SFX-100 owners... actuator assembly question

[ian_uk1975]

Just assembling the actuators and having some issues with the FK12 fixed bearings. Are they supposed to be a press fit on the ball screw? With everything at room temperature, the fixed bearing doesn't even slide on far enough to expose any of the threads machined into the ball screw. I can heat the FK12 bearing and try fitting it hot, but none of the guides I've read mention that step.

Have I got slightly undersize bearings?

 

[DJ_Psymon]

Just assembling the actuators and having some issues with the FK12 fixed bearings. Are they supposed to be a press fit on the ball screw? With everything at room temperature, the fixed bearing doesn't even slide on far enough to expose any of the threads machined into the ball screw. I can heat the FK12 bearing and try fitting it hot, but none of the guides I've read mention that step.

Have I got slightly undersize bearings?

It can happen, as these parts all have a slight variation in size, like +/- 0.0Xmm. I had to replace the first batch that I got. Some people mentioned that sanding down the ball screw fixed it for them, but I guess it would depend on how much it's off by.

 

[slikk66]

mine fit to various degrees.. one slipped on, the other only had a bit of thread, another I could tighten all the way and the bearing still spun, another when it was tight it seized the bearing and had to be backed off. are all of yours too small to fit or just one?

 

[ian_uk1975]

mine fit to various degrees.. one slipped on, the other only had a bit of thread, another I could tighten all the way and the bearing still spun, another when it was tight it seized the bearing and had to be backed off. are all of yours too small to fit or just one?

All of them are too small... they all slip-on exactly the same amount (see attached pic).

 

[Moxley6969]

Time to bust out the sand paper. Chuck the Ball screw in a drill to make it easier. Just be careful.

 

[ian_uk1975]

Problem solved... bought some plumbing freeze spray (freezes parts to -50C) and hosed-down the machined end of the ball screw with it for 30 seconds. Fixed bearing slipped right on.

 

[jayed212]

Just assembling the actuators and having some issues with the FK12 fixed bearings. Are they supposed to be a press fit on the ball screw? With everything at room temperature, the fixed bearing doesn't even slide on far enough to expose any of the threads machined into the ball screw. I can heat the FK12 bearing and try fitting it hot, but none of the guides I've read mention that step.

Have I got slightly undersize bearings?

Hi just finished building mine, yes i think you may have, try freezing the shaft ?