Metal drip tips are the culprit. It never even occurred to me that this was possible, but come to think of it I've never used an rda as tiny as the RM2 is.
Some metal drip tips, with an ever so slight downward pressure applied to them while inserted into the RM2, can come in contact with the top of the taller post. There is very, very little clearance going on inside the RM2 when assembled.
I've repeated the results multiple times now on an Ohm checker, with multiple metal drip tips. Wrapping your wires with the excess wire trimmed and bent facing up will only make this short even easier and likely to happen. But make no mistake, a short can occur with just the top of the taller screw.
Even with the excess wire bent and trimmed correctly, the screw down nice and firm; the height of the post and the base of your drip tip can still indeed come into contact with just a slight, slight amount of downward pressure on the drip tip.
Sort of unique circumstances for sure, but worth checking for safety while your building for the smaller RM2. I don't think this is as relevant for those who own older RM2's with equal height posts, and not so much so for those who are happy with plastics. My taller post looks like it's towering even higher than pics I've been able to look up so far on the web.
To check for this;
While the RM2 is connected to an OHM meter, screw on your cap and attach your metal drip tip. While the OHM checker is on, apply some slight downward pressure on the drip tip to make sure there isn't any wiggle room allowing for any slight contact and shorting out the device. With some drip tips it wasn't a short capable of collapsing the spring, but definitely a short lowering a 1Ω coil down to a .6Ω coil. Probably depends on the quality of the o-rings on your tip, and how and where else your tip comes in contact with the cap. (extreme ming/pawn style were the worst)
First for me... I'm out of town, and really glad I had the foresight to pack an extra spring with me.
Cheers Reonaughts,
-B
Some metal drip tips, with an ever so slight downward pressure applied to them while inserted into the RM2, can come in contact with the top of the taller post. There is very, very little clearance going on inside the RM2 when assembled.
I've repeated the results multiple times now on an Ohm checker, with multiple metal drip tips. Wrapping your wires with the excess wire trimmed and bent facing up will only make this short even easier and likely to happen. But make no mistake, a short can occur with just the top of the taller screw.
Even with the excess wire bent and trimmed correctly, the screw down nice and firm; the height of the post and the base of your drip tip can still indeed come into contact with just a slight, slight amount of downward pressure on the drip tip.
Sort of unique circumstances for sure, but worth checking for safety while your building for the smaller RM2. I don't think this is as relevant for those who own older RM2's with equal height posts, and not so much so for those who are happy with plastics. My taller post looks like it's towering even higher than pics I've been able to look up so far on the web.
To check for this;
While the RM2 is connected to an OHM meter, screw on your cap and attach your metal drip tip. While the OHM checker is on, apply some slight downward pressure on the drip tip to make sure there isn't any wiggle room allowing for any slight contact and shorting out the device. With some drip tips it wasn't a short capable of collapsing the spring, but definitely a short lowering a 1Ω coil down to a .6Ω coil. Probably depends on the quality of the o-rings on your tip, and how and where else your tip comes in contact with the cap. (extreme ming/pawn style were the worst)
First for me... I'm out of town, and really glad I had the foresight to pack an extra spring with me.
Cheers Reonaughts,
-B
