Max's M-2 Mule

You should use a thermocouple that will only stick 1 or 2 inches at most. If your looking to monitor things the core temp is really irrelevant. You just get used to seeing an operating range based on the output of this sensor. But the this temp reading will be much cooler than the actual temp at the heart of the process. But nothing will withstand those temps and oxidization for very long. So you need to place the probe where it can withstand the environment and is why this port is at this location.

I've read a lot of threads on DoW forums and seen the posts where "building a gasifier for the first time" and scroll through 100s of posts across years+ of people trying to get this right. So I was expecting gasification to be a really big learning journey for me before it runs right. But you really made it too easy :P

Now I get to focus on collecting and processing wood and running an engine instead of trying to build a machine.

On the topic of temperature sensor, have you already figured out what works there? Thermocouple I'm gussing. Certain length of probe? And does the probe stick directly into the charcoal, or should you use a thermowell?

Nice :) very familiar looking machine there. One thing I've done the last few times, is I just use the 12v from the generator small starting battery to run the blower as well. It's maybe just a little bit slower to get flarable gas, but still probably under a minute, and that gives me time to walk around, double check everything before I light the flare. 24V was a faster start up, but the flare was possibly too big, as shown in my first video of this thread. I'll eventually try to find a speed controller for it so I can dial it in exactly, but in the meantime the 12v seems to work without a problem.

I did screen my fuel after I made it, although on this last run I used the last of my fuel, and I had it stored in a 50 lb chicken feed bag, and when I was dumping in the very bottom of the bag I did notice a bit of a dust cloud when I dumped it in, I think whatever dust was left settled to the bottom of the bag, although I didn't notice anything that would seem like a clogged filter.

I'm now out of charcoal for the moment, and with the snow here it'll be hard to make more, but the good news is theres a lot of branches and trees that fell down this winter to make more :)

I'm wondering with the temperature probe, if I were continuously logging data, it seems there might be some things it would tell me:

1) if things are getting too hot, because water ran out, or the generator is sucking too much air through it, or theres an air leak?

2) establish a baseline normal temperature to tell if things aren't right.

and for the O2 sensor, do you have to weld in a port for it in the exhaust system? Or can you just place it at the exhaust exit and get a good reading?

I realize none of the sensors are necessary it's just something thats pretty interesting to me.

Oh, and one more question, for the long term should I put some sort of an airfilter on the intake of the air mixing valve?

If you have not seen this video it is one of the sister machines to your machine. The M-2 Mule is probably my favorite machine its quite capable for its size.

Yes there is automation in the works. This will be a continuation of the automation systems Ive developed in the past. However it is not for monitoring, there really is not point in that. Its either running good or it isnt. You either have bad fuel, your water drip is set to high / low or you need to clean the filters. There are two filters your ammo box filter and there is a coarse filter inside the Fusion Module. Generally you dont need to mess with the coarse filter unless you are not screening your fuel. If you not screening the fuel then yes you may need to check this filter. You simply remove the cover and use a shop vac to clean it. You can use a toilet brush to very lightly scrub the sides of the filter screen.

The port on the front is for a temp probe that is to tell my controller if the unit is running and in operating temperature parameters. You could add an O2 Sensor kit that will help you make more precise air adjustments. I use the AEM O2 sensor kits they are very expensive though nearly 200 bucks now. However I use an output to control an automatic mixture valve.

This automation package will be developed to plug and play with most off the shelf generators and will have the capability to self start the gasifier, light the flare after ignition and then self start the generator and shut down likewise. This will use input from an off grid battery bank so the system can run autonomously. Right now my development focus is on the new kiln tech so this controller will need to wait. :)

Haha, well now I'm feeling pretty good about myself that I was able to exceed the continuous rating for a bit, as a total beginner with gasifiers, and using not the greatest fuel (probably too wet and not the densest).

And no worries about the power rating, my main goal is to learn and try things.

Thanks for pointing this out as this is a typo in the listing. I will get this corrected. If you note the module above has a 2.5 kW rating. They are the same machine and outputs are identical. I will get this changed today. That rating is also dependent on the generator you choose. I rate them to max size generator that I also rate the machine to run. So if you go to a smaller 200 cc generator you are not going to achieve the max rating it will closer to half as its half the max cc rating.

The M-2 and the M-3 (non teamed) I rate to run the 420 cc generators. Regardless of the gasifier (the gasifier is irrelevant.) This size generator running on any woodgas can only achieve 2500 running watts consistent. Its good that you were able to achieve the 3 kW but I actually do not rate that high as this is the maximum. I generally underrate the machines so there is some cushion to soak up fluctuations.

Sorry about that this was an honest mistake

Yesterday I finally got around to doing some testing to see how much power I could pull out of the generator. I have an EV with an OpenEVSE charger, its 220V and you can configure the maximum charging current from 6 to 50 amps.

Results? First attempt, got up to 12 amps no problem, then stepped it up and motor RPM started to fall. Put maybe 1/8 or less turn more on the water drip, and then got up to 14 amps and held that for a few minutes before trying to step it up, but never got it above that. So thats just around 3000 watts, not QUITE the advertised maximum power but not bad for a complete beginner, this was probably the 5th time i've ever lit the gasifier, and I made my fuel long ago and it sat outside, so its probably not dry charcoal either.

I'm pretty sure there's improvements I can make as an operator. I start to feel like I need an extra arm, to be able to reach the water drip valve, the air mixing valve, and set the battery charging current.

It seems a lot of woodgassers, especially on DOW, appreciate having everything be manual and running it all by hand and ear. I think its a good way to learn the fundamentals but I also can't help but be interested in adding some instrumentation to start getting a better idea of how everything is running. Do you have any recommendations there. I see there's an extra port below the lighting port, I think I read that was for a thermocouple. Is there other instrumentation you would recommend that helps an operator see how the machine is running?

Once you get the engine running good, I generally open the valve until I hear the engine fall off and then bring it back closed to richen the mixture up.

Yeah the needle does have a pretty big range. You should not exceed a half turn. You should water form on the end of the drip tube and the incoming will grab it and form a mist. If you see it pooling inside the nozzle this is too much water. This can cause a steam crash and make your fuel too wet. That can take time to recover from or you may need to dump that fuel and mix it with dry fuel. Or just shut it down and let it stand and it will dry out.

Wanted to post an update, everything been working great! I was almost hoping to run into more problems for a chance to learn troubleshooting skills, but it's everything just works.

It's hard to describe the feeling of shock and amazement the first time the engine started, even though I've read a lot and watched a bunch of videos, seeing it in person is something else. The first run was unloaded. Next time plugged in an electric oil-filled radiator, through a Kill-A-Watt, 600/1000/15000 watts of load on low/medium/high. Generator is a Generac 7500, 420cc and nameplate 7500 watts continuous and 9000ish peak but never tested that myself.

Been trying to just observe things and ultimately would like to try to get a feel for how to run everything optimally. I spent a bit of time watching the flare and adjusting the water driprate. First thing I noticed was there seems to be a bit of a lag from the time the needle valve is adjusted to when you can notice any difference in the flare. To my untrained eye, the visual effects on the flare are kind of subtle, I'd have to say with more water the flare gets taller and pointier, without its a bit shorter and more of a dancing flame. It seems there is only a small amount of adjustment with the needle valve, before I start seeing water dripping out of the air intake holes. At that point I assume turning the valve further does nothing but make the ground wet.

Then the next thing I'm trying to get a feel for is setting the air mixing valve. Out of the whole 90 degree throw of the valve, it seems like there is only a very small range where the engine runs. At the very top and bottom of that range, the engine obviously starts to sound bad and RPM fall. In the middle of that range, there's adjustments I make cause very subtle changes to the way the engine sounds but I have no idea what's good. Do I want to be right in the middle, or as open as possible while still sounding good, or as closed as possible while still sounding good?

At one point during my first test run, the first time I put the heater on high (1500 watt load), the engine RPM fell and sounded like it was on its way to stalling, so I turned off the heater and everything was good again. Realized I had the water drip all the way off from earlier testing, cracked it open about 1/8 turn, and then 10 seconds later I was running the heater on high, turning it on and off and I could barely hear the engine react to the load. That was all I have, but I think for my next run I'll try to do a bit of testing using an EV charger as a load, since I can control the max charging rate, set the limit anywhere from 6amps to 40 amps at 220v. Basically I'm guessing one way to figure out what settings are the best, is to figure out what settings let the generator produce the most power. Though I have to start planning my test runs, since I'm running low on the charcoal I made, and everything is covered in snow now so its hard to make more.

Great machine, so much fun, I feel its the perfect way to get hands on with gasification for someone like me without the tools, skills, or materials to do a DIY build.

One thing I should note after you have the machine running and you open the hopper; keep your face away as the gas inside the hopper can ignite. It tends to have a little delay as well, so just be cautious of this.

That is the beauty of the ammo box filter, you have options. To find out if a media will work is to simply try it. The idea is to use saw dust from your wood processing. But you can certainly use other medias.

Very cool seeing that baby flare off, but yeah get that speed controller. :)