15" Small Bolt micro hydro

[wparsons]

Seriously? You must have REALLY limited boating experience if you think that 1/8" is too much of a gap. If you think that a smaller gap will stop the flex from putting load on the motor you've been misinformed. You have two scenarios possible... Either you have enough space and load gets transferred to the motor, or you don't have enough gap and you get binding when the flex shrinks under load and pulls the drive dog into the strut.

Even the link you posted says 3mm (1/8"):

Measure the total length needed and add 3mm for the space needed between the drive dog and the end of your strut.

[igottalongone]

3mm on a 3/16 cable!!!
1/8th gap for a 1/8th cable is too much, again, whatever...
good luck...
p.s.
As far as my "REALLY limited boating experience"
I think people can look at both our videos and figure out who knows what they are talking about...
I BUILT my boat from the hull up, I didn't let the chinamen do it for me...
You'll have to come to a bit bigger lake for our race, I couldn't even run my boat in that bathtub, LOL!!!

[wparsons]

I'm not going to get into a pissing match about this 'cause I have better things to do with my time, but:

1) I've been building boats since I was 15, if you want to do the math, that's 14 years of experience. I've built mono's, cat's, outriggers, hydro's, electric, nitro and gas.

2) https://forums.offshoreelectrics.com/...ad.php?t=11247
3) http://www.rcgroups.com/forums/showthread.php?t=1295340
4) http://www.modelpowerboat.com/conten...-RC-Model-Boat
5) https://forums.offshoreelectrics.com/...=gap+drive+dog

You talk like your small bolt is so much faster than anyone else's, but it's still pretty stock. Sure you disassembled it, moved the water inlet, painted it and fused the flex/stub, but that's about it. Did you fix the angles on the bottom of the sponsons (mine had a degree or two of anhedral out of the box, and the trailing edges weren't the lowest point), is your CoG in the right area, did you cut back some of the stuffing box to give the strut more adjustment? You're even running a close to stock (or totally stock) motor.

I'm not putting down your boat in any way, but you're talking like everything is custom on your boat.

If you want a race, I'll put a spare 3600kv 380s in mine and see how yours does :D

I bought mine to have a super reliable no nonsense cheap boat. I put a battery in it, tape the hatch shut and it runs for 6 minutes on a charge. I can let anyone drive it as well.. Sure it's fast enough to flip, but it doesn't do any damage if it does.

[igottalongone]

"Sure you disassembled it"

"but it's still pretty stock"

WTF???

WRONG YET AGAIN!!!

Better to be quiet and thought an idiot, than open your mouth and prove it...

What do YOU know about MY boat!!!
I bought a Hull on e-bay, I bought a Motor and ESC, I bought Drive Harware from Steven and BUILT IT!
I didn't disassemble sh*t!

I think your a talker, not a do'er...
If you had any stones you would have this legendary 3600KV installed allready, lol...

You pick the hull (mono-cat-hydro-rigger) and I'll lay waste to yours!!!
Videos with GPS to see who's the king of the pond...
No stories about what you "could do"

**VIDEO CHALLENGE**
Pick yer poison tough guy!
LOL!!!!!!

[martin]

Ok lets keep things things civil guys, I have a question about this design shaft that has the shouldered stub shaft & square flex. Why do to need to Loctite or solder or any other method these two together. Thanks Martin.

[wparsons]

^^ Agreed...

I could care less how fast you think your boat is (or how fast it really is), the whole point was about how much of a gap is generally a good idea. I gave 5 examples, and all you focus on is the degree to which you built your boat.

You can't seem read either, I clearly said I bought this boat to be simple and reliable, not a rocket. I'll be sure to build the tub wide enough in my 16" rigger to fit a GPS in it just for you though...


Back on topic, there's not really any need to fuse them together at all. I've got a good 15-20 runs through mine and there isn't the slightest sign of wear on either the stub or the flex shaft.

[igottalongone]

LOL!! Retreat!!!

My eagletree data logger fit's right in my mini, so your weapon of choice is Mini Hydro's??? at 40 paces, lol!!! Done!
There is a data logger on the swap shop right now, go get it : )

"Martin" all the fun aside... Look at your cable bro, look at that tiny little square end made out of twisted sh*t china metal... Then look at your prop shaft, picture that little cable twisting back and forth while pulling in and out... Seem like a good idea??? Seem like letting the parts move around together metal to metal is a good idea??? No... It's not... Thats why they have been affixing them since they started building them 30 years ago... Like I said before, you don't even have to be into RC boats to see why they affix cables... I have a mini rigger, with a ton of motor running this system, I just measured it, I have 1.85mm between my drive dog and strut, and there is ZERO wear on the thin teflon washer. Meaning, it is shrinking less than 1.85mm under load... So, 2mm is more than enough gap, exactly what I said 36 posts ago...

[Jim Bob]

For what it's worth, my rule of thumb for shaft spacing is 1/2 the diameter of the flex shaft. Been doin like that for 35 years.

[Basstronics]

Ok lets keep things things civil guys, I have a question about this design shaft that has the shouldered stub shaft & square flex. Why do to need to Loctite or solder or any other method these two together. Thanks Martin.

As a machinist and a mechanical engineer I can tell you there is no reason this "needs" to be done. I can also tell you that "red" loctite is permanent thread locker. This is not a thread. If anything the Retaining loctites should be used.

I got's fear is that he is going to twist that square end off while its moving about that little bit... I dont think theres a 2040 motor out there with that kind of balls...

I tried the "red" loctite ona wire drive. It held up about 10 seconds and 24 MPH... I switched to the proper stuff, Loctite 648 and I will be damned if I can break it...

[Basstronics]

Where at in Michigan?

Its boring down here in Toledo area...

[igottalongone]

"As a machinist and a mechanical engineer I can tell you there is no reason this "needs" to be done."

wow... ok, i'm done... you guys win...

So, CaptPBJ...
Just keep on digging your flex cable out of the stuffing tube with a screwdriver...
I found a bridgeport operator who says there is absolutly no reason to install your cable correctly... lol...

Just kidding Bassman ; ) It was a Joke!!!
But, you would have to agree that it's a pretty bold statement to say because you are a mechanical engineer that you have the final answer on this (to affix or not to affix) issue...
If you really are an engineer, you know that nothing is known for sure until enough data is collected... But for all I know you did your masters on tiny chinese drive cables...

The Tenshock rigger I'm running one of these systems on is putting out over 800watts, more than enough power to jack up an incorrectly installed cable...

"Where at in Michigan?"
I'm in Waterford...
I just drove down by you a couple weekends back to run in Monroe, they have a running river that never freezes : )
We have a sweet spot to run up here in Waterford, big lake all to ourselves...
Come hang out this summer and run boats...
Most of the guys I run with are flyer's as well, so bring a Seaplane if ya got one...
C-Ya...
Ron

[Basstronics]

We are talking the same thing here, right? The square end female and square end male flex cable?

If so there is no "need" for the loctite. If your cable is ground inaccurate to the point you feel you need loctite then it really needs to be replaced. Even the green loctite only fills in about .010" area. You could have more than that in such a case.

The whole design intent on this is to allow slip at that point so the drie can remain tight...

Im about 20 minutes SE of Toledo. Monroe isnt to bad of a drive nor is Detroit. This summer we should get together. Im sure you could give me some advice for my fleet.


have a good one.

[wparsons]

LOL!! Retreat!!!

My eagletree data logger fit's right in my mini, so your weapon of choice is Mini Hydro's??? at 40 paces, lol!!! Done!
There is a data logger on the swap shop right now, go get it : )

"Martin" all the fun aside... Look at your cable bro, look at that tiny little square end made out of twisted sh*t china metal... Then look at your prop shaft, picture that little cable twisting back and forth while pulling in and out... Seem like a good idea??? Seem like letting the parts move around together metal to metal is a good idea??? No... It's not... Thats why they have been affixing them since they started building them 30 years ago... Like I said before, you don't even have to be into RC boats to see why they affix cables... I have a mini rigger, with a ton of motor running this system, I just measured it, I have 1.85mm between my drive dog and strut, and there is ZERO wear on the thin teflon washer. Meaning, it is shrinking less than 1.85mm under load... So, 2mm is more than enough gap, exactly what I said 36 posts ago...

Whatever man, you're clearly just bored and trying to start fights.

I'd like to see what you're using to measure 1.85mm though, 0.05mm is about 2 thousandths of an inch. How exactly are you measuring that accurately with the boat together?

Look at it this way... What's the harm in running more of a gap, absolutely nothing. What's the harm in not running enough gap, snapped cables.

Also, since you're using red loctite which isn't a permanent glue, there's a chance that the cable is still pulling out of the stub a tiny bit under load, which negates the need for a gap at all.

Square drive stubs are designed to use a thrust washer or teflon washer at the drive dog to carry the load when the prop pushes the drive dog into the strut and allow the cable to shrink as needed unimpeded.

What motor are you running in your mini rigger that puts out 800w, is it a 20mm can? The smallest reasonably priced (not lehner, etc) motor I've been able to find that puts out that kind of power is a leopard 2845, but if I can get a 20mm can motor that puts out that much power I can drop it into my mini rigger tub easily.

[martin]

The design idea & theory of the 2 part shaft is a good design, But its not that popular with us boaters because its not so simple or easy to grease ( probably were being lazy ) over the ones where you just undo the coupling & pull out. My self included, Im sure most are aware of the advantages of the 2 piece shaft though. You cant loose your shaft & prop out the back ( unless the stub shaft breaks ).also you dont have to worry about setting dog to bearing clearance that allows for flex shrinkage, Because the dog runs against the bearing & not against the motor. The idea behind the square male & female is a floating shaft so it cant wind up to tight & snap the flex or where you have to adjust the clearance spot on where on a one piece shaft where you have to have the dog to bearing clearance right which in my opinion is pretty much impossible where you have exactally the right clearance that allows for shaft wind up whilst still having the dog running against the bearing. You either end up with shaft wind up with the dog not touching the bearing or the opposite where theres not enough clearance & the flex is then under load & will snap. The solid 1 piece drive shaft isnt realy a good design although most of us use them. On a front wheel drive car you wouldnt use a solid drive shaft, Thus putting the entire loads on the out put shaft bearings & not the wheel bearings. Just my take. Thanks Martin.

[wparsons]

I wouldn't call it lazy so much, some boats take a lot of fine tuning to get the strut set perfectly, and then to have to pull it off and lose that setting everytime you grease the flex would be beyond painful.

You would basically spend a run or two getting it right again, only to have to remove it again to grease it after a couple more runs.

[martin]

Thats the exact point i was making, I called it lazy. This is one big downside to this design where you have to keep removing the strut & loose your settings, So it possibly dosnt get removed as aften as it needs for greasing. I have friends that have this type & they leave the shaft in longer than they should where as the simple pull out ones the tend to grease more often because its simpler to do with less hassle re setting up again. Thanks Martin.

[igottalongone]

Whatever man, you're clearly just bored and trying to start fights.

I'd like to see what you're using to measure 1.85mm though, 0.05mm is about 2 thousandths of an inch. How exactly are you measuring that accurately with the boat together?

Look at it this way... What's the harm in running more of a gap, absolutely nothing. What's the harm in not running enough gap, snapped cables.

Also, since you're using red loctite which isn't a permanent glue, there's a chance that the cable is still pulling out of the stub a tiny bit under load, which negates the need for a gap at all.

Square drive stubs are designed to use a thrust washer or teflon washer at the drive dog to carry the load when the prop pushes the drive dog into the strut and allow the cable to shrink as needed unimpeded.

What motor are you running in your mini rigger that puts out 800w, is it a 20mm can? The smallest reasonably priced (not lehner, etc) motor I've been able to find that puts out that kind of power is a leopard 2845, but if I can get a 20mm can motor that puts out that much power I can drop it into my mini rigger tub easily.

As far as me starting fights, YOU made the first rude comment in our exchange, so blo me!
p.s.
I took a look at your you-tube videos, to see your RC prowess in action...
LMFAO!!!

Keep up the great work...

[igottalongone]

Just wondering fellers...
Anyone gonna help out the guy who originaly asked the question???
I attempted to help the man install his cable correctly, but the thread was then taken over with this stupid shyte...
CaptPBJ is at home right now digging his flex cable out of the stuffing tube with a screwdriver...
Well Capt, I'll shut up now and leave you to the pro's...
Ron

[Basstronics]

Mine was jammed in the square end also. The square end is ground by hand and isnt fully square. I did it a favor by cleaning it up with my dremel tool and a cut off disk. However in the end I decided to replace it.

[igottalongone]

Actually, if the cable was getting stuck in the prop shaft, he wouldn't have a problem, he would have it installed correctly...
But I won't go there again... lol..

The Captains problem was, when he removes the strut, there is not enough cable sticking out to grab ahold of.. So his only option was to use a screwdriver to poke the cable down the stuffing tube at the coupler....

[Rumdog]

How about just replacing it with a standard flex? .098 will be perfect. Who the hell wants to pull the strut to grease every time? You could also go wire drive.

[wparsons]

As far as me starting fights, YOU made the first rude comment in our exchange, so blo me!
p.s.
I took a look at your you-tube videos, to see your RC prowess in action...
LMFAO!!!

Keep up the great work...

Good to see you're still carrying on...

I could care less about your approval, which is why I haven't bothered uploading videos of most of my boats/planes/trucks/helis. I know that I know what I'm doing, and don't need to get into a pissing match to prove it.

Back on topic yet again, small pliers or tweezers work wonders for getting the flex shaft out. At the very worst you can take the coupler off the motor to push the flex further down the stuffing tube.

I cut about 1/4" off my stuffing tube to give the strut more room for adjustment, which also exposed more of the flex when I pull the strut off.

I'll be making a wire drive for it when I get any time to work on it so I don't have to go through all this trouble every time I need to grease the flex.

[Basstronics]

I purchased a wire drive for mine. The problem I seemed to notice was to much bend in it- making it hard to turn.

If the flex is stuck in the coupler grab it with pliers and pull it out. Get the coupler off the motor- remove the set screws. File the coupler where the set screws are- typical culprit of such things.

While your at it take the dremel and a cut off and sand the square end so it floats good inside the female square end.

[wparsons]

^^ Do you remember what diameter the wire was? I'm going to test fit one from another boat that's a .047 wire when I get a chance.

[Basstronics]

.062

[wparsons]

I'll try the thinner wire with a plastic prop first :D

[CaptPJB]

Thanks for all the info guys did not mean to stir things up. Lots of good info came out of the posts though and I learnt a lot. I won't stir things up again by saying which method I am going to use but lets say I have choices.
One of the things that made my life difficult was when I went to loosen the grub screw on the motor end it stripped but the flex end undid OK. hence I was trying to push the flex out with screwdriver/plier assist.

Now I guess I will have to find a small bit to drill out the stripped grub screw. Apart from making life more difficult to get the flex out it is holding fine so may leave repairs until I just have to do them and enjoy this little rocket.

Thanks again for the help
Peter

[wparsons]

You might be able to get the grub screw out by using a tight fitting torx bit, but there's no guarantee of that working.

[martin]

I had the same problem getting the allen grub screws out of the coupling all be it on a Tenshock mini eco which has a 2mm wire drive. The motor shaft screw came undone ok but the shaft one wouldnt undo without slipping in the hexagon. The keys i had were 1.5mm .058" so thought they might be 1/16".062"so bought a set of a/f size wrenches. used the 1/16" wrench & guess what it slipped the same, When i measured the 1/16" wrench it measures the same size as the 1.5mm. Whether they now use the same size wrenches for both these sizes because their very close i dont know. I managed to find a wrench out of many i had of this size that was new & had a bit of a burr on the end from manufacture so was a couple of thou bigger right at the tip which didnt slip & undone it. Thanks Martin.

[SweetAccord]

After getting this boat from KH and reading all the threads on this boat I can see where some decided to change it's setup. After seeing how it's been designed, I do see how there is much drag in the driveline. I decided to copy the Tenshock design and put a bearing in the strut instead of the bushing. Wow what a difference! It also has a tighter seal so water should have a harder time to enter also. Also I'm stepping down the drive line from the stock 3.18mm flexdrive to a 2.37mm one with keeping the 1/8 prop shaft which is the same as the stock one. I took a few hours to carefully drill out (by hand) the stock bushing and bore it out to accept a 1/4" bearing. Sanded with 1000 grit sand paper to get a smooth inside diameter until the bearing was able to be (fimly) pressed in. You can get these bearings at the LHS.