Finishing up the front “face” of the incubator chamber box 4/6/2012

•08/06/2012 • Leave a Comment

The box was left to dry after assembling all the parts and applying polyurethane foam. Now it was time to clean it up and add the front face so the box is ready for completion.

– overlapping polyurethane foam was cut with a sharp knife sometimes with pieces of polystyrene too
– the rest of the foam was removed by chisel, knife and sponge so whole internal PE box was clean and left to dry
– two strips of plywood cut: 60 cm length and 55 mm height, 12 mm thick to use for making the front of the incubator inner box/part equal
– two holes drilled 6 mm from sides (55 mm edge) on each side with 4 mm drill
– another two holes were drilled on the outer edge of the longer side 6 mm from the edge and 15 cm from the top respectively bottom
– silicon applied to the cover any holes between polystyrene and MDF/PE parts
– silicon applied on the inner side of the plywood boards
– 28 mm wood screws used to connect this piece of plywood to the MDF (NOTE – all screws in the project which I used and called wood screws were actually not exactly wood screws because they were missing the blank part close to the head, they had thread all the way to the head)
– another two pieces of plywood cut same dimensions except length (47.5 respectively 48 cm)
– four holes drilled in each piece with 4 mm drill 6 mm from outer edge every 5 and 15 cm from top respectively bottom
– silicon was again applied and the boards were screwed to the MDF
– silicon was used to make the seams??? in the inner PE box and made equal with a finger
– again silicon used to fill up the seams between all the layers in the ventilation hole
– the box was left to dry

Insulation done, all layers put together 31/5/2012

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The experimental box is going to  be insulated in order to lover the energy needed to the heating/cooling. Polystyrene sheets, polyurethane foam and silicon were used.


– polystyrene board (47 mm thick) was attached to the back of the chamber to the MDF board to the whole side with cutted on the bottom side to fit the bottom supportive plywood board later on
– in order to reinforce the bottom of the PE box and connect it to the box two 27 x 27 mm wooden planks were screwed to MDF box in parallel to the front side (on the edge, whole length 50 cm) and partly on the back (on the edge in the middle of the back side +- 30 cm length) by two wood screws (30 mm) (from outer side MDF to the wooden plank)
– plywood desk of 42.7 cm front side, 60 cm length and 15 mm thickness was placed on these two wooden planks and screwed to them by 55 mm wood screws (two in the front and two in the back) 15 and 10 cm from bracket, 2 cm inwards from the wall
– holes for door hinges were drilled into the MDF boards 18 cm from bottom respectively top (the middle of the door hinges)
– three M5 30 screws were used to screw each door hinge on
– ventilation hole drilled 25 cm from the front in the middle of the desk with use of 54 mm diameter holesaw, second hole drilled just next to it in the direction to the back (again d=54 mm)
– the hole was enlarged to the rectangle shape with oval corners and made smooth

Disassembling the Internal PE layer and reassembling 30/5/2012

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This is the final version of complete internal box before inserting in to the external box.

The inner chamber made from PE sheets and glued together on 24/5/2012 was not strong enough, therefore it was taken apart. The brackets were used to screw the sides together to make the frame more rigid.


– holes were drilled with 6 mm drill in the PE sheets, for the bottom 4 cm from each corner for the sides and ceiling 10 cm from sides (with few exceptions)
– simple brackets with one M5 12 mm screw on each of it’s side with washers were used to screw the sides and ceiling together, the bottom was left for later

Building the External Layer of the chamber from MDF boards 25/5/2012

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The material for the construction was bought on 22/5/2012. The price of the MDF boards which were precut was $32 (40 000 ₩) (he sizes were quite exact). The construction was started on 25/5 and the box was assembled during three hours or so. The 3D model of the box can be found here. The material used for construction were MDF boards of 12 mm thickness, cube shape with a=60 cm (external edge), for more info and assembly structure see the model. The box was held together by metal brackets with four M5-20 screws (two) on each side, with one screw with fitting small washer (9.8 mm external diameter) and one with bigger washer (20 mm).  The final box fit together quite well with exception of top left back corner and it was sturdy.

In order to accommodate the internal layer without distorting it’s shape due to the weight of the brews the supporting structure from MDF’s was created.

The LOG of the construction of external layer of the incubator box

– first a put the box together with tape holding the shape
– the desks were measured and 10 cm from each corner mark was made on the edge for the brackets
– the bracket was placed on the middle of the mark and the holes for the screws were copied on the board
– during the process of marking the places for the screws the box fall apart and the rest of measuring was done on the table board by board which was technically much more easy
– this was done for all the sides
– the holes were made by drilling with 6 mm wooden bit
– the ride sight was attached by the brackets and tighten by the screws
– the back wall was added and after that the left side, making sure that the front edge of all three sides is in line to make the doors closing easy
– the top part was added and whole box checked for sturdiness
– the top left back corner was bit off with the boards not fitting exactly (3-4 mm difference)
– during the construction several times the holes for the screws holding the brackets had to be enlarged to fit properly
– the resulting box

Shopping and building the Internal Layer for the chamber from polyethylene 22/5/2012

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  • Shopping for the material 22/5/2012

The material for the construction was bought on 22/5/2012. The price of polyethylene sheets (PE) of white colour which were pre-cut was $38.20 (47700 ₩) and the glue was $3.2 (4000 ₩). The construction started on 24/5/2012 based on the 3D model proposal, the thickness for the PE was 5 mm, the box was of cubic shape a = 50 cm (external edge).

  • The construction of internal layer of the incubator box from PE sheets 24/5/2012

– the PE sheets were evened up first
– when fitted together quite big differences in sizes occurred
– the PE sheets for the bottom and side were put on the top of each other
– two power sources on the left and two on the right were prepared to hold the side up
– the glue was applied on both edges of the box and the sides were held together by pressing for four minutes, supporting afterwards by the power sources
– the back side was added following the same procedure
– left side was added
– some sides were strengthened by application of more glue
– the top was added and whole box was left to dry over the night
– next day the box was checked for sturdiness and it was not good enough the sides started to separate quite a lot
– the final box was not sturdy enough and some of the edges started to separate when the box was moved so at the end the box had to be taken apart and another construction approach was tried.

Introduction to the Project of Experimental Incubator

•06/06/2012 • Leave a Comment

This project is about creating an incubator which allows for a creation of a controlled environment which is as friendly to the microbial cultures as possible. This blog is online LOG BOOK of the project for more info please see our wiki pages here. One of the major features is going to be the ability to oscillate temperatures in a controlled manner. The idea behind is that the cultures which are composed from many different microorganisms with different temperature optima would proliferate at these temperatures whoever they would have to oscillate. This is quite contrary approach compared to the currently used set temperature model which will in this case favour just some microbes which are close to this temperature. The goal is to keep the cultures like kombucha, kefir etc. as biodiverse as possible aiming to improve the vitality of the culture, it’s probiotic qualities and also it’s taste. The prototype is based on arduino microcontroller element, temperature sensor and peltier heating and cooling source. The device will be build to comply with principles of low energy consumption, easy to repair and upgradeable structures, sturdiness, all in accordance with the concept of environmental friendliness. This project is based on an open source aiming to bring together interesting people from various backgrounds collaborating, making this tool available to as many brewers and food hackers as possible. We hope to take it all the way to the commercially viable device.