"Gas Guage" and Auto hopper-filler inventions...

"Gas Guage" and Auto hopper-filler inventions...

PostBy: BurninCoalInRI On: Sun Jan 21, 2007 12:37 am

Its 15 degrees and howling wind and the house is quite warm. in fact since the mag is in the basement, the colder it gets outside, the warmer the floors get!

So I'm really liking my Mag Stoker, and would like to soup it up a bit. One thing I'd like to do is know what the level of coal is without visiting the basement. Also, I'd like to get the coal from the bin behind the stove, into the hopper with something wasier then shovel and bucket.

Here are my solutions:

gas guage... this has 2 options actually:

1) get a car gas tank sending unit with float and mount it to the hopper cover. Then install a generic gas guage upstairs. At a glance, I could see where it is from Full to Empty...

2) install a metal rod in the chase of the metal chimney, and connect it to a 5"x5" square board that rides the coal down as it drops. The chase could have small glass "windows" in it at each floor with a red line on the rod and E - F marks on the glass.


1) rebuild the coal bin so the bottom is above the hopper and slope the floor toward the center and install a chute (this option would lose me capacity from 4 tons to 2 or 2.5)

2) make some kind of auger that pulls coal up and dumps it in...

has anyone already done any of this?

PostBy: WNY On: Sun Jan 21, 2007 9:30 am

Same here, we will be moving the stove to the new house hopefully next weekend and it will be in the basement too. I was thinking of something similiar, but....

I was going to put a wireless security camera pointed towards the stove/hopper and then you can just switch you TV and/or computer input and take a quick look at it anytime and put some temp gauges within view, maybe a mirror so you can check the burn window if needed if the camera is out of view range. (range of $50-$200)

A few

This link is broken, either the page no longer exists or there is some other issue like a typo.

Haven't thought about the autofeed yet, until I get my bin built. But always thinking....
Last edited by WNY on Sun Jan 21, 2007 9:50 am, edited 1 time in total.
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

PostBy: coaledsweat On: Sun Jan 21, 2007 9:47 am

How about a lever float switch? Hook it to your stereo to play "loaded 16 tons, what ya get, another day older and deeper in debt". I forget the artist, maybe coalman knows. :)

As far as augers, I like the Axeman-Anderson style, it's a hollow auger that won't clog or overfeed. You could tie it in with the float switch. Just put a big paddle on the switch set at a 45 degree angle. Have the auger push the coal from the rear under the switch to the paddle pushing it up and shutting it off.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: LsFarm On: Sun Jan 21, 2007 10:57 am

Neither the ball on the float switch or the board riding the coal will actually 'float' on the coal, So an auto feed auger would bury the float in coal, and keep feeding the overflowing hopper untill the supply ran out. [if the float postion was what triggered the auger]

2-3 tons moved from the coal bin to a pile covering the stove, What a sight!!

Now if you can figure out a 'Rube-Goldburg' electronic float-retraction-solenoid' and put a timer on the auger so it can't over feed, drop the float back on the refreshed coal in the hopper. ..... I'm getting a headache....

Time it.. once a day, add to the hopper, empty the ash pan... or every two days.. whatever works.

I have to walk 50 yards outside to the boiler building, so going down to the basement shouldn't be too bad of a hike....

A warm house in the morning... what a concept....

Greg L

Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: coaledsweat On: Sun Jan 21, 2007 11:35 am

If you dump the coal on the float yes, if you push it up from below and behind, no.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: Paul Waelder On: Sun Jan 21, 2007 1:24 pm

hey, this is my first post ! how about two photo cells one on top (max. limit) one near bottom (min. limit) to control the feed ? might have to clean lens from time to time ? but far less mech. issues!
Paul Waelder
Stove/Furnace Make: LL-pio./Key.-90/Alk.-hearth
Stove/Furnace Model: home made w/ LL40k stoker

PostBy: Yanche On: Sun Jan 21, 2007 1:31 pm

coaledsweat wrote:Snip...

As far as augers, I like the Axeman-Anderson style, it's a hollow auger that won't clog or overfeed. Snip ...

But other than A-A where do you buy one? I can't figure out how I could possibly build one. How would you weld the helix inside the pipe? Anyone own an Axeman-Anderson? Tell us how the auger is built. Please ....

Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

PostBy: LsFarm On: Sun Jan 21, 2007 1:41 pm

Yanche, I've thought about the same thing, How about if the tube was split lengthwise , and the spiral was welded to one half of the tube, then the two halves of the tube rejoined?? Hand welding for the attaching the spiral inside the half-tube, but could use automated Mig welder for the two long outside welds joining the halves..... ???

I'd just try to find a regular type auger from the AG industry, something for moving peas, beans and corn. I ignored many of them at farm auctions years back.

Greg L
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: coaledsweat On: Sun Jan 21, 2007 2:57 pm

Just a long wound ribbon of flat stock is what looks like to me.


It only needs to be welded in a few spots, just drill the tube and spot weld the ribbon to it from the outside.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Coal hopper level sensor

PostBy: Highlander On: Sun Jan 21, 2007 3:39 pm

A common method to detect the level inside a bin or tank is to use an ultrasonic proximity sensor. They can be set to give a contact closure at a certain distance or provide an analog output to drive a meter or as an input to a PLC. They are usually pretty expensive, typically in the 2-$300 price range.

As an alternative you may want to try one of these Ultrasonic range finder kits. Here is a link to one that provides both a contact closure and an analog signal to drive a meter. http://www.electronics123.com/s.nl/it.A ... ategory=43 With shipping, its probably in the $50 price range.

If you can solder, and are electrically inclined, this just may be the ticket.
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Velleman ultrasonic range finder kit
Stoker Coal Boiler: Harman VF3000
Hand Fed Coal Stove: Vermont Castings Resolute
Coal Size/Type: Rice
Stove/Furnace Make: Harman
Stove/Furnace Model: VF3000 Stoker Boiler

PostBy: coaledsweat On: Sun Jan 21, 2007 8:38 pm

The Axeman screw doesn't need any level or speed control, once the downtube is full, the extra just rolls back down the bore of the screw. It cannot overfeed.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: bobkat On: Sun Jan 21, 2007 9:19 pm

That artist would be Tennessee Ernie Ford.
Stove/Furnace Make: Hitzer
Stove/Furnace Model: 50-93

PostBy: TechCurmudgeon On: Fri Jan 26, 2007 11:38 pm

I'm going to meander a bit with one possible solution with a thumbnail sketch hitting it's high points (the devil is always in the details), and to babble a bit more on other possibilities.

I have a friend who put together a pneumatic vaccum loader system, but didn't add any automation (loading simply by turning on the vacuum for 20 or 30 seconds to load, then turning it off, and waiting until it stopped dumping ... then repeating as necessary until the barrel was full). It worked fairly well, but he's since gone to oil heating (too much coal dust in his basement to use it for a laundry/rec room/computer study).

The two downsides were that the vac pump filter - he used a big Craftsman wet/dry vac for the pump - would block up with enough coal dust on a monthly basis to require replacement, and it is rather loud (sucking small rocks through aluminum piping isn't exactly quiet).

System layout


A 30mm capacitive proximity switch (NOT the more common inductive type) is used to detect fill level. They work well, and will last practically forever, but cost about $100 -$150 (see eBay comment).

My friend works in a plastics plant, and salvaged the vacuum receiver - the costliest part of the system - that he used from a decommissioned piece of obsolete equipment. A new receiver purchased from an industrial supplier places it outside economic justification. However, (and this holds for everything here) keeping an eye peeled to eBay, and waiting until reasonably priced salvage pops up (or knowing someone who can get one for nothing) keeps it in the game. There are a couple of Conair receivers up on eBay now, but, at $500 a pop, aren't what I'd consider reasonably priced for the home experimenter.

This is what a typical vacuum receiver looks like:

To add a bit of automation I'd probably use a Siemens Logo!. They aren't too costly even purchased new (~$150), and older, less capable models turn up occasionally on eBay in the $40-$60 range. The Logo model is 6ED1052-1HB00-OBAx (x could be anything from 0 - the original version to 5 (the current hardware version). Revision 3 and higher allow a bit of rudimentary HMI capability with a user programmable screen message function (and offer more 'function blocks' in the programming language).

The biggest cost here would be getting a copy of the ComfortSoft programming software, and special computer cable used to download the program you've developed into the controller. On the other hand (I'm not certain about the current generation) the original controllers could be programmed by keying directly into the front panel (a painstaking chore, however), and didn't need either.

Here is an electrical wiring sketch, and a basic program that would load for x amount of time, wait for y amount of time (to allow dumping), and trigger an alarm (and stop loading attempts) if an excessive number of load cycles were required.



I like the Logo because it gives a lot of flexibility for future additions. For instance, this particular model has an RTC (real time clock) feature, and you could do a bit of interfacing to monitor the auger motor, and add some programming to record how many minutes it has been running (that is, 'build' a run time hourmeter).

This would address the first part of your question, because, although you could add an analog form bin level sensing (the 'gas gauge' example) I'd go with elapsed run time instead.

For an auger run at constant speed x amount of coal will move in y amount of time. For instance, my coal stoker uses about 11.4 pounds of coal for every run hour, and the 55 gallon drum it feeds from holds about 230# of coal from completely full (level with the lip) to when the auger is uncovered, so I can run approximately 20 hours from complete fill to empty.

In my case, I could set up the Logo programming to give an alarm, and/or turn on a pilot light when the elapsed run time (since last reset) exceeded 18 hours, or whatever suited my fancy. However, if you automatically reloaded your hopper anyway, I don't know if I'd bother with monitoring it's level per se, and rely on the 'haven't filled in x number of cycles' alarm to let me know something was wrong.

Cheaper than the Logo! (or other controllers) would be to hard wire a set of relays for load and dump timing.

Sample hard wired timer circuit


Control relay CR1 latches up the circuit so at least one fill cycle will occur. Without this there is a good chance the vac pump would cycle on and off very quickly as coal level just uncovers the level switch - not good from a reliability or performance perspective.

TDR1 controls the load time. Once it hits setpoint the pump motor control relay turns off, and TDR2 (the dump timer) starts. When it hits setpoint CR1 falls out, and, if the level is satisfied, we're done. If not, another load cycle commences.

The motor contactor is a power relay with contacts rated for the wet/dry vacuum - a good choice here is a DIN rail mounted IEC relay. This one is a bit small for my taste, but here is one now on eBay to show they look like.


Even a home-built scratch project needs a suitable electrical enclosure - a 16x20x8 box would be my minimum. You could bolt everything to a chunk of plywood, and it would work ... but electrical stuff can burn up, and (if, say, a contactor pole burned open, and the wiring insulation caught fire) you could easily burn down the house.

Again, this type of stuff shows up on eBay, and (in addition to whatever electrical supply places are in your locale, for instance, All-Phase, Rexel, and others) there are a couple of web based stores that sell cheaply (in terms of industrial gear, that is), and sometime of this stuff can be found at web sites that sell miscellaneous surplus.

If someone has money to burn and wants to go nuts with home automation, coal burner style, check out cheaper lines of PLCs (programmable logic controllers) and HMIs (human machine interfaces).

Probably the least expensive one I'd recommend for non computer hardware gurus is the EZ-Touch PLC line.

Be aware that 'least expensive' is a relative thing, and here is in terms of typical industrial users - system costs could easily go to more than $2000 if you wanted to tie it to your home computer network, and add wild stuff like trend logging and others bells and whistles.

Links List
Automation Direct
EZ Automation
Siemens (Logo! controller)

Surplus (there are at least 30 other reasonable surplus resellers on the web; this is a sample)

Herbach & Rademan

Caveat - all readers should keep this in mind ... if you go this way be aware you'll spend a fair amount of time researching parts, weighing component selection decisions, and, depending on your background, learning new fabrication and programming skills.

These thoughts are batted around intended for the home hobbyist aware that they are on this road of exploration and discovery for their own education and enjoyment, and it's their responsibility to vet what they build, and be handy enough with tools in order to avoid bad consequences (burning down the house, slicing off fingers with a jigsaw, and electrocution are the first that come to mind).