Since this year is quite a cold spring, I went to the hardware store to see what would cost cold frames for my (homemade) raised beds. Minimum 200 EUR per bed - I have four of them - so 800 EUR. Crazy!
Then I looked around at the polycarbonate hollow chamber panels. With aluminum poles plus a lot of work, I couldn't get the price below 120 EUR per bed.
Next alternative: gardening supplies. There I observed that PET growing boxes with transparent covers are used in rough quantities. So I bought the biggest covers they had there, namely 50 cm x 32 cm with 12 cm height, cost 7 EUR/piece. For my needs, that was then only 4 of these hoods per bed, so much cheaper!
With the 3d-printed corner brackets published here, the appropriate PET hood and a wooden frame construction, it is thus possible to build a much cheaper cold frame which also works.
If you are interested, search for “Romberg Abdeckhaube 50x32” for getting the PET hood I used.
I used a board 9 cm wide and 2 cm thick for the wooden frame. The board could also be narrower, but at least 5cm. The screws were Torx 3.5 x 30mm.
Translated with www.DeepL.com/Translator (free version)
The author marked this model as their own original creation.