Doing my bit

Doing my bit

It’s been a crazy week! Here in the UK it’s (for me at least) been week 2 of the govt instructed lockdown, week 3 of working from home; a week of Free Joe Exotic meme’s and possibly the funniest Facebook group I’ve ever been in, and a week of being…well, useful.
I think I know my audience here, and that means you probably know me personally. So you’ll know I’m not a big follower of internet fads, don’t forward that message you sent me offering riches if I pass it on to 15 people. You know I don’t go in for following things as a rule, but this time I’ve made an exception. 
The 3D printer has been working on making some of these retaining straps for some medical professionals  in my area – they hold the elastics of face masks so they don’t get uncomfortable being held in place by the wearers ears.
50 so far have gone to nurses in a maternity unit, and another 30 to a local hospital.  I’ve got more filament on order and will make them until I kill the printer with over-work or they’re no longer needed.  Hopefully the latter 🙂

It hasn’t all been that though, I’ve still managed to make the new rotating frame.  The new design went together well, all fitted first time and is a better unit all around. 
Assembly was a bit of a learning curve, with a couple of minor changes on the fly (I had to design and print nearly 20 little spacers to take up some slack) but when I powered it up, a real surprise was in store……
IT WAS STILL JUMPY.
What? how? I filed the gears to make sure they were smooth, the bearings allowed everything to spin freely, I had printed stressed parts more densely to make them stronger. It was jumping as the top went down into the first swing, just like the original.  Then I had a thought – the whole design is a little top heavy due to the gearing. What if gravity was affecting it and pulling it down?  A few minutes in my design program, a few more minutes printing, and I’d made a counterweight for the bottom. 
And guess what? It only flipping worked! Yes, there’s still a small jitter, but not enough to be bothered about.  I set it going overnight with a test casting strapped in.  Came to it in the morning….. it was sitting clicking.  The frame was catching the side support.  After the set of 30 mask straps had finished I printed a newer support which gave some extra clearance, and that’s it – it’s done.  It works.

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