PM-727m New mill has arrived!

[Sloth2009]

Since this is "the go to thread" on the 727, I've got a note, w/ pic, and a question.
First the note, drained the gear oil today, again. Got curious, so vacuum filtered it to see the particulates. Oh boy... (see pic for what I mean).

Now the question ...I changed the oil because I noticed a lot of play up and down on the quill when I use the fine adjustment. Has something gone bad, hence the metal debree? What/where should I look first to resolve the play issue?
Side note, I'm going to completely flush the gear box this weekend.

I got close to that amount of crud in my first (only) oil change. Have many times you changed it before?

Looking at the pm-727m's blueprints It appears the coarse/fine feed shaft doesn't go into the gearbox. It goes below and to the back of the quill where those teeth are cut in the back of it. If you look under the head behind the spindle, you can see where they engage.

If there is slop up and down on the quill and only during fine feed then there might be an issue with the worm gear engagement. Maybe the clamp knob is not in tight enough? Gunk in the worm gear? To me , part (3) and (21) are worth looking at.

 

[tweinke]

Since this is "the go to thread" on the 727, I've got a note, w/ pic, and a question.
First the note, drained the gear oil today, again. Got curious, so vacuum filtered it to see the particulates. Oh boy... (see pic for what I mean).

Now the question ...I changed the oil because I noticed a lot of play up and down on the quill when I use the fine adjustment. Has something gone bad, hence the metal debree? What/where should I look first to resolve the play issue?
Side note, I'm going to completely flush the gear box this weekend.

The fine adjust does not go into the part of the mill with the oil in it, is the correct answer. My 727 also has debris in the oil that looks shiny but I'm wondering if its paint because if I stick a magnet in it don't get much on the magnet. I was thinking I should pull the top cover to take a peek and while I'm there flush out the inside

 

[fradish]

With my PM727 I have occasionally had an issue with the fine feed where I'll be watching the DRO and turning the
wheel and nothing seems to happen, then the quill just seems to jump maybe 10 thousandths rather than smoothly
moving. I had thought that possibly I had not cleaned off the outer barrel of the quill enough or lubricated it
enough or maybe even that I didn't have the quill lock loosened sufficiently and this was causing the quill to stick.

At this moment I have not been able to narrow it down to what is causing it. What I can say is that when I
received the mill the downfeed housing (#2 in the diagram above) was loose and I had to tighten up the bolts (#22). Maybe I need to dig into the downfeed and check the gears that Sloth2009 pointed out. I would hope that I don't
have a missing tooth on #21, but that might also explain what I am seeing, thought I mainly see this between cuts
as I release the quill lock and make depth changes, so maybe I'm just not loosening the quill lock enough.

I'll just have to play around with it some more and see if I can consistently reproduce the issue and if so, figure out
what it causing it.

 

[Sloth2009]

With my PM727 I have occasionally had an issue with the fine feed where I'll be watching the DRO and turning the
wheel and nothing seems to happen, then the quill just seems to jump maybe 10 thousandths rather than smoothly
moving. I had thought that possibly I had not cleaned off the outer barrel of the quill enough or lubricated it
enough or maybe even that I didn't have the quill lock loosened sufficiently and this was causing the quill to stick.

At this moment I have not been able to narrow it down to what is causing it. What I can say is that when I
received the mill the downfeed housing (#2 in the diagram above) was loose and I had to tighten up the bolts (#22). Maybe I need to dig into the downfeed and check the gears that Sloth2009 pointed out. I would hope that I don't
have a missing tooth on #21, but that might also explain what I am seeing, thought I mainly see this between cuts
as I release the quill lock and make depth changes, so maybe I'm just not loosening the quill lock enough.

I'll just have to play around with it some more and see if I can consistently reproduce the issue and if so, figure out
what it causing it.

I've had similar "slipages" occur. I figured it was due to a combination of the column lock and/or the fine feed locking knob engagement, as playing with those tend to fix it. I wonder if the order in which they are locked and unlocked makes a difference. I will look at mine too and see if I can figure out anything.

 

[fradish]

One thing I just saw tonight is that the quill dro shifts up and down by a fraction of an
inch when changing direction using the coarse quill feed lever. I probably need to take
off the knobs and face plate to see if I can locktite the screws holding the dro in. If the
dro is loose and shifting that might be causing the issue I am seeing.

Before I go to that trouble, maybe I'll wedge a business card between the dro and faceplate
to see if that gets rid of it.

 

[fradish]

Ok, it isn't the loose dro (thought I'll still have to fix that).

I think it is slop in key #23. I think when there is pressure on the key it turns
the shaft smoothly, but when the key reaches 12 o'clock or 6 the shaft slips by the amount
of the slop. I've had hub #18 off once already. I'll take it off again and mark a dot on the outside
of the hub in line with the key way and see if that is where I'm seeing the quill jump.

This isn't a big deal but I'd feel better if I knew why this was happening. At least then
I'll know how to work around it or fix it maybe by machining a tighter key.

 

[Sloth2009]

Ok, it isn't the loose dro (thought I'll still have to fix that).

I think it is slop in key #23. I think when there is pressure on the key it turns
the shaft smoothly, but when the key reaches 12 o'clock or 6 the shaft slips by the amount
of the slop. I've had hub #18 off once already. I'll take it off again and mark a dot on the outside
of the hub in line with the key way and see if that is where I'm seeing the quill jump.

This isn't a big deal but I'd feel better if I knew why this was happening. At least then
I'll know how to work around it or fix it maybe by machining a tighter key.

That makes sense. If I understand you correctly, the weight and momentum of the handle may cause it to shift on the shaft to take up the slop in the little key. If you can shim it or make T-shaped key you may have your issue solved. The hub does need to slide over the key though to lock to the worm gear, so dont get it too tight. See my below post.

 

[Sloth2009]

My particular issue I think is just operator error. The way I am understanding it, the worm assembly (3) from the fine feed is always engaged to the worm gear (21). When you tighten the clamp knob it engages the taper on the worm gear and locks it to the hub (18). The hub itself is locked with the quill pinion shaft (1) with the key [fradish] is talking about. When locked you are able to drive the entire assembly with the fine feed wheel.

I don't think I have consistsntly locked the hub in hard enough. I had actually greased it which likely made it worse. This caused the taper to slip if there was much force on the spindle. Now that I know this, I can watch the outer ring of the worm gear and make sure it is not slipping against the hub when locked.

Since this is "the go to thread" on the 727, I've got a note, w/ pic, and a question.
First the note, drained the gear oil today, again. Got curious, so vacuum filtered it to see the particulates. Oh boy... (see pic for what I mean).

Now the question ...I changed the oil because I noticed a lot of play up and down on the quill when I use the fine adjustment. Has something gone bad, hence the metal debree? What/where should I look first to resolve the play issue?
Side note, I'm going to completely flush the gear box this weekend.

There is a lot of backlash in the fine feed worm drive. Is this what you are seeing?

 

[fradish]

Sloth2009,

Yes, that's what I think is happening. I also noticed that if I leave the quill lock
a little bit tight, just enough to provide a little friction, the quill doesn't jump as
much. I think as long as I have a visual indication on the outside of the hub where
the keyway is, I might be able to use the lock to reduce the jumping. If not, as you
said, maybe milling a new key or even adding brass shim stock in the keyway, possibly
held in with epoxy might eliminate the slop.

 

[TheGov]

Had more time to check some things. The up/down slop is also present in the course feed. I noticed that with the quill down any amount, if I push up on it, I see the top of the spindle also move up. (Spindle and drive group).
Looking at the diagram, I see only 2 different possible loose items. 1-(38) Nut: M25, spanner type. 2-(12) Screw: M5x16, ph HD (3).
I wouldn't be surprised if the problem was 2 from above as I have found several screws/bolts in hard to get to places loose. (The slop is also less than 16mm)
Thanks for all the feedback and ideas of other things to check.