Solenoid issue.. 5

[itsmoked]

Why me?

I get called out to a job.
"I got a new machine,(used 1980), and it doesn't work, can you take a look at it?"

I get there and it's another press...

I start trying to understand it. Very strange. Belgium made.

It has two giant solenoids mounted up top. One clicks appropriately and the other is dead silent. It also smells as I get near it. Bad. No, Very Bad.

It has a name plate that sez STROKE: 8x2. Whereas its neighbor which is shorter sez STROKE: 8

This one has 4 wires the other has two. So I guess it has two coils in it.

We dismount it which is a lot of fun (NOT!) as it is integral with a huge solid steel spool valve that resides below the surface of the oil tank. But we get it pulled.

We get the case apart which requires grinding as some inconsiderate engineer had the ends swaged.



Here's the result (thumbnail):

Non thumbnail:

http://files.engineering.com/getfil...c-451d-8e43-819b11671f49&file=Sol_rebuild.JPG

It's not pretty. One coil appears to be OK. It measures 5.5 OHMs.

The other measured 0.1 OHMs.

My autopsy shows that the machine got rained on. This solenoid trapped the water that funneled into it. The slug rusted to the bore. The solenoid was activated and couldn't move. Death followed shortly thereafter. The plastic bobbin totally slumped. The wire lost all its enamel. This resulted in a one turn coil with very big wire.

I had to drill hunks out of the coil to get it loose enough to pry out.

Now I need to repair this. "Hurry, hurry, chop, chop."

The magnet wire measures about 0.033" diameter with the enamel burnt off. I guess this means it's 20AWG

My biggest issues are:

What do you suggest I use to replace the plastic bobbin or where can I get them?

Do I have to somehow count the turns of this mess or can I just wrap as much 20AWG as I can around the bobbin replacement?

Any other pointers will be eagerly snatched at.



Keith Cress
kcress -

http://www.flaminsystems.com

 

[MikeHalloran]

The trick to machining plastic is that the tool edge has to be sharp enough to draw blood with just a touch. Tools that have touched metal are too dull.

Next time you'll know...



Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

Hey after that many hours I would engage the autofeed and work on other aspects, then day dream about being finished, then remember with a heart pounding jar that true disaster was going to occur if I failed to return before the tool hit the machine somewhere. Anyway that's how I took the pictures -(look Ma no hands!)

Mike thanks for that tip! The boring bars were purchased new for this task. The facing tool was a carbide insert. (Used)

Keith Cress
kcress -

http://www.flaminsystems.com