[zephyr9900]

When I pull the plunger of my OEM lube pump, it retracts in about 6-8 seconds. That seems fast to me compared to what I "remember". I'm using the recommended Vactra #2 and the temperature in the garage/workshop has been in the 70's.

If this is abnormal, one possibility is a tubing or fitting leak. I always pull the plunger while the machine is moving (initial homing and during long runs) and there are no pools of lube under the machine or anywhere visible.

Another possibility is blowby of the plunger seal. But oil is consumed because I need to refill the reservoir every week or so.

A third possibility is things are working normally and I'm worried about nothing.

Any thoughts?

BTW, I made a wrench for the lube reservoir lid from a scrap of 1/4" PVC. I tighten by finger but appreciate the help to loosen. I'm attaching a DXF in case you want to make one too. Edit: Cutout needs .125" or smaller endmill, which is why I put it on different layer than the outline. I used .250" endmill to do the outline.

Thanks,
Randy

[Willyb]

Hi Randy

Mine takes about a minute to completely retract. The first quarter of it's travel moves rather quickly which I assume is air being purged out of the Ball Nuts and passage ways. The remaining three quarters travel is at about the same rate. I also notice Way oil in the bottom of my Stand after a few applications. The Pump has acted the same since the Mill was delivered a couple years ago.

6 to 8 seconds sounds fast? Maybe you have a ruptured line. What you could try, is to cycle the pump a bunch of times and see if you can see were the oil is going? If it shows up in one location, it might indicate a leak.


Willy

[zephyr9900]

Thanks for the reply, Willy. I'll do some concentrated pumping and see what happens.

Randy

[justgary]

Randy -

I don't think mine has ever taken a full minute to retract (and I'm sad to admit that on the internet...). In fact, it is much faster than that (I also usually only oil while the machine is moving). I'll measure it for you in the next few days.

Also, you adjusted your way gibs a few months ago; wouldn't that change how the pump acts? It should make the pump *slower* I would think, but what if you had a clog from the factory, and knocked it loose fiddling with the gibs so now it works correctly?

Cool wrench. Thanks!

- Just Gary

[zephyr9900]

Just Gary, thank you for your suggestions (and the compliment on my wrench).

Today the plunger is taking a good 30 seconds to retract. I just thought of another possibility--if I had let the reservoir level get low enough, I might have gotten an air bubble in the lube line, which has now worked its way out.

I'll keep tabs on the plunger behavior, but for now it seems to be behaving more like I remember it.

Randy

[MichaelHenry]

Randy,

Mine takes 20-30 seconds to retract using Vactra #2 and ambient temperature running in the high 60's/low 70's.

Mike

[zephyr9900]

Thanks for the observation, Mike. I'm going to assume that, because of the lack of puddles of waylube under the machine when I repeatedly cycled the pump yesterday, and the fact that my own pump is cycling at about 30 seconds now, that I had a bubble in the line (gosh, it's been decades since I had to bleed a brake line. Last time I remember was on my '71 VW bus... )

Randy

[benji2505]

If your systems had leaks or clogs, some of the points were not lubricated. I frequently check all the critical points with the well know "finger-wipe" method.

We also see Mike's 20-30 second time for Vactra 2 in the mid 60's.

Benji

[rwexec]

I had grief right at the start with my lube system.
I had two loose fittings and one broken line.
See pics on yahoo PCNC1142
I urge anyone who aquires on of these machines to carefully go over the complete lube system while the machine is in the air on the hoist.

I also took the pump apart to find a really thick discusting blob of goo.
I don't know if it was some kind of oil or what but it came out of the reservoir in one lump, kind of the consistancy of crystalized honey.

I do not feel it is the pump but the poor layout and quality of the lube lines.
Just my opinion.
Peter

[zephyr9900]

I urge anyone who aquires on of these machines to carefully go over the complete lube system while the machine is in the air on the hoist.

Peter, thanks for the cautionary note, and I intend to do just that the "next time" I have the machine off the base (which so far has been never...) Given the build quality of the auxiliaries (which are spotty) vs. the basic machine (which I think is excellent) I worry about something that is so fundamental but so inaccessible.

I actually would rather have the basic pump (http://www.lubeusa.us/products/oil_s...?page=2&uid=15) and a large, remote reservoir--just the thing to mount on the column side where I removed the keyboard arm--that was easily checked and filled. The stock reservoir is only 500ml and I probably don't top it up often enough--I cannot read the little sight glass at all where it is... Edit:The pump output is 8ml per stroke, so the reservoir only holds 62ish strokes' worth when full to the top.

Randy

[zephyr9900]

I registered at Lube's Japanese website in order to download DXF's of the pump, brought them into my CAD program and superimposed them--black is the basic pump and red is the pump with reservoir. Apparently the reservoir is just a shell that the pump bolts into (the entire front view, and the mounting flange and handle in the side view, are duplicated on both drawings and the top view is unique to the reservoir version). Removing the shell, making a mounting bracket and substituting a tube for the inlet filter should allow installing a remote reservoir. Sorry, my CAD program (VersaCAD) doesn't have a Japanese font...

Randy

[philbur]

Randy, I think the recommendation is that you check the lube plumbing on receipt, not three years after you have put it into operation.

Just kidding
Phil

Peter, thanks for the cautionary note, and I intend to do just that the "next time" I have the machine off the base (which so far has been never...)

Randy

[zephyr9900]

Randy, I think the recommendation is that you check the lube plumbing on receipt...

That I did, Phil. But now that I've taken a few test cuts with the mill it's about time to recheck things.

Randy

[David Bord]

Would drilling and tapping the lid to the pump and running a line from a remote res. that mounts to the column work?

It also seems that the lines that feed the head bleed down and it take a couple pumps to fill the lines and get oil up to the top of the mill.

David

[zephyr9900]

Would drilling and tapping the lid to the pump and running a line from a remote res. that mounts to the column work?

That is a reasonable concept, David. I'd rather plumb directly into the pump inlet fitting because that leaves less sealed joints to leak, but your way involves less disruption to the current setup.

The big question to me is whether having an elevated reservoir would "blow past" the pump seals and drain the reservoir unnecessarily (if the pump seal is, say, a cup-type like a bicycle pump). I don't know how much flow resistance the oulet plumbing offers in that case.

It also seems that the lines that feed the head bleed down and it take a couple pumps to fill the lines and get oil up to the top of the mill.

I do keep pulling the handle while the mill is ref'ing (I purposely park the mill in a position that takes some travel to home each axis) so hopefully each axis is adequately lubricated during the ref'ing.

Randy

[David Bord]

That is a reasonable concept, David. I'd rather plumb directly into the pump inlet fitting because that leaves less sealed joints to leak, but your way involves less disruption to the current setup.

The big question to me is whether having an elevated reservoir would "blow past" the pump seals and drain the reservoir unnecessarily (if the pump seal is, say, a cup-type like a bicycle pump). I don't know how much flow resistance the oulet plumbing offers in that case.


I do keep pulling the handle while the mill is ref'ing (I purposely park the mill in a position that takes some travel to home each axis) so hopefully each axis is adequately lubricated during the ref'ing.

Randy

Randy, the other option would be to pull the pump, drill it near the bottom of the resevoir tap it with 1/8 npt and feed to the bottom. You could then plug it if you decided to try something different.

You could mount the secondary resevoir just above the pump, and Im pretty sure that wouldnt create a problem with the seals. The other option is to put a simple valve inline that would prevent the leakage problem(if it did exist) when the machine was not in use.

David

[zephyr9900]

Randy, the other option would be to pull the pump, drill it near the bottom of the resevoir tap it with 1/8 npt and feed to the bottom.

David, I think I would just remove the drain plug from the reservoir, get a tube fitting that would thread into the pump where the intake screen threads in now, and lead the inlet tube out through the drain hole. That would take the reservoir out of the fluid path entirely (I would still need to seal the vent hole in the filler cap to implement your above suggestion with a raised reservoir).

Randy