Nerd Alert

Crisp jingly upper strings and deader wound is the opposite of nylon strings - dull thuddy uppers with big ringing wound lowers. I'll play nylon in the presence of beer to lessen longer term fingertip pain but it's a compromise in sound. Back in the day it was a set of strings per night and they got beat appreciably dead. Now I'm more like George measuring change intervals in years.

My neighbour has one of those 10 or $20k Martins and told me of spending a whole day trying to duplicate an earlier recorded sound in his mini studio. I empathise, playing technique is 80% of getting the sound out of a guitar. Mic-ing and signal chain is a lesser issue. One night we were playing all/both kinds of music, country AND Western, in a small town with two competing bars. Our's closed earlier so that band came to check us out early and we saw them later after closing. I tended to play with a light pick touch and went stock strat into deluxe reverb fresh strings. 0 bass treble ie flat. The other guitarist marvelled at my sound. He, on the other hand, kicked up the bass and treble and ham fisted the snot out of his picking and strumming. Pure mush sound. Technique IMO. Smoke got so thick, slowly coming down from ceiling height that you couldn't make out the people at the closest tables by the end of the night. Holy stank Batman.
 
Bart_ said:
Plagiarizing a post by user byQ 2014 hearth.com. I knew there were different firebricks but this is more in depth.

quote:


I'm building a masonry heater and I've did some research on firebrick. What I learned is firebrick generally comes in 3 or 4 duty statuses. The higher the duty status the more metal (alumina, up to 99%) and less sand (silica). The lower status firebricks will have like 20% metal in them and 80% sand. The more metal in the brick the better, right?

Not necessarily. The super duty/high metal bricks don't expand and contract very well - they form little fractures within the bricks. Wood stoves heat up and cool down so these bricks may not like this. They do better if they get very hot and stay hot (like in an incinerator). However these super duty bricks won't pit out like some of your bricks are doing. Your bricks are low duty firebricks and probably contain about 20 to 25% metal in them. They aren't very tough but with the higher sand content they expand and contract well so they won't form little fractures within them.

The best firebrick? Probably a medium/high duty firebrick - which contains about 35-55% alumina (metal). This brick will not get the little internal fractures and it won't pit out as fast from friction. Generally, the higher the duty status of the brick the higher the cost. If you are in the midwest Whitacre Greer (20% metal brick) and Alsey refractories (the smithfield a medium/high duty firebrick) are the go to firebricks for many masons.
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This evening, I pulled the woodstove out of my house and replaced the fire brick and welded up a few cracks. I just put in the cheap fire brick that Tractor Supply carries, because the stove is a cheap stove from Tractor Supply.

I had to cut a couple bricks to fit, per the factory design. Cutting them was far more difficult than expected, they definitely have a notable metal content. Diamond masonry wheels didn’t cut them very well, regular abrasive metal cutting wheels did not either. Very slow cutting and equally slow grinding, plenty of sparks and not nearly as much dust as I expected.
 
What was the stove brand? Ashley? Century? Haugh? Current crop of cheap stoves at big box stores are chinese origin it seems. Ashley is an old name, new lowered quality.
 
Bart_ said:
What was the stove brand? Ashley? Century? Haugh? Current crop of cheap stoves at big box stores are chinese origin it seems. Ashley is an old name, new lowered quality.
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The stove is a Country Hearth, but is actually made by Vogelzang. It works, but is not the best made stove, and did not stand up to the abuse my tenants put it through while I was away.
 
Usstove.com does those fwiw. Quick benchmark thickness of plate material used.

I found another good woodstove control project description. Break out the cranial scrub pads itsa cleaning time. Gotta get that brain washed. My understanding is he does pid servo on the stovetop temp and applies logic to going air closed, or set to fixed LO amount. Neat feature bases some logic on room thermometer reading and run time adjustments of setpoints - and a warning buzzer. Also shut air on cold stove. Trainman used two co-servos on flue and stovetop temperatures and (I didn't) but he also ran the forced air fan incorporating room temp.

gist.github.com

Arduino Wood Stove Controller

Arduino Wood Stove Controller. GitHub Gist: instantly share code, notes, and snippets.
gist.github.com gist.github.com

edit - in Firefox the source code remained formatted, in Chrome it lost all the indentation. I recommend trying to see it formatted if you're going to read it so try different browsers if necessary
 
Watch this if you want to feel old. Story: in high school our band's drummer wrote a fan letter to Bun E. Carlos to which Bun E, tried to phone back. His mom said he's over at (my) house practicing with the band so I answered the phone talking to Bun E., unknown to me till after my bud finished the call. Long story short we referred to a certain demo tape as the shoelace tapes. In our vanity we thought we heard hints of our stuff on their next album. Yeah, maybe not! Kids, you know.

 
Found a guy Smokeless Chimney who's using colorometric and light opacity in the flue smoke, good being correlated with abundant flames in the firebox, to control burn via primary and secondary air. His rig uses two fans and a dwyer pitot manometer so it's vulnerable to net firebox pressurisation - bad - but I think he's on to something. He has fan profiles changing in the seconds range to stir up and move the flames around. I'd have to call it a bit akin to pulsed welding. Neat!
 
SeanRuel said:
get a big round tree, make tree square, make big square tree round!
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"A strange thing, the butter warmer. We have that. We were cold, man originally was cold so he built a house, hot box to live in, warm box, live inside the warm box, pretty cold out here, warm inside the warm box. Everything was nice until he realized the meat didn’t keep in the warm box. So, he built a refrigerator, built a cold box inside the warm box. Meat keeps fine, but the butter doesn’t spread. So he built the butter warmer, put a warm box inside the cold box, inside the warm box. Strange folks."
— George Carlin
 
18 years ago youtube vid controlling draft full("ON")/OFF duty cycle based on flue pipe temp and using pneumatic cylinder commercial position controller.


edit - don't think it ever worked right based on the response time I've seen to draft change being about as fast as he cycles it - unless it was made into draft lever position proportional to temp
 
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2 years ago youtube vid where the guy puts a big motorised butterfly valve on the fresh air intake tube but runs the originall stove air control manually. Seems to be primarily over temp alarm/reaction system


edit - spotted the prequel video which has an app note special home brew rtd amp and logic thresholding if you read the circuit diagram ie no proportional air intake. Also can't spot air valve motor in diagrams (?)


edit2 - smoke inhibitor and hope for the best :)
 
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Pacific energy EBT patent - kicks in extra primary/secondary(?) air during peak burn, leaning to secondary as explained gasification bloom at peak needs more secondary air - "The control system works opposite to the traditional bi-metal control systems because when the temperature rises the bi-metal opens the flap against gravity, thus additional air initially increases stove temperature which causes the bi-metal control to continue opening the flap."

US6041770A - Bi-metallic control device - Google Patents

A bi-metal control flap for a wood stove is biased to close by gravity and is controlled to open an air inlet when the temperature rises which is opposite to the traditional bi-metal control systems which close when the temperature rises. The valve is a free pivoted L-shaped flap with a first...
patents.google.com
 
Seems these guys are all in.


note the wraptor inspired sheave and rope scraper at 8:05
Burrapeg check out 11:28
Also state awah store/site are grey market copies
Sour note - when he says Zhang Feng is the inventor of the drill powered unit in 2018 - we know better ours were circa 2014 wraptor maybe 2013
 
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This post is a real flyer hail mary, fully expect crickets, but what the hey,

Son's christmas toy train 0-13Vdc controller works fine for about 1 minute, rated 400 mA only drawing 250 at the train, traced it down to overheating PTC 750 ma continuous rated thermistor between the 18v ac in and the main bridge rectifier - it eventually gets burn your finger hot and cct shuts down. no smoke, burn marks etc there or anywhere else I'm figuring a slow decayed failure mode of the thermistor where it triggers at a lower than spec current. main LM317T is an actual national semi part even though cct is chinese and stays cool

Anyone face a failing thermistor before? thermistor is a chinese component quite low volt spec but rated 750 mA, open air cooled
 
Bart_ said:
This post is a real flyer hail mary, fully expect crickets, but what the hey,

Son's christmas toy train 0-13Vdc controller works fine for about 1 minute, rated 400 mA only drawing 250 at the train, traced it down to overheating PTC 750 ma continuous rated thermistor between the 18v ac in and the main bridge rectifier - it eventually gets burn your finger hot and cct shuts down. no smoke, burn marks etc there or anywhere else I'm figuring a slow decayed failure mode of the thermistor where it triggers at a lower than spec current. main LM317T is an actual national semi part even though cct is chinese and stays cool

Anyone face a failing thermistor before? thermistor is a chinese component quite low volt spec but rated 750 mA, open air cooled
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I don't know much about these things, but understand enough to know more or less what you're talking about. I just wanna let you know how much I love this thread. Please do let us know if you get this sorted out.
 
2nd theory is 20 year old lube is crapping out causing higher current draw - maybe just enough to break the camel's back. so shopping for oil, plastic grease. hey! there's just one best oil/grease and it's a consensus ! :)

best for plastic yet seems to be lithium carrier/thickener with silicone base oil, though I saw a vid using what appeared to be thin dielectric grease. The last tube of dielectric I bought seems to be much lower viscosity than in years past. maybe I'll just use that

edit - motor shaft was steel on plastic took a chance with thin mineral oil, worm drive plastic on plastic but eeny weeny sintered metal shaft bushings!!! other axles were metal on plastic, took out bunch of fine fuzz/hair relubed went from say 220 mA down to 170 mA guessing equal speed - thermistor still crapped out! :(

old man eyes and ho scale work = bad, no fun. damn near got a headache

edit2 - hooked floating scope channel across thermistor as a current sense, got a smooth waveform no o.c. discontinuities or s.c. spikes - and it just kept running! Then I realized an old tip from popular electronics circa 60's or 70's if you don't want to fry your component when soldering clip a gator clip on the lead to act as a heat sink while you solder - the scope clips were heat sinking enough to keep the thermistor happy. back to the head scratching. moral - read your dad's/grandpa's old tech magazines. I think it was my school chum's dad's magazine where I read it. Also - soldering to the tube socket, bend the wire to make a mechanical connection before you solder - don't rely on the solder (400V in a tube amp!). Ah, times gone by. I did my whole lighting wiring harness on my mx bike relying on only solder (it's only 12V) so go figure. Pounded that thing royally.
 
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Youtube served this up to me after a 650 km/hr rc drone video. Just like a villain in a sci fi cartoon!


turns out this guy is high electrical power adventurous shall we say



What could possibly go wrong?
 
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