I could not find a picatinny male to female UMP brace adapter, only either one. So I combined two models I found on the internet.

The first model is the brace from the mac daddy 2.0 zip file drop, the “brace housing & mount” stl file: https://odysee.com/@TheGatalog-PrintableFramesReceivers:9/The-MacDaddy-2.0:0

and the second UMP stock/brace adapter is from: https://www.cgtrader.com/free-3d-print-models/hobby-diy/hobby-accessories/arrow-arms-apc9k-rear-brace-stock-plate-adapter

Id like to thank the original creators of those models because without them I could not have made it as my skills only allowed me to frankenstein these models in tinkercad.

I used this model to use an sbti UMP 45 brace on a mac daddy 2.0. You can find the brace I used here: https://www.sb-tactical.com/product/sbti/

This adapter requires the use of two M5 x 35mm socket head cap bolts with their corresponding M5 nut for the picatinny, and a single M4 x 50mm socket head cap bolt with its corresponding M4 nut for the swinging hinge portion of the brace.

The 5mm and 4mm holes are snug and therefore may need just a hair worth of material to be reamed off using the respective drill bit.

Printed using Polymaker PLA pro, 215 print temp, 60 bed temp. 95% infill, 50mm/s speed. Tree supports.