[dgentile]

I've been working on my retrofitted BF20 (G0704 "clone").
Aside from replacing the open loop steppers with Clearpath SDSK integrated servos (hopefully delivery later this week) because I got annoyed by missed steps and such stuff...
I'm also wanting to install a central lubrification system

What I'm slightly "confused" about are the ball-screws...
I've installed central lube systems on different machines so far that needed some type of way-oil ....
But the ball screws I have are greased (by a grease nipple / zerk fitting),...
Can the ball screws be lubed with the same kind of oil that's used on the machine ways instead?
My experience with ball-screws is a tad limited.

from what I know - grease would offer longer maintenance intervals for the ball-screws,... but that would be a bit of a moot point, considering a central lubrification system would be activated at regular intervals anyhow...

Last but not least: Cutting oil-grooves in the ways...
I have a larger milling machine (conventional) and would thus have no problem milling nice oil grooves into the ways of the BF20... but on a small-ish machine such as the BF20, is it even necessary compared to a single-point of entry for the oil...?

[atomarc]

My two cents...we did a similar build on a G0704 (CNC) utilizing ball screws, but dumped the X and Z axis ways in favor of linear rails, and added one shot lube to the remaining Y axis as well as the ball screws. The same way lube was used for the ways and ball screws.

What we did wrong was to slot the way surfaces for oiling in a parallel fashion, when the proper method would have been canted/slanted so there was a 'wiping' action as the two surfaces slid. This method would tend to move the lube cushion over the entire surface of the ways. If you look at any commercially built machine tool you'll see that's how they machine the lube slots. Our thread has pictures that show how this was achieved.

Stuart

[dgentile]

My two cents...we did a similar build on a G0704 (CNC) utilizing ball screws, but dumped the X and Z axis ways in favor of linear rails, and added one shot lube to the remaining Y axis as well as the ball screws. The same way lube was used for the ways and ball screws.

What we did wrong was to slot the way surfaces for oiling in a parallel fashion, when the proper method would have been canted/slanted so there was a 'wiping' action as the two surfaces slid. This method would tend to move the lube cushion over the entire surface of the ways. If you look at any commercially built machine tool you'll see that's how they machine the lube slots. Our thread has pictures that show how this was achieved.

Stuart

Hey Stuart, THANKS A LOT

this was super helpful

Interesting on the addition of the linear rails - it's somthing I'm pondering for a future upgrade!...

you mentioned "our thread" - thanks - I've bookmarked it and will look through it...

I've got a set of clearpath SDSK servos incoming next week... and a 1kW Servo Spindle to replace the machine's spindle motor (and toss the gearing out)...
and am still pondering whether to keep my machines quick change SK20 (DIN 2080) Spindle (I had an idea to change the mech. release to pneumatic and then build a carousel ATC for it) or go wild and get a BT30 Spindle + housing an Pneumatic tool changer... the BT has a broader selection of quality tool holders... SK20 is a tad limited in this.


Daniel

[servtech]

I've been working on my retrofitted BF20 (G0704 "clone").
Aside from replacing the open loop steppers with Clearpath SDSK integrated servos (hopefully delivery later this week) because I got annoyed by missed steps and such stuff...
I'm also wanting to install a central lubrification system

What I'm slightly "confused" about are the ball-screws...
I've installed central lube systems on different machines so far that needed some type of way-oil ....
But the ball screws I have are greased (by a grease nipple / zerk fitting),...
Can the ball screws be lubed with the same kind of oil that's used on the machine ways instead?
My experience with ball-screws is a tad limited.

from what I know - grease would offer longer maintenance intervals for the ball-screws,... but that would be a bit of a moot point, considering a central lubrification system would be activated at regular intervals anyhow...

Last but not least: Cutting oil-grooves in the ways...
I have a larger milling machine (conventional) and would thus have no problem milling nice oil grooves into the ways of the BF20... but on a small-ish machine such as the BF20, is it even necessary compared to a single-point of entry for the oil...?

Ballscrews can be lubed with waylube oil, usually a 46 or 68 weight oil. 10ml flow poppers on each lube point, lube pulse every 30 minutes for 30 seconds should be ok. Monitor pressure achieves 25bar and returns to zero after the 30 seconds on time, to ensure lubrication function. Fit a lube level switch too.

[dgentile]

Ballscrews can be lubed with waylube oil, usually a 46 or 68 weight oil. 10ml flow poppers on each lube point, lube pulse every 30 minutes for 30 seconds should be ok. Monitor pressure achieves 25bar and returns to zero after the 30 seconds on time, to ensure lubrication function. Fit a lube level switch too.

Thanks for the details on the timing & pressure for the auto-oiler...

One question in regards to this... you mention to set it to 25bar?
seems quite high... most auto-oilers I've seen operate somewhere between 10 and 19 bars... the one I've got around my shop (leftover from an old project) does 15...
I guess with a lower (than 25) pressure I would adjust the timing - say pump every 30 minutes, 50 seconds...

[servtech]

Thanks for the details on the timing & pressure for the auto-oiler...

One question in regards to this... you mention to set it to 25bar?
seems quite high... most auto-oilers I've seen operate somewhere between 10 and 19 bars... the one I've got around my shop (leftover from an old project) does 15...
I guess with a lower (than 25) pressure I would adjust the timing - say pump every 30 minutes, 50 seconds...

Pressure sounds high but remember a 3 axis machine with 4 shoes and a ballscrew per axis will have 15 flow popper valves to open at one time and push oil through. Willy Vogel oil lub systems are fitted to most European and many Japanese machines, all have 25 bar pressure systems. Steel tube from the pump to axis mounted manifolds and plastic to the shoes and ballscrews after the manifold poppers, ie on the low pressure side.

There may be lower pressure systems, but this is what I am most familiar with.

[dgentile]

Pressure sounds high but remember a 3 axis machine with 4 shoes and a ballscrew per axis will have 15 flow popper valves to open at one time and push oil through. Willy Vogel oil lub systems are fitted to most European and many Japanese machines, all have 25 bar pressure systems. Steel tube from the pump to axis mounted manifolds and plastic to the shoes and ballscrews after the manifold poppers, ie on the low pressure side.

There may be lower pressure systems, but this is what I am most familiar with.

Good Info... I think I'll set it up with the 15 bar unit I have - and see if / how much Oil I'll get flowing....
if it ain't doing enough I'll hunt down a 25 bar pump...

thanks again

[Stigoe]

My two cents...we did a similar build on a G0704 (CNC) utilizing ball screws, but dumped the X and Z axis ways in favor of linear rails, and added one shot lube to the remaining Y axis as well as the ball screws. The same way lube was used for the ways and ball screws.

Stuart

What did you use for the linear bearings for lubrication? Did you use grease or did you add them to the oiler system? I'm currently installing linear bearings to both X- and Y-axes on my mill (Z done previously).

Stig

[atomarc]

What did you use for the linear bearings for lubrication? Did you use grease or did you add them to the oiler system? I'm currently installing linear bearings to both X- and Y-axes on my mill (Z done previously).

Stig

We retained the small Zerks on the linear rail cars and grease them regularly or as needed.

Stuart