Solved How to remove LM8UU's from Carriage

Have been trying to remove the LM8uu's from my Robo's carriage.

How do you do this?

I have been using a rod to hammer them in a vise, however it wants to keep shifting concerning me the carriage will break or crack.

I have seen a few people on here who have removed them... How do you do this!?

Thanks,

Rian

 

I used a 3 inch long 1/4 -20 carriage bolt, washer, nut, and a tube large enough for the bearings to easily slide into, but small enough not to slip off the carriage.

 

Alright so I ended up stripping the carriage of most every nut and bolt. Then putting the carriage sideways into the vise using as much surface area in the vise as possible. Also added some cardboard one either side of the vise's teeth.

Then with a rubber mallet I used a flanged bearing to start one of the LM8uu's out. Then finished popping it with the new LM8UU.

This is what the bad bearing looked like:


It appears to have left some scratches in the guide rods also.

Fun stuff.

 

This will happen if your rods are over sized, or your bearings are missing balls in tracks from the factory. I had this same problem. Measure your rods (if you have either micrometers or vernier calipers) they should be 8mm or less.

 

Did yours come oversize from the factory?

How long have you had your printer?

 

My Rods are ok, my specific problem was missing balls in one of the X-carriage bearings. It worked fine for a couple of weeks, then suddenly the x-axis would not move freely.
What happens if you have missing balls in any one of the "racetracks in the bearings, is that it will work fine until the balls work their way into the outer part of the track, at which point it's like getting flat tire and dragging the frame of your car on the roadway.
I knew when I bought it that there would be things to improve and learn about it. Having 20 some odd years running, programming and repairing CNC machines it's not a big deal, to me.
I've had the printer for about 3 weeks.

 

Exact Same Problem!

I've also have my printer a couple weeks.

Must have been something strange during assembly.

 

I imagine these small bearings are all assembled by a machine, and a certain percentage end of not having the proper number of balls in them. This says to me that the bearing manufacturer needs to step up it's inspection of it's products.
I ordered a set of 12 of these bearings; and lo and behold one of the bearings in the first package of two had missing balls in one of the tracks.

 

Good to know.

How can you tell if there are balls missing?

 

If their is a gap between the balls in tracks greater than one ball. You can get a toothpick and move the balls down and around the track; to see if the gap is hiding in the outside section that is not visible.

 

one more thing, when you are re-assembling your x-carriage. Check to make sure the X belt pullet is aligned so the belt runs parallel all through it's travel. This is to ensure the belt pulling the carriage does not "torque" it to one side or the other accelerating wear on the bearings.

 

Awesome!

Thanks for the info and tips!

 

No problem, glad to be of help.