Delta Force: Vortex Hydro

[10gauge]

DELTA FORCE VORTEX HYDRO BUILD

The Delta Force Vortex Hydro offers a great entry into hydros. It measures 22inx11in and has fiberglass construction. The hull is relatively inexpensive, lightweight, preformed, and is easier to complete and setup relative to many other hydro systems. Since the hull is preformed, you don't have to worry yourself over sponson design or tunnel dynamics. Everything used to complete the Vortex Hydro was bought from OSE. There are many ways to improve performance, even on a preformed hull like the Vortex. Here are some of the major variables in setting up the Vortex Hydro:

DF22 Vortex - Setup Variables to Performance:
1. COG (center of gravity)
2. Strut alignment, angle, and height.
3. Turnfin placement, length, angle, and shape.
4. Prop type and size.
5. Motor

Setup:
Hull: 22inx11in, Delta Force Vortex Hydro. Thin, lightweight fiberglass.
Hardware: Solinger Hydro System, 0.125 Flex Cable with 3/16in prop shaft.
Turnfin: 2inx1.5in, 6-degrees slanted towards hull in thick, angle
Motor: Feigao 8L
Battery: 3S1P/4500/30C Elite LiPo Pack
kv/rpm: 3072kv/34,000rpm
ESC: Castle Hydra 120
Prop: x637

Build
- I mounted my motor and strut about 3/16" to the right in this size hydro to counteract propwalk induced at higher speeds.*
- A 0.125in flex cable should be adequate for 3S.
- The turn fin should extend at least 1.25in below the water line and be about 1.25in wide. I used 1/20in steel sheet with the dimensions of 2.0in(L) by 1.25in(W) and mounted it to the right sponson transom. The fin should be slanted in towards the center of the boat about 5-7 degrees. More than this can cause poor handling.*
- COG is best 1" behind the front sponson for this size hydro.
- To set the alignment of the strut, set the boat flat on a table with the hull bottom parallel with the table top, resting on the sponsons. Don't hold the hull in your hand and eye it. Set the strut bottom resting flat on the table. This is a rough guide but should get you close to the right setting. If the boat is too flighty lower the strut. If the transom drags, angle the strut down at the back by 2 degrees.*
- The pictures shown below were taken right after completion.

Performance:
I started with a x438 prop. The boat ran 49mph after tweaking the strut. I've since been using a x637 prop and running 52mph on smooth water. The strut is positioned at a neutral angle. I'll have to wait for Spring for videos.

Conclusion:
This has been a fun and exciting little build as a first hydro that is capable of decent speed. It's a great smooth water performer. However, I wouldn't run it fast on much chop above 0.75in. After building a mono, then a catamaran, the hydro is the next level in complexity. A specialty of building hydros would be to setup a SAW rigger... The culmination of all the knowledge and experience in this hobby. It is the "Formula One" of RC boats. I must say that there is a big growth curve in learning how to maximize the performance of a hydro design over a mono or a cat. There are masters around, find them and apprentice their knowledge and experience as I have... Many Thanks to "Fluid" (Jay) for his humble generosity in rendering advice and sharing his vast experience.

(*) Advice received from "Fluid"

[Steven Vaccaro]

Nice job George!

[IONY]

yapp coool job

[rc123]

Thanks for the post
I have bought a hydro with a similar strut setup
Being quite new at this I thought it's wrong and wanted to rebuild.
Now I can't wait to test it in the spring

[lomdel]

Does the Vortex Hydro 22" comes with the stuff tube through the hull already installed? If not, please explain a bit more about the correct way of drilling, installing and sealing a stuff tube through a new hull.

[lomdel]

Thanks for the post
I have bought a hydro with a similar strut setup
Being quite new at this I thought it's wrong and wanted to rebuild.
Now I can't wait to test it in the spring

Which Hydro did you buy rc123?

[rc123]

Which Hydro did you buy rc123?

I've bought from Europe (were I am located) a Hydro & Marine Spider. It's a bit bigger than the vortex near to 28'.
I will put some pics of it. Not sure if this post will be the best place for this ..
I will send you a pm with the location after I post.

[10gauge]

lomdel, the stuffing tube does NOT come installed on the Vortex Hydro. Here is the protocol I follow to mount stuffing tubes.

1. Before drilling any hull, I place the boat on the stand and lay the motor in the desired position and mount the strut.

2. Hold the flex cable along the side of the boat and determine the bend you want in the cable from strut to motor. The bend should be smooth.

3. I mark the intersection of the cable through the hull. Cut the hull with a Dremmel cutting disk, then broaden to allow the stuffing tube to pass through.

4. Draw the outline of the bend on paper and take a 1ft section of the 1/4" K&S brass tube and bend it in that shape. Start bending from the middle because it's easier than starting from the end. You can always trim the excess with a Dremmel cutting disk. Always file, sand, and polish the ends.

5. Tape or use Blu Tac to temporarily hold everything in place and determine if the drive line is free, centered, and balanced. This is the most crucial step in any boat build! Don't be eager to get everything done at this point because if the drive line is not balanced, it will cause problems in wear, parts failing, efficiency, and speed. Come back the next day, and recheck that all is free and balanced by looking at it at all angles. Spin the flex cable, see if the flex cable repeatedly goes to the motor coupler freely from the stuffing tube without you guiding it into position.

6. If your happy with step (4), then affix the stuffing tube with JB Weld or epoxy.

Good Luck!

[Rumdog]

I notice that most hydros have the rudder on the port side of the transom. Why did you choose to go starboard? Yhe only thing I can think of is the you may get too much lift on the starboard side from propwalk and the rudder. Just curious as I am about to build the same boat with the same hardware. Thanks!

[Rumdog]

Sorry, meant too much lift on the port side.

[10gauge]

I've seen the rudder mounted both ways, and yes, it's more common to mount it on the port side. I've mounted the drive shaft 3/16in to the starboard side relative to the centerline to counteract propwalk. At the speeds that I am running the boat, I haven't had trouble with lifting either.