Vol 2, Page 11 – Getting Back To Work & Another Approach to Planetary Gears -FAILURE UPDATE AT END OF POST-

Next Gen Test Gear
After some unexpected personal business (death in the family) to be attended to, I am excited to pick up where I left off with the PIE 2.0. I had to remove the test rig from the test vehicle in order to transport several loads of “rubbish” from a deceased family member’s apartment to be delivered to either a charity donation center or a dumpster for disposal.
The Pie 2.0 is fastened back into the test vehicle, testing routs are mapped out for highway speed testing, and I am ready to start recording data.
As seen in the photo above, I have also been working on an improved method of obtaining and making planetary gears. The latest idea on this front is an inside-out chain drive/sprocket assembly. I don’t think that it is a long-term production solution, but it seems to present a reasonably inexpensive alternative to making gears from scratch.
The nice people at www.RollerChain4less.com(Nitro Power Products, LLC) have 17-tooth idler sprockets with a 5/8” bore bearing installed  (P/N: 40BB17-5/8) available for $11.98 USD at the time of this writing. They also have 17 tooth plate sprockets with a 5/8” center hole (P/N: 40A17) available for $5.75 USD at this same time.  Feet of #40 roller chain from them (P/N: RC40-1R-10FT) is just $16.37 USD, and they are one of the few companies that offer specialty connector links known as “Attachment Connecting Links” very reasonably (less than $2 each).

So the inside out chain sprocket is basically removing the teeth from a plain sprocket and fastening a chain to it in place of the missing teeth, effectively this creates a “male” and “female” gear set. The chain can have the rollers lay into the remaining recesses of the original tooth pattern and can either be welded in several spots, or connected at the ends with an offset link and fastened to the gear with “attachment” links. I chose to simply weld the chain onto the modified sprocket it for the first prototype gear. I cannot tell you how it is going to work out yet, as most of my shop time is being used  to adjust and collect PIE 2.0 test data.
A quick update, gear failure with pictures:
I attempted to install a pivot for the weight on the idler sprocket. These idler sprockets are hardened. The weld will break off with little effort, and if you do manage to get a hole drilled trough the gear, tightening a 6 mm bolt is enough to crack the gear. The plate sprockets are plain steel and can be drilled and welded, so I guess I will be mounting a bearing on one of them.

Welds Popped Off

Welds Still Have Sprocket Metal On Them

Ground Flat and Drilled – Cracked When Tightening Bolt

Ground Flat and Drilled – Cracked When Tightening Bolt

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