. .
  1. #1
    Wal's Avatar
    Lives in Stockport, United Kingdom. Last Activity: 30-03-2023 Has been a member for 9-10 years. Has a total post count of 491. Received thanks 71 times, giving thanks to others 29 times.
    Back in my day, if you didn't pay attention they'd give you a clout 'round the ear, nowadays, it would seem, they give you a fidget spinner.

    Click image for larger version. 

Name:	cap-diagram-MYCNC.gif 
Views:	370 
Size:	55.0 KB 
ID:	24172

    A good friend of mine asked if I'd make her seven year old son a custom fidget spinner - in fairness, he's a top little fella and very bright, so a total pleasure to make him something he's gonna (hopefully) enjoy.

    Didn't have the first clue about these things, but after a bit of searching (both the internet and my offcuts bin) I decided on a lightweight 7075 body, CZ121 brass weights and a miniscule R188 stainless/ceramic hybrid bearing. I kept the design deliberately simple, as my main priorities here were about focusing on decent interference fits for the weights and the bearing and having the thing actually function! - I may re-visit this project at a later date and try a more 'interesting' shape, but for now I'm okay with the (elegant?) simplicity.

    Click image for larger version. 

Name:	slow-spin-2.gif 
Views:	401 
Size:	1.10 MB 
ID:	24181

    Here's a vid of the 7075 body being machined:



    ..and a couple of pics of the results:

    Click image for larger version. 

Name:	tumblr_p7z19hYXbP1r7uds7o1_1280.jpg 
Views:	399 
Size:	247.3 KB 
ID:	24174 Click image for larger version. 

Name:	SPINNER.jpg 
Views:	377 
Size:	217.1 KB 
ID:	24173

    Then it was the brass - I used a hole-saw to cut out some blanks from a piece of 1/4" scrap - then machined 'em to size - well, 0.025mm undersize with a couple of spring passes.

    Click image for larger version. 

Name:	tumblr_p7z19hYXbP1r7uds7o2_1280.jpg 
Views:	444 
Size:	85.3 KB 
ID:	24175 Click image for larger version. 

Name:	brass_machine.jpg 
Views:	388 
Size:	84.3 KB 
ID:	24176

    Once that was done, I made a little press out of some oak:

    Click image for larger version. 

Name:	P1050562.jpg 
Views:	441 
Size:	136.2 KB 
ID:	24177 Click image for larger version. 

Name:	P1050564.jpg 
Views:	360 
Size:	152.4 KB 
ID:	24178

    Here it is in action:



    Then it was a case of jigging that lot up and engraving the lad's initial (G) onto the brass, along with a bit of a ball-nose chamfer. Don't have any video of that, but here are the results, fresh from the kitchen sink:

    Click image for larger version. 

Name:	SPINNER-28.gif 
Views:	357 
Size:	2.29 MB 
ID:	24179

    The last bit (and probably the trickiest) was to make the caps. Here's a vid of the round-over being machined to give a bit of clearance on the underside followed by a clip of the ball-nose cutting the circular contours.



    The female cap needed tapping which meant grinding a flat nose onto one of my M4 taps to give me the extra 'reach' I needed.

    The male cap had an extra layer of complexity insofar as it needed to be thread-milled (I don't have a lathe, but really want to get my hands on something small for jobs like this) - the M4 die barely starts cutting by the time it hits the underside of the cap, so no use in this situation. You can find a reasonably detailed write up on how I went about this over on my blog. Here's a vid of the operation:



    The design relies on a couple of little 'shelves' that clamp the inner race of the bearing. Then there's a bit of clearance within the interior of the rest of the cap - the inner race is a bit baggy by design, so you don't want the outer race that partially protrudes from the body fouling the caps.

    Click image for larger version. 

Name:	cap-detail.jpg 
Views:	402 
Size:	40.2 KB 
ID:	24180

    Once these were polished I pressed in the bearing with no issues - and fitted the caps. The finished article:

    Click image for larger version. 

Name:	IMAG1581_BURST002.jpg 
Views:	346 
Size:	228.9 KB 
ID:	24188

    ...and with a wooden carry case:

    Click image for larger version. 

Name:	WOODEN_CARRIER.jpg 
Views:	365 
Size:	206.9 KB 
ID:	24200

    And who could resist revving it up with the air line..? Not me:



    That's only at 2 Bar... <Opens it to 8, thinks carefully, then closes it again..>

    Wal.
    Last edited by Wal; 09-05-2018 at 06:15 PM.

  2. #2
    Wow,it really detail all processing,wonderful.

  3. The Following User Says Thank You to Johnson For This Useful Post:


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Custom Pulley Help - ATC over hall
    By andy_con in forum Denford Mills
    Replies: 11
    Last Post: 08-02-2016, 04:02 PM
  2. Metal Spinner
    By vueselection in forum Opportunities Available & Sought
    Replies: 0
    Last Post: 28-05-2012, 03:30 PM
  3. RFQ: Custom CNC work - Just wondering how much...
    By Mustang80 in forum Projects, Jobs & Requests
    Replies: 0
    Last Post: 02-10-2011, 07:53 PM
  4. Custom power DC supply
    By M250cnc in forum Electronic Project Building
    Replies: 11
    Last Post: 22-11-2010, 09:48 PM
  5. Want to make a custom CNC controller box
    By GeorgeD in forum General Discussion
    Replies: 2
    Last Post: 01-10-2010, 10:41 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •