Monday, December 28, 2015

Bolting Reel

I built a bolting (sifting) reel for the micro-mill, using old time mills like the one in Richfield as a pattern.  Although old sources recommend bolting reels that are 12, 16, or 20' long, I am hoping that I can get away with a much shorter reel since I do not sift very finely.  This reel is 12" in diameter and 24" long.  The mesh is 32 mesh T316 stainless steel bolting cloth, which has openings of 629 microns.

Here is the reel, 6 sided and built on a 1 1/8" dowel.


Here is the cabinet going together.  Angles are all 45 degrees, which works OK but I later found the flour can still hang up on the sides.

My Dad gave me a worm drive gearbox which had a 60:1 reduction.  This works great although the cabinet is resonating and the 1/4 hp motor is making a lot of noise.  The reel is turning about 45 rpm I'd say.  The bearings are all hardwood, lubricated with beeswax at this point.  I made the pulley on a lathe, quick and dirty.

Here is the bolting cabinet being tested with the mill.  Flour comes out of the mill and gets dumped inside the reel while it turns.  Flour comes out the small hole and bran the larger hole at left.  The extraction level is 90%, based on the first full bag I milled.  I am going to experiment with re-grinding the bran and increasing the extraction level.  This mill spits out cracked grains and it really needs to have the bolting attachment at this point. 

This 90% flour is really making a nice loaf.  Here is my second attempt, which was the lightest and chewiest loaf I have made so far:

Sunday, December 13, 2015

Millstone dressing

To improve upon my mill project I ordered a set of 250 mm composite millstones from the Danish company Engsko.  Unfortunately, the millstones would not produce good flour in the mill.  I made several attempts to carefully line up the stones, shimming the mounting of both the bed stone and the runner stone, and finally "tramming the spindle."  No matter what I did, the mill would not produce good flour.

So I eventually concluded that the millstones as delivered were not properly dressed.  My own hunch is that these stones warped at some point in the curing or aging process.  The 250 mm stones are very small and I suspect this company does not sell that many of them.  Anyway, I pulled the runner stone off the shaft, which was a giant pain since my homemade keyway had welded the fitting onto the shaft.  I really had to pull hard on the harbor freight bearing puller, but remarkably it worked and I got the stone slid off.  Here is what I found with the straightedge:

Both the runner stone and the bedstone are high in the middle.  

This is a combination of old school and new.  I painted soot and linseed oil onto a stick of wood that I jointed to be perfectly straight.  By dragging it across the stones you can see the high spots.  In the above pictures, before I started, you can see how little of the stone was actually available to grind flour.  They are almost 1 mm high in the middle!

Here is how it was looking after a few grindings.  Not nearly flat enough, as it turned out.  But it sure seemed pretty flat to me at the time.

I eventually converted the mill to run with the lower stone as the runner stone, which I discovered is the modern way of building a horizontal mill.  The eye stays cleaner and it seems to draw grain in more evenly.  Anyway, the mill ran a little bit better but it was clear that more aligning was in order.  Here I am using a dial indicator to align the runner stone to the shaft.  I got it even to within a couple thousands of an inch. 

But it still wasn't good enough.  I began to suspect that the landings were getting too glazed from the angle grinder, so I went at it with a pick to roughen up the lands.  A brick hammer is working pretty well, as long as I sharpen it regularly.

It's getting closer to making flour, as you can see the white powder in the below picture.  But it has to be better, so now I am painting the stones with food coloring, running them together, and then hammering away at the places where the stones touch.  I'm learning a lot about millstone dressing!  Will report back when it's finally working well...

Sunday, November 29, 2015

Grain dryer

I purchased 6 bushels of compromised red fife spring wheat that I hope will be viable for a planting in 2016.  The wheat measured 19% humidity when I bought it last Sunday.  Ouch!  The smell was obvious without any need of testing, and I was pretty amazed that it was not actively sprouting or getting black inside.

Anyway, I needed to build a dryer ASAP.  Turns out 55 gallons is almost exactly 6 bushes, so I grabbed this barrel and cut off the top.  On the bottom I built a wooden box with a small blower.  On top of the wooden box I cut 3" holes and stapled window screen over the openings.

So here you can see the setup.  After a couple of days I added the ceramic heater, so the blower draws in some hot air.  You can really feel the air moving through the grain and coming out the top.  For the first couple of days, the moisture level hardly moved.  But 2 full days of heat really got it going, and today it is testing in the 13's.  The volume has gone down noticeably--the pile of grain is about 3" lower now!  I will give it another day or two before bagging and storing, and doing a good germination test on the lot.

I'm really glad I took the time to build a gate to draw grain off the bottom.  I have been draining a couple of buckets each day and pouring it back on top, to agitate and move the grain around.  It should make bagging very easy, too.

Sunday, November 22, 2015

Mill Project

Here is my "mini-mill" project, which I am building as precursor to a more ambitious unit.  I have been studying historical sources and examining modern horizontal mills to get guidance and inspiration.

The shoe and damsel meters out the flow of grain into the eye of the runner stone.  It was fun to build this part and it works great.

Here you can see the runner stone and the octagonal housing I built.  I glued a little flag onto the outside of the runner stone to help create some wind to push the flour out.  You can also see that I ground the top of the spindle to create an eccentric that the damsel rides against.  This jostles the shoe and helps the grain flow out evenly.

The pattern is a classic layout of lands and furrows.  Grain enters from the top and moves out as it is reduced into flour or feed.

Here is an early fit up, trying to figure out how the housing is going to work.  The bed stone is bolted down to the base, and the spindle is supported on a bearing mounted on the bridge tree below.  The crane, screw, and bale (at right) can then be rotated to raise and lower the spindle.

This is the bedstone after removing from the form, with the top bearing I used. This top bearing seems to bind on the spindle and prevent it from moving up and down smoothly.  I am going to try a hardwood top bearing next.  Hardwood top bearings have been used in stone mills for centuries.

I cut the form to make the furrows and lands as a three-dimensional mirror image using a dado head on a radial arm saw, then dropped it into the bottom of a 12" diameter bucket and put in counter top mix cement.

Monday, November 16, 2015

November Survey

Garden status as of November 16.  There has really only been 2-3 nights of frost to date, not enough to kill the swiss chard or bok choi.  There is a bunch of stuff that I just did not get to.  The below pick shows the historical grains research plot, all healthy and strong.  To the right I have mulched some of the leeks and carrots to stretch them out.  The light green are daikkon radishes, which I planted too late to be of much use.

The oats and peas which were drilled over the spring wheat and garlic took well.  Weirdly, the South end is peppered with volunteer bok choi, really nice stuff that I have gotten many good meals out of.  Much better than the bok choi that I intentionally grew this season.

Three rows of garlic, trying a mulch for the first time.  I have so much wheat straw that I am just coming up with things to do with it all.

Red clover from the barley and winter wheat strips, and to the right is wheat and a little vetch which is a cover crop in the former corn ground.

Tuesday, October 27, 2015

Eco j oven project

Build sequence of the oven I built with Christin at the Eco-Justice Center.  We did most of our sessions together, and we each have at least 40 hours in this project.  It's a substantial undertaking, and we worked very fast and hard.  A more leisurely pace, or working without experience (this was my 5th oven) would make this project go significantly slower.  Material expenses came in around $1200, but I don't think this included the concrete slab that the concrete blocks are sitting on.

November 3.  Our last big session of work together, spent applying stucco to the cladding.  We used the cement mixer and used up 1 80 lb bag of stucco, using a mortar color to get the nice tan color.  The stucco took a lot of pressure to stick, but overall it went on nicely and the color is actually quite stunning to see in person.  The chimney height is a wild guess but it looks about right.

October 29.  Christin did some chimney work the day before and we did a small amount of planning on this day.  Too cold so we quit early.

Concrete cladding going on October 27.  We used a total of 14 60 lb bags of premix.  I used an air-entraining admixture to improve the workability of the concrete.

We used our hands, trowels, wood blocks, and a large random orbital sander to get the concrete to settle.

Cladding took around three hours, all hard work.  We pulled the forms off about 5 hours later and worked the concrete around the lip where the wall met the dome.  There was a little damage to the cladding when the form pulled away some small chunks down low on the sides.  We plan to fill this in with some stucco/mortar.

The dome covered with 3-5 layers of heavy duty aluminum foil, which reflects heat and helps to decouple the cladding from the brickwork.  Reinforcing wire is some ordinary fencing material.

The arched oven opening came out nice.

Christin jumped inside to tuckpoint some gaps in the brickwork.

Back corners were formed with just 4 bricks.  Cutting these bricks takes a long time on the 10" wet saw, which cannot cut all the way through a brick laid on edge.  So a double taper cut takes 4 passes of the saw.

By keeping the corners at the front and the back tight, the closing in process is greatly simplified.  In the back we just laid two courses in a staircase, then closed things up with bricks and 45 degree cuts.  This kind of cut is easy on the wet saw.

October 16--all three arches are up, and most of the outline is in place.  We did arches 2 & 3 in the same session, and I pulled the form out just a little too soon. The #2 arch slumped ever so slightly at the peak.

Arch work pics that Kate took, probably October 16 or so.

Closing up the front.  You need to set the front opening first, and then fit the sides of the oven to that opening.  This oven has 3 brick arches, which I think is probably a very good depth for most applications.  We would have liked to make this oven wider but this was the widest we could go on the slab that was provided.

October 14.  I put up the first arch.  After this point Christin laid most of the bricks while I spent most of my time cutting bricks and planning the next move.

October 12. Pouring the floating slab. This is the critical innovation in an Alan Scott oven.  The oven slab is suspended and decoupled from any mass that could draw heat out of the oven's mass, just being suspended on 5/8" re-bar.  The bottom of the slab is a vermiculite/cement mixture to add even more insulation.  Above the re-bar it is ordinary bagged concrete.  The slab came out good and flat, and pretty well tamped.

The front (over to the right) is open and 2 pieces of angle iron hold up the blocks.

First day of work was October 5.  The concrete slab we started with was uneven and we did some correcting with the mortar joints to try and get things leveled up.