PM-728vt design change request. Potential oil line failure.

[pdentrem]

Since it is only used when the machine is being used, install a shut off valve in the line, to stop oil flow when idle. Alterately move the oil reservoir higher if possible.
Pierre

 

[addertooth]

A stiffer spring (or spacers under the non-ball bearing end), will increase the "seating force" of the ball bearing. It may seal better without replacement after that minor change. If the spring is too stiff, then it won't open the ball/valve-seat opening enough to lubricate the Z-axis.

 

[rwm]

Hmmm. I performed an experiment on this. I took the original check valve and put a vertical length of tubing of about 16" on it. I then filled it with oil and held it vertically overnight. The oil did not leak down at all! The check valve is actually working as intended. This leads me to the conclusion that the oil is leaking antegrade into the ways for the Z axis. That is not something I expected. I am considering replacing the vertical tube with clear tubing so I can see what is actually going on with the oil supply.

Air filled supply tube:

Robert

 

[addertooth]

I flipped the Manifold over to help with the clearance of the oiler line and the lead screw. It is still making contact, but not as firmly as before. A message was sent to Precision Matthews with the problem, and a question. I had asked if the plastic tube is simply pressed into the casting. They said that was how it was installed on that end. At this point, it appears that with the manifold being flipped, there is too much plastic hose, which is part of the reason why it is still making contact with the lead screw. This weekend, the hose will get pulled out and shortened. I suspect that will deal with the unwanted contact.

One other minor change was made. The bolt which holds the manifold to the casting stuck out too far, and looked like it would interfere with a DRO bracket which was going to be installed. When the manifold was flipped, the bolt was screwed deeper into the casting. The only hiccup was there was a locknut at the casting, and another at the manifold. Screwing the bolt in further Reduced the gap between these two jam/locking nuts. My normal 8mm wrench was too fat to tighten one, without turning the other nut as well. But then, I remember there was a mill in front of me. An 8mm slot was cut in a 1/16th thick piece of metal, and it was used as a "thin wrench" to tighten the nuts.

It is always important to remember that when you have tools, you can use them to make custom tools.

 

[woodchucker]

I ere is too much plastic hose, which is part of the reason why it is still making contact with the lead screw. This weekend, the hose will get pulled out and shortened. I suspect that will deal with the unwanted contact.

I don't understand, why can't you just cut it now? Seems like an easy fix. Just take the hose off the T , cut it, put it back on?
I assume it's got a compression fitting and maybe an insert to keep it's shape?

a 2 minute job.

 

[rwm]

It's a 4mm compression fitting.
R

 

[addertooth]

Unfortunately, I live in Hooterville. Many parts/supplies are hard to find. This is especially true of Metric ones. If you go into a local shop and ask for metric plumbing supplies, you get the look which implies they wonder if your mother knew your father when you were conceived.

 

[Christianstark]

Unfortunately, I live in Hooterville. Many parts/supplies are hard to find. This is especially true of Metric ones. If you go into a local shop and ask for metric plumbing supplies, you get the look which implies they wonder if your mother knew your father when you were conceived.

Have you checked with Jeff Bezos?

 

[7milesup]

I'm thinking that Hooterville might be a rather pleasant place to live. Easy on the eyes maybe