[alexis221]

Hello, can anyone tell me what's wrong. I have two 64 inch iko linear rails and four blocks. The problem....well I think anyway...is that the blocks don't move down the rail freely. I have smaller ones that just by tilting the rails the blocks slide down them effortlessly. They seem to be tight and have resistance to them. The rails and blocks seem to be in good shape. Any help would be great. Thanks.

[LeeWay]

Larger blocks and new blocks will have some resistance on them. This is according to how well the balls are loaded or rather preloaded. I have brand new THK rails that take a little force to move. Gravity alone won't move them.
It would if there was a plate mounted on them though and then help in a vertical position.

I have had some smaller ones that were well broke in and they do fall with gravity.

[alexis221]

They are used and seem to be in good condition. Maybe if I clean and re-lube it would make a difference. The blocks are rather large. bigger than I need but got a great deal on ebay and couldn't pass it by. In any case these will be used on my cnc router. I just wanted to be sure the resistance is normal. Thanks.

[RICHARD ZASTROW]

IKO linear rails/blocks are preloaded as standard, I believe. Clearance is added when specified at no cost (I've been told, not positive). I ASSume as they wear (in or out) they will "loosen up".

Dick Z

[LeeWay]

Also when they are cool, it will take more to move the larger ones. They are full of grease. They will get easier as they warm up. This is why I like tuning my motors when the slides are cool. They can only get better from that pount on. That is unless you live up north of south Alabama.

[alexis221]

Yes. well....I do live north in Rhode Island 45 miles south of boston. I did clean them up quickly, and used a light oil just to see what the difference would be. It's deff. an improvement. I guess I will have to keep the temp. changes in mind.. my workshop is the garage...it is heated, but I try not to use it too much with the price of heating oil. I'll have to check and see if I can use a lighter grease when I get this forever cnc project going. Thanks

[LeeWay]

I wouldn't worry too much about that. I would use normal grease and then perhaps when really cool, use a warm up program on the machine for a couple minutes. The rehome or rezero and go from there. These motors are quite capable of pushing some cold grease around. With linear bearings and ball screws, thats about all they have to do until you start cutting.