Controlling Static Buildup
By Larry Thoman
This column will consist of questions that have been asked of the staff at Newgy or our replies to questions posed on the table tennis newsgroup, rec.sport.table-tennis. This month's question was asked in an e-mail by Les Jones. We encourage readers to send in your own questions. You may email us at email@example.com or fax or write us. All questions cannot be answered, but we will pick out one of them to answer in this column.
In using the Robo 2040, the static charge (in dry Arizona) builds to such extremes that the balls will 'stick' to the ramps and not roll back into the pick-up well. They actually repel each other and station themselves neatly in rows on the ramp and refuse to roll.
Have your engineers thought up a way to drain this charge? Where would be the best place to try to do so--on the return trays, at the discharge opening, or ???
I'm sure I'm not the first with this problem, so I am hoping you can give me some hints on how to stop this problem. It really ruins an otherwise really good practice session. I would be willing to experiment under your suggestions, but , of course, don't want to void my warranty.
Thanks for any insight you can provide.
Yes, I have seen that problem, although here in normally humid Tennessee, we only see this problem occasionally during the drier Winter months. There are actually several things you can do to reduce or eliminate static electricity on the balls and robot. Try one or more of these:
1. Order the Tray Liners from Newgy. These are soft rubber liners that cushion ball impact and will not by themselves carry a static charge. These will reduce, but not eliminate the effects of static electricity on the balls.
2. Place a humidifier next to your robot. Inexpensive ones can be found at Wal-Mart and other department stores for $20 to $40. Sufficient humidity will prevent static electricity. If these inexpensive units won't work, you may need to get a more heavy duty unit that can put more moisture in the air. Of course, the downside of humidifiers is that you have to replace the wick on occasion and you have to keep the unit filled with water unless you can find a unit that connects into your water supply (usually much more expensive).
3. Use an anti-static spray. The kind we use here at Newgy is "Static Guard". This can be found at Wal-Mart as well. Spray this over bare plastic trays and center trough and the balls. Only use this occasionally because you don't want the residue to build up on the balls and robot parts. This would not be something you would want to use every time you practice.
4. If you're mechanically handy, you could attach a grounding strap to the bottom of the right tray and then attach the other end to a ground. You could start by finding a wide (the wider the better) copper strap. Attach this to the bottom of the right tray with duct tape or some other strong tape. You want as much surface to surface contact as you can get between the tray and the strap. Make sure the strap is secured tightly to the bottom of the tray. Leave several inches of strap not covered by tape.
Now you need to attach the copper strap to an electric ground or common ground. You will need a long copper wire to go from the strap to your grounding point and also a way to secure the strap to this wire. The best way would be to solder the two together but you might get away with using thin copper wire to wrap the strap tightly to the ground wire. Another more elegant connection, and one that would be much handier if you take your robot off the table very often, is a some type of pin and plug connection. That way, you could easily disconnect the robot from the ground when you're ready to take it off the table. If you are not sure what a suitable ground is, contact a licensed electrician for installation.
Your robot will now be grounded and all static electricity will be dissipated. If balls in the left tray exhibit effects of static electricity, you may need to extend the strap to the left tray as well.
I hope one of more of these solutions will work for you. Good luck and happy ponging!
- Jena Newgarden