Curved Ice Scraper with engineered compliance

Design Goals

• Car windows aren't flat so the tools we use on them shouldn't be either. 
• It's cold out there, think about people wearing big poofy gloves/mits.
• Multiple part assemblies like replaceable edges lead to extra failure points, don't do that.
• I always choke up on the blade anyway, any sizable handle just means more filament/bulk. 

Therefore…

This scraper is curved to better suit being used on curved surfaces like car windows, but since there is no fixed curve that would work ideally will all windows the built-in curve is a smaller radius then one would likely find on any vehicle glass and has engineered compliance parallel to the working edge, but strong reinforcement along the lines of force applied by the user. This way the act of apply scraping force with the hand causes the edge to conform directly to the surface being scraped, but not flex along the tools length.

The curved edge meant printing the scraper flat on a smooth underside was a no go. Printing on a side edge meant the reinforcement ribs of the compliant design would need heavy chamfering, making them ineffective. That left printing on it's rear end, which works out well as the forces put into scraping would be compressing the layers, the direction of flex for compliance is along entire layers not across them, and the bending moment had the maximum surface are to be spread across. in this orientation a long handle would have its layers going perpendicular to its axil (no ideal) and make the print even taller compared to the footprint on the bed which would increase the odds of falling over during printing. So all the more reason not to have one.

With no plans for a handle of any note it became apparent I was going to get the feature of being “pocket-sized” for free, but for that to be a feature of value to people wearing big gloves you should have a way to extract it from your pocket without having to reach into it. I keep my keys on a lanyard which I let hang out of my pocket, which works great for exactly that problem. So I modeled in some generous strap holes for people to implement a soft solution of their choice, or not if they choose. Having a strap that goes around the hand or wrist also makes it very hard to fumble the scraper in general, and gives the user the opportunity to just let it dangle while handling other items. Pictured on my orange example is a shoelace from a hiking boot tied off with sliding barrel knots for adjustability.  (knot tutorial video not made my me)

Printing Suggestions

What matters most for this design is that the curving blade volume is printed solid. The blade is 2.4mm thick so printing it solid can be down with a wall count of 3 if you are using a line thickness of 0.4mm, or with a wall count of 2 if you are using a line of 0.6mm. 

Click on pictures for a large view. 

The small space within the reinforcement ribs is not a concern, in fact preventing any thing from infilling these areas lead to a smoother surface finish on the large flat side in my test prints. 

It is preferred to have some infill in the lower volume of the scraper so I set up cubic zone that disabled infill for the blade part of the scraper.