Another pneumatic valve trouble


When I just brought the mill home, the pneumatic motor driven
vari-speed adjustment worked well. Now it has become extremely
sluggish and seems to hiss and leak a lot of air when working,
especially badly when decreasing speed.
This is driven by this pneumatic valve:
formatting link

This seems to be a similar trouble to what I had with the brake
valve. Probably some rotted seal. Unlike that brake valve, this speed
valve has no markings. The procedure to fix it would seem to be to
take it apart and see what went wrong. Before I do so, I wanted to ask
for any suggestions etc about this, I would hate to fsck it up,
esp. since I am not sure what make/model it is.
If anyone knows who made it, , I woud be really grateful.
Reply to
Ignoramus29074
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When I just brought the mill home, the pneumatic motor driven vari-speed adjustment worked well. Now it has become extremely sluggish and seems to hiss and leak a lot of air when working, especially badly when decreasing speed.
This is driven by this pneumatic valve:
formatting link
This seems to be a similar trouble to what I had with the brake valve. Probably some rotted seal. Unlike that brake valve, this speed valve has no markings. The procedure to fix it would seem to be to take it apart and see what went wrong. Before I do so, I wanted to ask for any suggestions etc about this, I would hate to fsck it up, esp. since I am not sure what make/model it is.
If anyone knows who made it, , I woud be really grateful.
Reply to
Ignoramus29074
I dont have a clue as to model or maker..but I mentioned this before..that you will be finding a few of these issues for the next year or more as old seals start disintergrating under the normal working conditions. Nothing to be concerned about, just be aware of.
Gunner
I am the Sword of my Family and the Shield of my Nation. If sent, I will crush everything you have built, burn everything you love, and kill every one of you. (Hebrew quote)
Reply to
Gunner Asch
Yep. Just to confirm your own statement:
The rubber air hose that supplies incoming air for the mill, is also rotted, as I just learned. It is beyond redemption, and needs replacement. It leaks air when put on a barb fitting, due to cracks in the inner rubber layer.
No big deal.
i
Reply to
Ignoramus29074
I took the valve apart:
formatting link
I did not find anything obviously wrong with it, such as rotted out broken rings, etc.
I have a feeling, therefore, that it is not the valve that is bad.
I now suspect that the air motor is somehow bad. I will try to test it with an industrial fitting to 37 degree flare adaptor.
i
Reply to
Ignoramus29074
[snip]
Have you figured out what kind of hose is best for the replacement?
I need to buy some hose for argon-tank to welder hookup. The existing 2-year-old hose had small exterior cracks (but apparently no leaks) at each fitting. I dealt with it temporarily by cutting a couple of inches off each end and then not tightening the hose clamps as tight as before. However, I want to replace the hose with a better grade.
Reply to
James Waldby
A little update on the valve situation.
1. With the valve in, but hoses disconnected from the pneumatic speed adjustment motor, operating the valve electrically creates very robust streams of air from the hose.
2. With a blow gun connected directly to motor, the motor operates very robustly.
3. With the valve connected to the motor, the motor operates poorly.
On the surface, it kind of confirms a hypothesis that it is the outlet for air that is plugged. I will look into this some more.
Reply to
Ignoramus4779

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