school me on felxshafts

[MadProps]

Im not familiar with inboard drive lines my only experience with rc boats has been outboards....then I bought a genesis and the stuffing tube wasnt epoxied in place on the hull bottom ...just a big hole to leak water ....not certain how where how long the the flex shaft & liner should be, I didnt want to epoxy what I had here so I just hot glued the hole closed to test run the boat

everything is stock on the genesis I have it tuned well and have been running a 42 mm prop on 6s ....now want to address this hole in the hull bottom epoxy a tube in place proper and get a better understanding of the liner & shaft


the liner rotates on the flex & rides up the shaft and touches the collect after a run ...should it do this?

the liner is 4 inches shorter than the flex shaft is this OK? or should it be the entire length of the flex shaft?

I also have a 40 size leopard 2000kv to upgrade but I read most upgrade the flex shaft to 3/16.....
the stock shaft has been holding up very well so my question is ......is the leopard motor capable of so much more torque that I must upgrade the shaft to 3/16

if infact I pretty much must upgrade the flex to 3/16 I want to know more about the drive line since I cant trust what came out of the Genesis knowing the assembler was a slacker

thanks for looking

[rol243]

yes you need to go larger dia flex shaft with this 40mm / 2000 kv motor, i would sugest to buy the 3/16 inch flex shaft plus a matching brass tube log without the liner but you need the correct inside diameter brass tube to suit the flex shaft outside diameter of 3/16. liners can be nothing but a pain in the bum and providing you keep the flex shaft greased well it will last along time without wear. the total length of brass tube should end up approx 1/2 an inch from the motor collet end. OSE should have all what you need for this conversion upgrade.

[Fluid]

The OP has the choice of running a liner or not. Personally I haven't used a liner on any non-RTR boat in over a decade; never worn out a stuffing tube or a cable. I use gear oil, not grease. Use a piece of 1/4" brass tubing if you choose to not miss the liner.

The most common mistake when installing the tube is poor alignment. When gluing the tube in the hull, have the cable in place tightened in the motor coupler and run through the strut. This will help with proper alignment. Use a good epoxy and tape on the hull bottom to keep it from running out. Some will CA a rubber o-ring around the tube inside the hull prior to gluing the tube in place as a dam to contain the epoxy. Good luck.



.

[kfxguy]

Im not familiar with inboard drive lines my only experience with rc boats has been outboards....then I bought a genesis and the stuffing tube wasnt epoxied in place on the hull bottom ...just a big hole to leak water ....not certain how where how long the the flex shaft & liner should be, I didnt want to epoxy what I had here so I just hot glued the hole closed to test run the boat

everything is stock on the genesis I have it tuned well and have been running a 42 mm prop on 6s ....now want to address this hole in the hull bottom epoxy a tube in place proper and get a better understanding of the liner & shaft


the liner rotates on the flex & rides up the shaft and touches the collect after a run ...should it do this?

the liner is 4 inches shorter than the flex shaft is this OK? or should it be the entire length of the flex shaft?

I also have a 40 size leopard 2000kv to upgrade but I read most upgrade the flex shaft to 3/16.....
the stock shaft has been holding up very well so my question is ......is the leopard motor capable of so much more torque that I must upgrade the shaft to 3/16

if infact I pretty much must upgrade the flex to 3/16 I want to know more about the drive line since I cant trust what came out of the Genesis knowing the assembler was a slacker

thanks for looking

I rebuilt a genesis for a guy and ditched the stock tube and upgraded the flex to a .187 with no liner. I don't used lines unless it's a thick one, usually in a twin. I also upgraded the steering linkage and servo mount for him because slack in the steeering will cause wonky handling and scrub off speed. He wanted to go faster than 70mph that he was doing at the time. It ended up going much faster afterwards.

[MadProps]

Thanks for the replies gentlemen, I took your advice and ordered the upgrade shaft with NO liner
I have had problems with liners & wasnt aware there was a way to go without them!

as to the sloppy steering linkage I just went thru that as well it was causing the Genesis to chine walk kinda ...like a V hull...it was ugly

[MadProps]

since the parts were ordered and the stock Genesis motor is hurting I installed the Leo 4074 2000kv and got 1 run to approx 65mph and the shaft broke as you guys said it would

glad I asked you guys before ordering upgrade parts and learned about no liner..... great place for GOOD advice