doc4som said:
So..... after reading all these dissertations... can someone give an electrically -challenged individual a "grounding for dummies" version of what to actually do with a plastic and/or metallic DustDeputy connected to a Festool vac? Diagrams , pictures, part lists would be welcomed.
Unless you have some pretty sophisticated testing equipment, you can't know the exact path the static charge is taking from tool to ground. There seems to be a reasonable possibility that some of the failed boards in CT vacs was caused by static charge buildup arcing through the board. If you want to take all the precautionary measures you can to prevent this from happening, you need to think along the lines of those who work with PC boards. They typically work on anti-static floor mats and wear anti-static wrist straps. Using this in the tool shop would help dissipate the static buildup near the tool and not allow the operator to act as a capacitor (something that holds an electrical charge).
If you have anti-static hoses from the tool to the DD and from the DD to the vac, you're off to a good start. This is what Oneida says is included with the Ultimate DD:
Kit Includes:
- Industrial Static Dissipative, 9 Gallon (34L) container
- Dust Bagger, plastic bag hold-down system. No messy dumping - allows easy removal of dust in plastic bags.
- Static dissipating cyclone separator
- 6 feet of static dissipating hose with static dissipating cuffs
Although they say the cyclone is static dissipating, they include metallic tape and instructions that tell you to create a path from port to port and to one of the metal bolts that secures the cyclone to the collection bin.
You can see the ground tail coming off the bolt at the base of the cone.
So maybe the cyclone isn't all that static dissipating. And that may also be true of the hose that comes with it.
You can use copper tape to do the same thing as in the photo above. Then make a ground wire with something like an alligator clip on one end and a fork or ring terminal on the other end. The third from left is a fork terminal, the fourth is a ring terminal:
The ring or fork will attach to the bolt at the base of the cyclone (as in the pic above). The alligator clip should be attached to a known ground.
Now you should be dissipating static charges created from the tool to the cyclone and, to some extent, from the hose going to the vacuum. That should reduce a substantial portion of the static created.
Caveats -
1. Festool does not recommend third party accessories in between their tools and their vacs. My guess is they only test their products with their accessories. And they feel comfortable enough to warranty their tools as they do when used in conjunction with their accessories.
2. Static charges that are allowed to build up will eventually arc across the first thing they see as a path to ground. My OHM meter registers zero when tested across a Festool anti-static hose. But my meter only pushes 9 volts. Rubbing your feet across the carpet can create 10,000 volts. I do not know the inner workings of the CT or how, or if, an anti-static hose works to protect the vac's circuitry. Maybe that wasn't even a thought when they designed it. According to their website:
Festool's Antistatic hose design helps you work cleaner by preventing dust from accumulating on the exterior of the hose. It helps you work more safely by preventing static discharge or shocks. And you'll work more efficiently with a system that prevents clogging due to particulate buildup inside the hose.
They don't specifically say the hose protects your tools. But some have said after adding the DD, they started getting shocks at the tool. So you know the discharge path is being interrupted by the DD.
The DD does work great. But when you have to empty it, it can be a dusty mess. I got mine to keep my $35 "HEPA" shop vac filter from clogging and losing suction. It works for that purpose but I seem to lose some of the suction through the DD. So who wins? But when it comes to the CT vac, bags cost $7@. They can last a long time if you're sanding. If you're planing or routing, you could probably do well with the LongLife bag, which costs about the same as the UDD and doesn't void the warranty. So with all that, is the UDD really the best choice for Festool dust collectors?