VapCap DIY Induction Heating : Bits 'n' pieces

[PKOK]

Well they make some pretty tiny heatsink fans for motherboards.
https://www.amazon.com/dp/B01406OSNE/ref=psdc_11036291_t4_B072FW3DDQ

 

[TommyDee]

In industry, fans are a 50% hit on MTBF calculations, MTBF being mean time between failure. My XTAR charger can push this with convection so let's see. If I'm not mistaken, the FETs in the meter already have a heatsink so that may be sufficient.

I have an 18.5V power supply too. Come to think of it, it is 18.5V at 3.5A so that is nearly 75 watts, more than enough for the corded version of the IH directly. Marry that to the regulator and you have a power source with no cells to mess with. This power supply is the size of a a supply for small laptop computers. Inline power supplies are $10-15 all-in. Anywhere up to 90 watts could still be considered compact, plus it has all the safety reg's for the primary power source covered. Use the power supply as ballast for the regulator in clever packaging and you have just the single cord to the wand.

We need to find an innovative power indicator. I was thinking a tri-color led wired to change color depending on voltage level. This would be a readout at the wand and also a pack indicator. Unobtrusive but easily reflective of a usable range. And it will still be novel for a little while.

I keep forgetting to add, this could be done with some quality protected 18650 cells. I know it is heresy in the vaping world, but at 8 amps, this is conventional for a lot of protected vape cells. Mine are EVVA cells rated to 10 amps (8.5 amps in reality IIRC). I can't think of better protection for directly wired cells (fused). Fitting these longer cells could be challenging for cell holders since they are about 2mm longer, but they can be cut in half and stretched.

 

[PKOK]

In the vaping world we weren't adding protection or BMS boards either. Aren't you getting the best of both worlds this way? That is weird about the holders, if I remember correctly they'd jam into a single Keystone holder but is there a good enough reason? The video you showed me for a LED power indicator
well on the sidebar there were plenty of innovative designs at least a dozen. Something to put you to sleep.

 

[TommyDee]

I learned to trust the protection circuit as sufficient and robust for flashlights so they are more than good enough stand alone for cells in battery holders. Just remember to use holders that have leaf springs and not coil springs. Most industrial holders are for non-protected cells if they have limited range. In my case I will be printing the case and using the contacts from the holders I have. Very utilitarian. But you can cut the case and glue it onto a piece of metal or wood as part of the structure.

As to the meter, I am looking for a minimalist circuit. Red for the low voltage going green for mid range and blue for fresh charge. The proper transition would require a melding of the three colors rather than just on and off of each. A low voltage trigger signal would be useful too.

 

[PKOK]

You can buy the so-called leaf springs, I've got a bag of them, can't remember where. I agree even with the flashlights we paid good money for upgraded springs.
Why not use a meter? .....well I'm not sure which project we're talking about now but will your battery pack be in an enclosure?

 

[TommyDee]

I looked at Keystone Electronics for battery clips. They are more circuit board oriented which is a long term solution. The Chinese ones are very conducive to 3D printing.

I'm a minimalist at heart. A single small subdued light should be enough to tell battery condition. This is a basic circuit that can be used at many levels. One that I can use if seeing the wand is on standby and then when the VC is placed in the coil, it would represent the power level of the battery pack. This will quickly remind as to what session you are participating in. It is very true that you can drift off one a simple random thought while drawing and poof - smoke.

Didn't you have a 'compact' requirement? Of course I am defining product requirements, not DIY requirements. I think a variable color power meter would be 'different' enough to set things apart from dull offerings without needing any instructions or glasses.

 

[PKOK]

Well I wanted to have options so the enclosure I selected isn't small but not huge. 7.87 X 4.72 X 2.16
I may be able to get the second set of parallel batteries in there. Remember I did not have a battery version and I need it for back-up and travel. Having said that I've ordered many extras excluding the enclosure, so I'll be ready to play. Some stuff is arriving, I finally got some more glass the Cloupor tanks they've been hard to get.
If I do a 2nd battery version then I'll go small. This one is heavy-duty.
I'll also be all over the banger/nail heater, your a lot closer so I'll get to see proof of concept
TD what do you mean by product requirements vs diy? You going to get into it?

 

[TommyDee]

I don't do nails so that won't happened. I see a good opportunity for someone though.

You've got a good hold of your project. A meter is needed and the one you have works great since it comes with a nice panel mount bezel.
Can't wait to see your hobbying skills @PKOK . Always good to have a tank as a travel buddy. Shit happens out there!

My minimal space claim bid for a 3S 18650 IH portable one piece is now...
4-1/2" x 3-1/2" x 1-1/2" - it's a layout that makes sense now. That's about 24 cubic inches.
I don't consider that pocket-able yet. Glovebox Tough - yea, simple.
Now I can do the 2S 18650 in a 3-1/2" x 2-1/2" x 1-1/2" form-factor. That's only 13 cubic inches.
That is almost pocket-able!

Got any reference to glass I could use that has a bottom to it? Or at least a lip that stops the VC from going through it?

now here's the RV Camper Installation - it's actually a perfect size for the 3S layout looking at the specs.
https://www.wolfautomation.com/encl...mEIFHk25CoKS9wyU0g-348x4JEickV7kaAlhJEALw_wcB

And they even gave me the 3D model to print it! Sweet

 

[PKOK]

Got any reference to glass I could use that has a bottom to it? Or at least a lip that stops the VC from going through it?

Yes but comes in 9 pieces AND only 3 worked but the thick red o-rings fit fine at the lip on the bottom.
I too have never tried nails or bangers but will try assuming I don't have to use a touch.

https://www.ebay.com/itm/2-Long-9-S...284430?hash=item2cf2fddcce:g:AREAAOSwHjxdagSb

 

[TommyDee]

That might work. I also need to find a non-conductive 'jack' as a stop. That cap gets too hot for o-rings when I bake. I burn my fingers through the glass bottom of my vials. I might consider a wooden riser.

Let me know if the dimensions actually match the pictures rather than the description. The description defines some other dimension.

This is worth noting; I triggered the BMS protection tonight somehow. I had to remove all the cells to reset it. [CHK] Tested!

 

[PKOK]

That cap gets too hot for o-rings when I bake.

Dang! those thick Red ones are rated to 446°F

Let me know if the dimensions actually match the pictures rather than the description. The description defines some other dimension.

Well they should now because when I ordered the description had the OD at 16mm and came in considerably smaller, I complained, got the order free and he changed the description. But he torches the ends makes a little lip and can warp the OD enough to be unusable, like I said 3 out of 9 were good.
I imagine you could write him a note letting him know your requirements and he'd fix you up, he seemed fair.

This is worth noting; I triggered the BMS protection tonight somehow. I had to remove all the cells to reset it. [CHK] Tested!

Which BMS are you using?

 

[TommyDee]

The 20A end-pack modules like yours.

I don't see the margin on the orings as sufficient at these temps. Since I am drawing real-time while the cap is in the tube, I want to make sure I am not vaping polymers. Vaping a tree is okay.
Right now the bottom in the vial is adjustable by sliding it up and down in the coil. Works really well and provides an opportunity to seal off the enclosure. I can get the vials at $1 a piece but I need to order a 100.

So many options; so much time on my hands; so few parts to invent with

 

[PKOK]

Well cork or wood best option I suppose. The price of the vials too much. Put a glass bead works too.

Cool, so we can put a check mark on the BMS. Oh, here's those battery contacts-
https://www.digikey.com/products/en/battery-products/battery-holders-clips-contacts/86/page/2https://www.digikey.com/products/en/battery-products/battery-holders-clips-contacts/86/page/2

 

[TommyDee]

I was thinking of something like this one for circuit boards as they don't require back stops. Not sure if this would plug into a vector board.

I've looked for the ones they use in the Chinese holders - can't find them anywhere on the electronics warehouses or typical manufacturers.

I'll be damned! Look what Digikey is selling - https://www.digikey.com/product-det...-devices/BK-18650-PC6/BK-18650-PC6-ND/2330514

Today I wired up a few connectors. Moved the meter to the resistor/charger. Trimmed the cable on the 3S pack so I have some 18 gauge wire to work with.

I think I reset the 3S BMS with my ring so I Shoe-Goo'd the connections on the FET switch which doubles as a strain relief.

I am just about ready to commit The Runt to a 2S 18650 protected cell pack. It comes in at a reasonable size and level of comfort. I think it will be a fairly simple 3D print.

And the red momentary switch is working fine with the mosfet switch. It has just the right feel. Also took out a cumbersome design element with regard to compact.

 

[PKOK]

I'll be damned! Look what Digikey is selling

Oh yea they have most anything, if needed fast.

I think I reset the 3S BMS with my ring

I'm not aware of this procedure? It's not self setting?

I am just about ready to commit The Runt to a 2S 18650 protected cell pack. It comes in at a reasonable size and level of comfort. I think it will be a fairly simple 3D print.

And the red momentary switch is working fine with the mosfet switch. It has just the right feel. Also took out a cumbersome design element with regard to compact.

I'm looking forward to seeing it.

 

[TommyDee]

I shorted the inputs to the mosfet switch. That tripped the 30A onboard protection. Cells had to be removed to reset the BMS.

I'm getting the hint that short battery life is a turn off on these devices, even if considered portable. Industry just hasn't adjusted smaller cells to energy density. In this case the form-factor is inherently compact.

 

[PKOK]

Yea last night I was browsing utub on the subject and was disappointed to find not a lot of good reviews on the smaller boards. I've got them ordered so I'll use them, the balance board may fix their main complaints.
For reset through they jumped it with 12v (I think)

 

[TommyDee]

That might have done it. Basically plug it into a charger?

 

[jr1xt1]

Had a question about heating a dynavap with induction heating, hope this is an okay place to post it. I have a HydraVong and an induction heating unit I put together (using https://www.amazon.com/gp/product/B01GDVVANA/ref=ppx_yo_dt_b_asin_title_o08_s01?ie=UTF8&psc=1) and while it all works together pretty well, I find that it might be necessary to put the dynavap through 1-2 click cycles before getting really good vapor. Moving the screen up to make a smaller bowl does seem to help quite a bit, I seem to get either pretty good clouds on the first hit or a really big second hit.

Is that sort of heating cycle pattern sound normal for a dynavap? I will sometimes hold it in the heater for a few extra seconds but I don't do this too much as I think I've combusted the material 2 or 3 times doing this.

 

[TommyDee]

Wow, up to $14 for the module now! This is the perfect place @jr1xt1 - and welcome to the forum.

There are a couple of things at play. First of all, how easily does your VC draw? I've had times where the load fully baked but got next to nothing from it. Turns out the VC can loose all that vape to the air. I noticed this when vape honey started coating the inside of the little vial I use to hold the VC.

Where is the clicker in relation to the coil? I have a long coil and a short coil [gathered]. The long coil is as it came. I make sure the bowl of the VC tip is centered in the coil radially and axially. This delays the click and makes for a good hot load.

What are you powering the IH with? Measure the voltage on the IH itself to account for line losses. I find that an IH with 7 volts input has a very slow heating cycle. Excellent for terp-pruning or real time heating, to up to 12 volts which will blister a load in seconds.

Also know I am an advocate for real-time heating of the VC while drawing. I'm assuming you are using the HydraVong through water. I haven't tested this but there is no reason this won't work. The trick is to reduce power to make the heating manageable. You want fast heat-up true - but the slower roasting is like temp stepping. If you have a low voltage setup, hold the IH on until you hear the first click. Draw while holding the IH on - until you hear or feel that second click. You should have clouds rushing in at that point. At this point, firing the IH again and again, or even continuously keeps the goodies coming until it is all gone.

Get your VC to breath easier; turn over the CCD [screen]. Make the center convex instead of concave. Use a 5/16" tube to set the screen in the tip.

These changes above changed my relation to the VC to a whole new level.

 

[PKOK]

Welcome jr1xt1 it's just TD and I experimenting. 2 or 3 factors affect how hot or cold your cycles are.
The smaller your coil diameter the hotter, where you place your vap cap within the coil has an effect,
the material of your tip sst vs titanium. There are a number of discussions on all of these within the forums. Really though it's a matter of use to find what you like. For myself I reduced the number of coils
to just cover the cap while being slightly stretched. I also keep the very end of the cap even to just outside of the bottom coil. Hope this helps

 

[PKOK]

TD I've been watching utub till my eyes bleed but I think I've found the BMS boards that do a true balance and protection. Your doing 4s right https://www.ebay.com/itm/4-cells-20...msV2&brand=PCB&_trksid=p2047675.c100047.m2108

3s for myself https://www.ebay.com/itm/3-cells-20...a=1&pg=2047675&_trksid=p2047675.c100010.m2109

I may be wrong but I think these are the deal! Your thoughts?

 

[TommyDee]

Interesting circuit.

 

[PKOK]

Look at the sellers store as well. I've not looked hard but haven't found in China.

 

[TommyDee]

That is China but certainly a new level of Arduino fodder. I'm gonna like that store Thanks!