One thing DH and I are doing that seems a bit different - we are making bases for each of the treadle machines and the bases are standard on the outside, though we have to make them different to accommodate the actual machine.
We made a different treadle top that will fit the standard outside dimensions of the frame, and put supports so they drop in (like the table that the bentwood case drops into).
We haven't worked on this for several weeks (other projects and Work getting in the way).
This is the cabinet with the start of a base - DH wanted to make sure he had the dimensions right before going any farther.
We needed to make this so the treadle belt would not need to be unstapled to put it on the machine. We are also considering putting some sort of tensioner in the cabinet to take care of the issue of different belt lengths required due to different dimensions of the machines. Since the base raises and lowers, we can lower it a bit to get the belt installed, so that is not a problem, won't need to derail it from the main wheel.
Here is the supports the machine base sits on.
And parts of the base - it will have a bottom and the machine will be installed with barrel hinges so it can tip up for maintenance. We started collecting appropriate barrel hinges - I though they would be more universal than they are!
This is the original lift, set aside so we can put the cabinet back to original if wanted. It had been slightly modified to fit both Pfaff before we got it (and why all the treadle parts had been removed).
We had to take the top off the cabinet to remove the original lift and put in the universal support.
The demonsions are such that we will not be able to close the cabinet if there is a machine installed, and we can't push in the upper doors as the base support come down too low. So we took off the doors and will set them aside with the original lift. That won't matter for a portable frame though, since that won't be inclosed to start with.
So far, the machines that will go into this "universal" treadle are Davis, Singer, Standard 3/4 size, New Home, Free, Household, early Eldredge, National 3/4, Wheeler Wilson D9, White rotary. I also plan on getting an Eldredge Automatic chain stitch, so that will go here too.
I love treadles, and ran out of room. In other cabinets, I have Singers 27, 127, 66, 115, 15-30, the I also have White VS, Domestic, Standard Rotary, and National Two spool. I kept thinking - wait, I have 10 treadle cabinets, what am I missing- but I forgot about the universal one - that makes 10!