Mi-Log

I can wait

 

I too can wait. Well I think I can. God I hope I can. Every time I see this thread pop up on my list I get just a little bit excited. If for no other reason then because I like the convos it brings.

 

I think I got a little confused on an important aspect: who is the boss for this project? Alan or RBT?

IIRC it was explained us this was a long to come (not before zion) milana based log project in which Alan was only giving consulting for power supply solutions in exchange for the possibility to use RBt heater configuration for Alan's new projects.

In contrast with this information last RBT post seems to point out this is a new log Alan is creating using some RBT technology and original mi- log maybe will come out later on, is it right?

I checked Rbt web site (where mi log was showed at first) but there is no more shop page there, hence my question: who will be doing the wood job, sales, caring for eventual warranty issues, and finally earning the money for this product? @Alan ?

 

I suspect it is too early to answer these questions. There will be plenty of time to sort that all out before there is an actual product. This seems to be a project that will be finished after some other projects are out of the way.

At least that is MY take based on what has been said, but I have no special knowledge about it so I am just speculating.

 

@RastaBuddhaTao - Thanks again for the opportunity to work with you on this project. Your high surface area heater technology seems to be the future for on-demand convection vaporizers.
I don't have a Mi-Log specific waiting list. My plan is to offer it as an option to those that are on my HI waiting list. I wanted to be sure it was even possible to make one before promising to make any. I'm sure Ryan will also want to test out his version before committing to any list. Putting together a new vaporizer is not an easy thing. So many factors to consider.

Here is the first Mi-Log unit I put together. It is made from spalted birdseye maple and has a matching wooden stem. The glass fitting is held in place with a silicone sleeve that holds it very securely. No movement at all. It works just like a Milaana. The banana plug input jacks are held in place with a nut inside that also holds the electrical connection/wire. The switch will be held in place with white glue unless I can find a way to install a nut inside. That is a challenge with curved wood.
The heater unit is actually supported by the wires to the switch and banana plug input jack. They hold the halves of the heater apart well enough that the mica insulator board is not needed. The glass fitting can spin independently of the heater since I removed the heater screen. I wasn't sure if the glass fitting would spin in the silicone sleeve, so I wanted to be sure it wouldn't twist the heater if it did. There is more heat available for roasting since the heater screen is not there to soak up the heat. I always use two screens in the roasting tube anyhow, so there is no worry of anything falling onto the heater. It can have a removable bottom cap for cleaning it out if necessary. The bottom cap will contain the air intake hole. This hole will also give the ability to connect an air supply which will produce vapor whenever the switch is depressed.
Also discovered that an 12v 8A power supply is sufficient to power the voltage controller.
Have not tried connecting a 4.2v battery pack to see how it will work. Should be theoretically possible. Not sure if the cable from the battery pack will have the capacity for a fast discharge. The Milaana, Zion, or Mi-510 might be a better option for portability.

 

Wow! Say it backwards and it's still WOW!! Thats a sexy looking Mi-log you got there! Awesome work Alan!

 

Just amazing @Alan! Love the wood stem and design of the mi-log (maybe that name can be changed eventually). Are you getting an even heating across the entire load, or is stirring still necessary?

 

So fucking stunning @Alan!

Your tweaks sound like great improvements for a home unit, it's got the log feel but the RBT signature, a little more LSVesque too... It looks so nice and polished, that spalted stem is amazing as is the rest of the body, so clean with the inputs and button, nested glass bowl too

Can't wait to hear how testing goes, and then try one for myself some day soon! As always take your time, definitely well worth it

 

Amazing work, Alan.

 

Thanks @P.A.M. , @Lookatmeglow , @Shit Snacks , @Crussell27

The heating seems to be pretty much the same as the Milaana. The two screen method helps distribute the heat for more even roasting. I don't generally find it necessary to stir.

Longer 18mm male glass fittings will fit into it since there is no heater screen. The ID of the glass fitting just needs to hold basket screens.

 

Hmmm.. So three things: first I'll have to reiterate that using banana plugs like you intend to is a very bad choice, especially the way you did. It's not a matter of knowing if someone will rip the wires off, it's rather when. It's bound to happen.

You have two "hot" wires with bare male banana connectors a few centimeters apart. If you pull the device or the wires get caught, they will unplug and touch each other. Bam, your PSU is dead, magic smoke escaped from the FETs, end of story.

I understand that it's easier for you to use and mount though. If you really want to keep that then we need to source a single-piece dual banana male connector to put at the end of the wires. Maybe we could repurpose the kind of standard stuff that you can plug in multimeters... I'll have a look but I don't know if it's compatible with the diameter you used.

Second point: if I read correctly you removed the screen above the heater and let it exposed? I don't think this is a good idea. You like using two screens in your stems, and everywhere on the forum people tell you "put a screen on top of the load, solution to flying bits problem" or "put glass flowers on your bowl solution to all your problems" etc. But I'm sorry I don't like that! It's just a pain. You have a scorching hot part to remove everytime you unload, it's not practical and it's something more to lose.

With the Mi/Zi stems you just have to suck the load in, cash it, then blow it out. You can blow it in your palm and reverse the puck then suck it back, and voila it's even better than stirring! It's so simple and quick, I love it. Really a second screen works but it's more hassle than having a protected heater. And do you really find that the Mi screen sinks heat? I can touch mine at the end of a session, it feels cooler than the glass stem surprisingly.

Then the last point is about removing the mica insulator: I think it's also not a good idea. Drop the device once from your desk onto a hard floor, and you risk getting partial shorts and an anemic heater. Not good. Some Milaanas already arrived damaged by the shipping. If on top of that the user is able to insert anything into the heater because it's left open... I foresee embarrassing customer service moments...

 

thanks for sharing that some Milaana arrive damaged from shipping , KeroZen , gives me one more reason to pass up on it for its price . Aint that an embarrassing customer service moment

Surely the mi-log is still in the prototype / testing stage. By looks of it it could possibly be made in Left Handed or Right Handed versions

 

Nah I wouldn't pass up on it just for that. I said "some" but I only recall a single instance where it was determined that the rough shipping damaged the unit (since they are all tested before leaving RBT and this one was completely anemic yet working on arrival)

That's not occurring frequently at all, and RBT fixed the unit of course, as you would expect.

One aspect that is a bit counter-intuitive with these mesh heaters is how their resistance changes when you short them. If you have a single wire coil for instance, and you cut it in half (like what would happen if one end touched the middle part creating a short) the resistance would be divided by two. In an unregulated setup like this, it would be dramatic as the current would rise so much (times two) you would surely damage your power source (PSU or Li-Ion cells) The series resistance law applies.

With a mesh heater the dynamics are way more complex. We're dealing with a massively parallel system of interconnected fine wires. When you create shorts, it tends to remove paths for the electrons and the resistance will tend to rise. For the analogy it's like when you have a 4 lanes highway and reduce it to 1 or 2, cars have to slow down and it can create a traffic jam. Of course it's more complex in practice because it's a mesh and not just neat parallel lines. You got weird stuff happening at the edges etc.

Anyways the result is more resistance, less current through and thus less power output (i.e. anemic heater) Only parts of the mesh will heat up while others will stay cold.

 

Hi-Mi (sounds Jewish) {Seinfeld "Not that there is anything wrong with that."}
Me-Hi (sounds right!)

 

My name has just come up on the HI list. If the Mi-Log is viable, hopefully it will be the home solution I am looking for. With 3-4 family members all vaping on only 2 Zion's and a Milaana, we need a plug-in solution. Almost all of my other vapes have fallen out of favor since being spoiled by @RastaBuddhaTao heater tech. Literally EVERY single person (more than 15) that has tried any of the 3 RBT vapes I have, have been totally amazed by their performance. Their next question is always, "Where the hell did you get that VAPOR JUGGERNAUT??"

 

I like your safety reasoning, and share concerns on banana plug but I think removing mica is a great improvement if heater remains stable. I read some milana user reporting a little scratching noise when mi was cooling down and Rbt told it was the large surface heater dilatation/contraction scratching on mica insulator (making dust?) at the origin of the noise. I feel better if this can be removed from design

 

So what you are saying is, I should just buy everyone in my family a RBT product and I will be able to convince the remaining combusters to switch to vaporizers?

I wouldn't be buying them for me.... right?

 

@Andreaerdna : right, good point. We raised the flaking/dust concerns when Ryan switched to mica for the insulator. It was determined that it should not occur under normal use conditions, but as an extra safety feature, the heater screen was selected with a mesh fine enough to catch most dust particles that could escape (another reason to keep the heater screen if mica stays)

That being said my alpha Zion has glass insulator plates instead of mica. They were deemed less efficient, but efficiency is a concern we no longer have with a plugin unit (we can make the heater more powerful to cope with any loss due to the heat sinking)

I would like to seriously consider going back to glass insulator/reflector plates for the Mi-Log instead of mica.

 

Well I don't know how rbt heater were designed or are built but it sounds like Alan either tweaked it, adapted it or perhaps even fixed some concerns some people have had such as mica insultor and other...

I do know Alan prides himself with offering quality products that will last . Judging by his Toasty Top And HI threads , the quality of his products speak for itself and doesn't seem to be too many returns! I doubt he wants or is looking to change that. Trusting his modifications are for the best.

One lefty mi-log please !

Banana, banana, banana, split

 

@KeroZen - Thanks so much for the time to respond with your concerns. The manufacturers of the voltage controller must have anticipated that the output leads would get shorted, so they designed it so that it wouldn’t fail. The voltage display just goes to zero with a hard short. No harm done and it still works fine. The voltage controller also won’t allow you to over heat the Mi-Log. It shuts down unless you can keep removing heat by drawing air through it. Temperature is controlled by adjusting your draw to maintain a target voltage level. The voltage controller is protected against accidents and also protects the MI-Log unit from accidents. The way the plugs are configured with the twisted cable makes it virtually impossible for the plug ends to touch anyway. It takes a considerable amount of force to even remove the plugs from the sockets. The wood body would probably be destroyed in an accident with enough force to pull the plugs out. The cord is not long enough to hang to the floor, so there is less of a chance of snagging it as you walk by. The cost of the banana sockets is also very low. The hole spacing doesn’t have to be precise as would be required for a single-piece banana plug connector.
I agree with you about the heater screen. It is sort of a necessary thing even though it does rob away some of the heat. I wanted to be sure there would be no contact with the heater for my first Mi-Log, so I left it out. Production units will have them. Will make sure that the heater can’t physically touch the screen so that there is no chance of short circuit. The good thing about this type of heater is that an oxide layer will build up that affects the contact resistance so that it is less likely to short circuit. The less mass the heater screen has, the less heat it will rob away. Similar to how a wood stem robs less heat away from the roast. I don’t find the basket screen to be too hot to remove since it has such a small metal mass it cools quickly. It helps to not have a metal rim on the screen to hold (and rob away) additional heat. I never have to clean my screens using the two screen method. So much time saved not cleaning.
Was intending to use the mica board in the build, but it was so loose in the heater that it didn’t make sense to leave it in. I found that making the heaters requires great skill. They are not a simple thing. The mica board actually have more mass than the heater. Without the mica board, there is no additional mass to deform the heater in the event of a mechanical shock. The wires connecting the heater are stiff enough to prevent the heater from displacing in the event of high acceleration from a fall. An accident bad enough to displace the heater would be bad enough to break the glass. I don’t recommend the Mi-Log being used as a portable since it would require a battery pack modified with banana plugs. There would be too great of a risk of shorting the battery pack with the exposed plugs. This project is all about a desktop Milaana.

I aim to please. Left or right handed revisions can be made @P.A.M.

 

You sure do tend to deliver on that goal!

That all sounds great to me, the plugs, cord, and unit seem really nice. I agree some sort of heater screen is always safest even when using two bowl screens for any kind of spills. Being able to replace everything is great though, and yeah maybe a home unit doesn't need the insulator... Never had a problem with the mica but certainly not attached to it (Zion uses it a bit differently though, I wonder what you'll think of that? I guess we'll know soon enough )

 

Well I just got THE email and the Mi-Log is here. Timing couldn't be more perfect.

It looks absolutely beautiful Alan, as your work always does. I'll be emailing you back soon.

 

@Alan : for some (explainable, see below) reason, I keep forgetting that you are going this route, with a PSU and a separate voltage converter unit.

For the prototype Zion PA, I went for the cheapest Chinese 20A PSU I could find (it's a power supply for LEDs operating in CV mode, cost me around $20 shipped) and I would never trust the built-in protection of such a device. I'm not even sure it has any, and if it has it might just be a non-resettable fuse which doesn't really warrant that you won't blow a component or two before it goes away. But you get what you pay for anyways, the unit you got is surely of more acceptable quality.

I'm not sure to understand the part where you say it would prevent from over-heating. Could you please explain by which mechanism it works? Temperature probe in the DC-DC converter?

As for the reason now: I was wondering why go the trouble of having two external components when the Zion guts are probably small enough to be integrated inside the device itself and are already proven and tested for the job? The Murata chip is super small and surprisingly capable!

I know that you came from the Milaana PA you built, and thus followed this path. But I think that it would be better to create a desktop Zion instead. This is why in my mind it was important to have a keyed connector like the XT60 or the Deans, to protect against reverse polarity (which fries instantly the poor chip)

About the mica plate(s), two things: inertia and health concerns.

I did a lot of experiments with various SS-based heaters, different configurations, materials, geometries, even toyed with mesh, and it's clear that the large surface area is the way to go for instant convection. But that doesn't explain why the Zi and Mi have that incredible inertia: you can release the trigger and continue gulping vapor for a long while (several seconds, esp. in the Zion) We like to call that "riding the falling edge of the heat wave"... but I digress!

If you say that the heater mass is quite light in comparison to the insulator plate(s) Could it be possible that they play an important role in that inertia effect by creating some sort of heatsink?

Now you may wonder why would I want to have inertia in the device? To be honest I don't know, apart that I'm just used to it... Thinking of it, I'm not even sure this is a desirable trait. As long as the heater can handle and stay steady under large enough draw speeds... All this energy that went into heating the plates is more a waste than anything... At the same time you called your technology "heat island" for a good reason too, no?

Finally, seeing problems with mica come from breathing its dust and particles, and even if our use scenario is surely very far from creating harmful concentrations... Wouldn't it be better, just for the peace of mind to revert to glass? Deep lung inhalation on a daily basis does constitute a chronic exposition afterall. Sometimes it's the frequency that is more problematic than the dose. But I'm no materials safety expert.

 

@KeroZen

Obviously I can't speak for Alan but I have some thoughts on his design decisions vs the questions/suggestions you're asking.

The zion guts could fit in the bottom of the log, sure, but then you're introducing electronics into the unit itself. I'm not sure how Alan's air intake is exactly but I believe it moves up from the bottom of the unit, past where the chip would be. Aside from that, it's hard to fit the rest of the features into the log itself. A voltage display and knob are hard to fit into an elegant log when you already have the power cord and the button.

You could build an external unit with the Zion chip with the short cord, but at this point you're just adding labor when these existing buck units are already available. So from a production standpoint a 12v power brick and a variable voltage buck is pretty much identical in material costs to your idea but requires less labor, so it's far more economical. Also easier to troubleshoot and repair should anything go wrong. The voltage buck being a separate unit means it can be replaced of even upgraded without opening up or sending back the Mi-Log itself. So while you say "why go through the trouble of going through two components" I don't really follow, because it's actually less trouble in a lot of ways, and using the OKR chip is still going through two components, you've just moved the placement of one of them.


As for mica, I'm happy to see it gone in the Mi-Log. In the Mi, the inertia was important since we were trying to make the most of battery life and didn't have unlimited wall power or adjustable voltage. When your voltage is always dropping, you want to get the very most out of every hit. With very fine control of the voltage I don't think "riding the wave" is as necessary. (But it is kinda fun) Though I'm very curious to see how much heat retention is left without the mica. Mica can flake into fine particles and while I'm not sure if there's any real health concern with the Mi or Zion, if those flakes are notably unhealthy or if they even make it through the heater screen, I like the peace of mind knowing that's not even a factor in the Mi-log. Definitely worth any inertia loss imo. But I'm a bit of a stickler for materials so ymmv.

A glass replacement for the mica would probably work fine, but it sounds like Alan has configured the heater in a way where even that isn't necessary. Which is good, since the added glass would be. again, more labor and materials to produce.

And I just want to mention again how thrilled I am at Alan's solution for mounting the heater glass. So much better than glue in every way.

I'm pretty sure this is going to be the real VAS killer for me.

 

Agree 100%

this two small (or smart) fine tunings made this device a lot more appealing to me than its original packaging

And despite what it was said, it seems it wasn't neither so complicate or expensiver to get rid of both of them after all