should New THK linear Rail runs chunky?

[vacpress]

Hello..

In preperation for building, hopefully, a nice router, I have been collecting tid bits. Ive gotten lucky, I think, and purchased 4 new 12" THK HRW-21 linear rails, each with a brand new HRW-21 bearing block.

I got the first pair of 2 in the mail yesterday.. They are extremely handsom. Powdery colored grey finish, brand new.. no rust, clear grease. brand new.. $30.00 each rail\block, including shipping (around $200/each new normally)

OK. my question is. How smooth should the movement on these be right out of the wrapper? They were sealed in plastic bags... They were quite stiff at first, and began to get smoother with some manual manipulation. However, they are still quite.. chunky.. and loud.. i beleive they can ahve their preload adjusted via a set screw, and I also remember learning that some linear rails run much smoother, and with less friction under load...

Anyone know what I am talking about?

Thank you!

Robert

[mxtras]

New they do run stiff. Load them down and the motion will smooth out. Much of the sticky feel is likely the wipers and/or side seals.

I am sure they will be OK. I have torn down blocks that were so packed with MDF dust that I was amazed they even moved at all, but they moved fine.

And, yes - they do run louder than one would expect. Grease will quiet them down a little, but not by very much.

Just don't lube them with anything but a light lithium grease or an oil - do not use just whatever you have laying around - get the right stuff if you are inclined to lube them up! For a dusty environment, I would suggest using an oil feed system set up on a timer - give them a shot of go-juice every once in a while. Grease is a dust magnet.

Scott

[vacpress]

all of the 5 or 6 linear rails ive got have grease ports. i am going to purchase a grease gun, for this reason.

i am going to try and design my machine so that the linear components( bearings, ball screws, etc) are completely protected.

I suppose I will just hope they break in after some use.. the used ones ive bought have ranged from very smooth and quiet movement, to sorta nasty and robably not that usefull..

these are obviousely unused.. i suppose they will be fine...

i may call thk and say hello..

thanks, robert.

[miljnor]

Hey Vacpress Why does your websight go to a vacuum cleaner page?

[vacpress]

grrr. need to change that.. .defunct company...

al ive got up is www.clockworkchicago.com/robert.htm