SI 1/4 scale 3 pt hydro electric conversion.
 

Well, I made the decision to convert this boat to brushless Lipo electric power.

Attachment 2235277

The Super Tigre g2300 mk2 came off as well as the radio box and fuel tank (obviously). I mocked up the placement of the electric components and was not happy with it because the center of balance was way off due to the weight of the Lipo batteries.
I had to reluctantly cut holes into the tub to be able to slide the batteries back enough to move the CB. I'll make trays to slide the batteries into so they don't slop around in the hull.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

I can smell the burning electrons already... :D. Looking good so far!

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

HOw about a few specs... motor kv prop size

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

OH yeah, that would be helpful. :D

The motor is a Turnigy 160. 290kv 10 cell capable.
Esc is a Hobbywing boat 80 amp high voltage water cooled. And the batteries are the turnigy nanotech 65-130c 5000mah 5 cell.

[link=http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=23176]Motor,[/link] [link=http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=33255]batteries[/link] and the [link=http://www.hobbypartz.com/07e-c-seaking-80a-hv.html]ESC[/link]

I'll try a 16x10 APC prop first.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Did more work the past few days. I got the battery trays done and installed, made the long, bent, radio box cover and sealed most everything so far with thinned epoxy. I'll be working on the wiring and ESC cooling very soon....Must think of the shortest route for the wires without getting in the way of the swinging prop.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Crispy - no worky on the latest pics. Thumbnails aren't showing up and clicking them just gives "Loading..." ... I wanna see! :D

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Are they working for you now? They show up in my browser. [&:]

I haven't done a water test yet, but I do have a video. The set up seems to work great.
At full throttle (static) 2300 watts (3 hp), 9200 rpm and pulling 65 amps. Motor timing set to 0%
http://youtu.be/OY3l66-kV2Y

I needed a way to protect the motor wires and the cooling tube from the prop so I made a removable cover plate.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Pardon for butting in!! Now are you the gentleman who built the blue airboat and had a video of it running on the snow by your house? I admired it for ages but went a more simple route of building a airboat. I wanted a fancier airboat like your blue one. Cajun of Libera,Miss. helped me on my simple airboat till his site went down. He was a real nice gent too. Have a good day! I see he posted here of late. BTW, your present airboat looks great.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Working now, yes. Impressive indeed! Flies go splat in the prop arc! =D

Now lets see a lake run! [8D]

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Thanks Mike.
Not at all, butting in is accepted here. I don't recall building a blue airboat, silver, black and natural wood are all that comes to mind. The only blue one I built was a 3 pointer that never saw snow. I can't even think of the one to which you refer, or who owns a blue one. [&:]

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

I tore it all apart, sanded the top of the hull and sprayed a fresh coat of epoxy on. Assembled this morning and I have no clue when the maiden voyage will be. :eek: I need to find a camera man to take a proper video.

The weight is a tad out of control at 17Lb 7oz but that's only a pound more than the Zenoah powered gas version without fuel, so I should be ok.

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Well, here is the first electric run....

http://youtu.be/vWvSbMsgntQ

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Excellent work Crispyspa! I bet with less wind and calmer waters that electric conversion will be a lot faster. Your conditions on the video did not look to be too good. Put up a video when you have a calm day and I bet you will have an ear to ear grin. Dennis

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Thanks DJ. Yeah, the wind wouldn't let up and the chop was horrible. A storm blew in and I got soaked from a short, hard rain. I had all my stuff out on the tailgate. Radios, charger, tool box, batteries....all got a little wet. My buddy high tailed it to his truck so he stayed dry. Good times, good times. LOL

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Although sad to see the internal combustion engine go, it still looks good on the water, and I'm sure more speed will be had on calmer waters.

Do we have to plan another meet?!? :D

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

I was thinking about that. There is a place on the west side of Rochester called Whistle Binkies on the lake. They have a nice pond. I was wondering it they'd let us run there. Nice central location and we'd have a place to eat when we get hungry.

[link=https://maps.google.com/maps?expflags=enable_star_based_justifications:tru e&ie=UTF8&cid=4420046260263243481&q=Whistle+Binkie s+On+the+Lake&iwloc=A&gl=US&hl=en-US]Whistle Binkies on the lake[/link]

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Sounds fine by me. My wife owes me a few personal days off anyway. I don't think I want to haul the canoe that far though... Got an idea for retrieval?

I wonder if the pond is weedy... Have you been to that place and seen the pond semi-up-close?

RE: SI 1/4 scale 3 pt hydro electric conversion.
 

Drove by it a lot during my sickness and trips to mayo. Seems to be almost weed free.

Got this boat really moving! Last year it got up to 58mph https://www.youtube.com/watch?v=fOC2shAAhVs

But that wasn't good enough. I added batteries and a larger speed control and ran again. https://www.youtube.com/watch?v=DjIEAuLrlhc
and https://www.youtube.com/watch?v=n23sFTlRZmM

Not quite making my goal. Bad part is, I cant seem to keep the sponsons on when it does flip.

Add fiberglass cloth inside the sponsons and load it up good and wet with resin. Sand it coarse between coats to get good adhesion. I did this with both of my SI3's.

Is it deck flex?

I did that on the one sponson that literally blew apart, but without disassembling the other one, I'm afraid Ill have to stick with doing the seams from the outside.


Yeah, pretty sure it is. The darn thing is so big there's no really good way to stiffen it up without adding a ton of weight.


The fiberglass mat and epoxy seems to be working well on the one sponson. I tried regular poly resin and mat today. It did not adhere to the wood and I peeled off a large section much like a scab.

If you were trying to adhere polyester resin over an epoxy sealed surface, it won't stick. Polyester and epoxy are incompatible. Bare wood should accept polyester or epoxy equally well, especially if thinned or warmed. At least in my experience.

I sanded the surface of the ply with a die grinder and a Roloc disc 60 grit pad just past (and into) the the top layer of ply to give the resin something to stick to and to provide a channel of sorts to allow for sanding afterword.

You think the epoxy got that far into the ply? I did use thinned epoxy brushed on as the initial sealing coat when I first built it.

Well, firstly I don't like polyester. Body filler, fiber resin, or gawdy Christmas sweaters.. LoL, kidding aside. Based on my finishing experience, when a product doesn't bond to the substrate, there is a reason for it. Contamination is usually it. If you ever see a fisheye in your resin, the substrate wasn't perfectly clean. Some finishes are finickier than others. I'll bet the epoxy made it half to three-quarters of the way through the first ply. Thinned epoxy soaks in really deeply. Using a non-thinned finishing resin on my boats with 1/32" ply on them gets through the first layer so quick it makes it kinda transparent and shows the glue layer between the plies. So if poly peeled right off even after sanding really well, I suspect there was still old resin left behind. Go back to using epoxy - it's so much better anyway.