Help! X axis power feed install

[Firstgear]

I am updating my x axis power feed to an Align unit. I have struggled with the amount of shins to put inside the unit to give the gears proper clearance so they mesh correctly.

I think I have a big backlash issue that needs to be resolved first as the gaps between the gears are impacted by it.

I have tried to adjust the backlash under the X axis. But that doesn’t seem to really make a difference.

Ideas or suggestions? As long as that drive screw moves in and out like it does I am not sure how to get the power feed adjusted correctly. The handle moves about 270 degrees before I get movement in either direction.

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[davidpbest]

Your movie isn’t viewable. But I had a similar issue. The split nut is not the source of the problem here. This backlash is due to the x-axis lead screw not being properly constrained (preloaded) against the bearings at each end. Both ends of the lead screw must be in slight compression against the bearing race/boss at each end, otherwise when you turn the lead screw, the lead screw itself slews sideways until the opposite end bottoms out against the bearing race/boss at that end. Unless both ends of the lead screw are in slight compression against the bearings at each end, your x-axis will have terrible backlash and the table is free to be displaced under load. It’s a fussy adjustment and not the greatest design since there isn’t any way other than shims to adjust the preload. Details here (which you’ve probably already seen):

https://flic.kr/p/281xCHc

You have to add bushings between the boss on the lead screw and the needle bearing assembly in the feeder, and getting the following collection of bushings and shims to the proper combination is the key to removing the backlash:

https://flic.kr/p/29nbM2a

In addition, some users I’ve talked with have had to skim off the bevel gear (rather than shim it out) to make the bevel gear interface to the worm/drive gear fit properly. When the bevel/worm gear interface is adjusted properly, it should function/sound like this.

Hope this helps.

 

[Firstgear]

Your movie isn’t viewable. But I had a similar issue. The split nut is not the source of the problem here. This backlash is due to the x-axis lead screw not being properly constrained (preloaded) against the bearings at each end. Both ends of the lead screw must be in slight compression against the bearing race/boss at each end, otherwise when you turn the lead screw, the lead screw itself slews sideways until the opposite end bottoms out against the bearing race/boss at that end. Unless both ends of the lead screw are in slight compression against the bearings at each end, your x-axis will have terrible backlash and the table is free to be displaced under load. It’s a fussy adjustment and not the greatest design since there isn’t any way other than shims to adjust the preload. Details here (which you’ve probably already seen):

https://flic.kr/p/281xCHc

You have to add bushings between the boss on the lead screw and the needle bearing assembly in the feeder, and getting the following collection of bushings and shims to the proper combination is the key to removing the backlash:

https://flic.kr/p/29nbM2a

In addition, some users I’ve talked with have had to skim off the bevel gear (rather than shim it out) to make the bevel gear interface to the worm/drive gear fit properly. When the bevel/worm gear interface is adjusted properly, it should function/sound like this.

Hope this helps.

That short piece that goes in before the bearing bushing is something I have fussed with, but as you say it sticks the gear too far away from the motor gear and I thought about having to trim the big gear, but thought that can’t be....well it is from your comments. So I need to put the backlash adjusters back where they belonged and then I will get after this again tomorrow. Thanks David, nothing is ever easy!