The HighLighter (Glass-Core Open-Source Halogen Log) Kit Hosted by REFC Labs

[3l3tric]

Today I'm playing around with controlling the Highlighter with a PID. It simply turns it on and off to maintain the temperature... not the best for bulb life, but it does seem to work. My aim is to have it crank a bit harder when in use to eliminate the refractory period between back-to-back baskets. I'll let y'all know how it goes...

I'm curious if there's a thermocouple/thermistor that can be placed within the beads for a more responsive reading. I'd found this amphenol glass-encased thermistor that looked somewhat promising, but I'm not 100% certain about the safety of putting dumet wire (copper coated nickel IIRC) in the vapor path, and the maximum operating temp is 300C, pretty close to the highest temps you'd see in the barrel already. One idea I had was using a dremel to grind two shallow grooves in the ground glass joint and put the thermistor leads there, mounting the thermistor right above the proforma screen so it would only be measuring airflow, although you'd have to make your PID controller figure out when you're taking a draw and when you aren't, since there would be drastic differences in readings between when there's air flowing over it and when there isn't.

Also, regarding the method of temp controlling: I did some research awhile back, and I think a better solution for bulb health would be to build a VVPS that could be controlled by an arduino or other PID capable microcontroller. Integrated circuits like the LM338K use a potentiometer (variable resistor) for their voltage control, and digital potentiometers are available for arduinos that could allow for .1V stepping (or likely even finer steps). This way you could keep the bulb always on but have fine-tuned control over exactly how much heat the core would be generating.

One nice thing is these two problems can be solved independently, so you don't have to figure out a solution for the temp-monitoring issue before proceeding with working out the arduino VVPS (far easier IMO). Once I get one of these myself I'll probably go right into making the arduino controlled VVPS for it sans PID functionality, which will still provide some nice features like being able to implement voltage boost profiles. Then later down the line, I can work on installing a thermistor and PID code for actual temp control.

Materials safety is a pain, though, and I'm thinking it's gonna be pretty hard to find a responsive thermometer that'll be fully safe in the vapor path. One possible idea I had was a "passive TC coil", where you'd put a coil of SS wire into the core outside the beads, and measure with an ohmmeter to calculate the temp (similar to how TC ecig mods work). The main problems here are I'm not sure how responsive this method would be (if it takes 20 seconds after a change to yield accurate temps, kinda not worth it) and you'd only be getting an average of temps across the whole heating tube, not measuring the air temp at the end which would be more accurate/responsive to what your bowl temps should be. Regarding thermistors, it also looks like the majority top out their operating temp at 300 degF, which makes measuring right beside the bulb way more iffy. Maybe there'll be some miracle thermocouple someone finds one day with a 400 deg operating temp, glass encased, with leads made from a vapor safe material.

 

[KeroZen]

Thermocouple Types | Watlow

Click to learn about the various types of thermocouples (B, C, E, J, K, N, R, S, T) including uses cases, pros, and cons of each.

www.watlow.com

 

[3l3tric]

Thermocouple Types | Watlow

Click to learn about the various types of thermocouples (B, C, E, J, K, N, R, S, T) including uses cases, pros, and cons of each.

www.watlow.com

Among these, only E, J, and K would be relevant to this use case, since every other type's useful range lies outside our vaping temperatures. (T technically works as well, but is more intended for cryogenic purposes anyway) However, the link you provided omits an important detail, which is the type of metal used for the actual thermocouple. Each type also identifies which combination of metals makes up the sensor itself, as seen here.
As we can see, type E and K both contain Chromium, which isn't a desirable metal at all for the vapor path, while type J contains a copper/nickel alloy in one lead (not super researched but IIRC nickel isn't an ideal vapor path metal either). This doesn't completely discount thermocouples though, only bare lead ones, as a fair number of thermocouples also come in shielded packages intended to protect them from harsh environments (but in our case, protecting our vapor from harsh metals).

Now, this is one example of a maybe-suitable K thermocouple. Designed for temps above 100degC, usable up to 500degC, the tip encased in stainless steel. The only real questionable element (for me at least) is the cable shielding, made of fiberglass. It sounds like the fiberglass is included in the "good up to 500C" guarantee, but fiberglass is a big no no to breathe so I'd hate to even chance some of it accidentally dislodging and getting into the vapor.

That's the big issue I've seen with a ton of thermistors/thermocouples in a nutshell, the leads. Either heatshrink is used right behind the shielded sensor, or the leads are bare and made of an undesirable metal, or I just can't find any information on the leads. I really wish the thermistor types also specified what material the leads were covered with, since as far as I can tell virtually all of them aren't suitable. That's one thing that attracted me to the thermistor I linked in my previous post, since its leads do have a copper coating and copper is maybe suitable for the vapor path? But a big issue specifically with thermistors is the lead length too, most have short enough leads that you'd be hard pressed just spanning the distance between the bulb and the ceramic socket, much less connecting to measuring equipment. You'd definitely have to use some kind of stainless steel crimp/copper wiring solution or something similar to extend the leads further on.

Note that all of this is just my personal thoughts after looking around at the products available (and this was awhile back that I researched all of this), so there may be some misunderstandings or products I just haven't seen. But thus far, I haven't seen any protected thermocouple with suitable shielding to stick inside the vapor path. I'm absolutely open to someone coming by to let me know of a product/fact I overlooked. For all I know, maybe the fiberglass braid is completely fine which would make that adafruit one linked above pretty ideal for testing. I'm mainly just speculating that it wouldn't be ok, but maybe someone more familiar with the material could give more insight.

TL;DR Thermocouple types don't tell you what the wiring will be covered with, which can typically be a problematic material for the vapor path. You also just can't use a bare thermocouple due to material hazard, it has to be a shielded one, which also tend to be less reactive to change by design. It seems extremely difficult to find a thermocouple/thermistor that would be suitable for the vapor path while providing accurate, responsive measurements, in part due to inconsistent/a lack of proper documentation of many products available online.

 

[Cheebsy]

Just a thought @3l3tric , Ask taffee what kind of thermistor they use in the bowle

 

[badbee]

Everyone draws their own line on material safety but you might be overthinking it. The heavy metals in a thermistor are trapped inside the glass bead and aren't getting out unless you grind it into dust. The leads are significantly less of a concern. There is also a matter of scale, a bowl made out of a bad material would weigh several grams and have multiple square centimeters of exposed surface that could leach. The hair thin leads on a thermistor weigh maybe a couple of milligrams with a surface area measured in square millimeters. You would have to use that thing for a thousand years to get the same contamination level.

Personally I think you get more heavy metal exposure every time you ride in a car.

I would love to see you get this going with an mcu. I've played around some with arduino's and thermistors and getting stable and properly compensated readings from them can be a challenge.

 

[KeroZen]

No worries with Chromium in these temperature ranges. Many vapes have nichrome or stainless steel heating elements and Chromium is part of their alloys. As long as it doesn't glow it's deemed safe. You get daily Chromium intake when using stainless steel kitchenware anyway. There's been some minimal scaremongering online about hexavalent Chromium, but this oxide should not be produced under normal operating conditions.

In all commercial vapes which have been gutted open collectively by our community, even old school conduction ones like the Arizer Solo, there are temperature sensors in use, so it's perfectly possible to make it work. And many have the leads sleeved with silicone tubing. I bloody hate silicone tho, and for a convection vape it's a bit different indeed as the temperatures seen are higher than for conduction ovens.

I agree with you that fiberglass is probably terrible. There are issues with bare leads thermocouples though as you want the heat applied to the tip and not to the leads themselves to get correct readings, so your best bet would be to have just a pinpoint hole with just the thermocouple (or thermistor) head exposed, then use any kind of insulation to prevent the leads from touching but outside of the air/vapor path. But puncturing the glass is not really trivial unless you make provisions for the hole while the piece is blown.

 

[mistergyro]

how do i go about getting on the waiting list for one of these?

 

[androponic]

how do i go about getting on the waiting list for one of these?

go to https://refc-labs.com/ and scroll down to the bottom, sign up for the newsletter. red sends out notifications when he is dropping kits. they sell out within the hour so move fairly quickly. limit is one per customer until demand slows. good luck!

 

[3l3tric]

Just a thought @3l3tric , Ask taffee what kind of thermistor they use in the bowle

I haven't looked too in-depth into the bowle, where is the thermistor located in there? In a lot of vape designs I've seen, the sensor is either embedded within the heating element somehow, or is held outside the vapor path (like on the outside of the chamber).

@badbee and @KeroZen : thanks for your info on materials, I hadn't thought much about both the scale and the fact that chromium has seen use in other alloys. It's seeming like the bigger issue with thermocouples is the lead coating and how to get just the sensor in the vapor path for accurate readings.

I wonder if it's possible at all to custom order one of the heating tubes with a hole in the side? Not really sure about the problems that could arise with glassblowing that, but that may end up being the best bet to bring temp control to the table. A lot of designs with the temp sensor embedded in the heating element itself have issues with chain hitting, since you can have a situation where the continued draws cool down the airway considerably without the heating element increasing output enough to compensate properly. The thermometer "reaches temperature" and the heating element throttles well before the airway has actually properly recovered in temperature. But now that we're seeing just how difficult it'd be to add a thermistor/thermocouple to the vapor path directly, it's easy to see why a lot of engineers have been ok with this flaw in their devices so far, lol.

 

[SixStringToker]

I haven't looked too in-depth into the bowle, where is the thermistor located in there?

It's directly in the airpath, just above the screen in the main body. When the pot is inserted, the sensor ends up immediately above the herb.

 

[3l3tric]

It's directly in the airpath, just above the screen in the main body. When the pot is inserted, the sensor ends up immediately above the herb.

Very interesting, I guess I'll have to shoot them an email to see what exact part it is

 

[Pukka]

Maybe this would work to make the hole you need

 

[virtualpurple]

Did something happen to the email list?

I used to get emails about drops (although it seemed like they were sold out within minutes), but it has now been a few months and I haven’t received anything at all.

I want to keep trying, I really do.

 

[4everpushingaboulder]

I haven’t seen a new drop in a few weeks. I know last message Red said he was working on some new suppliers to eliminate some of the delay in drops….hoping he’s successful!

 

[Abysmal Vapor]

@Improvaper From experience the PID with a Halogen heater blinks a lot,probably not so annoying with dimmed glass,but yeah not great for the bulb life. I would rather have a Temp read without it being PID controlled,but that is personal preference. Anyway if you are going to keep the probe on the outside. I suggest using a K-type like this one.https://www.sweetmarias.com/k-type-thermocouple.html Very little lag compared to the shielded ones ). Maybe put a strip of SS or Copper foil above it so it can get fixed to the glass and get better reading.

 

[kimura]

It's taken me a while to comment in here, mostly because I wanted time to get this thing set up and dialed so I could provide fair and honest feedback. first of all big ups to @RedEyeFlightControl for putting the parts list out there. unheard of in the industry and hugely appreciated.

assembly for me was a little trickier than I expected, and I'm pretty handy. I guess it came down to seating the o-rings properly so that I felt there was enough tension to hold everything in place. in the end, I'm not really comfortable with putting any kind of pressure on the wires going to the bulb, since it can be pulled out. it will hold itself in just fine for normal usage, but if you give it a decent tug it will pop out. I know I'd eventually pull it out by accident when everything was hot, so this sorta let me to a wooden housing from @Ed's TnT , which BTW is very nice. but I still don't have a solution for holding the DC barrel plug in place inside of the wooden housing. currently resisting the urge to use glue. any suggestions?

onto the good part - this device absolutely performs as advertised. there's a lot of power here, enough potential to keep up with a very fast draw, if you turn it up. flavor is excellent at lower voltage, and you can really crush these little basket loads. I was able to zap a micro load in a single hit by accident. went back for the second hit and there was nothing left! the smaller basket size sets it apart from my other desktops, but it really hits just as hard. I love the log form factor. IDK, I have/had some fairly top tier desktops and this thing is right up there. still cheaper than most even with Ed's wooden housing. I'm getting great clouds and flavor all the way down around 4.5v, turning it up to about 5.5v to finish. seems to appreciate a decent heat soak. subjectively speaking, the vape signature is on the heavy side. chalk it up to some lovely radiant heat working in harmony with convection. nice to have another halogen vape, and this is my favorite one yet.

to sum up, pretty great. awesome work and thank you @RedEyeFlightControl. this is old school FC shit right here

 

[RedEyeFlightControl]

Did something happen to the email list?

I used to get emails about drops (although it seemed like they were sold out within minutes), but it has now been a few months and I haven’t received anything at all.

I want to keep trying, I really do.

It's been some weeks since I've been able to do a drop, but I'm preparing another currently. TBQH I deal with some sporadic long-term health issues which can, and have been, holding me up for a bit - but I am back in action and want to start launching more kits. I appreciate everyone's understanding - big thanks to those who kindly checked in while I was out of comish <3. These things happen sometimes when you are a full stack shop of one. In that time, I've been able to source and stock a few more items!

Yes, I've also been working on acquiring some new suppliers that should help reduce some operational overheard and let me get kits out quicker. I've also got some new parts stocked - Pulsar worked catches, restock of the 17" pulsar Gridline rig including a new color (yellow!), new Pulsar 2-tone catches, and... now stocking 14mm to 18mm HLT basket WPA's ! (finally, right?)

I've also begun stocking Scrubber Duckys 4.0 glassware cleaning kits as well. These are really cool! They are washable and reusable felt-coated magnets that let you scrub your glassware from the outside in!


Those who have signed up for the email, keep your eyes peeled

It's taken me a while to comment in here, mostly because I wanted time to get this thing set up and dialed so I could provide fair and honest feedback. first of all big ups to @RedEyeFlightControl for putting the parts list out there. unheard of in the industry and hugely appreciated.

assembly for me was a little trickier than I expected, and I'm pretty handy. I guess it came down to seating the o-rings properly so that I felt there was enough tension to hold everything in place. in the end, I'm not really comfortable with putting any kind of pressure on the wires going to the bulb, since it can be pulled out. it will hold itself in just fine for normal usage, but if you give it a decent tug it will pop out. I know I'd eventually pull it out by accident when everything was hot, so this sorta let me to a wooden housing from @Ed's TnT , which BTW is very nice. but I still don't have a solution for holding the DC barrel plug in place inside of the wooden housing. currently resisting the urge to use glue. any suggestions?

onto the good part - this device absolutely performs as advertised. there's a lot of power here, enough potential to keep up with a very fast draw, if you turn it up. flavor is excellent at lower voltage, and you can really crush these little basket loads. I was able to zap a micro load in a single hit by accident. went back for the second hit and there was nothing left! the smaller basket size sets it apart from my other desktops, but it really hits just as hard. I love the log form factor. IDK, I have/had some fairly top tier desktops and this thing is right up there. still cheaper than most even with Ed's wooden housing. I'm getting great clouds and flavor all the way down around 4.5v, turning it up to about 5.5v to finish. seems to appreciate a decent heat soak. subjectively speaking, the vape signature is on the heavy side. chalk it up to some lovely radiant heat working in harmony with convection. nice to have another halogen vape, and this is my favorite one yet.

to sum up, pretty great. awesome work and thank you @RedEyeFlightControl. this is old school FC shit right here

Thank you for the kind words! Swappable heat shields are still a fairly new concept, so I'm sure we'll see better forms and designs down the road. The official heat shield spec calls for o-rings to bush the core into the center of the shield with recesses, much like the glass on a wood oven. Though this isn't necessary, it does make for a SOLID log. I dropped mine from my desk onto a concrete floor, on. It bounced a little, but was just fine.

If you are using a handle or heat shield, you can secure the wiring to the assembly. Otherwise yes, you'll want to be careful of pulling on the wires. This is the trade-off of using a tool-less, friction-fit design.

 

[kimura]

looks like the HLT will probably also work with the miniVAP flexicone+basket. I'll give it a shot tonight

edit: yep, works great. give it a try if you've got em

 

[thunderstealer1337]

I did it, sold my vapbong, I've only used it once since picking up the highlighter in past few months.

Tbh my rotations have stopped daily now, this thing is just a beast of a extractor,I still use my dynavaps and p80 but only when the highlighter is warming up

 

[kimura]

wow the flexicone is definitely my new/current favorite way to use the highlighter. Flexicone basket module installed in a j hook. Highlighter pointing up, flip the j hook upside down, come in for the landing, take a rip, lift off and set it down. Vapman station vibes, sorta. Same way I used to hit the Helios direct draw. Just Beautiful

 

[masonjars]

wow the flexicone is definitely my new/current favorite way to use the highlighter. Flexicone basket module installed in a j hook. Highlighter pointing up, flip the j hook upside down, come in for the landing, take a rip, lift off and set it down. Vapman station vibes, sorta. Same way I used to hit the Helios direct draw. Just Beautiful

Does the flexicone seal well with the HLT when you're taking a hit?

 

[kimura]

Does the flexicone seal well with the HLT when you're taking a hit?

Seals just about perfectly with light pressure.

 

[masonjars]

Seals just about perfectly with light pressure.

Sounds like a similar experience when I use the HLT on the lotus bowl (with o-ring for seal)! I think I still prefer the baskets for my everyday/go-to, but every once in a while I like to overfill a lotus bowl and go to town at some lower temps

 

[kimura]

Cool! I’ll give that a try too

 

[RedEyeFlightControl]

HLT drop, 20 kits @ noon Sunday Oct 24 Eastern (NY) Time