This week I have finally finished the design of my mk4 butt stock, and the first parts are printing as I write this.
Assuming I got the tolerances right and nothing needs to be adjusted and reprinted, I should be able to try it out at the next hi-power practice.
This version is designed to be adjustable without tools and is much more complex than the previous versions, which is why it took longer to finish than I expected. I have also designed the length adjustment mechanism to be separate from the system that attaches the stock to the rifle, which I have found to be a problem. The whole thing becoming loose when I want to adjust the length is frustrating and I am afraid that I will drop the rifle if it is in the wrong position when I loosen the bolts. It seemed like a neat solution when I first thought of it, but I now realise it is a flaw that needlessly complicates the use of the system.
I am making this one in PETG which promises better strength and flexibility than the ABS I used for the mk3, and also promises to be easier to print, suffering less shrinkage and warping during production. I previously bought a spool of a material called PET+ which has printed well but is considerably more expensive than ABS. The PETG (from a different supplier) is much closer in price to ABS, but at the time I bought it it was only available in a few colours not including black or white.
The print currently in progress is using a semi transparent filament in a lovely shade of yellow. I think it will be quite fetching.
Below is an image of the first part to come off the printer. It is one of the adjustment knobs intended to allow tool-less adjustment.
More photos and updates will follow.