[FunkedOut]

When I had my SX2 (from LMS) apart, I weighed the head and all that sits on it; comes out to 33lbs. I figured that number would be handy for replacing the torsion spring with a gas strut or counter weight.

As I put her back together, I did all I could short of redesign to smooth out the Z axis. I shimmed the rack, de-burred the worm gear enclosure, shimmed the joints for the fine adjust, redrilled the "pocket" for the knob set screw. Between all that and lapping the gibs/ways, it really helped out a lot.

Now I can feel when the torsion spring stops helping and starts fighting me as I try to lower the head. It does nothing at the top and bottom. If the gibs aren't snug, the head will drop an inch or so until the spring is loaded enough to stop it. Tighten the gibs and that behavior goes away. That got me thinking...

Why replace the torsion spring with anything?
Why not remove it all together and have all 33lbs. weighing down on the end mill?
Seems to work fine without it. Am I missing something here?
What possible negative effects will I experience without head weight compensation (if any)?

Thanks.

[photomankc]

I'd be leery of the fact that's it's rack and pinion, so if it decides to start sliding on you it can go fast. I took the spring off my X2 and just kept the gibs snug and it was alright. Didn't like the feel in the loose spots though when drilling so I eventually returned the spring.

[B-RAD]

I agree with you if you had a stepper motor to hold the lead screw from turning, but as that isn't the case I'd keep the spring for insurance reasons... 90% of the time it may fight you, but 10% of the time it will save you...