Monday, June 28, 2010

New turn fin

Final post of today! - How to make a turn fin. My way anyway...

.063" (1.6 mm) thick 7075-T6 aluminium sheet. Printed out copy of the turnfin to be made, spray glued and attached to the plate.

The center of the holes are punched and the outlines are scribed with a hobby knife (that can be excluded also as you can make it ready with then paper still on the aluminium).

Close up.

3.5 mm holes are drilled and the two bends are done. Now it can be cut-out. I do it in my band saw and then shape it with a disc sander and the Dremel with a sanding drum...

The disc sander is used to make the sharp edge. Make it almost sharp and make the last bit with a file. Its very easy to go too close to the edge so to speak with the disc sander. I also sand the turnfin with a sanding block and sandpaper making sure all edges are sharp that will be in the water.

Done. :)

Instant NiMH battery pack

New rigger is in the works so I made a couple of new battery packs. The cells I used is the new type of "Instant" NiMH type that are charged and ready to go when delivered. The self-discharge level is very low also. The brand name is Vapex Tech and they are called "Instant" - the capacity is 850 mAh. Thats plenty of power for a 3.5 cc rigger. Do note, they dont like fast charging so much - my suggestion is to charge them with no more then 0.4A (I use a Great Planes Triton charger).

DIY pipe mount

New home made pipe mounts made out of K&S 1/4" brass strips. I made 3 sets for 30, 32 & 34 mm diameter muffler sections.

Spraymax 2K

2K spray can clear coat that works!

New .21 VAC cowl

I also (this past weekend) had to make a new cowl for a new Kep's .21 rigger that had originally been planned for a front exhaust engine. Now it will use the new CMB .21 VAC engine so I had to make a new cowl for it, and pipe mounts etc...

The design is not tested yet, this will be the first time I use that edge design. I hope it works. :) Do note the front air induction hole! ;)

First its a couple of layers of spray can base white. Then 15 minutes later, spray can Dupli color fluo red/orange. Wait for 20 minutes and then 2K clear coat from a spray can!

The water anti-spray air duct on the inside will hopefully prevent water from be sucked down to the VAC carb below...

New rear sponsons

I also made some new Kep's 21 rear sponsons this past weekend. They are the exact ones that are included in the latest Kep's 21 RACE2010 rigger drawings. They are foam cored (Divinycell H60) and sheeted with 0.8 mm thin aero-birch plywood (CA glued with ZAP green and kicker). The 7 mm wide step on the bottom is 1.5 mm thick. They where also prepped with one coat of Z-POXY finishing resin, sanded and clear coated with Spraymax 2K clear coat. I will add some fluo Trim Sheet Monokote to the sides a little later.

Here you can see the simple paint stands I use. Just mount the prepped sponsons on the area where they will be mounted on the boat with some double sided tape. After they have cured its just to remove them and mount them on the boat.

The total weight each is about 14g - clear coated and RTR.

New boat stands

I had a busy weekend and made some new outrigger boat stands that are stackable... The design is pretty basic and its made out of 20x20 mm pine spruce that are just CA glued together. If any one is interested in the measurements I used then mail me and I will publish a simple drawing...

I will add some foam to the areas where the boats will rest. The top stand is not for a rigger, its for my FSR-V 3.5 boat.

I used a simple peg that is sold in hardware stores for making your own shelves. Drill a 5 mm hole and epoxy glue it in place on the top piece. Then a matching 6 mm hole on the bottom of each stand...

After it was glued and sanded I prepped it with one coat of Z-POXY finishing resin and re-sanded it. Then clear coated with Spraymax 2K "rattle can" clear coat. It worked fine.

Now updated with a drawing. The stand size is suitable for .21 sized outrigger hydros. If you plan to use it for bigger riggers you need to make the short cross members slightly longer. Make the 2+2 cross member end pieces slightly longer then 20 mm. Glue it together and sand the ends flush. Do note, the notch for the stuffing tube is not drawn - you need to add that yourself depending on your rigger flex-shaft design. All material is 20x20mm pine spruce.

Tuesday, June 15, 2010

NAMBA 2010 Nats

The 2010 NAMBA nats is race right now (June 12-19) in Florida (USA) by Voo Doo Model Boaters club in New Orleans.

ME Time Productions
is broadcasting the race - log-in and upgrade to an Premium account and see the race live!

For results click HERE.

All pics below is borrowed from HERE.

The 2010 NAMBA Nats website.

Here's a clear evidence the race is not run in a Swedish lake/pond...!

C-Hydro top 3 (.67 engines):
1. Justin Hill / 1225 Points
2. Chris Grim / 1225 Points
3. Stu Barr / 850 Points

G-1 Hydro top 3:
1. Chris Grim / 1600 Points / Grim Reaper / CC engine / 2716 prop
2. Mark Grim / 1225 Points / Grim Reaper / CC engine / 2816 prop
3. Erik Lis / 900 Points / Rico rigger / CC engine / Propworks West prop

B-Hydro top 3 (7.5 cc):
1. Mark Grim / 1100 Points / Crapshooter / CMB .45 VAC / Octura 1655
2. Bill Annabel / 1038 Points / WideBoy J-3 / CMB / ABC H22
3. Stu Barr / 994 Points / Crapshooter / CMB .45 VAC / ABC 60x80

A-Hydro top 3 (3.5 cc):
1. Chris Grim / 1100 p / Blackjack 21 / CMB .21 VAC / 1445 prop
2. Mark Grim / 1000 p / Reaper 21 / CMB .21 VAC / 1445 prop
3. Justin Hill / 469 p / Scratch build / AA .21 /

X-Hydro top 3:
1. Bill Annabel / 1400 points
2. Justin Hill / 1225 points
3. Alan Hobbs / 1050 points

Alan "AA" Hobbs in the pits.

Al Hobbs Eagle.

In Europe we dont have this (or a drivers stand) - we launch our boats ourselves and drive from the pontoon...