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Old 10-26-2017, 02:45 PM
scottyk scottyk is offline
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Default Re: First Tamiya truck build, MACK Dump truck 6x6

Here is some of the trickier stuff. The dang split rims! I couldnt bear to pay the price for 3d printed plastic wheels so I designed them myself and still thought the plastic was pretty hokey. Took quite a few revisions of these rims to get them fairly close scale wise in the design and prototype phase. Then to get the scale correct AFTER they are cast and still fit the hex drives and bearings without machining was tough. but the first go around turned out pretty decent, had issues with the kiln during burnout which gave me some surface finish issues but I think I know the reasoning behind that.

Anyway these are designed by me, I 3d print them in house as well, the 3d print is mounted on a sprue tree, which is then encased in a plaster mix called investment, then put in a kiln to burnout the plastic and you pour molten metal in there and bam, metal wheels!

These will be 2 piece as you can see, I am drilling and tapping 2-56 threads and using brass hex bolts to hold them together. I think I may try to cast the centers out of a brass alloy for extra weight, and I can either paint or polish that, figured Id polish the rim at least. I am excited to try a few different things on the next batch and increase the surface finish quality for quicker cleanup. but it really only took about 1.5 hrs to clean these up from raw casting to how you see it now, just hand files and belt sander.

20170508_220809 by Scott Kositzky, on Flickr
20171022_195507 by Scott Kositzky, on Flickr
20171021_141651 by Scott Kositzky, on Flickr
20171022_165425 by Scott Kositzky, on Flickr
20171022_165435 by Scott Kositzky, on Flickr
20171022_230149 by Scott Kositzky, on Flickr
20171024_122705 by Scott Kositzky, on Flickr
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