+1, I have to agree. The only way to adjust the power of the vape on a mech is by coil building to suit the available battery voltage. They are not well suited for pre-made coil tanks. Moreover, the QC on coil heads leaves a bit to be desired, which (in addition to the iniquitously expensive cost) is why I have been rolling my own for years; and the former reason is why they are unsafe on a mechanical mod. Further, I also agree mechs are not for beginners, or even long-time vapers who do not understand the interplay of the various factors in Ohm's Law. Mechs can be used safely; I have been doing it for years. But it really is a good idea to do some reading first, and measuring your coil value before firing is an absolute requirement.
All that said, The HCigar Hammer clones-- and all the rest, AFAIK-- use a cheesy spring as the contact between the two buttons under the 510 connector. One button faces up, to contact the atomizer, and the other faces down to contact the (usually brass) sleeve surrounding the battery and carrying the current to the inward-end of the battery. This spring actually carries the mod current; there is no other means of contact between the two buttons.
Three gets five, if the battery is charged and the topper making good contact, that spring is south. You can try taking the piece apart-- the engraved ring surrounding the 510 unscrews and the buttons and spring will cheerfully fly across the room if you're not careful. You can try polishing the ends of the spring and the inner cups of the buttons to make them better contact, see if that helps. AFAIK, there is no place to buy a replacement spring, although I have heard, but never tried, the replacement switch spring for a King V2 mech will fit and work. You could also try to spec the spring and buy something similar from a spring supplier. However, at the price of a new clone Hammer-- you can find them under $20 on eBay-- and considering the price of getting a single spring from a supplier, you might be better off getting a new one.
Go ahead, if you like: ask me how I know all this...
