New EDF powered fast-electric boat project

[a.flynn]

Hi to all on the forum.  For what it's worth I've just started a new fast-electric boat project that will be powered by an electric ducted fan, or EDF.  So far I've just ordered the hull which is 3 foot long and have done a rough plan.  See images below.  Anyway, any ideas, pointers appreciated!  Thanks.

[McGaskil]

Nice idea, but why an EDF over a regular prop, and what sort of performance are you aiming at.  Also any stats like length of hull, etc?

[blag-it Admin]

I'm no expert on fe-boats although I did build an rc electric boat a looong time ago which was a sort of tug boat...  Going by the first image it looks about 30-odd inches long?  I would suggest as powerful an EDF as possible (budget allowing...) for a hull that sort of size, which atm doesn't include the deck or anything else, to get reasonable performance, so for an fe-boat 45+mph minimum.

[cybernut]

Nice grooves on a nicely pointed hull there.   So happens I've built two fast-electrics so hope some of this helps.  Going by your mock-up diagram it looks like you're going for a flat deck which is a good idea as this will afford some down-force on either side of the canopy and so keep the bow down and reduce bobbing.  However you would need to set the edf slightly further back to prevent pushing the bow down tooo much.   For a boat that size you'll need at least a 9cm fan with brushless outrunner that has high rpm and min of 12 LiPol cells; ideally 12cm fan with 18 cells.  For the deck use either fibreglass which I think the hull is, or gel coated styrofoam.

[a.flynn]

Nice idea, but why an EDF over a regular prop, and what sort of performance are you aiming at.  Also any stats like length of hull, etc?

An EDF should produce less water spray, also my work conditions aren't ideal atm, and so installing an EDF would make my job slightly easier over a conventional prop set-up.  The hull is 3-foot long, so 36" and I'm looking at hopefully 45-50mph realistically for a first attempt.

[a.flynn]

I'm no expert on fe-boats although I did build an rc electric boat a looong time ago which was a sort of tug boat...  Going by the first image it looks about 30-odd inches long?  I would suggest as powerful an EDF as possible (budget allowing...) for a hull that sort of size, which atm doesn't include the deck or anything else, to get reasonable performance, so for an fe-boat 45+mph minimum.

Thank you. Length is 36" and I agree that as powerful an EDF as possible is a main consideration as the weight of the boat will o.c increase somewhat once the deck, hardware and canopy is added.  If I can get 45+mph I'll be happy

[a.flynn]

Nice grooves on a nicely pointed hull there.   So happens I've built two fast-electrics so hope some of this helps.  Going by your mock-up diagram it looks like you're going for a flat deck which is a good idea as this will afford some down-force on either side of the canopy and so keep the bow down and reduce bobbing.  However you would need to set the edf slightly further back to prevent pushing the bow down tooo much.   For a boat that size you'll need at least a 9cm fan with brushless outrunner that has high rpm and min of 12 LiPol cells; ideally 12cm fan with 18 cells.  For the deck use either fibreglass which I think the hull is, or gel coated styrofoam.

Great to know someone on here has built two FE boats! Yes, I'm going for a flat deck more or less for those reasons although I also intend to use trim tabs to further reduce porpoising.  Thanks for the fan and battery spec tips

[blag-it Admin]

Good to hear you're sticking with it and hope the build goes well for you, how about some pics?

Admin

[McGaskil]

Yea!  Would like to see some pics of the construction so far!

[a.flynn]

I've not started building it yet, still some other parts to arrive, etc, but did take a few pics of the hull.  Unfortunately I can't find the cable to transfer the pics from the camera to the laptop LOL.   Instead, here's a pic of the battery pack that was in the email confirmation.

It has 8 LiPol cells at 5000 Mah with a 29.6 v rating.