I'm having some trouble with my SV evo I picked up, I'm letting it warm up for 15 seconds and then drawing extremely slow for 15 seconds and I'm not producing any visible vapor. I'm getting a very strong ABV taste but the buds are still green!
Try doing three, distinct, steps. Don't cheat. Try it, you can modify, use as is, or abandon it for other ideas later.
First off, with the bowl empty and the batteries charged, fire it off and watch the core through the holes in the bottom of the bowl. Notice how as it comes up to final temperature more and more of the stuff in the core starts to glow? That energy being given off is mostly caught again by something else in the core which gets that bit hotter still, making it glow brighter. Eventually you reach a stable condition where the additional power is going to more losses to the outside world, the core itself is as hot as it's able to get, stored energy is at maximum. We need to reach this state every time. Try it a few times. It is shorter if it's hot already, but it gets longer as the charge in the battery gets run down. Since you can't see it, you'll need to go based on time and a bit of 'feel' from experience to know when you're there. When learning you can also get a clue by holding the cold unit in your fingers as it heats, this is, of course, useless on reheats.
So much for step 1. Step two is indeed a steady draw but not "drawing extremely slow for 15 seconds". Rather we need a much
faster draw if we're going to transfer heat up faster than it drains away. "Medium fast" is the call, a rate that will completely fill your lungs in that 15 seconds. Maybe even a bit faster if the air you draw feels too cool. It has to be warm, nearly hot, before vapor can happen. You learn to pick up on that too and modify technique, but for now shoot for full lungs in 15 seconds. As it warms up,
taste the hot air. You'll learn to sense vapor. When you do (or are just too curious to keep going), do a test puff. Tim's invention. Like the name implies puff the bit in your mouth out and go right back to pulling hot air through....it's a convection vape and you're the convection and convectee both. When the test puff comes up positive, solidly positive (or draw a bit more) you've done step 2, go immediately to step 3. If you don't get a good test puff by the end of your lung capacity, dump the air and keep going a second time, 30 seconds or so total. If you don't get it by the end of the second lung full, abort and go back to step one to replace the heat in the core and try again.
Step 3 is the hit you get when you finally get steps 1 and 2 sorted out. Half a minute into the cycle? Once you get a solid test puff, immediately dump the wimpy hit in your lungs and hit it like you really mean it. The bowl will be up to the magic temperature, the core should still have plenty of heat stored to support heating the air you're about to pull in, that heat goes directly to vapor production since all other losses 'are covered' at this point. This is the state you're looking for but you need to do steps 1 and 2 right for that to happen.
A key insight is the heater doesn't produce enough heat to support a big hit by brute force, it can't with such modest power levels. Energy has to be stored before hand and used wisely so there will be enough left to power the hit. Another insight is the core itself. I uses Infrared Radiation to transfer the heat, not the air hitting a hot surface. It's the glow that does the work. The core is designed so air flow through it is turbulent so the average molecule is 'in the hot zone' a nearly average time. This gives uniform heat. This means there's a 'sweet spot' to step 2 you eventually learn to find without thinking about it. Also important is a botched attempt (or one that just ran slow...) may take too much stored heat to recover from you should abort and try again.
All along it's eating battery, but while you're learning the system don't sweat that, keep swapping in fresh batteries when they get even a little weak. Later on you learn how to 'read' their condition and economize on power. It happens naturally, really. The key is to get useful results to start with.
Anyway, that's the story. If it's up to snuff (and they basically all are) it comes down to technique. 3 steps seems to work well for most guys to get them going.
Good luck.
OF
