Dual Engine DF Vortex34 Build

[CraigP]

Hi All,

Finally getting around to a build I’ve wanted to do for many years, a dual engine hydro! I got the stuff from Steve today and here’s a pic where it all begins. This has the majority of the hardware in the boat. Struts and rudder are in the back. Motors where I plan on putting them. I got one T-120 in there and some weight to emulate the second ESC. The batts are where they will go, same place as my first Vortex. Can’t wait to hear this baby out on the pond, screaming thru the corners!

These are Leopard 3650 2050kv motors running on 4S and powered by twin Turnigy 120A ESC’s. That’s the same ESC as in my UL-1, you can just see it on the floor. That boat needs a rudder I’m waiting on...

Here’s a pic of the new boat layout. With parts shown as is, CG is 1.23” behind back of sponsons..

[srislash]

Oooh!!! Twin hydro

[fweasel]

Don't see many twin hydros. Looking forward to seeing it done!

[785boats]

Cool.
It's probably something most of us have contemplated from time to time. I know I have.
Looking forward to watching this one develop.

[Navherc130]

With all that sponson work you did on your other one, why do the same hull? Interior space? Just asking...

[CraigP]

With all that sponson work you did on your other one, why do the same hull? Interior space? Just asking...

Yes, so much space in this hull! And I got big hands. I did measure the sponson AOA on the granite table today and found them to be a whopping 3.78 degrees. That's way past my comfort point... I have a much easier way I'm going to use to bring that to 2.75 degrees, which is my preferred value. I'll be posting when I get to that stage.

[CraigP]

DAY 1:

There's a start to any project when the rubber meets the road, and that's the first hole! I always like to get a pic of that... The rudder is going to be placed on the true center of the hull, as indicated by the black line.

This first hole is important because it is nearly impossible to keep a drill free-hand from torque wandering to the right. So I get this first hole in, then using a round file, it whollar out this hole to put the bracket exactly on target then tighten up that bolt. I then use the bracket as a drill fixture to put the other 3 holes exactly where they need to be. The rudder bracket will cover the whollared hole, and it gets silicone on during final assembly...

[CraigP]

After that, I figured out where I want my struts and motors to be. I chose them to be 3.5" apart from each other, spaced evenly from center. I have an AutoCAD drawing on this to figure out and see it more clearly, before cutting! This is the fun part, making drawings and making chips!

[CraigP]

Next, I installed the port side Strut. I'm using the large rudder assembly, because I like the big king pin that is used. More bearing area, so it stays much tighter. I am using the small, 3/16" Speedmaster Strut Assemblies. Since half the power is being delivered on each strut, it made sense to save some weight here. I've also decided to use a 0.150" flex with a liner. This requires the lowest amount of power to spin, and this boat has small motors. The biggest props this boat will probably see will be 45mm, so the 0.150" flex shaft should hold up to that just fine. These are OSE flex shafts, I have had great luck with them.

You can see my whollared out first hole in the first pic...

[CraigP]

Next, the Starboard side Strut, same game plan, just try not to make any mistakes and keep the distance apart and vertical placement on the transom as close as I can. I got them to about 0.005", close enough...

I then use my granite surface to check everything out. It came out good, I was pleased!

[CraigP]

Next, I needed to get the large grommet pass thru, usually used on the radio box. The grommet is big, and I had to modify the rudder bracket by increasing the radius cutout on the port side. I did this with a Dremel tool. I wanted it to nest up in that side cutout on the rudder bracket nicely. I didn't have a lot of space, but my CAD drawing kept me on the right direction.

[CraigP]

End of Day 1: Lots go goodies going thru the Transom!

[785boats]

DAY 1:

There's a start to any project when the rubber meets the road, and that's the first hole! I always like to get a pic of that... The rudder is going to be placed on the true center of the hull, as indicated by the black line.

This first hole is important because it is nearly impossible to keep a drill free-hand from torque wandering to the right. So I get this first hole in, then using a round file, it whollar out this hole to put the bracket exactly on target then tighten up that bolt. I then use the bracket as a drill fixture to put the other 3 holes exactly where they need to be. The rudder bracket will cover the whollared hole, and it gets silicone on during final assembly...

It's all looking great Craig.

But in reference to drilling holes, in fiberglass, ply, plastic etc, find yourself a set of 'Brad Point Drill Bits'. They don't wander, & they cut clean edges without chipping. I realise that it is a bit late for this project, but will be useful for future projects.
Here's a link to show what they look like. They should be available at any number of sites or hardware stores, over there in the States.

https://www.ebay.com.au/itm/Frost-by...4383.l4275.c10

[CraigP]

I like those Paul! I’ll look about for a set, thanks for the tip!

[fweasel]

I like those Paul! I’ll look about for a set, thanks for the tip!

Clever, I see what you did there...