High Strength Shafts Different Sizes


#1

Our team found something interesting when changing regular shafts out for high strength ones. Our 3.9" HS Shafts can’t fit into the V5 Motors, but the 12-inch ones can. It seems like the shorter shafts have a larger diameter. The short ones don’t spin very well in the bearings, but the long ones are just fine. Is this a thing? Are the shafts 2 different sizes?


#2

I mean, if you notice their sizes being different I guess they are. I never had anything but the 12" ones, so I can say myself, but this might be caused by just wear and tear on your 3.9" shafts, are they new or have they been scuffed up a bit?


#3

All the shafts are BRAND NEW. Like, never been used before.


#4

hmm that’s odd. try using a dial caliper or some other measuring tool to see how different their thicknesses are. and of course, you could always sand down your 3.9" shafts to give them a smooth fit.


#5

I was gonna try a caliper yesterday to prove it to my coach, but the only calipers on campus were in another teacher’s room near to our VEX room, and they weren’t there, so I need to wait till Tuesday to measure them.


#6

Probably just go along the shaft with sandpaper lightly. Its probably a tiny difference and is just manufacturing defect. I have bought short shafts and they worked fine, as did long ones.


#7

It’s not a small difference. The small ones will not fit into the HS shaft collars at all.


#8

Post a picture of your shafts next to each other?


#9

Not gonna be back at school till Tuesday


#10

I think the manufacturing process changed at some point for the high strength shafts. Some of our shafts are a square with a concentric OD to fit into the vexpro bearings and others are a square with fillets that are not concentric (presumably) to work better in the EDR plastic bearings. Some shafts fit into the vexpro bearings and some are a tight press fit or don’t fit at all. We’ve measured some at 0.299" “OD” and others at 0.302".