This is a collection of printable hardware that I used to mount printed utility arms into a wooden Senna style frame. Note that the dimensions of the parts are based on my frame and the arms that I am using (Mr. Baddeley arms, but I don't think they are the most current version he offers). You should measure your frame using the techniques demonstrated by Mike Senna in this excellent demonstration:
After measuring you may need to adjust the parts accordingly. The holes in my Mr. Baddeley arms are approximately 8.6mm so the pins included are that diameter. The centering pin has a point that you can use fitted to the arms just to see where the center of the pint will be on the frame. There is a long pin (58mm) and a short pin (46mm) that fit into my frame, but you may need to adjust the length for your frame. All pins should be printed flat on the bed with 100% infill for maximum strength and durability. The washer will be what the arm actually rides on so its position on the pin should be adjusted accordingly and is a pressure fit.
The holes on the pressers are for #4 1/2 inch wood screws, you might only need one but I used 2 in each presser. Theres a presser with three holes and a presser with a slot, any of them should work with 1 or 2 screws. The idea behind the slotted presser is that you might have a little adjustability without having to redrill a pilot hole if your presser needs to shift to the left or right.
The carrier piece also has #4 screw holes but I just used CA glue on mine once I was absolutely sure they were in the correct position.
I will add some photos eventually but for now you can see this hardware installed here: https://www.instagram.com/p/CbYetoNuNBf/