snhdss

well, i recieved my .08mm birch, and my 1mm birch, both 4ftx4ft sheets. I'm still waiting on 3mm balsa i ordered. bought a dremel, and some gorilla glue. Also, went to office depot and printed off the templates. Will be starting soon! Can the OS leg be used, or is this particular boat better suited for the hobbyking outboard. I may have some questions along the way, as this is my first (boat) build. Thank! Shane

Dirk Jan

Sounds good. Just take your patience cutting the frames. The more accurate you build, the less time you need for finishing the hull nicely.

if you have any questions, just drop them in this topic

Dirk Jan

I just had my sponson tips fixed and painted them today:








I will paint a black separator line in between and finish it off with some clear coats. I cannot wait to drive this tunnel again

Dirk Jan

@ SNDHS: I guess the OS leg is too large. This hull is built to fit the TFL / OSE / HK mini outboard unit.

I finished painting the tips. Yesterday I went to the pond to run the Cozy F1 again!



Of course I had to install the outboard motor again. I like the looks of the cowl that comes with this unit.



It was very windy yesterday, not perfect for this little hull. I had to be gentle on the throttle. The hull flipped twice. First time it rolled back on its sponsons, but the second time I had to rescue it.
The top speed was 54.4 km/h / 34mph. I have another motor/prop combo that I will try soon.

snhdss

Well I've started the tedious process of cutting and sanding the different pieces. Going to be a fun project.

Dirk Jan

Great, keep us up to date

Dirk Jan

This evening I installed the 2800kV outrunner. This motor is twice as heavy as the little outrunner it replaces.


I will try this motor with a Aluminium 35mm prop, shown below together with the brass 33mm prop that comes stock with the HK outboard.





I don't like the looks of this outrunner sticking out above the cover. But I'm curious how this setup performs. This week I will test it.

Dirk Jan

This morning I ran my Cozy F1. I already tried the new setup last week with good results, but I had to sharpen the prop still.

This morning I sharpened it and I took 2 lipo's with me; 1 old one and a brand new one. First I ran with the old lipo. The Cozy F1 ran nicely with the hull floating above the water. The top speed was 35.0mph.
The new lipo improved the performance condsiderably; more punch and a top speed of 37.0mph

Some pictures and a video of today:





https://www.youtube.com/watch?v=5_CDCamKho0

Dirk Jan

This week I took my chemicals, mold and CF laminate to make a carbon fiber cowl. I waxed the mold one more time and applied a PVA releasing wax on top of that.





I use a 200gr/m2 cf cloth. On top of that I apply a glass cloth of 110gr/m2 to make the surface more smooth. This cowl should become 20% lighter than my glassfiber cowl. I will also make another paint/decal design for this cowl.

Dirk Jan

Yesterday I went to a Dutch meeting for 152VO - class boats (www.152vo.de). I took my Cozy F1 as well and my buddy took some action photos:







Old vs new: 1950's Foo Ling You - Utility Flatbottom (152VO class) against the Cozy F1 on the straight:

Kruegermak3

Dirk,

What kind of servo did you use?

Dirk Jan

I used a standard size servo, in my case a digital one I had laying around. I recommend at least 100oz/in of torque.

DanielCardona

Hi Dirk Jan

Did you considered to make the hull in ABS plastic? I mean Vacforming. something similar like those bodies in RC cars. It should be even lighter, more flexible and easy to make replacements after making the mold. BTW you design looks really a winner, You done a wonderful job.

Regards
Daniel

Dirk Jan

Hi Daniel,

Thanks for your input. Actually, ABS is not the best material for a boat. It cracks pretty easily and it ages and can become brittle. The wooden rib structure of this hull makes it very stiff. Also, wood is probably even easier to work with / come by than ABS.
Vacuum forming has a disadvantage that you cannot make really sharp edges; something you need for the bottom hull to make a fast boat.
I did think about this boat design and build, with much of my knowledge acquired from the forums!

DanielCardona

Hi Dirk

Sorry I made a mistake I didn't meant to say the Hull but the TOP TUNNEL, (the part that you made in fiberglass). ABS hull won't be good for sure, But a mix of balsa for the skins and liteply I think it should do then cover with light fiberglass cloth as you did.

Regards
Daniel

Dirk Jan

Ok, I understand now Yes, ABS is a good option, or polycarbonate, as used for rc car bodies. I did think about vacuumforming, but as I want to do everything myself, laminating was the easier option for me.

I think the carbon laminate cowl will be very light. But I make it more for the fun of it than real weight savings. The boat runs well already and I just drive it for fun