ballen
Diamond
- Joined
- Sep 25, 2011
- Location
- Garbsen, Germany
A month ago I got a Jones and Shipman 540 APR, details are in another thread in this forum.
I've now had enough practice with the machine that it's time to dust the chuck, which is slightly tilted (about 0.01mm) from left to right.
Before doing this I decided to take off the chuck. The problem with rust is that it occupies several times the volume of the iron that it replaces. So I thought that perhaps the tilt in the chuck was due to pressure from rust growing underneath.
Here's what I found. I am sure that this chuck has not been removed since the machine was sold in 1986.
So before dusting the chuck I am going to clean this up a bit. First step is getting off the rust without doing any further damage. A nice way to do this with Evaporust, which I have used for similar things in the past:
Here is the chuck in its bath:
and here is the table of the grinding machine:
In a few more hours, these will be pitted but rust free. So here are a few questions for the experienced:
(1) Before putting the chuck back, what should I treat the surfaces with so that they will survive coolant without too much corrosion?
(2) The chuck is retained with two tongues right over the center line.
Won't this tend to "twist" the table? Wouldn't it be better to support the table at three points, so it doesn't tend to twist the table?
(3) I suppose the right thing to do is to regrind the top of the table and the bottom of the chuck. But I don't want to do this yet. I think the chuck was installed properly and professionally 30 years ago, and expect that after the rust is removed, the surfaces will again be flat. Anyway, I'll check the chuck on a surface plate. Any advice for the ignorant on these topics?
I'll post some more photos after the Evaporust baths are finished and the surfaces are free of rust.
Cheers,
Bruce
I've now had enough practice with the machine that it's time to dust the chuck, which is slightly tilted (about 0.01mm) from left to right.
Before doing this I decided to take off the chuck. The problem with rust is that it occupies several times the volume of the iron that it replaces. So I thought that perhaps the tilt in the chuck was due to pressure from rust growing underneath.
Here's what I found. I am sure that this chuck has not been removed since the machine was sold in 1986.
So before dusting the chuck I am going to clean this up a bit. First step is getting off the rust without doing any further damage. A nice way to do this with Evaporust, which I have used for similar things in the past:
Here is the chuck in its bath:
and here is the table of the grinding machine:
In a few more hours, these will be pitted but rust free. So here are a few questions for the experienced:
(1) Before putting the chuck back, what should I treat the surfaces with so that they will survive coolant without too much corrosion?
(2) The chuck is retained with two tongues right over the center line.
Won't this tend to "twist" the table? Wouldn't it be better to support the table at three points, so it doesn't tend to twist the table?
(3) I suppose the right thing to do is to regrind the top of the table and the bottom of the chuck. But I don't want to do this yet. I think the chuck was installed properly and professionally 30 years ago, and expect that after the rust is removed, the surfaces will again be flat. Anyway, I'll check the chuck on a surface plate. Any advice for the ignorant on these topics?
I'll post some more photos after the Evaporust baths are finished and the surfaces are free of rust.
Cheers,
Bruce