Waterjet-Mini hopper probs...

[Watersquatch]

hello from a noob, all!

I have exhausted all other resources. I have a serious static problem in the nylon tubing that runs from the base of my mini hopper to the cutting head. Everything is grounded to the z-carriage, and from there to the main ground for the machine. The bulk feed hopper has 3 grounds on it. I have gone as far as to run a single strand of copper wire through the tube, and ground it to the machine, no dice. I have tried grounding the anti-backflow as well. Nothing is working. Ultimately, the abrasive backs up into the mini hopper, and starves the cutting head. When the abrasive is coming out of the mini hopper with no tube, there is no problem. But when I add just the 5 inch section of tube above the anti-backflow, the static builds up so bad you can see it flying back up and sticking as far as 3 inches up the outside of the tube.

Any help would be appreciated. I have talked to Barton, WardJet, JetEdge, ingersoll-rand (about possibly increasing moisture level in the air) as well as several other experienced people, and everyone is stumped. My machine is north-east of Denver, so it is very dry. I had asked Barton what the nominal humidity level is for effective delivery of 80 HPX garnet, but did not receive a response. I think that would be a last resort.

Sorry for the long post, but it's the first so I should make it a good one.

Regards,
j


WardJet Z-813 Dual head
JetEdge 55-100B 100hp dual intensifier

[laka]

I've experienced the exact same thing lately. We ran out of the stock tubing on our Omax, and all I could find in the mean time was some nylon. Every 5-10 minutes I kept hearing a large *crack* and then I finally saw a huge spark come off of the tubing. Anyway - the stock tubing is from Saint Gobain called Tygon I can't remember the exact model #, but I'll try to take a look tomorrow. You should get rid of the nylon and you wont have any more issues.

[waterjet expert]

I see you own a WardJet Z-813 Dual head waterjet. Sounds like you should give WARDJet another call - they should be able to help you out.

They build custom waterjets and sell mini-hoppers -- I've only heard good things about their tech support.

[laka]

I checked our tubing, and it is Tygon polyeurethane tubing.

[Watersquatch]

Thank you! I will definitely try the poly tubing. I have been working closely with Ward Jet, and we have been trying to come up with a solution. We are going to try switching to an alluvial abrasive from crushed, as that seems to have helped others in my area. I am also going to thoroughly inspect all of my elec. grounds.

Thanks again for the help, and I will post the final corrective action taken.

Regards,
j

[laka]

Just curious if the nylon tubing came stock with the machine or not?

Ours started the sparking immediately when we switched to the nylon. And once we switched back everything was good. We use Barton 80HPA garnet.

[Watersquatch]

The nylon tubing did come stock, and still does. I currently use Barton 80HPX abrasive.

[M Ferreira]

Hello,

I think you have to try the poly tube, we use this kind in all machines that we sold and we have no problem.

Good luck

Marcelo

[tpankratz]

I was just curious if you ever found a solution to your problem? We have a Wardjet machine also and the abrasive tube is constantly plugging up. I never thought of the static electricity causing it.

[laka]

Use Tygon tubing and you will be good to go. The nylon stuff is not good with the static. Our waterjet tech told me there are massive amounts of static that build up in waterjets. A good machine will have grounding cables all over to get rid of the static.