Thread: Mystery Oz PDR prototype

Well, the OzRacer Mk3 won the World championship PDR race yesterday. On the way to the race, when crossing a mountain pass, I took a picture of the temperature on my truck, a balmy -4c! It was 19c on the valley floor where the lake is. Two laps of 4.3 kms, two of the legs were mostly upwind due to an unforseen windshift just before the race. Winds were light, between 3 and 15 kmh, mostly around 5 kmh. The Mk3 outperformed the other boats due to a larger sail area by almost double, and superior foils in the light airs. We even measured the boats to see if they were 'class legal' and the Mk3 was within tolerance according to the person operating the measuring tape. I brought my Mk2 as well, and it was out of tolerance. Go figure.
Anyways, I went around the course, won the race, and jumped into my Mk2 with a version of a Sunfish sail on it, and caught up to the back of the fleet still on the lake. A pretty nice day, and a nice result for one of MIK's designs.

Rick Landreville

Congratulations Rick!

What was the fleet size this year?

Looks like a great location!

MIK

Rick,

It looks like the transom on your Mk 3 is shorter than the transom on the Mk 2. That and the bow angle are the most noticeable differences between my "class legal" OZ and the unrevised version.

I've read the Mk 2 with a class legal bow angle can't be built with three sheets of plywood but I did it. The height difference at the rear of the side tank faces leaves just enough for the foredeck length if you butt them together and cut on the lines. I used a fitted pattern for the side deck faces so there wouldn't be any waste.

Congratulations on your win.

Brad

Originally Posted by BradLH

Rick,

It looks like the transom on your Mk 3 is shorter than the transom on the Mk 2. That and the bow angle are the most noticeable differences between my "class legal" OZ and the unrevised version.

I've read the Mk 2 with a class legal bow angle can't be built with three sheets of plywood but I did it. The height difference at the rear of the side tank faces leaves just enough for the foredeck length if you butt them together and cut on the lines. I used a fitted pattern for the side deck faces so there wouldn't be any waste.

Congratulations on your win.

Brad

I did something similar with #472...changed the Mk 2 hull shape to be legal, and extended the bow point to make the bow angle legal. I did end up making the transom a little shorter.

I think everything will fit on 3 sheets (I am cutting pieces as I go), but I may have lost one of the bits the rudder box is supposed to come out of. I'm just about to start on the side air tanks.

Torsten

Originally Posted by BradLH

Rick,

It looks like the transom on your Mk 3 is shorter than the transom on the Mk 2. That and the bow angle are the most noticeable differences between my "class legal" OZ and the unrevised version.

I've read the Mk 2 with a class legal bow angle can't be built with three sheets of plywood but I did it. The height difference at the rear of the side tank faces leaves just enough for the foredeck length if you butt them together and cut on the lines. I used a fitted pattern for the side deck faces so there wouldn't be any waste.

Congratulations on your win.

Brad

Thanks for that Brad. On the weight of the drawings it didn't look like it would do it.

I'm just telling people if they want to build a OZ Racer - as it is now - that if they want to change it into the PDRacer then they have to look at the rules and adapt the design.

The freeboard of the MK3 is a little less than the Mk2.

MIK

I forgot to mention I put the carlins below the side decks. That shortened the side tank faces and left more for the foredeck also.

Originally Posted by Boatmik

Congratulations Rick!

What was the fleet size this year?

Looks like a great location!

MIK

Hi MIK;

There were only 7 boats at the race, which was kinda disappointing, but not surprising considering that I was not able to post on the pdracer.com site to advertise.
The lake we were on is Okanagan Lake, and it is HUGE! 135kms long, and between 4 and 5 kms wide. Nice spot to sail a boat.

Rick Landreville.

Here is a picture that was sent to me of myself sailing (not really, more like waiting for wind) in my MK3 at the World Championships.

I am laying down on the bottom of the boat resting against a spare life jacket while enjoying my lunch. In light airs, I have taken a fancy to sailing in this position because I can rest my elbow on the boat bottom, while steering with my fingertips with my head and shoulders supported by extra life jackets.
With my weight down this low, there is quite a bit of stability. The wind has to really pick up before sitting on the side decks becomes neccessary.
I carry a synthetic chamois (towel? What do you call a Sham-Wow in Oz?) to mop up any splashes or water from my feet from launching so I don't get wet while reclining.
If another boat comes by, I will sometimes swing my legs over the opposite side deck while sitting on the bottom resting against the other side air tank. Its embarrassingly comfortable, and I don't want the bigger boats to feel bad.

Rick Landreville.

Originally Posted by BradLH

I forgot to mention I put the carlins below the side decks. That shortened the side tank faces and left more for the foredeck also.

Excellent workaround Brad

MIK

Originally Posted by pdr311

Here is a picture that was sent to me of myself sailing (not really, more like waiting for wind) in my MK3 at the World Championships.

I carry a synthetic chamois (towel? What do you call a Sham-Wow in Oz?) to mop up any splashes or water from my feet from launching so I don't get wet while reclining.
If another boat comes by, I will sometimes swing my legs over the opposite side deck while sitting on the bottom resting against the other side air tank. Its embarrassingly comfortable, and I don't want the bigger boats to feel bad.

Rick Landreville.

Looks very luxurious!

The synthetic chamois always have "Sham" in their name - even here. There are a few different ones.

MIK

Hi all,

MIK asked me to post a bit of info about the 'MK III' that I built. The short story is that I decided to build a sailboat to teach myself to sail and generally mess about in, I stumbled across the Wikipedia PDR entry (loved the philosophy more than anything else; well done Shorty) and from that found out about the OZ Racer design of MIK's. Bought the plan, and while waiting for stuff to turn up from various online orders, kept looking at every site I could about Puddle Ducks.

At some point I stumbled across this entry about the MK III on WWF and loved the idea of the 'off-centreboard' giving a nice clean centre to the boat. Oh, BTW, sorry about my terminology. What I completely missed, or maybe didn't fully understand at the time, was the MKIII attempt to get the hull back to the official PDR curve.

As such, though I've got a finished boat, it is exactly the same shape as the OZ Racer. I thought there was something strange when I was looking at things like the size of the bulkhead but thought it might have been camera angles and stuff.

Anyway, here are some shots from launch day. Tiny little breeze that was just enough to get us out and prove that it floated and sailed. My son had sailing lessons in high school, about five years ago and had never sailed since (Lazers then, he thinks). I'd never sailed. We still got it out and had a great afternoon. Looking forward to some real breeze so I can get a real feel for it.

The build story is enormously long and in summary occasionally frustrating but mainly a totally satisfying barrel of fun. Thanks MIK for a great design and plan.

Cheers, Andy.

Thanks hugely for the rundown Andy.

My next PDR project (rushing up rather fast) is doing the instructions set for putting together the Mk3 kit that will be produced in Texas.

It will be a true PDRacer as John Owens the kitmaker is working with shorty on the hullshape so I don't need to supply any contentious measurements. Just concept, geometry, rig, sails, foils rigging etc.

MIK

Ohhh, the horror,
I've taken Rosa-J out a couple of times now but each time there were two people in the boat, both grown adults.
Today, for the first time, I went out by myself. The breeze was 'stiff'', no idea of the actual speed. Wow, Rosa-j was fast and very responsive... almost 'twitchy' in how quickly she responded to rudder movements. Actually, it was a bit scary. The first turn I did the sheet pulled hard, she tipped hard sideways and I was nearly in the water. So different to having the weight of two adults in the boat.
Well, I thought I was getting the hang of it when I tried another turn. The sheet went very tight, she started to tip and then SNAP!!!! Suddenly I had two bits of mast instead of one. I was in the middle of the lake, hoping the wind would push me to shore otherwise I was going to have a long swim.
So, finger jointed pine is NOT the material to make your mast out of.
Back to the drawing board and time to contemplate what makes a good mast and what doesn't.

Hehe, glad to hear you're safe though.

Well yes, so know we know to rule out both knotty pine AND finger jointed stuff for masts .

My finger jointed boom (GIS) is holding up well though.