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FP2 First Gen possible gearbox selector issue

Laurentian

Stainless
Joined
Mar 2, 2008
Location
Canada
A little background :

-Former Northern Electric ( Nortel ) Ottawa R&D dept. machine
1967 low to medium hours, great shape
-We installed 2010 and all oils-grease-coolants were changed
-Machine ran an average of 2 full days a week at first and now almost daily 8-10 hours shifts, religiously oiled every morning at start up.
-Staff is careful with feed speed changes machine off and making sure plunger is set with lower dial at 6 o'clock on both handles.

Earlier this week my apprentice was running the mill with Z power feed upwards and heard a momentary gear grinding noise. Happened twice so second time he went and got my senior machinist that has extensive experience on it and had him check everything over. Nothing unusual and all dials were well set.

Then maybe a half hour later we heard this loud horrible heart wrenching gearbox grinding noise that jolted me upright and raised my pulse. Apprentice shut off power feed and hit emergency stop within 3 to 4 seconds, quick thinking !

Went back there with visions of machine apart for months on end sourcing parts and having to purchase another one at now inflated prices with unfavourable US/ Can exchange rates..

-Checked dials, all set as should be.
-Manually spun back handle all ok
-Hit start-stop same horrible crunching sound from centre or base of machine
-Took machine out of preset feed and dialed in another. Seemed a little notchy until I spun a complete revolution or two going through all the feeds. Did same with spindle speed, nothing unusual there.
-Calmed down a bit, triple checked everything, asked my guys a few questions, nothing out of place except a feed change earlier from one setting directly to the next without going though a full revolution to exercise machine like I like to do.
( at this point I'm suspecting sloppiness - backlash in the feed dial mechanism )
-Came over here to read up.
-Gearbox oil levels standing still : feedbox upper window mark ( clear ) and speed box half window ( slightly dirty tan colour ) Last changed in 2011.. ( kicking myself for not changing sooner, work for that mill crept up on us and now were're already in 2019..)
-drained both looking for gear teeth or metal shavings, nothing.
-filled with clean diesel fuel and drained both looking for gear teeth or metal shavings, nothing.
-filled with clean left over pantograph light spindle oil and drained both looking for gear teeth or metal shavings, nothing.
-filled to upper window limit with Shell Tellus 46
-hit start-stop all good and oil movement from slinging oil, level dips down to halfway mark on upper, upper 2/3 mark on lower. Upper oil still has a little tan colour maybe just the window but will change out again later.
cleaned, oiled, greased, double checked everything machine runs great and seems a little quieter.
-let it run for an hour or so as I put everything away and cleaned up after myself. No heat, all good. Multiple feed / speed changes all good as new.

This points to either a bearing going out, the rapid feed mechanism acting up but most likely slipping out of gear due to a feed-speed selector dial issue.

I'm confident in running the machine as is until I can get the operators side panel off and clean - inspect the dials and look into the gearbox directly. I did run a mini camera into the oil fill and drain holes and the teeth appeared normal for a 50 yo machine.

 
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Upper gearbox oil level seems to have dipped after one shift's use. Stays at half way mark as I first found it prior. Could it be that any overfilled upper gearbox oil gets slung out and makes it way into base / sump / coolant tank of machine ? Lower gearbox same unchanged. Will look over Wrench's CD see if any mention.
 
Hit start-stop same horrible crunching sound from centre or base of machine

Under the support, covering the Z-axis leadscrew, is a sheet metal cover. If you squeeze it together at the top, you can pull it off.

Now you will see a metal cover with the top of the Z lead-screw nut visible at the top. As I recall, the cover is held in place by four SHCS. Remove the screws, lift up the cover. (It has a gasket which might be glued in place so you may need to split it off with a razor blade.)

Under this cover are a pair of bevel gears. Once comes straight out of the machine. The second one spins the vertical power feed shaft which brings rotational power up to the support.

Based on the description above, it could be that one of those two gears is messed up, or the bearings that they ride in. Here is a photo of this area on my FP2:

attachment.php
 
Will do Ballen thanks ! Yes I remember lifting that cover a few years back but I didn't go as deep as in your picture, will check it out and report back !
 
Will do Ballen thanks ! Yes I remember lifting that cover a few years back but I didn't go as deep as in your picture, will check it out and report back !

Note that in the photo that I have posted, the Z-axis lead screw nut has been removed. It will be in your way, but you should still be able to inspect the two bevel gears and the bearings that they ride in.

I would not normally expect to see a problem in this area. I flagged it because it seems consistent with the location of your "gear grinding" noises.
 
OK will do Ballen thanks again. I'll get to it possibly tomorrow if not Monday evening. I was also hoping someone would chime in and say that our mishap has been experienced before but it seems that machine go down til repaired when this is the case. I did pop off the cover yesterday to see what I'm looking at and looks like the cover may rise up over the Z elevation screw as you mentioned. I have yet to go through Wrench's CD so that is another thin for me to look into as well.

Also going to top off the upper gearbox but I'm beginning to remember reading that excess gear oil filling will be met being slung off and out.
 
I did pop off the cover yesterday to see what I'm looking at and looks like the cover may rise up over the Z elevation screw as you mentioned.

Run the support to the top of its travel, remove the sheet metal cover and the screwed down cover. You can then run the screwed down cover up the lead screw/feed shaft to get it out of the way and inspect what is underneath.

Let us know how it goes!
 
OK will do Ballen ! On a aside note that upper oil level standing still is at half mark and shoots up in the window when spindle is run, guess it's just being slung. Will keep an eye on that as well.
 
Update all is good for now will post up pics and video tomorrow leaving for the day is late over here.. I'm suspecting the lower knob simply wasn't clipped in and it moved off centre ( really hoping that's all it was ) I'll definitely be removing the operator side panel but only in the next couple weeks to look into the feed selectors and gearboxes. ( is a big job ) The rear belt and motor covers as well as removing the head to clean inspect that I'll do later over the week.

Ballen : Looks great in there, cleaned and flushed out with Vactra 2, put all covers back securely.
 
Have worked a fair bit on FP2's having the crank and dial gear selector setup....Never an issue, seems very reliable in my experience.
If i was a betting man, i would say your view that the crank was not properly engaged is most likely....
In my experience gear problems don't come and go...they usually continue having mesh (noise) issues once it started.....
The fact that the machine was being run by one of the less experienced persons reinforces this......

I would move forward, believing that this is a unique event and pass it off to operator error.....Some additional focus on making sure that the operator is vigilant in setting the gear selector crank and handle would
be in order just to be sure...
Cheers Ross
 
Thanks for your support guys ! Here are some pics followed by a short clip. All is fine in the Z feed bevel gear area so I'll be moving to the rear of machine for panel removal, cleaning and lubing simply as preventative maint. The operator panel removal will have to wait, and as Ross mentioned most likely operator error combined with my case of nerves not recalling if I found the small dial clipped in or not. ( I literally sprinted back there when the gears ground ) It did have play for sure from and from 6 to 9 o'clock but for the life of me I can't remember if I found it as such or if I actually pulled out the plunger myself, all this before resetting and running through all feeds again. I'd make a horrible witness if ever I got called in to testify on anything lol !!

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010.jpg[video=youtube;GB5bBMWWndo]https://www.youtube.com/watch?

v=GB5bBMWWndo&feature=youtu.be[/video]
 
Here's the oil being slung around in the upper spindle speeds gear box after having topped it off from recent oil change. It's now at 2 litres in, doc. says 1.5 litres. I wonder if it'll drain back to half mark again by simply splashing out ? There seems to be a somewhat separate cavity up there thus the two drain plugs. ( requiring running to splash around everywhere ) Anyhow not really important I just want to do it right as I feel kinda guilty not staying on top of it other than regular way flushing and coolant changes. We do add Vactra 4 to the spindle brake bearings time to time. Went through that 2 years ago to reset, spindle itself is fine still original untouched from factory.

 
I'm cautious about overfilling with oil. Sometimes it puts seals under too much pressure, and sometimes it leads to oil being "whipped to a froth" by parts which are not supposed to come into contact with it. But it probably does no harm here.

Regarding the bevel gears at the bottom, beneath the support. If that area is still open, check that the "oil drain" holes in the Z-axis lead-screw nut are still open. If you look carefully you will see a short "drip tube" emerging from the top of the lead screw nut, in the direction pointing to the back of the machine. The idea is that oil runs down the Z-axis lead screw, runs onto the nut, then drains down through a small hole which connects to this little drip tube. That drips oil onto the horizontal bevel gear, which then spreads it to both gears and bearings.

Check that oil coming down onto the nut exits through that drip tube and falls onto the bevel gear.
 
OK will do Ballen ! I'll get to it in next couple days when I service the rear panels and belt area, thanks for the tip. In retrospect doesn't seem to be getting the volume of oil it should.
 
In retrospect doesn't seem to be getting the volume of oil it should.

The oil coming down the Z-axis lead screw is bedway oil, which has additives that make it cling. So very little is needed, probably one drop an hour would be plenty to keep a thin film on those gears and bearings.
 








 
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