Category Archives: Miscellaneous

Miscellaneous

A good “Springerle” recipe

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A good recipe for “Springerle”, a traditional German Xmas cookie, there are many around but this time I took precise records to ensure consistent results.

My intention was to make somewhat smaller Springerle quickly, and the key point is a slight anis smell, some anis seeds, and nicely developed “foot” of each cookie.

The results turned out very well, and in the meantime, all have been consumed.

The “foot” is clearly visible, so are the anis seeds.

The recipe is adapted from an old book, a famous general cooking book of Ms. Paula Horn, but it is lacking some precise measures and temperatures.

Apart from the recipe, you will also need a roller, similar to this one.

250 g of Eggs, (weight includes the shell)
500 g of powdered sugar

Combine and beat it very thoroughly to a creamy mass.

Mix in 500 g of freshly sifted flour, mixed with 3 g of powdered anis, and 1 g of sodium bicarbonate dissolved in about 10 mL of warm water.

Rest the dough for 30 minutes, then roll it to about 1 cm thickness. Don’t add too much flour when rolling.

Then uniformly push in the carved roller to leave impressions. Cut to rectangular pieces and put them on a non-stick paper, lightly sprinkled with anis seeds. Keep these 18-24 hours at room temperature so that the cookies dry, on an flat surface, so the cookies won’t deform.

Then bake without touching the cookies first, 18 minutes at 150°C upper/lower heat should be just fine. The final cookies were about 8 mm thick, before baking. Thicker cookies may take longer, just ensure that they stay white, only the edges can turn very lightly brown. Don’t worry about the ammonia smell.

Once they come out of the oven, they may still be a little soft, don’t touch them yet.

After letting them rest for 2 weeks, they should be pretty hard, but delicious.

Miscellaneous

A new Honigkuchen recipe

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A new recipe for delicious christmas cookies, called, “Honigkuchen”, say, honey cookies:

Prepare a mixure of 250 g wheat flour, 100 g rye wholegrain flower, 15 g christmas spices (anis, cinnamon, etc.), add,

300 g of honey – heat so that it is fully liquid but don’t boil

2.5 g potash (potassium carbonate), 5 g hirschhornsalz (ammonium bicarbonate) – dissolve these salts in about 10 mL of warm water (don’t worry if it doesn’t all full dissolve), add to the mixture.

Mix and kneed to a thorough dough, let it rest about 2 days at room temperature, well covered.

For cookies about 8 mm thick, then bake at 175°C for 15 minutes.

For a glossy surface you can paint them with condensed milk before baking.

Earlier recipe, here: Christmas Time: Honigkuchen (honey based cookies)

Miscellaneous

Bauhaus VoltoLux LED Lamp: a early failure sickness finally subsided

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Some of the ceilings in my house have LED lights installed in false ceilings, a total of 45 led lamps of the same kind (GU10, 4 Watt reflector LEDs). These are of regular quality, sourced from Bauhaus, a normally trustworthy outlet. But certainly these LED lights cannot be trusted at all. Of the 45 pieces installed, already 4 failed in the first year – occasional use. And another one just failed recently.

The advantages claimed are various, long lifetime, rugged, etc., but Bauhaus doesn’t say that you need to buy 10% more lamps than you need, just to replace the early failing lights. Not even to mention about the effort or replacement, etc.

All of the LEDs are 25360318 with frosted front, 10 LED chips per piece. The failure mode is normally intermittent, so the LED will come on for a little, then go off, it may also come on after a little while, unpredictable.

As it turns out, these LEDs are actually repairable, but removing the front glass disc (frosted diffusor), which is done by heating it for a little while with hot air at about 200°C. The front disc seems to have fixed with some epoxy glue.

Poking around, it becomes clear that the failure more is a broken interface between one of the LED chips, and the aluminum heat-conducting round board they have been soldered to. So, either the design has some flaw, or there are thermal issues or solder/flux issues when manufacturing. Shock or vibration effects can be excluded, because these lights have ever since the renovation been mounted in the ceiling, with no touch or vibration.

To fix it, I just re-flowed the solder, after applying a little flux, and the issue went away. Now you can close the light again, using epoxy glue, and it may provide some further service. No statistics yet on the lifetime of repaired LEDs.

In any case, buyer beware of any of the praised LED lamps, many may fail on you well before their expected lifetime ends, better keep all receipts, so that you can have them replaced by the Bauhaus hardware store, or wherever you prefer to buy your lighting supplies.

Miscellaneous

Metalworking: strange defects of long-used tools

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Recently, I found two strange defects in my workshop, noteworthy to write it down.

Ever since I expanded my workshop I notices some losses of compressed air, i.e., when coming back after a business trip, the pressure of the compressed air pipework is down from normally 6.5 bars, to only 2-3 bars, or even less after a longer vacation. I had attributed it to some leaking air gun or something like that, but finally I did a search and found various leaks at one distribution point.

(1) the water mist filter had a leak at the drain valve — fixed it by closing it altogether. There is not too much water collected, it is installed only to avoid dust and such getting into the system further downstream.
(2) one of the fitting was leaking, because strangely there are some air fittings available that neither have a seal surface, nor conical thread, to it is hard to get it tight by tread tape in the first place (sometime I resorted to gluing-in those fittings with Epoxy glue).
(3) Still, when checking with some soapy water – bubbles at the distribution fitting (5 connections 1/2″). Strange, strange, strange.

Clearly, a defective casting with a hairline crack leak. Maybe the temperatures or the mold or the liquid brass were not right, or the pouring wasn’t steady enough.

The defect line goes all around the fitting, otherwise I would have tried to file it out and solder it tight. Anyway, it is not worthwhile to fix such part at the risk of it failing again. So I replaced it with a new fitting at the cost of EUR 9.90 and at least 3 hours of work to get it all investigated, replaced, fitted and leak tested. Maybe a good idea to fully upgrade the pressurized air system of my workshop, which is now a combination of various distribution pieces, hoses, connectors. But there are trade-offs of perfection, cost, and efficiency — I have actually installed some air pressure distribution pipes for others (like, polyamide pipe, PE-Al composite pipe), but at my own workshop, I will be dealing with a less perfect system, at least, the major leaks have now been found and eliminated.

Another instance of strange failures, I noticed some problems with a bench vice, the smaller size vice I use regularly, and have been using since my childhood. If I remember right, I bought it for something like 35 Deutschmarks way back around ~1990. After all these years, it had some failures, the spindle pin sheared off once (maybe because I tightened it too much), and also a retaining piece of the front part of the spindle wore out (probably very soft steel and insufficient lubrication). Also some part of the casting broke off before, circled in black. Now, I almost injured myself as a part came loose unexpectedly, finally, as they say, always check the tool before you use it.

Didn’t need to go far, a major crack of the dovetail guideway.

It is cracked through, but holding on enough so that the defect is not easily seen without disassembly.

Finally, a cast iron bench vice, after 33 years of service (not always careful use), it may eventually break.

For replacement, I wanted a slightly bigger bench vice, 115 mm width. Also, a solid steel vice that is not too bulky and has a strong grip. These don’t come cheap, but I found a good (but rusty) Peddinghaus Matador steel vice for 35 EUR used, listed in online adds.

After some cleaning, adjustment, and other TLC, it is installed on the bench and working great. Definitely a step up.

Miscellaneous

Wood and Steel, covered in Paint: a new garden bench

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Recently, some heavy metal work in the precision workshop. Amongst other projects, I decide to build a new bench, to set it up behind the workshop building, to enjoy warm evenings during summer. Surely you could buy a bench, but I wanted certain dimensions, in particular, flat and somewhat wider seat area. A rough sketch shows the main dimensions. A cushion can be added, it matches 200 cm wide, 50 cm deep size.

All is made from solid flat hot rolled steel, one piece bent (after heating it with an oxygen torch, and using a small bending fixture), the other pieces welded (TIG).

All the angles were nicely hit.

I made a full size template drawn on stiff cardboard, so the welding and alignment could be easily done, then, fine adjustment by using the electronic level.

To get the right angles I had a look at some benches in public parks, etc., better to compare new design and existing know-how!

The seat, a little inclination to make sure water will drain.

The wood, douglas fir, it has a fair amount of resin and is quite resistant against weathering. It may darken, but it is not prone to rotting. I painted it with some sun-protecting varnish, two layers.
My uncle kindly provided the wood, from my ancestors village, ready to use. Saved a lot of time, compared to cutting and preparing the wood with my humble small woodworking tools.

The metal parts, carefully removed the rolling scale, added rust-proofing primer, and then two layers of solvent based lacquer. You could also consider hot zinc treatment, but such solid steel, painted, should last a hundred years, or longer.

Finally, after some hours of work, and drying the varnish for 1 week during a business trip: finished and at its final place. Very comfortable!

Well

Spring repairs: Fixing and frost-proofing ball valve

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Recently, I have been setting up the watering system for my vegetable garden again. In my area, the soil is a little sandy, not bad for growing vegetables because slugs and snails don’t like such soil, but surely it needs proper watering.
All in all it is about 200 meters of 16 mm drip irrigation pipe, 16 mm size, with drippers every ~33 cm, nominal 2.1 L/h each. The system is run at about 1.5 bar. Some specific plants like pumpkins and certain berry shrubs in other area of the garden have their own supply by 4 mm tubing and individual adjustable drippers.

In the past years, the system has severed me well, and just last year, I have upgraded the water supply by setting up a new well. So there is plenty of water, and every day, at least in summer, the system supplies about 400 L a day, in two portions (like, at 6:30 am and 6:30 pm). Glad I don’t have to carry all that water.

All the water system, pump and distribution piping had been empty over winter, to avoid frost damage to the pipes. I keep the ball valves at about 45° angle, but this year this didn’t help to prevent damage to one of the valves (all the other valves are OK).

It is a combined, low cost China-made ball valve with strainer, I bought two of these some years back.

It is tight when closed, but when opened, water comes out at the crack indicated in the picture.

How can this have frost damage? Well, with the pipe empty, it should be safe? There is considerable dead space in this valve, the ball also has an indentation (cut-out) at the side opposite to the handle. It is brass, chromium plated.

As luck would have it, I had the second valve still in a box, it had been in service for some years until someone broke-off the handle (never throw away parts that may be suitable as spare part donor…). Surely it would be quick to just replace it, potentially, even with a better quality ball valve, etc., but why now study it and fix it?

Breaking open the valve, the two parts are screwed together fairly hard, and glued with some kind of epoxy or similar glue.

But nothing that can withstand a large spanner and a pipe wrench! So, the front part with the PTFE seal looks good. Also the spare valve (with the handle missing/broken off) was disassembled in no time.

Now, how to frost-proof ball valves? It is quite easy, and a well-known trick. Just dill a hole, about 3-4 mm in the far side (low pressure side) of the ball, then it will drain the dead space, when left open (or at an angle).

It is essential to remove any burrs, so I countersunk the hole, and polished the edge with some find sandpaper.

Everything put back together, I used some acrylic compound to seal and tighten the screw threads of the two-part valve. Good as new!

Miscellaneous

Outdoor movie theater: a digital projector ceiling mount

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In preparation for warm spring weather and long summer nights I am already gearing up my outdoors installations, in particular, a video projector will be handy to screen some movies.
It will be working together with a Miracast Wifi display, so it can show streams from practically any device.

The projector is a fairly lightweight model, because I only desire an about 150 cm wide screen.

There are various commercial ceiling mounts, but they all seem about flimsy and inaccurate to adjust. So I quickly fabricated a precision-adjustable mount.

First, a metal plate was affixed the the projector, with a standard UNC 1/4″-20 screw. It is about 10 mm thick hard aluminum, just a piece of leftover scrap (that’s why there are various holes in it).

On the projector side, a 1 mm NBR rubber plate is used to avoid movement and scratches.

The adjustment uses three M6 screws, 1 mm pitch will allow very precision adjustment by Allen key.

For the ceiling side, we use an 18 mm thick piece of plywood, and a M10 bolt. Surely, a longer bolt, rod or pipe could be used depending on the needed distance and rigidity. For the current setup, the M10 bolt is plenty rigid enough.

There are three springs (stainless) to keep the holding plate – mounting plate system tensioned so that the adjustment screws can work precisely.

Still, we need to get a suitable projection screen, and some speaker.

But already now looking forward to various summer movie screenings.

Miscellaneous

Laser cutter setup: air supply, off-gas and various cutting tests

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Finally I find some time to document all the remaining parts of the laser cutter, Workshop Upgrade: Laser cutter and engraver SCULPFUN S9. The cutter itself is just the common off-the-shelf kit, but the air nozzle and enclosure has been custom made. If you want to cut wood, paper, plastics, there will be a lot of bad-smelling and potentially toxic fumes, so better you enclose the machine and provide adequate ventilation. Also, for wood, paper and such, you will need a strong air flow to ensure clean cutting without burn marks.

The setup is now arranged in the basement, so that it can be used quickly and without setup time. There is a metal plate inside, zinc plated steel, so thin materials can be fixed by magnets.

The enclosure, made from 15×15 mm square steel tubing, painted, and the openings closed with white PVC sheet, and yellow (laser-blocking) Plexiglas.

The exhaust is a fan I had handy, a Dalap AP series 125 size, it is quiet and powerful, but surely any similar fan could be used.

There are some openings around the cover (upper) part of the enclosure, accordingly, air can enter and flush out the fumes. The off-gas is connected to an old, disused chimney.

Next, we need a reliable air source. In the main workshop, I already operate a larger air compressor, but it is noisy, and there is no pipeline to the house. Rather than building such pipe system, I decided to setup a second compressor, a quiet compressor, to make the work with the laser cutter more comfortable (hard to focus on any work close to a running compressor…).

It is a Hyundai brand silent compressor, quite decent built quality, and inexpensive for what it is.

With these data, it is running about 30% of the time, when the cutter is taking the full amount of air.

The tank is running with 6-8 bars pressure, by on-off regulation. The line pressure is set to 5 bars, so the pressure to the laser cutter system is stable.

There is already a moisture (water droplet) filter at the compressor, but I added another air filter, a simple model, EIF 4000-04, which is a centrifugal filter including a 5 micron particle filter. This is prevent particles from getting into the needle valve (potentially affecting or blocking the air flow), and removing any water droplets (condensate) in the line.

For easy use, there is a cut-off valve, and precision needle valve (Festo GR-QS-8) to set the air flow at the desired value.

The GR-QS-8 was cheaply available, but sure any similar precision needed valve will do.

The flow meter has a built-in needle valve, but strangely, when using this valve (partially closing it at inlet pressure of 5 bar, outlet pressure basically atmospheric), it causes the metering sphere to rotate quickly and with noise, showing completely incorrect readings. So I believe the design of this built-in needle valve is somewhat flawed.
Be sure to install any valve BEFORE the flow meter, because if you operate the flow meter under pressure, it will show completely incorrect readings. 16-18 L/min is plenty enough for the cutter to work without any burn marks. I have not optimized this much, but maybe you could also work at 12 L/min for most situations.

Cutting plywood works just great, with maybe 0.2 mm cut width.

All the contours are nicely defined.

Even stars or pointed objects can be cut without any trouble. These are just about 3-5 mm size!

With some materials, like, rubber and aramid enhanced seal papers, these don’t cut well, or not at all. And even the vendor (Klinger of brand Klingersil) doesn’t recommend or even support laser cutting of these materials, such seals still need to be cut or punched.

Other seal materials, like, reinforced paper (cellulose) materials including Elring Abil brand materials, these could perfectly fine.

Miscellaneous

Baking 1&1: delicious cocos cookies

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These cookies are not only delicious at xmas time:

250 g soft butter
250 g sugar – beat thoroughly
add 1 egg – beat again thoroughly
add a dry mixture of 1/2 baking powder, 200 g cocos (ground), 250 g flour.

Make rolls of about 2.5 cm diameter (about 30 cm long so that you can easily handle). Let these harden in the fridge for a few hours or overnight. Cut slices about 1 cm thick. These slices will change shape while baking. Surely you can also make other shapes.

Bake at 185°C upper-lower heat for 12 minutes (until the edge is just a little brown).

Miscellaneous

Baking 1&1: hazelnut cake

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A very quickly made cake, if guests announce their coming unexpectedly:

100 g soft butter
80 g of full far margarine (80% fat)
150 g sugar
3 eggs
beat thoroughly.
add 90 g milk, mix thoroughly.

add 180 g flour mixed with 1/2 baking powder (or self rising flour) and 200 g of ground hazelnuts.

Bake at 180°C upper-lower heat for 40 minutes.

Let it cool down in the mould for 15 minutes, then remove.