Here are examples [illustrated on computer drawing] of a question - what is the shiyur of the Zadi Pshuta's foot/guf?
The minimum length of the ZP is not an accurate measure in kulmusim (from head to toe) – but a measure of the extension of the guf below the connecting Yud.
The Pri Megadim (quoted in MB's MS ois zadi pshuta) that bdieved if it has the length of a yud (k'mloi ois ketana) it is kosher. [this is clearly if there are no other problems of shinui tzura, and has been clarified by a tinok – if needed].
According, if the connection is low [exa. 2k under the rosh] the shiyur of the foot will be 3k [total with head 4k]. If the connection is 1k under the rosh the total hight of this ZP will be 3k [head 1k, above the connection 1k, below 1k]. If the connection is 1/2k under the rosh the total hight of this ZP will be 2 and 1/2k. Shorter than the line, and not extending under the shita!
Even according to the MB's shita that the shiur mloi ois ketana is a yud with the regel (I brought his shita in "common problems with yudim") it’s a minimal regel, leaving the shiyur of ois ketana something like 1.3k, and this ZP is still shorter than the line.
The Pri Megadim (&MB, MS ois Pai pshuta) write the same law in regard to a short Pai Pshuta, that if it extends mloi ois ketana under the nekuda of the pai it is kosher. Again leaving the final measure as to how high/low the nekuda is placed.
One may wonder that maybe the PM & MB meant only after the ois pshuta (zadi or pai) extends under the line, then in addition there must be mloi ois ketana under the nekuda of pai or connection of zadi, making this addition a l'chumra measure, not a l'kula. [in a pai the difference is somewhat minimized, since the gag & nekuda are always more than 2k].
But the MB doesn’t even hint to saying so. In addition it doesn’t fit with his general shita [explained in "common problems with yudim"] that the basic measure in vav & zayin is shaylas tinok (after mlo ois ketana), so in our case it should be the same, even l'kula that the zadi/pai pshuta were shorter than the line, or equal the line.
I have further thoughts in regard to this subject. Does anybody have any ideas?
B. Another problem that may occur in a zadi, is that the connection slopes in to a v shape. Here we can not say the regel is extending 1k below, measuring from the top part of the connection, because in regard to the lower part there is no further extension (or this may occur that the extension is less than the shiur mentioned above).
I think it is accepted to pasel such a zadi.