larger flex shaft

[Crash]

is it possible to use a larger diameter flex shaft with the stock stuffing tube?
I am wondering if a larger more durable drive shaft would fit in stock stuffing tube with no Teflon liner.
its seems the stock size shaft is at the limits of what the voracity puts out.
thanks guys

[arrover]

Are you breaking flex shafts? Have you tried the OSE HD flex shaft? I saw your question on the stinger upgrade. Are you having problems with your stock strut/nose cone?

[Crash]

My questions are sum what hypothetical in nature although, from the little knowledge I'm learning is that the 3/16 flex shaft is at its limits with this set up.
I have had some issues with mine mostly user error, due that they are given so much abuse there is no room for set up mistakes.
My stinger bushings are sliding around and does seem to be the largest source of friction threw out the drive line.
To combine my to threads into one real question, how to improve the drive line to point of, (a term way over used in RC world) "bullet proof"
I want to be able to take mine to the lake and not worry about breakage.
after breaking 2 flex shafts I can see they are not very strong to start with.
NO I have not bought the OSE HD drive shaft, I want to give ProBoat a 2nd and third chance only because it was my own fault the first two broke. 1st time I ran it with loose collet 2nd time the stuffing tube came loose and slid forward and I did not notice, that heated up the flex shaft at nose cone where it eventually failed. I'm running my 3rd and it is showing wear after 3 sets of packs
I would like a adjustable stinger with ball bearings using a larger flex shaft for durability.
This is my amateur opinion at best that's why I came here to get opinions and suggestions.
thanks, Dan

[arrover]

I wouldn't call myself an expert in RC boats but I have been running the Voracity a lot since it first came out. I ran my original with a loose collet like you and that was the cause of it's eventual loss. My second flex failed at the nose cone of the strut. At that time I was also having a big problem keeping the nose cone on the strut. Even with careful cleaning and Loctiting, it would not stay on for even a full set of top speed runs. With the nose cone off I could see that the flex was wearing on the inside of the nose cone. My theory is that this rubbing was causing the nose cone to come off and caused my second flex to fail at that point. I bent my stuffing tube up VERY SLIGHTLY. I'm talking an almost unperceivable amount. I've been running the boat this way with an OSE HD flex for a long time now and have not had any more problems. Much of this time has been with the Leopard 4092 motor and speeds up to 72 so far. Another option MIGHT be to pull the liner and run a 1/4" flex. I haven't tried this but I did just measure the outside diameter of the stuffing tube. It looks to be 5/16 tube and the brass 5/16 tube in the OSE store says you can run a 1/4" flex in it without a liner. So it might work to run a 1/4" flex but I'm not sure it's necessary.

[Crash]

thanks for your reply, have you seen any stingers with bearings or is that not a real thing...I have found adjustable stingers with very little technical info of the internal shaft or any with bearings.
My stinger in the voracity has 2 bushings that do not meet in center of stinger. The rear bushing is working its way loose every run now.

[arrover]

I really haven't looked at aftermarket struts so I'm not sure about the possibility of having bearings inside. It kind of seems like I have seen them... Do you think there is a chance that you've run any props that are out of balance?

[Crash]

the prop I'm using came from the manufacturer really in ruff shape and is not balanced.

[arrover]

I think that's the problem. At this high RPM, an unbalanced prop will probably cause the wear problem you're having. The stock prop should be close enough to balanced to run fine. CNCed aluminum props don't need balancing but props like Octura, ABC, Prather, etc need sharpening and balancing for sure.

[Crash]

great point, thanks

[kfxguy]

If you run an unbalanced prop it's going to cause issues for sure. Not being sharp is another no no. More load on the driveline.

I've run .187 flex in everything I've built and I can assure you that you are not past its point of failure due to power. Do you have at least a 3mm between the drive dog and strut? If not that can cause breakages. Are you lubing after every set of batteries? That needs to be done. Post a close up of your flex and where it's failing.

[Crash]

Thanks.
I do lube after every trip out.
I am using a gap at drive dog.
The wear I am seeing in this flex is rite around stinger inlet, by wear its heating to the point of changing color after only 3 packs threw it.
The previous flex shaft failure was the drive dog twisting off.
One before that was at the collet end , it unravelled the flex cable.

[kfxguy]

Can you post some pics. The flex may be running inside the strut or brass tube. I always solder the end that goes into the collet. Unraveling is from having the wrong rotation flex or using reverse aggressively. I've heard of people getting weeds caught around the flex and jamming it in reverse to sling the stuff off. This is a foolish idea. So I hope your not doing any of that.

[Crash]

yes, the unraveling of the flex was from using reverse when the collet was loose.
the learning curve from land to sea has been a steep one for me.
with 13 plus years with hobby grade rc's, I think I know more then I really do....lol
Ill snap pics of my flex shaft later today.
thanks for the insight men, I shall get a balanced prop before next run.
Dan

[arrover]

A couple things that I learned from guys here: Tighten the collet fairly tight with two hands. Then put the wrenches on the collet and tighten it pretty much as tight as you can get it with one hand only. You don't have to bear down on it super hard but that is a good gauge of tightness. The other thing was from a thread that KFX started I think. Always clean the grease off the tip of the flex after it slides through the stuffing tube and before it slides into the collet. There isn't much room to do this but I think it's worth the time. I clean it off several times with a piece of paper towel while I slowly turn and insert the flex into the collet. Then I do it a final time with a sterile alcohol swab. One of those swabs in the tiny square pack that already has alcohol on it.