2024/25 VC performance discussion thread

[dmccoole]

That's a great setup!

I have a Thermoworks signals/billows that I can monitor/control my bbq/smoker temps from my phone.

I would just like a WiFi/monitor/phone app so I can view the stove temps on my phone as we mostly sit in a different room from the stove. And we can't hear the Auber controller alarm from our bedroom.

Does anyone know of a good temp monitor with wifi and a phone app for the k-type temp probes? Auber has a controller and app for bbq/smoker but not for the k-type probes.

 

[arnermd]

I've been meaning to report back here with my little project and this seems like a good time. I owe you guys big for helping me completely rebuild this stove several years ago. It was completely disassembled down to the smallest part and completely rebuilt by my hand.

So, I've been using an ESP32 and a few other parts to constantly monitor and control my stove.

The thermocouples in the flue, catalytic converter and griddle monitor everything and keep the temperature within safe limits. The potentiometer adjusts the desired cat temp (900 to 1500 degrees).

There's a soft overheat limit where the butterfly valve on the air intake will shut and a hard overheat where a very loud peizo alarm starts going off. I can monitor the temperatures and see graphs on my phone and it will (soon) send me texts if it overheats or if I need to add wood (The variable for "FEED ME SEYMOUR" is triggered when catalytic temp drops below 800). The numbers on the displays will also start to blink as it approaches the overheat limits.

The adapter for the butterfly valve is 3d printed out of ASA and uses a servo for positioning. The valve has a silicon seal on the inside and seals very well. I also had to weld together an adapter to go from the square air intake to the round butterfly valve housing which turned into me drilling a hole in the wall and turning it into an outside air intake.

I also have it hooked up to a backup battery in case the power goes out. I usually leave the air flow on the stove at the half way mark just so if something goes terribly wrong it doesn't get full airflow but it has now been 3 years with no maintenance and it has worked flawlessly after some PID loop tuning and firmware fixes.

There's plenty of room for improvements and size reduction but I haven't seen a need to rebuild the thing just yet. This is version 2, version 1 was purely monitoring. The big red button silences the piezo alarm for 30 seconds, the led with a piece of paper taped over it is lit when it has an active internet connection and the switch to the right is a hard override and completely shuts down the air supply. The center is just a potentiometer for setting the target cat temperature with a silly oversized knob.

Very cool! Do you have any plots of cat, griddle, flue temps and valve position?

- I assume you leave the manual air lever wide open and let the butterfly control the air flow?
-Did you make any mods to the secondary air flow or is it wide open?
- Which stove are you running this on?

 

[bullittman281]

Hello everyone,
Haven't been here in years but have a new toy and wanted to drop by and say hello. Here are a couple of pics of a Dauntless doing its thing rumbling along on some ok-ish Siberian Elm. Stove is new this year and has a beast of a learning curve. I mostly mastered it and it cooks along fine most of the time. No cat, no fancy probes and telemetry like some of you run. So far I'm a happy camper.

 

[Woodsplitter67]

So im pretty sure its been weeks since my stoves been cold.. getting some real ash build up. Looks like maybe this coming Saturday may warm up so that s probably over 20 days with the stove 24/7. Stove performance has been excellent with many liw burns during the day and at night averaging 12 hours. Im really going through some wood right now. My auber has acted up twice making an alarm for no reason

Heres my stove this morning.. the coals are deep like 80% up the anirons

 

[Jmorg]

Nothing better than walking out to the woodshed in the snow! Been burning 24/7 for a couple weeks now. We finally have a real winter here in Virginia.

 

[dmccoole]

Same here. The stove loves to run when it's cold out! We hit 35 yesterday so I let it mostly die down and shovelled out most of the ash and restarted. I couldn't get the cat to engage. Stt > 600. Cat was anywhere from 300-700 all day and into the night. Stove was throwing some serious heat though. I packed it full for the night. This morning it looked the same as yours but the cat temp was still low even after burning off the glass and adding a few splits to get it going again. Your post reminded me my Auber was acting up 2 weeks ago as my wife dropped it off the mantle. It was acting like a loose wire. So I just moved the wire around and power cycled it. And sure enough it started reading 950-1000 and was being responsive with the air supply. Currently cruising at 1002!

 

[Eman85]

I'm very happy I waited to order my Auber until they finally offered it with the standard mini plug like the rest of my meters.
Like others my stove has been hot for quite some time now. I do open it wide in the AM and burn the glass and warm the house while I drink coffee in the AM. My best burns are when I'm around the stove and I can manually control the air in small increments and keep the cat hot also keep the house warmer. I can't remember the last time I emptied the ash pan, current wood burns pretty complete and I just stir the coals before reloading hot

 

[Turbo89]

Installed a CAT temp sensor in my Encore and was burning all day. She was running good, with 1100-1200 degree CAT temps all day. Around 8:30 I pushed the coals to back and stuffed it to the top… by 9:30 my cat had shot up to 1640 with the stove all the way turned down (STT was only about 500 on the griddle).

I haven’t figured this stove out yet… I’ve been burning conventional stoves for years, this is the only stove I’ve ever seen go nuclear turned all the way down.

All tops welcome… I probably won’t stuff it to the brim tomorrow, lol.


Edit: just checked it, STT temp crept up to 675, and cat to 1690…. I pulled some wood out.

 

[56knoise]

Very cool! Do you have any plots of cat, griddle, flue temps and valve position?

- I assume you leave the manual air lever wide open and let the butterfly control the air flow?
-Did you make any mods to the secondary air flow or is it wide open?
- Which stove are you running this on?

I haven't needed to run the stove yet, it is unusually warm in my area of Washington for this time of year and I can't find any old pictures of the graphs but yes I do monitor cat/griddle/flue and valve position over time. Because the butterfly valve is non-linear in terms of airflow as it opens I didn't have good results simply using the pid loop to output a 0-90 degree servo position (it would oscillate and have large swings) so I used some math I found online to approximate the airflow of the valve in terms of percentages and then used that to modify the requested servo position, if that makes sense. It allowed much finer air flow control as the valve approaches the mostly closed position.

I leave the manual air lever vertical or just a little more open from vertical when running normally.

Secondary air flap always gave me issues so I have it disconnected and completely closed.

Stove is a defiant encore 0028.

The funny thing is that the entire system stays safe even if an older family member forgets to close the bypass to the cat after reloading wood. The flames will start licking the flue probe, it will approach 700 degrees and the air valve will snap shut before the audible alarm goes off. It will just sit there and loudly oscillate between 625ish and 675 until someone notices the loud servo gear noises and closes the cat bypass. Though the dog absolutely hates the servo noise, she will run and hide.

 

[Woodsplitter67]

Stove performance was getting lack luster near mid day Saturday and really wasn't running well yesterday.. smoke coming out of the chimney and cat temperatures way to low.

I hadn't cleaned the stove in weeks and I let the ash build up way to high. The ash was well over the epa holes and when I cleaned the cat the was a ton of ash in it. Normally I scrap the ash in the pan here and there moving the coals aside.. Im definitely going back to that

Heres the stove cleaned out and secondary combustion in the box cat temp at 1400

Back to running well again

 

[Eman85]

I hadn't cleaned ash in quite a while and the stove was working well. Burning the coals down and the ash was very fine, all I would do is push the hot coals and dig down in the ash letting some fine stuff fall in the pan. I'd check the pan and it wouldn't have much so I continued with the burning continuous and everything was great. Then I decided to really rake the coals and afterwards dump the ash pan. I reloaded and had it going well and went out. My wife was home and she heard the blowtorch sound in the stove and the cat was at 1650 with the air intake fully closed which is how I left it before I left. I think I'll leave the ashes from now on. My stove doesn't have any internal epa air holes that others mention.

 

[arnermd]

This mornings crap show. Stove has been running pretty good, although my new cat rotinely peaks at 1550 - 1600. I bumped my cat alarm up to 1650 and try to stop caring..... Anyway, thought I would try running with air full closed, big mistake.

• Cat was at 475 when I loaded on top of a nice bed of coals. 80% full load of oak.
• Gave the load a few minutes to catch and then closed the bypass, full air
• Cat went to 1000 quickly and I closed the air down a bit.
• Closed the air down incrementally till about 1200 on the cat and then closed it all the way down.
• Just let it go.... (and kept increasing my alarm temps as it went nuclear.)

For those who think I have an air leak:

• Look at griddle temp, 400 -500 the whole burn, not what I would expect from an air leak.
• Load burned for 11 hours and when I opened the air at 16:30 there was still fuel in there to heat things back up.

Measured draft with the cat at 1700 and it was 0.13 iwc, seems reasonable to me.

So if it is not an air leak and not excessive draft what it it? Damned if I know....

Glass is a mess will take me days to burn it off. No more running full closed on the air for me. Woudl love to hear what the factory thinks.... fat chance.

 

[arnermd]

Because the butterfly valve is non-linear in terms of airflow as it opens I didn't have good results simply using the pid loop to output a 0-90 degree servo position (it would oscillate and have large swings) so I used some math I found online to approximate the airflow of the valve in terms of percentages and then used that to modify the requested servo position, if that makes sense. It allowed much finer air flow control as the valve approaches the mostly closed position.

Yep makes total sense. Butterfly valves are highly nonlinear in terms of Cv vs position. But like you said you can make it workable with some math.

How does the logic work? Are you keying off the griddle or the cat temps? Or both?

What would happen if you set the secondary air 50% open and controlled based on cat temps? Have you tried it?

 

[AsylumResident]

This mornings crap show. Stove has been running pretty good, although my new cat rotinely peaks at 1550 - 1600. I bumped my cat alarm up to 1650 and try to stop caring..... Anyway, thought I would try running with air full closed, big mistake.

• Cat was at 475 when I loaded on top of a nice bed of coals. 80% full load of oak.
• Gave the load a few minutes to catch and then closed the bypass, full air
• Cat went to 1000 quickly and I closed the air down a bit.
• Closed the air down incrementally till about 1200 on the cat and then closed it all the way down.
• Just let it go.... (and kept increasing my alarm temps as it went nuclear.)

For those who think I have an air leak:

• Look at griddle temp, 400 -500 the whole burn, not what I would expect from an air leak.
• Load burned for 11 hours and when I opened the air at 16:30 there was still fuel in there to heat things back up.

Measured draft with the cat at 1700 and it was 0.13 iwc, seems reasonable to me.

So if it is not an air leak and not excessive draft what it it? Damned if I know....

Glass is a mess will take me days to burn it off. No more running full closed on the air for me. Woudl love to hear what the factory thinks.... fat chance.

View attachment 335118

I have tried four full loads this season. Each time the cat went north of 1,600. If I keep the loads to no more than three large splits I can keep the cat from getting too high (usually). I have been worried about blatant air leaks adding to the primary combustion but I have pretty decent control of my flue temps as I open or close the air. This leads me to believe I don't have much for air leaks in my stove. With the way the last three years have been with this beautiful looking stove, it's not meant to run full loads and keep the the temps in the check. I'm going to say there is a design flaw (what else could it be) and I don't have the luxury of longer overnight burns. Vermont Castings largest firebox, of which I can only really use half of.

 

[Eman85]

Isn't this fun!
Last night loaded over hot coals and gave it a chance to get good and hot. Engaged cat and all was good at 900-1000 cut back to 1/2 and at about 1200 cut the air all of the way. Checked on it later and the cat had cooled into the 700's. Gave it air and it came back up, shut it again and again it went way down. One more time before bed and when it rose to 1100 I shut the air. Of course then it decided to keep rising and stay hot. It did finally calm down and cruise but not before the anxiety of the whole ordeal just before bed. I did get up once to check it to be sure.
Now this morning, over 12hrs later I reloaded and let the box get fully engaged flipped the damper and it slowly rose to 1000. I cut the air to 1/2 and it's cruising at just below 1100 at 1/2 air. I think it just likes the attention.

 

[arnermd]

I have tried four full loads this season. Each time the cat went north of 1,600. If I keep the loads to no more than three large splits I can keep the cat from getting too high (usually). I have been worried about blatant air leaks adding to the primary combustion but I have pretty decent control of my flue temps as I open or close the air. This leads me to believe I don't have much for air leaks in my stove. With the way the last three years have been with this beautiful looking stove, it's not meant to run full loads and keep the the temps in the check. I'm going to say there is a design flaw (what else could it be) and I don't have the luxury of longer overnight burns. Vermont Castings largest firebox, of which I can only really use half of.

Have you tried running a higher air setting? I generally find I get lower temps with more primary air, typical overnight for me is 40 - 60% setting. The STT is hotter but the cat peaks are shorter.

Running with really low airflows gives you a longer, smokier primary burn and it creates a lot of fuel for the cat. So it effectively shifts the combustion load from the primary to the cat and leads to higher secondary temps for longer and low STT's. When I run low airflows my glass blacks out and if I open the griddle a crack I get a huge cloud of smoke out....

I found things are more controllable with higher airflows, but my metal cat is also peaking at 1550 - 1600 on a full load.