Hi all -
I’ve got a 770MX purchased in 2020. We subsequently moved and I couldn’t use the machine for several years. Now happily bringing it back into service.
The question: I’ve got the automatic oiler. It powers up fine and runs a cycle. Oil level is full but haven’t changed it (I will but it is nice and clear). Can also run a manual cycle. The issue is I’m unsure if oil is getting to the ways. Starting with the obvious: Move to left x-limit to expose a small segment of the ways. And that’s the issue. It looks dry which is why I am questioning this.
How can I verify that oil is bring delivered? Let’s say that old oil is gumming up the lines…How would I know/check?
Edit: I realized I could open up the Y and Z bellows. Attached is what I see. It does seem that there’s a problem. Not sure if all surfaces should be “wet” or just outside. Unsure how I would do similar for X. And then of course…what do I do about this?
Thanks,
Charlie O.
The X/Y distribution manifold is, iirc, under the machine table so to access that you have to remove the table. Never done it myself but I’ve seen a walkthrough or two and it doesn’t look terribly difficult, other than managing the weight of it once it’s off the machine. Other than getting that far into it, I’m not sure there’s really any way to find or fix a clogged line. My first thought would be to blow air through but that’s likely to just blast out the open lines and leave any clogs right where they are.
Not sure about the 770 but on an 1100 the distribution block is on the saddle on the left side
If you remove the X-Axis motor and bearing nuts the table can be pushed all the way to the right side of the enclosure…. The block can be removed and individual lines pumped with oil… I have done this twice to replace the X-Axis ball screw
I took the table off and ran the pump till oil came out. I also found little, what i think were bleed screws. Straight slot screwdriver type. Those had debris in them. Cleaned it all out. Run it till oil comes out, reinstall screw. Might take a while. Prelube ways helps until you bleed.
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Bruce - Did you need a lift to take the table off or was human power sufficient? And how bad was the realignment process when you put it back together?
Thanks,
Charlie
I took the whole table off. Quite easy actually. Run the table 3/4 to the left or so. Support the x axis motor carefully. Don’t want to bend the ball screw. Unbolt the motor from the table. Remove gib adjusting screw on the right, I believe. Slide the table to the right the back and gib should slide out a bit. Remove it. Move table to get clearance and tilt it up and lift. You’ll see. Now you can clean and check everything. Just pay attention on disassembly. Should go right back. Adjust gib if need be.
Not bad really.
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Did you open it up Charlie?
I’ve started the process and I could use some guidance. I’m awaiting hook wrenches to remove the spanner nuts that are in the housing. But in the meantime, I’m now confused as to the plan. I need to get to the oil manifold and fittings that are underneath the righthand side of the table. See below. Is the idea that I remove the housing, etc. on the left and then slide the table further to the left to expose the manifold that’s under the right end? In which case, I should probably start with the table shifted further to the right?
And if above is the idea, then I also need to create some supports (wood) that will hold both the table and the ball screw. Correct?
You should be able to do as you described.. on the 1100 the distribution block is on the other end
You will probably have to remove the casting on the left side to allow further movement to the left
You may want to just pull the table completely since you’re this far… if it can be lifted… the 1100 would need a hoist for sure… also since you’ve gone this far… idk how much time is on this machine but bearings are easy to replace
Good luck
Ed
Any idea on the weight of the table. I’m guessing over 100lbs. I don’t know but I wouldn’t remove it completely unless you have to. Seems like a nightmare trying to support it with the enclosure in place. Unless you have a wood platform you can slide it onto as the table comes off the saddle.
I guess I’m doing this. Support platform taking shape. I’ll put some UHMW tape down for the rails to slide on.
And….it’s opened up. Well supported by the platform which is actually front and rear halves. And between the platform halves there’s a small steel saddle that is supporting the ballscrew.
Anyway, now we can see that there’s a lot of junk on the ways but it was also pretty wet. You can see I’ve cleaned up about half of both (my wife’s toothbrush in the solo cup of mineral oil 
worked quite well). I’m now running a small experiment with mineral oil on a section without scrubbing to see how well it loosens things as this may be the answer for the Z-axis. This also clarifies something I was clueless about: What the oil channels actually look like. They are literally human scratched channels in the surface. Did not expect that.
Next step: I’m planning to replace all the fittings and hoses. Probably not 100% necessary but on the chance that one or more are gummed up, better to replace everything than to find that something doesn’t work right after it’s put back together. I don’t have pricing yet but I understand the parts are quite reasonable.
The y-axis appears to be quite wet from all the oil I pumped in at the start. More testing needed but I’m hoping to avoid going through this in the Y direction too. It would be a bigger deal because I believe it would require me to (a) fully remove the table and (b) as there’s less front-to-back room, I think the housing would have to be disassembled.
For the Z-axis, I’m still worried. I can pretty easily get fluid to flow to the outer ways but not so consistently to the inner ways. I’m not even sure how lubrication gets to the inner ways as the emitter appears positioning only to address the outer ways. If anyone knows more about this, I’d be grateful for input on this.
Note to those who may read this in the future as part of their own 770 disassembly: Once the spanner nuts and the bearing cover are removed from the inside of the motor housing, the motor housing cap screws can be removed and the housing can be slid off. It can hang up along the way but it’s just a snug fit. Most important thing: Once that housing is off, there’s nothing to support the left end of the ball screw so you have to have something prepared to hold it BEFORE you slide off the housing. I used a piece of half-inch high steel c channel, flat side up, screwed down to front and rear support platforms and positioned against the flat part of the ballscrew. Once the ballscrew is supported and the housing is off, the table can slide to the left pretty much unimpeded. Fortunately I was very careful about making the platform level with the ways and so movement was easy and very smooth. I have not removed the gib and don’t plan to (one less thing to have to get right on the way back together).
Great job so far!!
A bit nerve racking I’m sure
Sorry, I guess I wasn’t clear enough. You didnt have to take all that apart. Unbolt the motor / cast iron frame from the table while supporting it. Remove gib. Slide table to the right a bit. Table comes off.
Looks like the ways are riding heavy on the left side. Gib adjustment probably. Look for the little straight slot plugs. Clean everything and pump oil till it comes out everywhere. No need to replace lines unless they are kinked or really old. Snug all fittings. Remember gib adjustment changes everything. Recheck tram etc. While you’re at it, adjust the other gibs too. Might as well before you check everything. Play with snugness. You can put an indicator on one end and lift. See how much it moves. You won’t get rid of all of it.
Bruce - “Looks like the ways are riding heavy on the left side…” What makes you say that? If it’s that you see that on the right the ways are clear, that’s just because I cleaned that area before the photo. The entire ways looked as that carmelized area when I first opened it up. Am trying to avoid taking the table off because (a) it seems really heavy and I don’t have a lift, (b) more alignment work to be done if I do and (c) doesn’t appear to buy me a lot that I can’t already do with sliding it to the left.
Ah, ok. As long as the turcite looked uniform when you slid it over.
No table alignment necessary. Gibs do it all.
