Flex shaft resistance.

[Ryanrodfl6363lu]

Love the forum everyone it's been very helpful, thank you. I bought a blackjack 29 v3 as my first boat w the intention to get into the hobby and possibly build my next.

My question is how much resistance should be on the flex shaft. Let's say there is no motor in the boat. How freely should I be able to turn the prop by hand? Obviously the more free the better, but after adjusting the strut and and bending the tubing to match how much resistance is to much?

[tlandauer]

This is entirely a subjective feel especially if you are new to this. Let's say w/o the motor , and WITH the teflon liner, you should be able to turn with a nice smooth/cushioned feeling. You won't be able to spin it---( meaning not in the general sense like spinning something and expect to see continued rotation). Now if you grease it, it will have a "molasses" feel to it, but your instinct should be able to tell you if there is unwanted binding.
The feel for a cable in a tube w/o the liner is yet different: When there is NO grease in it you should be able to turn it with none of the aforementioned "cushioned" feel, and you might even register as a more free turning experience than with the teflon liner. With grease you will feel the molasses character but with less drag.

[Ryanrodfl6363lu]

Thanks for the reply. Very well put. I feel mine is normal compared to your description. And I figured, based on common sense that mine was fine all along... However the motor and esc are currently on their way back to HH due to that smoke escaping out of the motor for sure, and possibly the esc. (And yes I was running 6s, I'm a newbie, I'm allowed to!!). So I'm trying to make sure my drive line wasn't the culprit. While I wait for electronics to get evaluated I'll be sharpening and balancing a x440 for a nice 4s setup, and probably purchasing a 1500kv to experiment with.

[tlandauer]

Sounds good!
Enjoy boating, my friend!!

[ray schrauwen]

Remember to leave at least a 5/32" gap between the end of strut and front of drive dog when you get your parts back.

[Ryanrodfl6363lu]

Yes I've been doing that. I actually added a sliver of waterline between the drive dog and strut kinda like a bump stop/seal. Not sure if that's the right thing to do, but it's held up, and it made sense to me.