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Pneumatic automation

Waidrill

Plastic
Joined
Mar 19, 2018
Hi team,,

I’m self employed with a pneumaticly timed/automated casing hammer that i am having problems diagnosing again.

It’s a bit of a mare to even explain it, but i do have a good body of it playing up (stops in off position) and also showing he few different things that help to reset the rhythm temporarily.

I have been over the standard things like leaks and lube, but short of a full rebuild and not knowing which part fixed it, I am starting to run out of ideas and am well past the point of frustration.

The whole thing runs on a v6 powered Sulair compressor, the control box is regulated while the main feed to the hammer is just controlled via supply tap and only fluctuates a very small amount if a down hole block up occurs.

If someone fancies their odds at this or can help me to upload a video or at least a picture to show the guts of it all, then I am all ears.

There are x2 of 5 port valves in the control system and this is self timed by using a pressure chamber and some little part i don’t fully understand on the outlets of 1 valve and flow controllers on the exhaust ports, this in turn activates the second valve at the correct speed, the outlets of the second valve go on long signal hoses to control a larger 5 port valve with quick exhaust on the signal lines, this third valve has its own air feed and controls the large air supply to the cylinders.
The exhausts on the second valve simply exhaust into the vented control box.

When it stops in the off position I have, greased the large 5 port valve and installed new quick exhausts on the signal lines to it,
(This worked in the past when it has been stoping mid cycle)

This didn’t work, so I checked the on off switch was getting and amending enough air to start the cycle, i found a small split, once rectified it worked for a short while then back to the same problems.

I have tried new lines from the control box to the large valve, but went back to the originals as it made no difference.

I also added a wad of silicone grease into the inlets of the smaller valves and allowed it to cycle through, the pressure briefly changed the timing but still did it’s stopping thing,

I have a brand new valve from the last time it didn’t fix the issue and this feels the same to move manually as the ones in use.

To reset the cycle when it stops I can turn it off and back on, Or restrict the exhaust port on either small valve, (i put a reducing Bush in the one that exhausts freely, this worked for half an hour then needed more restrictions to work). I can’t permanently change the one with the flow controller as this will affect the speed too.
Or I can briefly disconnect the charged outlet and it will cycle again, this charged outlet is the same one that should be charged when the unit is off.
Or I can up the pressure going to the control box, however leaving it up doesn’t fix the cycling issue, just restarts it then it will stop again at the higher pressure after a few hits.
Or I can manually push 1 end of the second valve in control box and this works for a few hits.

I know I will have left something out here and it possibly makes bugger all sense, but a video may help. If I can get it on here.

It’s hard to hear much over the screaming Detroit diesel but i do briefly hear air bypass or extra exhaust somewhere in the control box just one click before it stops cycling.
I’m going to try hook up just the control box to a small cylinder in the workshop today to maybe hear something better but thought I’d check on here if this makes any sense to anyone then it’s a good start, and I’m happy to give more detail.

Problems when diagnosing so far,

Too much noise, burning any profit while trying to diagnose
On a work site not a workshop
Any “fix” is temporary so doesn’t point problems out,
Closest “pneumatic expert” is 2 hours away and would rather I brought a heap of parts from him and fully rebuilt, or after seeing the description above and a video, he still says check the signal hoses. “Yeah the ones I’ve already bypassed with no effect and told him about so I doubt he’s even reading it properly.”

Lastly the man who designed and built if for me 3 years ago knows it very well, however he is 12 hours away and won’t return phone calls or emails, probably because it took me longer to pay him than I would have liked because the build bill was almost twice the quote and i had no notice of this till the bill arrived and I’d been using it already. However he was paid but not as quick as I would have normally liked to.

There it is and here I am, not perfect but honest.

Any help appreciated, I’m happy to email the video to someone if it’s easier than uploading it here.

Cheers all.
 








 
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