Gas station without pumps

2019 October 18

Book progress update

Filed under: Circuits course — gasstationwithoutpumps @ 22:33
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At the beginning of the summer, I set myself the goal to clear the 161 to-do notes from the draft of my book by the first of December, which meant doing about 1 a day.  I kept up for quite a while, but I am now a little behind schedule, with 48 to-do notes left, which would have me finishing on December 5, if I maintained one a day. The book is now 637 pages, with 315 images in 256 figures (many have subfigures).  I think I may be done adding figures, but the remaining to-do notes include adding a few pages of text (which may or may not increase the page count for the overall book, depending of how much white space there is at the end of the relevant chapters).

I was keeping pretty well to schedule over the summer, but I fell behind during the Santa Cruz Shakespeare trip to the Oregon Shakespeare Festival in Ashland. The trip was worth the time—I saw six plays: two very good (La Comedia of Errors and All’s Well That Ends Well), one well-acted but with a bit of a thin script (Mother Road), one well-acted but with awkward sets and strange direction that did not really work (Macbeth), one interesting but deliberately uncomfortable play (Between Two Knees), and one awful production (As You Like It) that failed in almost every way.  The original script for As You Like It is good, but the director managed to mangle it by rearranging speeches, assigning them to the wrong characters, cutting excessively, and generally making a hash of it. Gender roles were randomly reassigned, the wrestling match was played for laughs (like a video game), Touchstone was played very stiffly, and Jaques was changed from a melancholy character into a giddy one.  The costuming was also poor—I felt very sorry for the actors having to put up with such a poor interpretation of the play.

I’m on leave this quarter, so I don’t have to teach, go to meetings, or hold office hours, but I’m taking a physics course (PHYS 102, which is an introduction to quantum mechanics).  The homework for the physics class has been taking quite a bit of time, and I have been prioritizing it over the book writing. I brought my laptop with me on the Ashland trip, but I didn’t do any writing for the book—I finished the first homework for the physics class instead, as it was due the day after we came back.  Today I finished homework 3 for the physics class (due Monday), so I should work on the book this weekend.  Maybe I can get back on schedule? (Or maybe I’ll try mowing more of the back lawn—I’ve cleared about a quarter of it.  Creative Procrastination!)

I’ve also been wasting a lot of time reading news, humor, and a few subreddits on the internet—the physics class is only taking about 15 hours a week, so I can’t really blame the class for my being behind schedule on the book.

2019 August 31

Shakespeare cookies v7

Today (2019 August 31), my son and I baked shortbread cookies using version 7 of the Shakespeare cookie cutter, which is a two-part design with a separate cutter and stamp:

Version 7 of the Shakespeare cookie cutter uses a simple outline for the cutter and a separate stamp for adding the facial features. Version 6 of the stamp failed, because I made the alignment markers too thin and they did not survive even gentle handling.

In addition to the new cutter and stamp, we also tried out the “cookie sticks” that I made for rolling the dough to a consistent 6mm thickness:

I made two different sticks: a straight one and one with a 90° corner. The OpenSCAD file also allows other angles, so I could have made 120° corners for a hexagon.  I made the sticks about as big as I could print on the Monoprice Delta Mini.

The hooks at the two end of the stick lock the sticks together.

I made enough of the sticks to make a rectangular frame almost as big as my cookie sheets. I ran out of the ugly green PLA filament after only 3 sticks, so I did the rest in the Hatchbox gold PLA filament.

I made the same shortbread dough as last time: 1 cup butter, 2 cups pastry flour, and ½ cup powdered sugar. I cleared a counter to make some workspace:

I had a cookie sheet,a rolling pin (a piece of birch dowel that I sanded and coated with mineral oil decades ago), a silicone baking mat, the cookie sticks, the cookie cutter and stamp, and a shallow bowl for flour.

The entire batch fills about 2/3 of the frame when rolled out:

For the first batch, we tried rolling the dough directly on the silicone baking mat, and removing the excess dough without moving the cookies.

The cookie sticks worked well for getting a uniform, consistent thickness to the dough, and 6mm is about the right thickness for these cookies. Having a complete frame around the dough meant that I did not have to worry about the cookie sticks shifting position, nor what the orientation of the rolling pin was.

The stamping is easily done on the cookies, but removing the excess dough from between the cookies was harder than we expected. It probably didn’t help that it was a warm afternoon and the dough got sticky quickly, even though we refrigerated it before rolling.

For the second rolling, we rolled the dough onto waxed paper, then transferred the cut-out cookies to a baking sheet lined with a silicone mat, doing the stamping only after the cookies were on the baking sheet.

We ended up with 19 cookies from the batch, and they came out pretty good:

This picture is a bit misleading as these were probably the best two of the nineteen.

The biggest problem was with dough getting stuck in the nose when stamping—it might be easier to do Tycho Brahe cookie cutters!

The second biggest problem was getting accurate alignment of the stamp with the cutter. For several of the cutters we were a millimeter off, resulting in an extraneous line at one of the alignment markers.

Despite these minor problems, the v7 cutters were much easier to use than previous versions, and I don’t have any immediate ideas for improvements (other than changing from a 3D-printed cutter to a injection-molded cutter, which would require a lot of changes and cost a few thousand dollars—something I’m not prepared for.

2019 August 19

Shakespeare cookies v5

On Saturday, my son and I baked shortbread cookies using version 5 of the Shakespeare cookie cutter:

The difference between version 4 and version 5 is mainly around the left eye (on the right in this photo). Version 4 had a lot of trouble with the dough getting stuck in the small regions there. (See prior post for cookies made with the V4 cutter.)

Despite the simplifications, Shakespeare’s head is still quite recognizable.

We used the classic recipe (2 cups flour, 1 cup butter, and ½ cup confectioner’s sugar), but this time I used pastry flour instead of a mixture of all-purpose flour and sweet rice flour.  The dough works about equally well either way.

The cookies came out good, but the cookie cutters are still having problems with dough sticking to the cutters. Chilling the dough after rolling helped a little, but stickiness was still a problem. We also had problems rolling the dough out to a uniform 6mm thickness—sometimes we had the dough too thin, and the interior lines were not clear, and sometimes we had it too thick and couldn’t get the cookie out of the cutter without destroying the cookie.

My son had two suggestions, both of which I’ll follow up on:

  • Go back to having separate cutter and stamp (as in Version 3), but don’t try to connect the two.  Make the stamp just have a few alignment marks so that it can be hand-aligned to the cookie outline.  The stamp can have a lot of open space, so that the visual alignment is relatively easy, and so that the cookie dough can be easily separated from the stamp.  The stamping can even be done after the cookie has been transferred to the baking sheet, to make distortion from moving the cookie less of a problem.
  • Make a set of 6mm thick sticks that can be put down around the dough, that the rolling pin can rest on.

Version 6 of the stamp failed, because I made the alignment markers too thin and they did not survive even gentle handling.  I’m now printing Version 7, which has more robust alignment markers.

 

2019 July 24

Shakespeare cookies

Tuesday night I tried making shortbread cookies to try out my Shakespeare cookie cutters, both the version 3 stamp and a 1-piece cookie cutter (version 4).

Back view of Version 3 (the cookie stamp) and Version 4 (the cookie cutter)

Front view of Version 3 (the stamp) and Version 4 (the cookie cutter).

I’m not quite ready to release the design on Thingiverse, as there are still a few problems.  One is that the handle is not aligned in any way—it is glued on with just a pair of flat surfaces without any alignment features.

This back view of the cookie cutter shows the handle, glued on with FlexEpox.

This closeup of the handle shows the lack of any alignment features.

I looked online for shortbread cookie recipes and found a lot of them.  The proportions of the ingredients were all fairly similar, with small fluctuations:

 1 cup butter
½ cup confectioner’s (powdered) sugar
½ cup rice flour or cornstarch
1½ cup all-purpose flour

The biggest differences were in the ratio of the flours—the total flour-to-butter ratio was nearly always close to 2:1 but the rice flour or cornstarch varied from 0% to 33% of the flour, with 25% being the most frequent in the recipes I looked at.  Most recipes called for sifting the dry ingredients together—a useful precaution, as both the confectioner’s sugar and the cornstarch had lumps.  I used a little cornstarch to use up an old box, then made up the rest of the ½ cup with sweet rice flour.

The instructions for mixing the butter, sugar, and flour varied a lot (beating with a spoon, pastry blender, shaving frozen butter, mixer, …).  I opted for one of the simplest methods: softening the butter, beating it with a paddle in the mixer, then adding the sifted dry ingredients and beating the dough for a minute.

The dough came out very sticky, and I contemplated adding more flour, but decided in the end to just chill it in the refrigerator for an hour.

After chilling, the dough was firm enough to roll out between two sheets of parchment paper, but it softened quickly, so I rolled out half the dough while keeping the other half in the refrigerator.

The v3 cookie stamp was a complete failure, with the dough sticking to the whole face of the stamp.  Perhaps if I had used enough flour on the stamp, I could have reduced the problem, but eliminating it seems unlikely.

The v4 cookie cutter was more successful.  The first attempt resulted in a lot of dough getting stuck in the crevices of the cutter, but after cleaning that out and flouring the cutter more heavily on each cut, I managed to get some clean-cut cookies.  Because they were not close on the parchment, I transferred them with a spatula to a cookie sheet that was covered with another piece of baking parchment.

Temperatures for baking the shortbread in the recipes varied from 325°F to 375°F, with baking times from 12 minutes to 35 minutes (and the longer times were not necessarily for the lower temperatures).  On my wife’s advice I opted for the low-temperature end of the range (325°F).  At that temperature, the cookies took about 25 minutes to bake.  She says she does shortbread for even longer at 300°F.

Here are 4 good cookies, two of which are slightly overbaked (30 minutes instead of 25). Even the good cookies sometimes have trouble with the Bard’s right eye and the curl of hair next to it.

Here are three failed cookies. The one on the left has a divot on the top of the head, probably from transferring the cookie to the baking sheet. The top right cookie is missing the curl of hair by the Bard’s right eye—a fragile feature that often gets stuck in the cutter. The bottom right is missing part of the ruff, which broke off when transferring to the cooling rack.

I’ll probably make one more design iteration on the cookie cutter before releasing the design, with two changes:

  • opening up the space by the Bard’s right eye so that cookie dough does not get stuck there so much, and
  • adding some alignment features to the back and handle, so that the handle is more easily glued on.

2019 July 15

Shakespeare cookie cutter v3

Filed under: Uncategorized — gasstationwithoutpumps @ 20:27
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My first post on the Shakespeare cookie cutter was about versions 1 and 2 of the cutter and stamp—both of which were basically unsuccessful.  I had two ideas for fixing the problems: making the cookie stamp larger and simplifying the artwork.  For version 3, I tried both.

The face is still vaguely Shakespeare, though the mouth is not right. I increased the size to 85mm (from 50mm and 60mm for the first two versions), which is the largest size that would fit on the 100mm-diameter bed of my Monoprice Delta Mini printer.

The printing was much more successful this time, with very little stringing or blobbing.

Here is the front view of all the pieces. The knob is still the one from version 2, as I saw no need to reprint it.

The back view shows the side that was against the glass baseplate (except for the knob, which I forgot to flip over).

I was worried about installing the shaft crooked, and figured that if I just used a machinist’s square, I’d end up supergluing the tool to the stamp. So I printed out an alignment jig:

The front view shows how the alignment jig holds the shaft directly in line with shallow hole in the back of the stamp.

The top view shows how I used 5 cylinders as to fit snuggly around the stamp to hold it in a fixed position.

The hole in the alignment jig closed up a tiny bit, so I held the metal rod with vice grips, heated it, and shoved it through the hole to make the hole just big enough.

Unfortunately, the only superglue I had in the house was several years old (though in an unopened little tube) and it did not set when applied—it was still soft after 15 minutes.  I’ll have to get some more superglue (or other quick-setting strong adhesive) tomorrow to attach the shaft to the stamp.

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