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Blew the drive between the motor and shaft in my modified Dolphin (1st pic) - The motor shaft is 4 mm and the solid steel shaft it connects to is also 4 mm (pic 2) - will the part that is pic 3 work? Any suggestions on how to set up a wire drive or another dependable drive for this 25 in. boat - Thanks - Steve
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The coupler shown in pic 3 can work, BUT you will need to ensure that the motor and shaft are prefectly aligned otherwise the resulting vibration will cause havoc in the hull. There are 4mm to 4mm universal joints available. I believe Graupner make one and I know Kyosho and Academy make them too. I have a couple in my spares bin.
For help with setting up a wire drive we will need more pics of your hull.
Side, from the rear, top and bottom.
I make my own wd's and they are very easy to setup and for me a lot less expensive than using flex cable.
That said, wd's are not for every boat as they do not like a low radius bend.
Put up some pics and let's see if we can help you out.
Cheers
Simon.See it....find the photos.....sketch it it....build it........with wood -
can you move the motor a little to the front?
if yes, I would suggest using a second coupling (as pix #3) and put a short piece of 4mm flex between the two coupling! I'm using this assembly without any issues, in the worth case the piece of flex is disposable!
can you get some? that's the question?Comment
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Pics for Wire drive help
Thanks Simon - Here are the pics you requested - inside diameter of the tube that holds the shaft is 4 mm. Thanks again for your help as I hope to get this boat going this season - SteveComment
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Hi Simon - Yes but will those Graupner Universals work at the high RPM and torque that is going to be produced - Pretty beefy motor (maybe a bit on the edge) with 2 li-pos 7.4 in series - I have posted pics to the thread as I like the wire drive the best in all my studying - I am a newbie at these fast brushless boats - have a lot invested in Charger (Hyperion Duo) and MaxAmp Batteries - But I am very keen and have a great place to get used to the speed. Thanks Again - SteveComment
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Hi Ed - I like your idea too - but to move the motor I would have to strengthen hull and install proper motor mount (which I sort of want to do) - Also I can get 4 mm flex cable from the same guy who has these 4mm to 4mm collets in Hong Kong on EBay - I am looking at a wire drive system as well and will come to a decision soon and order some parts - Thanks - SteveComment
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If that is a straight hard shaft you can put a wire drive directly in to the stuffing tube.....size it down for a 1/8 shaft (easy to make for $2 worth of parts. Get a coupler and you are done.
If I were you, size that tube down with KS tubing and run 1/8" props. Also, what KV is that motor and how does it run on 4S? I like the can water cooling on them. Also, which ESC are you running with it? Is the motor a 4mm shaft?Comment
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Yep - That's what I want to do - a wire drive in that stuffing tube but I can't seem to find a coupler for the 4 mm motor shaft however - Yes it is an Xpower B28 motor - KV 2700 with a 60 amp water/cooled Pulso Boat ESC. - 1/8 inch props eh? - I have already invested in a few 3/16 Graupner props so I was hoping to try them out - Any ideas about a coupler that would allow me to go to 3/16 - where I would not have to strenthen bottom of hull and re-position the motor with a new mount - although I figure I may have do that in the long run.Comment
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Judging from your first photo, I would venture to guess that the reason you blew the drive coupler is due to the misalignment of the two shafts. The coupler may have been able to compensate for this misalignment with the low-powered “stock” system, but throwing additional horsepower it was more than it could handle.
I just re-examined that first photo; and the motor mount appears to have been bent by supporting all the cantilevered weight of the motor. Try re-bending the mount and putting a support under the forward-facing end of the motor.
Regardless of what type of coupler/drive you use, spend some time getting the motor shaft to line-up with the drive shaft. You can use shims, washers, and the like to move the motor position; possibly re-file the bolt holes in the motor mount; or if all else fails, make a new motor mount.A nation of sheep breeds a government of wolvesComment
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Steve, I have couplers for whatever you need. Just go up to 3/16" Shaft. What is the current shaft size? I now make some cool step up shafts that run in 1/8" (or whatever size needed for the strut ) and the they step up to 3/16"Comment
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IMPBA 20481S D-12Comment
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Thanks Guys - I am on it - SteveComment
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Etti Wire Drive w. Carbon fiber tube
I shall try this 2mm wire drive with 4 mm to 2 mm coupler and hope for the best - Will I blow any parts with "Lipo 3000HV 2S 7.4V" (2) in series - it's a XPower 2700 KV only recomended for 3 cells. I am getting a bit frustrated as I keep buying $$$ parts that arn't compatable - boats that don't work - batteries that are too powerful etc etc. I hate to say this but maybe I should just go get a Super Vee.
SteveComment
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