get your strut size figured out? I am about to order some for my x3 and I'm curious to know what you ended up with and how it's working out for ya so far.

Does anyone know what the weight of the head is on the x3?

The stock x3 milling head = 90 lbs. Just weighed it. ;)

I just cnc'd my X3 with 275 oz/in steppers and the Z needs a counter balance, it will only rapid at 10 ipm with no CB. I've read the X3 head is 80 lbs so I'm going with the 75 lb strut from McMaster. I figure the 5+ lb difference with help with backlash in the Z acme screw. McMaster P/N: 9416K543 (Gas Spring with Threaded Ends 29.33" Extended Length, 13.77" Stroke, 75 Force (Same as 9416K54)) $16.97

I also read that the head was 80 lbs... and also 50-60 lbs. So I weighed it myself and according to my scale it was closer to 90 lbs.

The head by itself is about 66 lbs. The spindle motor & brkt are approx. 13.5 lbs, and the cap/cover that fits over the head & spindle gearing is about 9 lbs. The combined weight is about 88 1/2 lbs. Then you have the weight of the tooling to account for if you want to get really anal about it so I calculate that it's very close to 90 lbs.

I'm curious about your choice of strut size, the compressed length on that strut is like 15 1/2 inches. Are you planning on using the quill when you need to get the spindle down lower?

This strut should let me take the spindle within 1.5-2" of the table top depending on mounting location. I was planing on mounting it on the outside of the machine, but now I'm thinking on mounting it inside the column. I need to check how it will fit in there. I figure my tool and work piece will always be more than 2" and if i need to touch the table I can always us my quill.