I bought a Lagun! Now I have questions.

[pontiac428]

Thanks. I’m trying to make sense of the lubrication system - hope to have a manual soon.

Jim, I don't think the manual covers the plumbed lubrication systems. I think they were add-ons that were fit to order when the machines landed in L.A., same as power drawbars and servo drives. I'd have to look to be 100% certain, but I don't recall seeing any of it in the diagrams or parts lists.

 

[jimmcw]

Jim, I don't think the manual covers the plumbed lubrication systems. I think they were add-ons that were fit to order when the machines landed in L.A., same as power drawbars and servo drives. I'd have to look to be 100% certain, but I don't recall seeing any of it in the diagrams or parts lists.

I did order the manual today from Lagun - but that's disappointing, because I'm baffled how the lubrication system works. I was expecting something like a "one shot" pump handle, or some mechanism powered by stage movement. But today I removed Y table to get a better look, to see if I was missing something. I don't get it. See photos - everything is clear in terms of the lines, where they are coming from and going to. But how does it "go"? What is the pump mechanism? I need to pull the cover off that cap next to the site glass and see what is inside.

 

[jimmcw]

Since I had the X table off already, I decided to go ahead and remove the Y table. I figured I might as well get a good look at both X and Y lead-screws and ways. To my novice eyes, the lead-screws are not obviously worn in center relative to ends - I will do some backlash measurements with the nuts later and compare end to center.

Flaking on X axis ways is still visible except at ends. Y axis ways show flaking across entire surface of the ways but clearly more worn in the center. I think this is "good enough" for my hobby use - opinions welcome. I will do some relevant measurements once I have it back together.


After fully (or substantially) educating myself on VFD's, I ordered a Lapond SVD-P on Amazon, rated for 2HP. I know - but this is a hobby, and after reading many positive reviews of the Lapond, I couldn't see how I could justify a Techo, Ac Tech, etc. I was fascinated learning about how VFD's work - I knew of them for years and had a self-invented notion of how they worked, which was totally wrong. I thought they were what I now know are digital phase converters.

One of the reasons I removed the Y-table was to get a better understanding of the lubrication system - see my separate post on that. Here is a picture of all the X and Y axis parts laid out on my work table.

 

[pontiac428]

I may have been misguided- your oiler looks integrated into the saddle. The pics haven't been very clear of the unit itself. I'll check the manual when I go into the shop in the morning and see if there is detail on that. If I find something, I'll post a snapshot to ease your mind while you wait for yours to arrive.

As far as condition goes, I think it looks pretty good. The flaking is very thin, so the wear may be visible in the tenths, but I wouldn't expect it to be outside of a thousandth. Still lots of good parts to be made on that mill.

 

[akjeff]

The oil pump on my circa 1978 FTV-1 was built into the right end of the saddle facing forward( in the red box of the first photo ) The output of the pump was a tube passing through the interior of the casting, and fed the distribution manifold.

Here's a closeup of the pump. Around the corner from the pump is the sight glass, and filler plug.

 

[jimmcw]

Here's a closeup of the pump. Around the corner from the pump is the sight glass, and filler plug.
View attachment 478641

Interesting - I'll take some better photos and post, but my oiler looks similar, but not identical. Major difference is the T-handle shown in your photo is missing on mine - looks like a busted off nut/screw where the T-handle should be. Other difference is that the filler plug and site glass on mine are on the front surface.

 

[dabear3428]

regarding the VFD, there are 2 main issues with older motors and VFDs:
1. the insulation of the windings particularly at the terminations has a hard time with excess voltages induced by the sudo sine wave (call it ringing) an output inductor/higher end VFD will help with that or keeping the freq. down will help.
2. the sudo sine wave induces current on the motor shaft this leads to stray current going to ground thru the bearings, most new inverter duty motors have insulated bearings and a shaft grounding wiper or brush. keeping the freq down will also help with this but not enough IMO. your best bet is to install a grounding wiper on the shaft. BTW the issues is that the current passing thru the grease in the bearing tends to coke it and the bearing will self disassemble, this also carries on to any shaft that is solidly connected to the motor shaft. the tell tail in the motor postmortem is what's called fluiting in the bearing race.

there are several issues with the steel laminations that result in efficiency losses but they wont stop the parade.

 

[akjeff]

regarding the VFD, there are 2 main issues with older motors and VFDs:
1. the insulation of the windings particularly at the terminations has a hard time with excess voltages induced by the sudo sine wave (call it ringing) an output inductor/higher end VFD will help with that or keeping the freq. down will help.
2. the sudo sine wave induces current on the motor shaft this leads to stray current going to ground thru the bearings, most new inverter duty motors have insulated bearings and a shaft grounding wiper or brush. keeping the freq down will also help with this but not enough IMO. your best bet is to install a grounding wiper on the shaft. BTW the issues is that the current passing thru the grease in the bearing tends to coke it and the bearing will self disassemble, this also carries on to any shaft that is solidly connected to the motor shaft. the tell tail in the motor postmortem is what's called fluiting in the bearing race.

there are several issues with the steel laminations that result in efficiency losses but they wont stop the parade.

I've seen the same warnings posted numerous times, by numerous people, on numerous forums. That said, I've run several machines with older non inverter rated motors with VFD's, as have several friends of mine, over the past 20+ years. Neither I, nor my friends have ever had any of the above happen on our machines. Maybe we've just been lucky. Or we've upped our odds by not buying junk VFD's off Amazon? Until I have result different from past experience, I won't hesitate using a VFD.

 

[dabear3428]

I've seen the same warnings posted numerous times, by numerous people, on numerous forums. That said, I've run several machines with older non inverter rated motors with VFD's, as have several friends of mine, over the past 20+ years. Neither I, nor my friends have ever had any of the above happen on our machines. Maybe we've just been lucky. Or we've upped our odds by not buying junk VFD's off Amazon? Until I have result different from past experience, I won't hesitate

That does not surprise me you can get away with a lot with light use and it takes the right conditions for it to crop up, that being said those issues are what can go wrong, a little insurance like shaft grounding will go a long way. These issues are what I see on motors with heavy use. I also never said don't do it I just say to add some insurance.
Out of thousands of VFD installs I have only seen 10 or so failures but 4 were on the same motor before we got a handle on it, and that turned out to be a lead length issue.

 

[akjeff]

That does not surprise me you can get away with a lot with light use and it takes the right conditions for it to crop up, that being said those issues are what can go wrong, a little insurance like shaft grounding will go a long way. These issues are what I see on motors with heavy use. I also never said don't do it I just say to add some insurance.
Out of thousands of VFD installs I have only seen 10 or so failures but 4 were on the same motor before we got a handle on it, and that turned out to be a lead length issue.

Don't get me wrong, I'm not saying it can't happen, but we're talking about hobby use of 3-5hp motors. A 3hp in the case of this Lagun mill. That's only a bit over 2000 watts of total energy available when it's maxed out. You would have to have a VFD that is either woefully mismatched for the purpose, or have the correct VFD configured all wrong to produce enough stray energy to induce enough of it into the bearings and actually coke the grease. Even in an industrial setting, I can't see this happening on 5hp( 3750 watts ) and under applications. This is also assuming one uses best practices when it comes to the electrical installation on both sides of the VFD.