Handle for Scotts Hand-held Spreader

thingiverse

The crank handle on my Scott's hand-held rotary broadcast spreader, which is over two decades old, finally gave out again. I managed to complete the job by rigging up my cordless screwdriver with a cordless screw and then examining the broken part carefully. In the past, I had epoxied the cracked drive cup, but when it broke in a different spot this time around, I used an excessive amount of epoxy. With my 3D printer at my disposal, I could have wasted hours re-engineering a part that I could easily replace for under $20. Obviously, the best choice was to save the $20! Two hours later, with Fusion 360 on my computer, I had created a very accurate copy of the original handle. On the second print, I made the necessary dimensional adjustments so that the holes fit perfectly onto the drive axle of the spreader and the original paddle knob's slip-fit axle. The crank needs to be printed with support material, which is a new experience for me. The cosmetic finish of the first layer printed over support is unsightly, no doubt due in part to the .8mm nozzle I've been using, but fortunately this item lives in my garage where aesthetics aren't a priority. If necessary, the cosmetics can be addressed with a future project. I decided to duplicate the paddle and discovered that slip-fit pivot pins are too weak when printed in the Z direction. However, the Paddle turned out great! After a slight remix, I separated the slip-fit pivot pin into its own piece, allowing it to go both ways. It gets printed on its side, which gives it enough flexibility to compress in the hole while still being strong enough to keep the pieces joined.