Kids toy 01.
The kids toy is basically two piece of 10 mm thick acrylic put together with a channel on the inner faces.
The oil filled channel allows the ball bearings to slowly follow the path down by gravity vs viscocity, speed varies according to slope, slow on the slant and faster through the curves, when done just flip it like an egg timer.
Essentially you have a round section ball bearing in a square section channel, ball bearing diameter should be as close as possible to channel width, but just under. You know how your mill cuts so make allowances as required.
e.g. buy your bearings FIRST and measure them.
Acrylic adhesive doesn't actually glue, it welds, so when done you have a very strong and very safe container that won't leak.
Cut the two parts out.
Tap the 4mm holes to 5mm.
Flame polish the channel and outside edges.
Assemble it with the bearings and fasteners. NOT THE OIL OR GLUE.
Check it all works, e.g. bearings run from top to bottom and back again and that the two surfaces mate well.
Tap the breather to 3 or 4 mm whatever you prefer.
Split, leave bearings in, use enough adhesive around the edges and fastener holes to make a 100% seal, but not so much that it squeezes into the channel and buggers up the channel.
Set is aside to cure for a hour.
Add oil using the small breather at one end until full, plug breather with grub screw and thread sealant, set aside to cure.
1/ Two pieces of acrylic 300 mm x 150 mm x 10 mm.
2/ Sixteen off 5 mm dia by 15 or 20 mm long cap screws (15mm if you countersink the heads) Plus one 3 or 4 mm grub screw.
3/ Three or four 10mm diameter ball bearings
4/ Acrylic adhesive
5/ Small bottle of baby oil.
Job's a good un.
Any queries contact me direct.
Included .jpg screenshot, .3dm Rhino drawings, exported .stl files, and Mashcam generated .nc files using a 3mm diameter end mill.
Suggest around 75 mm/min feed per 1,000 spindle rpm if you feed over ride.
NOTA BENE
Have included TWO sets of .nc toolpaths
The standard set uses a single 3mm dia end mill to do everything.
The other set has "* 6mm.nc" names and uses a 6mm dia end mill, much faster but does not include the 16 fastener holes, ONLY does the channel.
You choose.
24th June 2009.
John
Kids toy zip contains everything, 1.9 MB
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