Expectations 1/8 scale hydro electric conversion

[Fluid]

Exactly what props have been used? If they are lifting props then the problem may be the prop forcing the bow down. Jim is right, the prop angle may be part of the problem since an angled prop will lift the transom as the boat accelerates. 10S or 8S? Makes a difference on prop choice. The big Scorpion HK4035/800 pushed my 22 lb cat just fine on 10S.

Too, the Dumas hydros were not the best designs and are designed to be toss-launched. This technique could help the OP get the boat on plane.




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[PJBJ]

Can not adjust strut (or remove solid shaft, adjust motor angle, build in flex with strut)

Props used S-265 2.61"/4.0" and 1657/1.6 lifting props? 8S. conclusion solid shaft with dumas hull does not work?

No like handtoss. considering building new wood 1/8 hydro. info on good running hull appreciated. thanks

Exactly what props have been used? If they are lifting props then the problem may be the prop forcing the bow down. Jim is right, the prop angle may be part of the problem since an angled prop will lift the transom as the boat accelerates. 10S or 8S? Makes a difference on prop choice. The big Scorpion HK4035/800 pushed my 22 lb cat just fine on 10S.

Too, the Dumas hydros were not the best designs and are designed to be toss-launched. This technique could help the OP get the boat on plane.




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[JimClark]

Can you post a picture that shows the strut and shaft.

Sent from my SM-G900T using Tapatalk

[PJBJ]

P1000663.JPG

added spacers

P1000664.JPG

prop now half inch further back and behind transom.

thanks

[JimClark]

is that the prop you were using?

[PJBJ]

last run: the prop on the picture above made the boat go under.
with lipo's in the back, the boat does not plane nicely.

P1000665.JPG

before: 1 time out of the water and on plane.
with lipo's in front and weight in the rear.

[PJBJ]

P1000666.JPG

prather S-265

[PJBJ]

Found myself again on this internet because I am building a small roundnose hydro which was lying in the cupboard for some years. Sold the Dumas boat. It never ran the way it should.
I remember one time with full throttle it went under water like a sub and I could see it go for 10 meters or so. Now I will try again with what I have lying around and hopefully make it work. I enjoy wooden boat building because the wood is of a higher quality than balsa in planes. I now have a Osborne models kit 1/12 scale hydro and I need to make the best of it using a solid shaft. I think this tread can be deleted. Bye