cheap motor retainers for LPR and MPR

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bjphoenix

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I noticed one time when I replaced windshield wiper blades that some of them have little metal strips embedded in them. I pulled out one of those strips to save and just found it in my garage. It looks very similar to the material in Estes engine hooks. I measured an engine hook at 0.128" wide x 0.024" thick, and the piece from an old windshield wiper blade measured 0.160" x 0.029" thick. It is 50% heavier than the Estes hook but also stiffer and stronger. If used for D and larger motors the weight wouldn't be as much of a penalty and they could be formed to whatever length you needed if you wanted to use them for an Aerotech single use motor for instance.
 
This is a standard hack.

I haven't gone down the rabbit hole, but I'd bet there are different stiffness requirements for different size wiper blades, and thus different reinforcement sizes available. One might go dumpster diving in the can outside a local auto parts store and see what one could find.
 
I’ve pulled the spines from several sets of wiper blades for my cars when replacing them. The short rear window wipers’ spines are of a lighter material.

When I redid the wipers on both cars a couple of weeks ago I didn’t bother as I have enough stock on hand to make motor hooks for a goodly number of scratch projects.

Having this stock means one can make non-standard lengths (like the 3-inch one Odd’l sold for a time that let you use a motor block on both sides of the forward hook, not just forward of it — to prevent them tearing out rearward from repeated ejection charges on much flown models) or for 29mm BP E/F motors without having to buy the special long ones….
 
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