Modular Restraint System by KinkyEngineering

Last crawled date: 3 years, 1 month ago

I finally have a majority of this project designed and printed to test fit. It is unfortunately not compatible with the previous design, but that is because this design eliminates almost all needs for hardware while also having a much stronger joining design. Everything is printable in regular PLA, and should fit a normal Ender bed (235x235mm). Please note the Modular Assembly Preview STL is just to show a preview of one assembly model, not for printing. Here's a brief description of the types of parts included.
Cuffs - Number is the inside diameter of the cuff. Diameters include 2.0", 2.2", and 2.5" through 7.0" in half inch increments.
Blank - Has no dovetail fitting, does not connect to anything other than another cuff.
Male - Has a male dovetail fitting to connect to various bars and accessories.
Female - Has a female dovetail connection to connect directly to a male dovetail.
Bars - Number is the overall length and/or height of the bar. Bar lengths generally go from 2" to 10" in 2" increments.
Bar - Just a straight bar with a female dovetail fitting on either end.
T Bar - A three way connection in the shape of a T.
PT Bar - A three way connection in the shape of a T, except the middle bar is rotated 90° to be perpendicular to the other two.
X Bar - A four way connection in the shape of an X, either at 90° or 60°/120° angles. Both versions are 6" from one end of the X to the opposite end.
Misc
Captive Pin - These pins snap in to the holes on cuffs, bars, and other accessories. No other hardware needed.
Lockable Pin - These pins are completely smooth and have a slot at the end for a small padlock, cotter pin, or anything else 1/8" (.125") or smaller in diameter.
Coupler - A fitting to connect two female dovetail connections together.
Ring Coupler - A fitting that connects two female dovetail connections together, and has a ring embedded within it. The ring is 5/16" (.3125") thick with a 2.0" diameter (so ID/OD is 2"±5/32").
Elbow - This has female dovetail connections on both ends and allows you to set a fixed angle between two parts in 10° increments. This requires one M4 Button Head Screw and M4 Nut.
Counterbore Base - This 2.5" wide base has one male dovetail connection, and four counterbored holes for bolts up to 1/4"-20 in size.
Countersunk Base - This 2.5" wide base has one male dovetail connection, and four countersunk holes for screws up to #12 in size (.228" dia hole).
All the cuffs and bars can be flipped over and assembled in either orientation, except the perpendicular T bar. All parts should import in to your slicer with the correct orientation to maximize strength of the dovetail connections. Supports should not be needed for anything except the cuffs and the ring coupler. I have test printed everything except for a perpendicular T, and I needed full supports for the cuffs and touching build plate supports for the ring coupler (tree supports might work, but you don't need them in a lot of areas on either one).
The 1.4" pins are for cuff hinges, and the 1.0" pins are for the dovetail connections. The captive pins were tweaked based on the ones I printed, so if your E steps/flow aren't well calibrated you might have slight fitment issues with the pin being too loose/too tight. I would test print one and see how well it fits. You can scale on only the X and Y axis as needed to get a better fitment. I'd suggest about 2% scaling at a time (which would increase or decrease the diameter by 4-5 thou). They should require a small amount of force to snap in, but still doable by just pressing on it with your thumb. I didn't intend for the captive ones to be removed often, so I'd only use them for one hinge of a cuff, not both.
Alternatively, you can use over the counter hardware instead of these printed versions if you prefer. Both pins are nominally sized at 1/4" (.25") diameter. You can also use 6mm pins if those are standard in your area, though they will be slightly looser fitting (since .25" = 6.35mm).
If there is anything in particular you think should be added to the collection (like if you have a big printer, and want a 14" long bar), feel free to ask. I sometimes don't login to this site for a while, so it's usually best to contact me on reddit, /u/KinkyEngineering