New Knee Mill Owner. Question about "exercising" variable speed turret head.

[jambesBondo]

I recently came across a very good deal on a Lagun FTV-2 knee mill in my area. I am very green when it comes to machining. I have it set up in my shop and am in the process of slowly leaning how to properly use and care for this thing. On the side of the turret head is a notice to run the mill through the entire speed range at least once every day. Can someone explain what the purpose/importance of this is? Is it necessary to do if the machine is just going to be used in a hobby setting? There could be times when it sits unused for a month or two. My best guess is that it is to help keep lubrication on all of the components as well as exercise any springs in the variable speed head. I was curious if anyone could tell me for sure?



Thanks!

 

[matthewsx]

I’m curious about this too as I have a similar sticker on my little Samson baby Bridgeport. I know my variable speed doesn’t go up to the full advertised 4200rpm, don’t know if it ever did. Maybe it has something to do with the belts.

I figure eventually I’ll have to rebuild the head but I’m wondering about setting it at one place and using a VFD to change speeds. I know how a reeves drive works and am not anxious to dig into it.

John

 

[matthewsx]

Also, nice looking mill….

 

[Net30]

Likely to stretch the belt/pully but am 100% certain that sticker is assuming a production shop. Like "oil every day" basically means whenever you use it.

Most of these machines sit idle for years or even decades and run fine, some need basic wear parts replaced, but it's not going to destroy it lol.

Does it have a one shot, because that'd answer the oiling question.

 

[Martin W]

Spindle warm up, literally adds hours of life to spindle bearings.

 

[Ischgl99]

When they want you to run something through it’s ranges, it’s usually to distribute lubrication evenly. Running something at lower speeds all day long might not get lubrication everywhere its needed, but it will at full speed. For grease, the higher temperatures at full speed will help separate out some oil from the base soap to make sure it gets into the bearings. Since your mill will be sitting for long periods of time, it would be helpful to warm it up through its range like Martin said so that all the parts are well lubricated.

 

[mksj]

Decreases the chance of the Reeves drive from freezing up, and also the belt to take a set. I often recommend to people using a VFD in combination with a Reeves drive to use the mechanical drive for speed adjustment as opposed to the VFD, this gives you the mechanical advantage of the drive and decreases the wear at one point. I also recall somewhere that at the end of the day when you are done using the mill, to bring the mechanical speed adjust to the low speed position. I do not see that the spindle lubrication should be an issue, nor would one need to exercise other parts of the machine on a daily bases. The Lagun are very nice mills, but the Reeves drive can be expensive to repair. As a hobbyist I wouldn't worry about needing to exercise it daily, but probably once a week to prevent anything from freezing up and the belt to take a set.

 

[benmychree]

I'm thinking that it would be a good thing to "park" the Reeves drive somewhere near the center of its travel to reduce the tendency of the belt taking a set by having it bent to a minimum radius at the extremes of travel.

 

[Jake M]

My best guess is that it is to help keep lubrication on all of the components as well as exercise any springs in the variable speed head. I was curious if anyone could tell me for sure?

That pretty much sums it up. It keeps all the slippery bits from getting sticky in unused spots. It keeps the sheaves clean and polished. And a dozen other related things that are pretty much just that.

In a hobby setting, it doesn't mean you've got to start the machine daily. It means that you just run through it when you use the mill, and then it'll be fine for a day or a month or to whenever you get back to it. Nothing to panic about, it's not gonna blow up if you miss doing it here and there, it's just maintenance, like the daily oiling points.

 

[mksj]

I think the idea on setting the drive to the lowest speed at the end of the day was twofold, one may have been to decrease the tension on the adjustment end of the drive (the motor end is self adjusting), the other was that if you had a larger cutter or boring head, it wouldn't start out at high speed. The drives should only have their speeds adjusted when the spindle is turning. Per what Jake indicated, as a hobby machinist the machine will most likely see light use, and mush less of an issue, but still want to keep those parts from seizing up if left at one spot for a long time..