Seal-Saving Car Wrapping Knife

The pro knives cost a fortune for a simple plastic-handled, guarded-blade knife. $57 USD! Mine is a little fatter, could use a diet, it's a work in progress and I might refine it. It uses standard X-Acto #11 sized blades. If you have the money to burn, you can buy the knife that inspired this from the link below:

https://signmakertools.ca/collections/frontpage/products/wrap-defender

10-pack of their blades is $16:

https://signmakertools.ca/collections/frontpage/products/wrap-defender-spare-blades-10pack

They have a lot of cool products for the vinyl wrap industry, but expect to pay Snap-On prices for them. 

I got a ton of blades from Amazon, knock-off brand, $8.99 USD with free Prime delivery for 120 blades (7.5 cents per blade):

https://www.amazon.com/dp/B09NSNVCRY?ref=ppx_yo2ov_dt_b_product_details&th=1

It has been tested to fit these blades, hopefully the other brands aren't too far off in size. Expect a tight fit, and you may need to file out some corners to get the blade in. The blade is tightly secured when fully assembled.

To keep the inner locking notches clean, I printed the main handle on its narrow edge with 10mm brim and supports painted on the angled part of the handle that is off the bed. A little carving and sanding was needed to smooth up that overhang, but since it would be nearly impossible to clean up the interior of the handle if laid flat on the broad edge with the long bridge (2mm vs 20-ish mm). I designed it in multiple pieces so the handle very securely keeps the blade from coming out, but I might experiment with a 2-piece slender model with a simple slide-over locking ring to hold the blade.

I should also share my X-Acto #11 revised model from Grab CAD as the model I found there to aid in my design process was off by more than 1mm from the actual dimensions, and the dimensions for the blade guard to fit properly are extremely critical.

Modeled in SolidWorks maker edition.