How do I lubricate correctly?

Hello everyone,
While building my future milling machine, I encountered a small problem of understanding.
There are grease nipples on the carriages of the linear rails and on the ball screws.
Which grease gun and which grease should I buy to lubricate them properly?
The nipple on the ball screw nut is somewhat problematic, as there is very little space between the nipple and the spindle nut block.

These are the carriages and ball screw nuts I bought:
www.sorotec.de/shop/CNC-Mechanics/linear...w-spindle-12-x-4-mm/
www.sorotec.de/shop/HGH20CA-slide-block--short.html

Thank you and best regards,
2tinker

That might be a question for Sorotec. They also offer grease guns and lubrication products, and should be able to make a recommendation:

www.sorotec.de/shop/Tools-and-utilities/...roducts/Lubrication/

HGH20CA is a Hiwin part number, although I suspect that Sorotec is selling generic clones. Hiwin has an extensive linear guide and ballscrew lubrication guide at the following link (737KB PDF). They recommend viscosity grade NGLI 2, and list specific greases (see attached table).

www.hiwin.com/wp-content/uploads/lubricating_instructions.pdf
 

Interesting, thank you very much.

Does anyone have experience with this grease gun?
www.sorotec.de/shop/Professionnal-Grease...set-120ccm-6796.html

At €100, it's not realy cheap!

I bought a similar grease gun. You can get cheaper ones off ebay if you search for Jiabara threaded style for 70-80 gram tubes. 
The tubes are a clever accordion that screws onto the grease gun.
I did not like the nozzle/rigid stem. It locks on really tight. So maybe the real deal works better.
If you have old LM blocks with brittle plastic, you risk the chance of pulling the grease fitting out of the plastic threads. 
Be aware that some manufacturers use grease fittings with an odd pitch of M6x0.75! In case you need to modify something.

I have a machine that recommends 2 different greases. NSK Grs AS2 for the LM blocks and LR3 for the ball screws. AS2 is probably fine for both. 

I'm thinking of adding a centralized lubrication system to my current project instead of trying to access each block under the way covers. 
I have used Bijur pump and metering units adapted to ball screws and LM guides in the past using vactra no2.
I'm interested in finding out what others are doing that is more of a modern system. 
I know Haas went through a couple of redesigns with their remote lube/grease systems.
 

Here's what I came up with for my Mill's Y-axis saddle.  Much simpler than running grease/oil lines to a central lubrication pump...make them just long enough for easy access.

• Hose is Kynar (PVDF), I believe 4mm OD
  • any fluoro-polymer hose/tube should be fine (PTFE, ETFE, etc), stay away from anything else.
• Fittings are just cheap air-hose push-to-connect (same as 3D printer filament tube size)
  • The cheap push-to-connect o-rings will likely fail after some years, but it'll be obvious when it happens and I have a dozen or so spare fittings
  • Drill out the PTC fitting to remove any unnecessary constrictions (it's surprising how small the ID is)
  • The fittings on the actual trucks are compression w/ferrules, so no o-rings to worry about
• Manifold is a really kludged DIY thing - drilled/tapped for the fittings
  • it's not actually a manifold... each port is separate
• I'm using NLGI #1, no moly.  Any thicker (or much longer hoses) and I'd run the risk of a hose popping out of a fitting.

Z-axis has a similar 'remote fill' system as the Y-axis.

Couple pumps 3-4 times a year (low use machine) and no issues since installed.

Good info.
I used Nylon tubing in the past. I think. Whatever it was has been holding up well. I'll look into Kynar.

What are the compression fittings you are using on the trucks? That is usually the more difficult part to source due to the odd pitch of 0.75 on some LM blocks.

Push to connect fittings are fantastic except for some that grab the tubing without a proper release mechanism. Meaning the collar that gets pushed in doesn't slip over the teeth to release causing tubing to become shredded during removal. That can contaminate critical components. I wanted to mention that as I recently went through that with cheap fittings. 

For a lathe I would need 10 remote ports if direct fed like on your setup. That might be okay.
Equal length tubing may be a solution to avoid metering units if running it off a manifold. Any experience with that? 

 

OT-CNC wrote:

Good info.

What are the compression fittings you are using on the trucks? That is usually the more difficult part to source due to the odd pitch of 0.75 on some LM blocks.

For a lathe I would need 10 remote ports if direct fed like on your setup. That might be okay.
Equal length tubing may be a solution to avoid metering units if running it off a manifold. Any experience with that? 


 

A search for "M6 x .75 grease fitting adapter" resulted in a bunch of hits on Scamazon for 4mm tube compression fittings (both elbows and straights).

They aren't as cheap as the push to connect, but if you're worried about it you should be able to fully plumb up the lathe for appx $100 (20ftgs and tube)

Since mine are individual, I wasn't concerned with metering.  A pump or two and watch for some grease to ooze out of the truck or ballscrew before a long, slow warmup cycle to spread things out.  A manifold, metering components, or similar was just going to be a complication.  Once they are easy to access it's not a burden to lubricate.  And grease generally stays put for quite a while - no need to grease every day like an oil system.