As of late I have been pushing the limits of the turnigy C80100. Just yesterday I was going to see if I could average 2500 to 3000W on my commute home. This would require using 8th gear. In the process of shifting from 7th to 8th under WOT, the bike underwent a surge of roughly 5000W input power and it all resulted in a bent motor shaft and a toasted bearing. I'm impressed with the power output of this little motor yet not surprised at the result. There are clearly some shortcomings in terms of motor construction that it make difficult for the motor to handle these power levels. I plan to replace the shaft with something from McMaster-Carr, unless someone knows of a better source for the 12mm shaft. It will also be the third time I will be replacing the bearings. I'm surprised that these tiny bearings last as long as they do at these power levels. Following the rebuild I will dial back the power to levels that will prolong the life of the motor.
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From McMaster
Hardened Shafts
Shafts are case hardened and precision ground for exacting diameter and straightness tolerances. They have a 9 rms micron finish (unless noted) for inch sizes; 12 rms micron finish (unless noted) for metric sizes. Straightness tolerance is 0.002" per foot for inch sizes; 0.03 mm per 300 mm (unless noted) for metric sizes. Ends are beveled.
See our selection of shaft supports.
View minimum hardness depth for these shafts.
For technical drawings and 3-D models, click on a part number.
Metric Sizes—Steel
Shafts are 1055 steel (except 3 mm and 13 mm Dia. shafts are 52100 steel and have a straightness tolerance of 0.025 to 0.050 mm per 300 mm). They're stronger than stainless steel shafts but are less corrosion resistant. Case hardness is Rockwell C59-C65.
Lg.,
mm Each
12 mm Dia.
200 6112K103 $6.09
400 6112K104 12.53
500 6112K52 15.62
1,000 6112K53 31.25
1,200 6112K17 37.51
1,500 6112K54 46.85
2,000 6112K55 62.52
Metric Sizes—Stainless Steel
These 400 series stainless steel shafts have good corrosion resistance but are not as strong as steel shafts. Case hardness is Rockwell C52-C56.
Lg.,
mm Each
12 mm Dia.
200 6459K23 $11.26
400 6459K24 22.44
600 6459K26 33.67
800 6459K27 44.85
1,000 6459K28 56.11
1,200 6459K29 67.29