Thank you. I've tried everything (and I'm on my second negative contact). I'll be sending it in for service this week. I believe something is wrong with mine, but mechs are so simple it's hard to determine what it could be. Has anyone tested voltage drop? My workhorse is firing noticeably weaker than my other copper/SS mods. Is it fair to compare palladium coated contacts with copper and brass?
Palladium plated brass contacts would have the same or less voltage drop then copper or brass, see our Rhodium/Palladium Sticky above for why. If it's firing weaker, it's probably not the contacts (unless they just simply aren't making good contact for some reason such as damaged, misaligned, not tightened etc).
With a few rare exceptions (like the GGTS), most all mechanical negative ground bottom button mods use the same basic switch design we pioneered over 5 years ago now, where the button (usually with a replaceable contact of some sort screwed in it), makes direct contact with the battery negative end to complete the circuit.
The returning negative current on all of these mods completes the ground when it touches the negative end of the battery via two electrical paths (so called "dual" grounding):
(1) through friction between the button and the walls of the supporting cylinder/bore it slides up and down in when depressed (Where the name "Mechanical" mod originates from, they operate by metal to metal contact, no wires) and
( 2) through the spring which contacts the body and the button simultaneously. The exception to this is when the spring is replaced with magnets, it then becomes a single ground, via friction only.
If you are having weak performance, it is 9 out of 10 times due to oxidation interfering with the electrical path. Stainless steel oxidizes too, albeit it a much slower rate then raw brass or copper and is invisible.
Things to consider when "cleaning" a mod.
1. Looking clean doesn't mean its free of oxidation. Stainless oxidizes too and is invisible to the eye. There needs to be some mild abrasive to literally remove the oxidation build up, this is what we mean when we say "clean". Soap won't do it, some polishes wont do it, despite them looking all shiny afterwards(some polishes even leave a layer which further reduces contact). Try a pencil eraser on the contact surfaces or some very fine steel wool.
2. An often overlooked part is not just the button, but where the button rides up and down in the bore. The electricity passes from this bore wall to the button so clean it.
3. Clean the ends of the spring with the same abrasive as well as clean the body and switch area where the spring contacts.
4. If you have a telescoping mod, be sure to "clean" the brass compression band inside the lock ring.
5. Be sure to clean out the juice well in the positive pin area (this is an area where just soap, hot water and a toothbrush comes in handy) Juice and gunk buildup in the positive pin area can effect connection dramatically.
6. If you have a "hot button" (do a youtube/internet search and you'll see no negative ground mod is immune) and have determined there are not any shorts in the battery or atomizer, your problem may be increased resistance due to oxidation build up or the build of the coil is too low of ohm and drawing to many amps for the switch to carry. Thoroughly clean the mod and if it persists, replace the spring with an HD version if one is available for your mod or intertwine two OEM springs or an HD and OEM spring, it will increase the amp carrying limit of your switch.
