Love the self righting idea. Do you have problems with flex shafts breaking?
I have replaced the Teflon liner with a 3/16" brass tube and use plenty of grease, better but still breaking shafts.
I am in the process of painting a dragon Hobby DAC to look lie my friend's real boat.
I'll be ready in May.

Within 10 runs or so, I already broke 3 flex shaft all in halves! Yes, I did grease after every run but the curve is too much and I did run it hard with 4S.

I tried with and without the teflon liner as well as the brass tube to no avail.
I made the drive train with slightly larger .130 flex cable but it broke too.

I wrote the dealer who in turn sent it to the manufacture but I don't think there's much they can do.

I bought a new outdrive from OSE with less curve but didn't get a chance to replace the stock outdrive.



As you can see from the above picture: the green line shows the better outdrive whereas the red line shows the stock one.

I put the 1/4" weather foam tape around the bottom of the hatch.



Then I drill holes and installed 2 nuts and bolts on each side for the silicone o-rings to pull the hatch shut.

Note: the pictures are from my other F1 with similar hatch design i.e. front lock so no need for the front hold.

Well over the winter I bought some 0.130" flex cable from Field's Hobby in Buffalo, NY. I replaced the 0.120" stock size shaft with the 0.130" hoping that would last longer. Thanks to another member of this group, Buzz, a prop safer idea saved me from losing the prop, prop dog, and prop nut. So we're still trying to come up with a better stronger flex cable. Anyone? Don't forget it has to work in the tight confines of this outboard.
Thanks Jeff

There may be no suitable cable that will last for long. This is quite a task to perform.

I speak while keeping in mind that with the 70- to-90 degree bend required of an outboard plus the very high RPMs experienced, the wires that make up that cable are being severely flexed back and forth over 3000 times per second, every second as it rotates at 20,000 rpm. That's the stress it has to deal with, and the flaw with this drive concept. Flex cables can spin fast under a heavy workload like in my boats, or work around sharp bends nicely as they do with my Dremel grinder extension cable,..... but when they are asked to do both at the same time....

Just a thought. How much larger in diameter can you go?

One of my best friends was the crew chief for a real full scale F1 race Team, Wyatt Nelson, who was hurt in 2007 from a bad blow over and can't race anymore. While his son Jason won the F-Lite series last year, Wyatt can still be the crew chief for him. Bill, Wyatt's former crew chief told me that the real Merc F1 motors only last a short period of time before they will have serious break down issues and need to be replaced. For example the high rpm's of those real F1 V-6 380+hp motors can cause the roll pins in the pistons that line up the piston ring gaps can come out and ruin the piston and cylinder wall after time.
So now that I have the "prop saver" needle pin hanging out of the tower housing exhaust, at least I can live with just replacing the flex shaft. As we used to say when I raced full scale "B-Stock" Runabouts years ago, "That's Racing". So until someone comes up with a carbon fiber super strong durable flex shaft, I will, as do the real full scale F1 Teams, keep track of how many runs I get out of the stock shafts and try to replace them before they fail or just run until failure and go retrieve the boat. Now I will work on faster ways to disassemble and replace the broken shafts.
Thanks for your ideas and input!
Jeff

Has someone already eliminated the problem with the flex shaft?

Greetings from Germany!

No, and it is extremely doubtful anyone ever will. Why? First, economics, there are too few OB owners to justify the cost of development plus the cost would be more than most would pay. Second, the technical hurdle, the tight bend, high rpm and constant vibration from the prop cause fatigue, the 0.130” cable diameter is too small for the power applied, the quality of these cables is poor. As stated above, the cable is an expendable item, nothing lasts forever.


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It is possible to increase the size of flex shaft in some of these small outboard legs if you have enough room for the bigger cable ,some have 4mm stubshafts while others use 3mm stubs but the flexs remains the same dia. and as Airdogge has mentioned in previous posts rpm is the most critical part of the problem even using a tiny prop the flex shaft can't handle the extreme forces on the flex when being bent many many times per second depending on rpm.

I have the mini TFL outboard leg which is one of the outboards mentioned with flex shaft problems , after i replaced 6 stock ones in a very short period I sought out a way to correct this failure with a bigger flex cable with a larger stubshaft aswell , there is plenty of room in the leg to do this allowing a bigger teflon liner to fit the bigger .150 flex cable with .187 or 3/16" propshaft, this particular outboard has 3mm bore reverse threaded bronze bushing that comes stock with it but it can be removed and the leg can be drilled to 1/4" to accommodate lead teflon bushings 2 of them inline to get enough length to support the propshaft, ( the bushing that were used was standard Octura 3/16" lead teflon bushings with a 1/4" o.d. and 9mm in length and using 2 of them inline gives you 18mm of bushing to support the propshaft) another thing I did was reduce rpm on the flex shaft with that extreme bend in it ,the stock outrunner motor was 3000kv designed to use 3s(11.1v) at over 33000rpm unloaded , I dropped kv to 1800kv and use 4s(14.8v) so bigger props can be used but the cavitation plate has to be raised to give enough clearance .

So the flex shaft problem is a thing of the past. After 4 waves broke, after a total of 5 minutes driving time, I changed the entire outboard. The new outboard now has bevel gears and holds. Unfortunately, the hood over the driver's dummy broke on the last trip. Does anyone know where to order them or does anyone else have one?

Greetings from Germany

Don't know where you'd get a new canopy but I fixed mine with plain old clear packaging tape. Also I remember a time when the boats didn't have a canopy at all. Is the geared motor the same scale - 1/10th scale I think. Maybe you could make a wooden block the shape of a canopy and heat some clear thin plastic and shape one over the wood block?