A simple bench-changeling, made of polypropylene pipes.
My wife asked - I did.
We take the d32 pipe, it seemed to me that it would be the most durable - 2 pieces of 2 m. * 143r / pc = 286r.
tee d32-8 pcs. * 21 rubles / pcs. = 168 rubles.
corner d3 90 deg-8 pcs. * 7.6 rub. / pcs. = 60.80 rub.
Total = 514.80 rub.
Next we saw in size:
6 pcs. - 240mm.
6 pcs-145mm.
4 pcs. -345mm.
4 pcs. - 30 mm.
Usually such things are cut with special scissors, but I didn’t have them and I used a hacksaw for metal, it worked perfectly.
Using a plumbing soldering iron, solder all the parts together.
Saw 2 pieces of plywood to size and fasten with screws, pre-drilling holes for them in the attachment points - otherwise polypropylene has a chance to crack in the future - it is not designed to screw screws into it ...))) Glue soft material on top - I used the old foam travel mat - glued 2 layers on the seat, 3 layers on the knee stand, glued on the usual "moment".
Then the wife sewed a removable cover so that it could be washed.
For everything, not counting the drying time of the glue, it took me no more than 3 hours.