Author Topic: Stocking stuffers for greatt nieces and nephews  (Read 1117 times)

Offline ddmckee54

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Stocking stuffers for greatt nieces and nephews
« on: December 18, 2017, 07:44:22 PM »
I decided that I was going to make some stocking stuffers for my great-nieces and nephews for Christmas.  I got the STL files from Thingiverse for 3 point, 4 point, and 5 point fidget spinners that use 1/2-13 nuts for the weights and started printing.  The 3 point spinner looks like a ninja throwing star.  It looked cool, but I had print issues with the points wanting to lift of the print bed, so I re-designed it to be minus the points - no more lifting issues.

I didn't want any little fingers getting stuck in the threads of the nuts, so I designed a 1/2-13 plug that screws into the nut to make them finger-safe.  This was the first time I had tried designing a 3D thread, so it took me 5 different prototypes and more than that many hours before I got a version that worked.  I have discovered that it's a stone cold bitch to design an imperial thread using a drawing package that thinks in metric, consequently I'm fairly proud of that 1/2-13 plug.

It took me a while to convince myself, at least 4 prototypes, that the design for the plug was correct.  The thread spec's were correct, but on the first couple of prototypes I had been applying the internal thread specs' to an external thread - the root radii are different.  I eventually determined that the stinkin' printer was printing about 2% oversize.  Up to this point I had always had fit issues between parts that usually required some fettling to get them to fit - this 2% oversize discovery explains those problems away.  I thought it was just the way 3D printed parts were going to be, and was happy just to be able to get the part to print.  I am now printing a prototype at 98% scale and checking fits before I move on to the next part.

I don't have any pictures right now, so I know that this adventure obviously didn't actually happen.  But, if anybody wants to see the parts, I'll take a family shot tonight when I get home and post it tomorrow.

Don

Offline b.lindsey

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Re: Stocking stuffers for greatt nieces and nephews
« Reply #1 on: December 18, 2017, 08:45:20 PM »
Yes please!!! Would love to see the final results.

Bill

Offline ddmckee54

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Re: Stocking stuffers for greatt nieces and nephews
« Reply #2 on: December 19, 2017, 07:27:45 PM »
OK, my camera is not the greatest and the lighting is crappy, but attached below is a family shot of the 3D parts I am printing for the stocking stuffers.  With the white parts, the detail just washes away to nothing if I try using a flash, so this is what we have to work with.

In the front row, left to right, are the 2 grips for the bearing, the 1/2-13 threaded plug, and a fully assembled 3 sided spinner that to me resembles a throwing star.  In the back row are my re-designed 3 sided spinner body, a 4 sided spinner body and a 5 sided spinner body.

I'm also attaching a 3D PDF of the 1/2-13 threaded plug if you want to see what it looks like.  I know it's rather crude, my next attempt will be more refined, but I was happy just to get it to print and then fit when printed.

This is the first time I've tried to attach anything to a post, so I just MIGHT screw this up once or twice.

Don
« Last Edit: December 19, 2017, 07:34:12 PM by ddmckee54 »

Offline b.lindsey

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Re: Stocking stuffers for greatt nieces and nephews
« Reply #3 on: December 19, 2017, 08:31:06 PM »
The attachments came through fine Don, and they turned out well. They will love these I am sure.

Bill