Thanks, @Shelly142
Hope this isn't too boring…. the “design” as it were, was mostly just guess-work. I knew the dim of the hose over the fitting to be just over 3/4” and adding about a 0.05 wall, worked from there.
Fgured approx 0.88 nominal “jaws” + 0.01 & 3/8” per side for the jaws which came to about 1.65 diameter.
I had a chunk of 3 1/4” dia S.S. and machined it to 3/4” thick. Bored the ID to the 1.65 dia. Milled 6 flats to obtain 3” width. Tapped 3/8-16 holes through the flats at centerline
In addition, 6) 1/4-20 holes were tapped for the jaw retaining collars. To make the jaws, I turned another piece of steel 7/8” thick to 0.75 ID, 3” OD, and turned a step diameter to fit the 1.65; leaving a 1/8 flange. A hole pattern was drilled to allow fixturing to a block of alum, this round piece was then saw-cut into 6 pieces, then milled sides parallel to 0.75 wide using the previously drilled holes & mounted to the alum piece. A few additional cuts were made at 45deg on each jaw so that the material of the ferrule could bulge outward into the “void” The amount was mostly guessed at, but when done, seemed to be about right.
A 5/16 blind guide hole was drilled into the surface that was the 1.65 diameter. The ends of 6) 3/8-16 gr8 bolts wre turned down to 5/16 dia to fit the blind holes.
a suitable mount was made to hold the assembly.
Tightening the bolts in sequence crimped the ferrule nicely.
So, I did have many sketches, but many changes were made as it prgressed.
One certainty…. I'd not use S.S. again…much too difficult to tap, even using bigger than std tap-drill sizes.

Many, many years ago, I built a hose crimper for a company I had worked for. It used 4 dies actuated by toggles inside a large ring. This was used on ag sprayers.
It saved them a lot of assembly time as they could pass completed crimped fittings through the crimper, whereas before they had to crimp the hoses onto the barb fittings and screw them together to make up the needed lengths. There had always been a lot of fussin' around getting the drops oriented. This new crimper solved those problems.

OR….. one could buy this

https://www.amazon.com/dp/B0DC6M1FFP...WxfdGhlbWF0aWM