DIY seed roller - you can crush a tank with it.

Hi all,

as mentioned in my other tread my husband and me are since February separated due to COVID. I am at home in Thailand and he is on a wind farm project in Taiwan.
But nevertheless we have daily contact and main subject is our for end of 2021 planned food jungle.

He is a hands on grafter and before he is buying any equipment off the shelf he disappears for days in his workshop, annoys the neighbors with hammering, grinding and welding and builds the equipment in a quality that lasts a life long.

We have since weeks a discussion about a must have seed roller from Jang which seems for me one of the best on the market but my Will seeds only a fiddly, weak and breaking easy piece of thin sheet metal on wheels.
In his "Made in Germany" mind it has to be build solid and artillery proofed..
So he came up with a drawing how he sees things and I fear this will be a 50 pound piece of solid steel pushed through the beet rows.
No doubts, what he builds is always functional and highest quality but when the receipts from the different stores are falling afterwards in my hand, well it costs a weeny bit more than a store bought copy (as he calls them)

has anyone ever built a functional seed roller and if yes, would you share the drawing with me, just to impress him with a counterfeit of his design where I still miss some details like measures for example before a bicycle size roller for may be 2000$ is leaving his workshop after he returns.