Icenberg part 3: A satisfying first batch of ice cream

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The very first batch has been made: apple banana coconut sorbet with chocolate oat cookie chunks and roasted soybeans. It took way too long to get a good consistency because of the bad insulation but tasted way too good to not continue with the project. Next step will be a waterproof case with proper insulation and a worm gear drive for the paddle. Then motorizing it with a window wiper motor, a PWM or BAM driver and a microcontroller which monitors everything. I plan to measure the current of the motor and establish a correlation of ice cream consistency and current consumption. With a small LUT (Look Up Table) the controller can then achieve a set consistency and hold it – from slush ice over sorbet up to heavy gelato.

A look into the cylinder of joy.

A look into the cylinder of joy.

The final version of Icenberg will have a proper enclosure with an insulated top lid that will guide the axle.

The final version of Icenberg will have a proper enclosure with an insulated top lid with a hole that will guide the axle.

Ice crystals form on the outside immediately after pulling the container out. Don't lick it!

Ice crystals form on the outside immediately after pulling the container out. Don’t lick it!

At some point the cordless drill and hand crank method failed because the viscosity was getting too heavy. The powerful lathe with VFD and transmission could help out with ease.

At some point the cordless drill and hand crank method failed because the viscosity was getting too heavy. The powerful lathe with VFD and transmission could help out with ease.

Cleaning up is quite easy with water and a cordless drill attached to the axle. Memo: Need to make a cap for the little window when mixing with 600rpm.

Cleaning up is quite easy with water and a cordless drill attached to the axle. Memo: Need to make a cap for the little window when mixing with 600rpm.

Icenberg part 2: Upcycling a fridge to an ice cream machine

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Successfully acquired a leftover fridge from fellow hacker friends, now frankensteining the thing together. Next step: Insulation.

Shopping at home depot, unfortunately they don't have any end caps for pipes of that diameter.

Shopping at home depot, unfortunately they don’t have any end caps for pipes of that diameter.

So we machine one ourselves: Rough formatting a piece of PA6 plastic on the bandsaw.

So we machine one ourselves: Rough formatting a piece of PA6 plastic on the bandsaw.

Then turning it down on the lathe for a proper fit.

Then turning it down on the lathe for a proper fit.

Old refrigerator acquired from fellow hacker friends, let's start to rip it apart.

Old refrigerator acquired from fellow hacker friends, let’s start to rip it apart.

Surprise, mold at the top insulation. Many fridges start to build up moisture there over time when the top cover is removable - which makes sense for under-the-counter scenarios.

Surprise, mold at the top insulation. Many fridges start to build up moisture there over time when the top cover is removable – which makes sense for under-the-counter scenarios.

The polyurethane glue is nasty, one can spare to hit the Gym for a week after disassembling a well built fridge. #rawForce

The polyurethane glue is nasty, one can spare to hit the Gym for a week after disassembling a well built fridge. #rawForce

It looks like it peels off easily. Which is so not true.

It looks like it peels off easily. Which is so not true.

Slicing the insulation very thoroughly into small pieces and prying them off to not damage the cooling system.

Slicing the insulation very thoroughly into small pieces and prying them off to not damage the cooling system.

After an hour of slicing and dicing.

After an hour of slicing and dicing.

The whole evaporator unit consists of glued double mild steel sheets with lots of rectangular channels.

The whole evaporator unit consists of glued double mild steel sheets with lots of rectangular channels.

Some hours later. That black mesh is the condenser and radiator. Thermostat hanging out to the left.

Some hours later. That black mesh is the condenser and radiator. Thermostat hanging out to the left.

There's a long track of evaporator tubing in the freezer compartment and only a small loop for the actual large refrigerator box.

There’s a long track of evaporator tubing in the freezer compartment and only a small loop for the actual large refrigerator box.

Frame disassembled, the black thing is the compressor. The little black box contains a relais and a starting capacitor for the motor.

Frame disassembled, the black thing is the compressor. The little black box contains a relais and a starting capacitor for the motor.

Two copper tubes are combined into one, here under the black gooey thing: A little capillary tube from the condenser is coaxially inserted into the backloop copper tubing coming from the evaporator.

Two copper tubes are combined into one, here under the black gooey thing: A little capillary tube from the condenser is coaxially inserted into the backloop copper tubing coming from the evaporator.

Where the magic happens: An expansion valve. From there on the coolant starts to boil and get's a lot cooler.

Where the magic happens: An expansion valve. From there on the coolant starts to boil and get’s a lot cooler.

Evaporator fully extracted and ready for transplantation.

Evaporator fully extracted and ready for transplantation.

Meanwhile I finished the top cap for the ice cream container.

Meanwhile I finished the top cap for the ice cream container.

Due to the lack of proper material insulation and waterproof material for the freezing compartment I used OSB-3 (oriented strand board for interior use) for a quick mockup.

Due to the lack of proper insulation waterproof material for the freezing compartment I used OSB-3 (oriented strand board for interior use) for a quick mockup for now.

Expansion valve again.

Expansion valve again.

Evaporator inside the wooden box.

Evaporator inside the wooden box.

I noticed a cold bridge at the stainless steel threaded axle which sticks out of the freezer and made this insulator out of plastic so that no metal is protruding from the freezer.

I noticed a cold bridge at the stainless steel threaded axle which sticks out of the freezer and made this insulator out of plastic so that no metal is protruding from the freezer.

One side bored and tapped to M16 so that the axle is covered, the other side has got a smaller thread for a hex bolt.

One side bored and tapped to M16 so that the axle is covered, the other side has got a smaller thread for a hex bolt.

The finished plastic insulator. Also visible: The new top lid with a small window - this is where the ice cream consistency can be probed later and where the chocolate, fruit and glitter pieces can be added just before finishing the run :-)

The finished plastic insulator. Also visible: The new top lid with a small window – this is where the ice cream consistency can be probed later and where the chocolate, fruit and glitter pieces can be added just before finishing the run :-)

The hex nuts are redundant now because the plastic insulator can cover their function.

The hex nuts are redundant now because the plastic insulator can cover their function.

First dry run with pure water went well, but definitely lacks a proper encasing and insulation.

First dry run with pure water went well, but definitely lacks a proper encasing and insulation.

Icenberg part 1: Building an ice cream machine

Turning a bearing surface directly onto the paddle so no metal parts from the axle will ever be in direct contact with the ice cream.
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Prototyping a next level ice cream machine because.. ice cream!
First iteration with 1.33l container volume. Now searching for a leftover freezer/fridge from which I could upcycle the compressor and tubing.

In a further iteration I might design a proper spatula which can be mangled through CAD-CAM and then machined on the 3 axis CNC milling machine.

The outer container is face turned on the lathe to make a snug fit for a waterproofing cap.

The outer container is face turned on the lathe to make a snug fit for a waterproofing cap.

The polymer-rubber sandwich cuts like butter with sharp HSS tools.

The polymer-rubber sandwich cuts like butter with sharp HSS tools.

Turning a recess at the top cover, which will not be a fully closed lid. The fit was not good though and I turned another one out of wood for a first try.

Turning a recess at the top cover, which will not be a fully closed lid. The fit was not good though and I turned another one out of wood for a first try.

Due to the bad fit as a lid this piece was upcycled to a  handle.

Due to the bad fit as a lid this piece was upcycled to a handle.

POM (polyoxymethylene) cut to length on the horizontal band saw. Often used for medical equipment, this material is very well suited for any equipment which comes in touch with food.

POM (polyoxymethylene) cut to length on the horizontal band saw. Often used for medical equipment, this material is very well suited for any equipment which comes in touch with food.

Improvised fixture with some clamps. It's only a soft polymer after all.

Improvised fixture with some clamps. It’s only a soft polymer after all.

One of the most handy tools: the infamous one-hand clamp.

One of the most handy tools: the infamous one-hand clamp.

Ready for a pilot hole and a long bore operation.

Ready for a pilot hole and a long bore operation.

After reaming for a snug fit the hardened and ground axle was inserted.

After reaming for a snug fit the hardened and ground axle was inserted.

Milling the spatula.

Milling the spatula.

Wondering whether the resistance will still be too high to be turned if the ice cream starts to crystallize. Let's see.

Wondering whether the resistance will still be too high to be turned if the ice cream starts to crystallize. Let’s see.

M16 axle inserted into the spatula paddle and locked in place.

M16 axle inserted into the spatula paddle and locked in place.

Stock paddle on the lathe between two centers.

Stock paddle on the lathe between two centers.

Turning a bearing surface directly onto the paddle so no metal parts from the axle will ever be in direct contact with the ice cream.

Turning a bearing surface directly onto the paddle so no metal parts from the axle will ever be in direct contact with the ice cream.

Bottom cap with an oversized press fit turned out of Nylon (PA6).

Bottom cap with an oversized press fit turned out of Nylon (PA6).

Bottom cap on the lathe.

Bottom cap on the lathe.

Needs a few hits with a mallet - perfect fit.

Needs a few hits with a mallet – perfect fit.

The natural PA6 material is translucent.

The natural PA6 material is translucent.

Top lid from Multiplex wood, a fine plywood. Final piece will be out of POM.

Top lid from Multiplex wood, a fine plywood. Final piece will be out of POM.

Enough room for the copper windings from the compressor and/or a cooled fluid.

Enough room for the copper windings from the compressor and/or a cooled fluid.

First test with cooled salt water (1:2.42) at -21°C.

First test with cooled salt water (1:2.42) at -21°C.

The paddle withstands pretty much anything, but the resistance is too hard after a while. The efficiency is also lowered due to the work which is converted to heat in the ice cream after all. Next step is now to decrease the resistance further with more milled slots.

The paddle withstands pretty much anything, but the resistance is too hard after a while. The efficiency is also lowered due to the work which is converted to heat in the ice cream after all. Next step is now to decrease the resistance further with more milled slots.

Laser cut open source bee hive model for the OSBH project

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The Open Source Beehives project proposes to design hives that can support bee colonies in a sustainable way, to monitor and track the health and behaviour of a colony as it develops. Each hive contains an open source sensory kit, The Smart Citizen Kit (SCK), which can transmit to an open data platform: Smartcitizen.me

These sensor enhanced hive designs are open and freely available online. I forked the little desktop sized bee hive model, made it metric and CNC laser cutted it for OSBH. It will be displayed at the OuiShare Summit Berlin and advertise the OSBH-workshops which will happen in July.

First

First

50W laser cutter running the first test cuts in a scrap piece of MDF, slightly out of focus.

50W laser cutter running the first test cuts in a scrap piece of MDF, slightly out of focus.

Finished OSBH desktop model at the OuiShare Summit BBQ on the Tempelhofer Feld in Berlin.

Finished OSBH desktop model at the OuiShare Summit BBQ on the Tempelhofer Feld in Berlin.