BaKx (heating principle) inspired desktop vape

[CaleidosCope]

I tried another stem. 8.5mm OD. It takes way longer to produce vape in my 14mm chamber. Taste ist not comparable; of course with many draws at rising temps I get many terpene profiles. 10 draws +.
My 13mm stem gives 3 to 5 good tokes with less restriction.

With those high temps I use the vapor "feels" different in my lungs compared to any ball vapes I used. AND: I don't need to cough a lot. I reminds me to combusting. I left the 220°C-230°C range because of coughing. As I was combusting I didn't care about temps anyway. And coughing was no big deal - thanks tobacco.

EDIT: And because I just looked at it... It really reminds me a lot of smoking a joint because if I inhale very slowly or very quickly, the situation changes significantly. You can feel it and taste. Maybe someone with an unregulated vape (Nomad, Toad...) can tell us something about this topic.

The conclusion from the test is that there are many conditions involved here. First of all, it's not just about the heat in the oven - that's not enough. There are also many other important components. Among other things, how much distance do I have between the heating chamber and the mouthpiece? Also, how thick is the wall thickness of the glass. How fast do I draw. How big is my herb chamber. Then how deep do I put my mouthpiece into the heating chamber... The smaller the system, the greater the effect of the smallest change. It's really fun.

EDIT: Somehow it reminds me of that mini steam engine that CEOs must have on their desk and screw around with

https://imgur.com/a/FFNr1SM

 

[highvaper]

how much distance do I have between the heating chamber and the mouthpiece

I think this affects the taste so much - as it cools past a certain point the taste drops off maybe i need to trim the 10mm ID one down and test it more but not sure my jars can take it as when full is about 0.5g

I know what you mean about the different temp feel and the joint like experience - when i finally stopped combustion it was due to me moving to a dynavap (i did have a volcano for years) - just wish i had this to move to instead as its the closest thing so far to a joint for me.

I have been doing a bit of messing with the PID tuning and have come to the conclusion that the D part is probably not that helpful and seems to just fight with the P & I - from research D is more useful for slower processes where its more important not to overshoot the setpoint.

Also trying to tune it for normal heating up AND to a heavy inhale isnt really doable as they are two completely different situations like swimming in a still lake compared to a fast river. For the 6mm & 8mm ID stems it does a pretty good job but with the 10mm the temp drop in the tube can be over 20C and if you keep inhaling the PID will overshoot trying to compensate when you stop inhaling. Maybe for the 10mm stem i need more thermal mass like some glass beads around the stem but would need to move to the 24mm or 30mm tube to fit them in.

The setup is very tunable - but you can get very consistent vapes - but you do need keep to the grind constant and how hard you pack the stem is very important as these affect things a lot as well.

I have found using a stanley knife blade to finely chop bits from bud and then manually poking them into the stem produces a nice draw and vape with the 6mm stem - with the 8mm one being able taking a bit harder tamp before the draw is too tight.

 

[CaleidosCope]

from research D is more useful for slower processes

from my research the simpelst explanation is: D predicts the future in seconds. "What would that temp be from my information now in 3 seconds?"
I use it after I tuned the P and the I.

Meanwhile my wired 25mm long heater got a "don't burn your fingers"-housing and a wrap with a 0.3mm Titanium-foil for more stable temps (but it is still dancing in a 15°C range up and down). More tuning is required. Now it looks a little well-behaved. Before it was type of "dangerous - this guy knows what to do!" ... you can't have it all. - housing improvement to come - the repairability right now is like with Apple products. Glue everywhere.

Terpy dreams.

https://imgur.com/a/FDZHm5Y

 

[highvaper]

from my research the simpelst explanation is: D predicts the future in seconds. "What would that temp be from my information now in 3 seconds?"
I use it after I tuned the P and the I.

Have a read of the below article as i found it explains D very well.

Understanding Derivative in PID Control | Control Engineering

The third factor in PID is the least understood. Derivative action can do good things, but when used improperly, it causes headaches.

www.controleng.com

Out of interest what PID controller are you using?

Your build is looking great.

 

[CaleidosCope]

... Sinotimer MT-S ( I love the white and blue digits - and hate the grey housing ) or this ...or else- exchanged the mechanical relay (the clicking sound is annoying - while "r" is 1 in my settings) and trigger a 8a-SSR with the SSR outputs.
My first build, with a Shelly1 inside... the daily driver is smaller - used a ShellyPlug as a timer/switch:
https://fuckcombustion.com/threads/ballvape-rack-iteration-evolution.53676/

To get cheapo I am thinking about avoiding plugs. Housing for the Sinotimer: 3D print. Screw all the wires to the PID. Restricted; but I don't often change the PID/Coil combination. Some controllers have a lot of free space in the housing... for the 8A-SSR and a fuse!!!

 

[highvaper]

Not really done much recently other than tuning the PID for the 3mm nichrome and 20mm tube and lots of testing - the git repo has been updated with the pin, tuning and heater settings to the top of main.py to make things simpler to setup and more in one place.

I did look at nozzle end for rockets - https://en.wikipedia.org/wiki/Rocket_engine_nozzle in relation to stems and how the air exits

Just wondering if anyone has put a nozzle at the mouth end of the stem so that the air spreads out in the mouth and cools there as it expands - or have a smaller diameter inner tube with the nozzle shape and a slightly wider one around it as the mouth piece so only a cm or two or so is wider and expands just before you breath it in

I have drilled a holes in a couple of the 18mm tubes and will see how that works out with the thermocouple inside as I have only done that with the 20mm tube and quite liked the 18mm tube feel.