The variable output has been discussed before. Most of us are connected to a grid that is effected by the amount of power being sucked at any point in the day. The less users = more power output. A lot of people find that the output is less in the day (peak periods) and noticeably hotter in the small hours.
Also, as has been discussed, not all Zaps run at the same temp - especially if the resistor isn't hitting around the 20 ohm mark. The wood type and shape will affect the performance. Have you tried using a coozy/sock to squeeze out a bit more temp. Try it with a couple of socks - it might just give you the edge you need to get the vapor you want.
And herb dryness is a MUST! Let it sit out overnight uncovered and see if you get better results tomorrow.
Happy experimenting
I noticed this post yesterday already, but I was to high to type up a proper response at the time
Some of us have the same experience in the UD thread though, so I figured I'd chime in.
Technically this shouldn't be possible I believe. If you use a regulated PSU it should always put out the same current, as long as the input is between the specs (lets say between 110 and 240V, which are common values).
Now I'm no expert and just repeating what I was told (feel free to chime in here if you read this Hazy), but if this is correct we should look at other causes for these warmer and colder running logs me thinks.
Is it possible that people who experience this (I'm one of them) don't leave their logs on 24/7 (I don't), and that we just experience our vapes as a little hotter because it has finally fully warmed up after hours of heating by that little 5W element?
I can tell my UD performs better after it has been on for 4 or 5 hours or so. That's how long it takes for mine to feel nice and hot (not warm) to the touch on the outside as well. It'll produce nice clouds after ten minutes of heat up, but it takes hours of heat up before I can extract everything out of my bud and create the dark brown ABV I want. The difference may be small, but it's definitely there.
Perhaps I should add I have a particularity cold log with a resistance of almost 23,5ohm, but I run it on 14,3V to compensate for that. Oh, and I can turn that down to 13,8V after 4 or 5 hours or so. If I don't my pup will get really hot to the touch on the outside and I blaze through my bowls like a mf.