[crjohnson]

Hi guys,
I bought some genuine THK C6 caps for my SHS25 rails but noticed these now have a small hole in the center.

I remember these (years ago..), NOT having a hole in them. I plan on adding flood cooling to my machine soon and also wanted to stop chips making their way into the carriages, but I'm not sure about coolant seeping through these little holes now.

Has anyone used these style caps and had issues with coolant or anything else?

[mactec54]

Hi guys,
I bought some genuine THK C6 caps for my SHS25 rails but noticed these now have a small hole in the center.

I remember these (years ago..), NOT having a hole in them. I plan on adding flood cooling to my machine soon and also wanted to stop chips making their way into the carriages, but I'm not sure about coolant seeping through these little holes now.

Has anyone used these style caps and had issues with coolant or anything else?

I think it is to let the air out when they are being installed, if they are exposed then yes, they could get something inside, how big is the hole.

[crjohnson]

I haven't measured it yet but guessing 0.5-1mm.
I wonder if the coolant surface tension would be enough to stop it running or seeping in?

[mactec54]

I haven't measured it yet but guessing 0.5-1mm.
I wonder if the coolant surface tension would be enough to stop it running or seeping in?

That's quite a big hole, I would say that coolant would get in there, try and see if you can either plug the holes with an epoxy glue, or get some without the holes

[crjohnson]

I had another look and tried to measure the holes, they are around 0.4-0.5mm. I will look at sealing them up somehow but hope they dont allow any debris to enter the bearing blocks!