Problem- Spindle & Ballscrew cooling system

[Gerald Sande]

Well the latest problem I ran into with my Fadal 4020HT is a coolant leak at the "Y" ballscrew. I fill the coolant tank with a 50/50 mix and unfroze the pump motor, I plugged the pump motor in and watch the antifreeze level start to go down, when I didn't see any fluid in the return line, I looked around and found it leaking. I was wondering if someone has worked with this type of problem? I have a maintenance pdf that states it could be a "O" ring leaking I have to do a better cleaning around the "Y" ballscrew to see if a line is leaking . On a special note, I have 2 Fadal 4020HT's both with 15 h.p. spindle motors and 1 has a extended "Z" of 28". this is the 1 with a coolant leak. The other machine is now operating after replacing the coolant pump and I will be able to learn the C.N.C. language with it. 1 is a 1994 vintage and 1 is a 1996 vintage. These machine will run in a limited production situation, probably making Hot Rod part's or some other items. Jerry

[Neal]

My first thought is that the "anti-freeze" probably destroyed the seals creating the leak. Anti-freeze is NEVER to be used in this system.

Neal

[Gerald Sande]

I used the term "antifreeze" as a generic word for Dowfrost. It still could be the seals leaking though. I will get a better look tomorrow, when I'm able to clean the machine. If the seals are bad, what will it take to replace them? Thanks Jerry

[little bubba]

I've unplumbed the ballscrew cooling on two machines. The screw is quite a good size and the rapids are really pretty pathetic, how hot is that screw getting? The screw cooling to me is nothing more than a marketing tool and a headache.

Had a mazak running next to the Fadal with the same size screws and much higher rapids and harder acceleration, a wee bit more rigid so it was pushed harder too, not cooled and no problems, 12 years old(the Mazak).

Un-plumb(<--- is that even a real word??) it, and buy some new thrust bearings, you will be replacing them shortly.

I'm not picking on Fadal, its just a crappy useless feature, its not a bad idea, but once you get in there and see how they did it, its bad, as soon as there is a leak, bye-bye thrust bearings.

[Gerald Sande]

Well I found the coolant leak at the "X" ballscrew. The lines were cut and hanging in mid air. This Fadal has the "X" motor on the left side and the previous owner must of done maintenance on it. The cooling holes into the ball screw are on top and plugged. They disabled the X,Y,Z and spindle cooling . So next week I will see if I can change the "X" cooling holes by turning them to the bottom. I didn't look to see if the screw is dual tapped "top and bottom" yet. Jerry