Wasabi Wooden Offshore Mono Hull.

Our club is starting an Offshore mono & Cat class this year as a demonstration class. If there are enough entries throughout the year, it will become a fully fledged race class next year.

Well, always up for a challenge I decided to build a wooden mono, as I've never built one before.

CornelP posted some plans of a Wasabi 900 some time ago, & I know he has had some success with the hull.
Although the freeboard is probably a bit low for Offshore racing, I have always liked the look of the hull & thought I'd give it a go, blown up to 44" in length.

I've made a few alterations.
Firstly I had to remove the ride pad as we are not allowed them for racing here in Australia. I simply just made it a rounded V.


Secondly I didn't use the motor mount frames because I will be making it a twin drive mono. And outrunners at that. Well, if you are going to stuff something up, you might as well stuff it up properly.

So two of these on a 6s pack each will drive it.

http://www.hobbyking.com/hobbyking/s...ass_Heli_.html

Here's a few pics so far.

Cheers.
Paul.

Man Paul you are one building machine do you ever sleep?

Hi Jim.
Yeah! I get a bit of a kip in now & then.:laugh:

Looking good, and tough!:thumbup1:

Thanks Doug.
Yep. 4mm ply formers & 6mm stringers. 1.5mm skins.

Managed to spend a bit of time on this one yesterday.
Fitted the side skins & the angled deck skins.
I'll have to seal the inside with epoxy resin & add the foam before I add the top deck.

Got it sealed & foam added.Because the volume of the front is so large I added some pool noodle first & poured the foam around it. Mainly to save weight, & of course foam, but still have the strength. After allowing the foam to fully cure for a couple of days, it was all sanded flush, then the front deck was added & roughly trimmed to shape.
I'll have to fit the stuffing tubes before I can add the rear deck. The motors & drive gear all arrived last week so I can get started on that.

Very nice Paul. I really like the design of the hull, I've never seen one like it.

Yes it is a nice design. Kits are available at 'RBC Kits'

I basically scaled up the drawings on this page.

http://www.rbckits.com/shop/index.ph...product_id=882

Man I need to learn how to build a wooden kit. I have a mystic mono to build.

ls1fst98
Wooden boats are a satisfying build. Even though this is my first wooden mono hull, I'm enjoying it.
The Wild Thing would be a great wooden kit to start with. A well tested hull. Great price too. I've seen one of these hulls on the water & they can be a rocket. The 34" might well be my next wooden mono.
http://mlboatworksrc.com/index.php?m...index&cPath=66

Made up a motor mount from some 6mm aluminium plate. Drilled a few water ways in it to form a U shaped path around each set of mounting screws. Cut & drilled a pair of carbon side plates & sat it in the hull so I could form up the stuffing tubes & epoxy them in.
Here's a couple of picks with it all just sitting in place.


Now I can add the rear deck & start on the cowling.

Haven't done much lately because we had our first race day of the year yesterday & getting ready for that took up some time.
But I've added the rear deck & built up the cowling from some 1/8" ply for the base, some 3/8 balsa for the formers, & some 1/16" ply for the covering.
A bit tricky getting all the angles & curves to match. But it's done. And for the size of it, it's not too heavy.

Here's a couple of pics & some of the set up on our first race day of the year.

I finally dragged this thing out od the dust & over the last few weeks have slowly got a bit done on it.
I made up some brackets to mount the rudder I was originally going to mount it to one side but decided to mount it in the center.
Then I added some battery trays & did a quick test fit of the motors, ESC, rudder linkage & servo, batteries etc.
So, with all the holes drilled in the hull for all the hardware, water inlets & outlets, safety loops,rudder linkage etc I stripped it all down again.
I had done all the sealing, high build primer & filling & sanding many months ago, so now I cleaned it up & sprayed some white enamel primer on the hull.
That was followed with a couple of coats of green. Just needs a bit of a windscreen painted on now.
This morning I refitted all the hardware & motors, added all the cooling lines & the fancy water outlets.
This afternoon I hope to get the linkage to the rudder fitted. And the shafts cut & fitted.
Should get a practice run or two over the weekend.

I can find info on prop direction for cats but not much for twin monos.
So the question is, for the first test, inward at the top or outwards at the top. Handling is probably more important to me than speed.
Any info would be a help.

Well, we managed to have a couple of runs with the boat this morning & Trev was kind enough to take a video of the second run for me. Thanks Trev.
The first run was running stable but extremely wet. The 4518 props had too much lift.
So I changed them for a pair of 4514 props. I also raised the Trim tabs to such an extent that they would have no effect.
Unfortunately those changes were too much & in this video it was running too light. Yeah. I know. One thing at a time. It was a helluva crosswind too.

Anyway, here's the result. Some more adjustments & testing tomorrow .

https://www.youtube.com/watch?v=ivkOtWf1iDg

A bit of a test run from yesterday.
Running a bit better.
https://www.youtube.com/watch?v=mQpZXdaf_lg

The pickups in the rudder didn't seem to be pumping any water through the systems. The motors were hotter than I am prepared to accept. So I've added a couple of underwater pickups.
I couldn't get my hands into the very back of the boat so I drilled in some 3/16" aluminium tube through the transom & out of the bottom of the hull.
A slight angle on the pickup to help scoop up the water.
We'll see how that works on the weekend.

I like your water pickups, what size escs are you using?

Thanks Beaux.
They are Sea King 180A ESCs

Thanks.

And, any updates? Did the water pickups help... or did she hit the shelf?

Sorry Jesse.
I only saw your post on this thread today on the train on the way home after work.
The water pickups worked a treat. Much more flow than from the rudder pickups.
But also yes, she has been on the shelf as the offshore class really didn't get up and running.
Motors & ESC's have been robbed for other projects.