EFM 520 Auger Pitch

Here ya go! This is probly a simple question but it is one I need to know the answer to. What is the rate of slope that the auger on a EFM 520 set at. I'm building a new bin this weekend and want to have it all set up to just move the stove over and couple the extension worm to the starter worm. Is it 2" per foot or something like that? Thanks. Scott

its prolly something like that..... dunno but waiting to find out also

Over a length of 96", it rises about 18", something like that.

Thanks for the reply Chris. So that works out to about 2 1/4 inch per foot. After I posted, I went to the EFM manual website and found where they stated if the 4 foot auger is used then raise the boiler 7" to keep the bin the same level. That works out to be 1.75" per foot. My mixup here is I measured the difference on the pitch going across the boiler and it is 2.5 inches per foot.

Here are the exact numbers:

Over a span of 107", measuring from the bottom of the pipe, it rises from 0" to 14 1/2"

That is pretty close to what the extension auger rate would be. How do you know what would be the otimum pitch? It seems like too little or too much would cause unnecessary auger wear or put more torque stress on the gearbox. One more question. The manual says that the coal will run at a 45 degree angle but will slide down a 20 degree angle. What is the best angle to put on the bin. Making it 20 degrees would allow a much bigger capacity for the same bin footprint as a 45 degree. What pitch did you use on the showroom bin?

I will go out and measure my 520 for you concerning the auger pitch. I always elevate the base two or three 4" solid cement blocks and make up the difference in the bin or barrel height, depending upon the length of auger used.
You are sure right about 'fudging' the pitch, because the extended auger will bind and cause unnecessary wear of the auger, tube and drive mechanism. I think it only requires 2 ft lbs of torque to turn the auger.
I seem to thing the pitch was 2/12, but I'll check it right now. I measured 2.25 in 12" Hope it helps. :discuss:

Forgot about the pitch of the sides. I use 22.5 degrees when size is critical, and cover the surface with aluminum coil stock. You can't stand on it very well, but the coal will generally slide down it.
Two of my 9 ton bins have a 45 degree angle, but that was because I have lots of room and plenty of headroom.
If you are the 'Anal Engineer Type', they probably want 56.35 degrees or some freaking number that can't be done easily on site. For hand fed units, I make the bin with a flat concrete bottom and perpendicular sides, well reinforced with a 'drop in' type of entrance. Remove boards as necessary.....
Scott, if you are a real stoker-man Gear Head, have an all steel bin made with 22.5 sides. Use 8' plate stock and 4 by 4 by 3/8" angle. It will withstand a Taliban mine and deliver every piece of coal it holds.
PS: don't go inside it with wet or snowy feet unless you have a good deal set up with your dentist.

You could even have a vibrator installed, hydraulic gates and hydraulic dog house. (for the coal, not the damned dawg) :bsod:

I got this 12 ply plywood off a friend that they use to pour concrete on horizontal surfaces. Its super strong but the best part is that it has a real "slippery" outer coating. I guess it makes the concrete release better. I'm set up right now for 45's but if it will slide,,,,,, You guys up there let the dawg out of the coal house once in a while?

Scott, the measurements I got are from the assembled coal pipe at efm. Everything is tight and that's what it came out. Our bin slope is only what it took to cover the pipe angle. I wanted to go for maximum quantity of coal vs. slope. I don't plan to let the bin go empty and I can rake whatever I need on a daily basis when it gets low.

Just an idea to present.....

On my 520 I use the short auger and 55 gal plastic drum.... for a number of reasons...

But.... there is one place that we deliver coal to, that in my mind is the idea set-up for a big bin. They built the bin out of cinderblocks, and at the bottom there is about a 1 foot by 1 foot hole. The bin has sloped sides covered with sheet aluminum, and when the coal slides down through the hole, it enters into another small cinderblock box that is app. 1 foot by 1 foot with no top and then the long auger enters the bottom of this box.

The big benefit to this..... Most rice coal these days is generally pretty clean, but never any garuntees. This is a six ton bin, and if something would plug the auger, you only move about 25-50 pounds of coal. I sure as hell wouldnt want to dig out a six ton bin to find the auger at the bottom.

Just a thought... Im sorry if that is clear as mud. I am sick as hell with the flue (pig flue maybe? )

Tyler

That's how I built the bin at efm, but without the steep sloped sides or aluminum.

I'd stay with the 45 degree. Your plywood source is the best you can buy. You owe him a favor...that grade isn't 25 a sheet, more like 125.00 a sheet. Great idea about the auger pit. I refuse to dig out anyone's coal bin. If you aren't bright enough to make provisions for maintainence, then you and Chuck Norris can dig it out together! I have never second guessed why folks do a 55 gallon barrel with an EFM. I've seen many AA's with 10+ ton bins that had the moisture issue in the fines. No need to be the village idiot, most towns have multiple candidates anyway. Perhaps Malta is exempt.....
Work smarter, not harder......

You can also use the drum inside the bin cut a 2 1/4"or 2.5" hole in the side of bin for auger tube by using it if you have to fix anything on the auger or have to take it out for any maintenance issue it is much easier to clean 1/2 of the drum of coal out and move it out of the way to get to the Auger /Tubes then it is to shovel 6 to 10 tons out of the way put the drum inside the bin and Just keep coal in the drum the coal will be high enough to keep the drum filled by itself for awhile when the coal starts to go below the drum then you will Just have to shovel coal into the drum once and awhile.
No matter how you do it in a bin you will have to shovel or rake coal eventually the drum Just makes it easier to move and get to the auger & maintenance

The efm design in the manual, although not well explained, only keeps a small amount of coal in the pipe area. I keep about 300 pounds over the auger at any time, just in case, and that allows me forget about it over the weekend in this type of weather. In bitter weather, I'll just add some boards and put 500-600 pounds in that area for the weekend.