Delta force mini sniper 23 build for newbie

[eehess81]

Hello all. New to the forum and boat building. Have only done some upgrading of inexpensive RTRs so far.
I'm going to be getting the hull for the DF23 soon and need some advice.
I think I'm good on the external hardware installation and electronics but need help with the electronics internal mounting and hatch water sealing.
What is the best way to mount the motor and servo? Do I epoxy wood/plastic/alluminum mounting plates down or do I need to make stringer rails?
How do I make it water tight with the hatch?
The boats I have run have been app. 18 inch self righting boats with outrunner motors. Will a 23 inch boat with an outrunner be self righting? I'm gonna start with a 4000kv outrunner on 2s lipo.
will probably switch to 3200-3500 kv on 3s once I dial everything in. Any help would be appreciated.

[eehess81]

I think I'm gonna make wood/fiberglass stringer rails with a platform in front of motor and over stuffing tube for esc and servo. Do I need to do a flood chamber for a 23 inch boat or will the torque of the outrunner be enough to flip it upright?

[ray schrauwen]

The boat doesn't need stringers since it's so small and built very robust. I've built several (still building one now) and I just use a motor mount from OSE. I make an aluminum servo mount out of 1/16" thick 3/4" x 12" angle aluminum and I make a wood wedge platform for it.

I run 28mm x 60mm leopard motor, 2550kv on 4S.

I don't bother with self righting and if you want that you will need to experiment with it. Th boat will not self right without a flood chamber afaik.

[eehess81]

Without self righting what do you do if it flips? Go for a swim? Hehe. Is that motor an inrunner or outrunner? What speed you get out of it? If you could show me some pics that would be really helpful. Thanks for the reply!

[ray schrauwen]

I never did flip it and I sold them. I won't sell this one though. The motor is an inrunner but the boat was originally designed with an outrunner in ARTR form, forget the KV??

Need to sleep, more tomorrow...

[Panchothedog]

Don't ever go swimming to retrieve a capsized toy boat. A spinning reel with
A tennis ball at the end works real good. Tape the seams of the hatch prior to running with electrical tape and you boat will stay dry on the inside, inside down or not. Don't forget to add flotation.

[Panchothedog]

Upside down or not. Dam tablet thinks it knows what I want to say.

[eehess81]

What do you mean by add flotation? The fishing pole and tennis ball is a great idea. I had to borrow a person's boat to retrieve my boat when the driveshaft fell out last month. They weren't home but I'm sure they wouldn't have minded...
Do most people run bigger boats without some kind of self righting mechanism?
I have a 2860 2800kv outrunner that might have enough torque to flip a 23 inch boat but will have to try it out.

[Panchothedog]

For flotation some people use pieces of pool noodle ( a kids pool toy ). I
like to use pieces of construction grade Styrofoam. It can be cut and shaped
to fit the hull and then epoxied into place. The idea is to keep the boat from sinking even if it completely fills with water. If it sits upside down
long enough this can happen and you don't want your boat, =$$$ going to
the bottom. Self righting is from a chamber on one side of the hull that fills
with water and the weight causes the boat to sorta roll back over. It seems like it would almost need to be manufactured into the hull and I don't know how you can add this after the fact. I have been in the hobby of electric boats since 1987, have owned 25 to 30 different boats over the years and have never had a self righting boat. I don't think I would worry about it too much of I were you. As far as torque flipping the boat, too large of a prop for the hull is probably more dangerous than too large of a motor.

[eehess81]

Oh ok, that makes sense. What size prop you think would be good for 23 inch boat. Gonna use outrunner motors so I will have more torque. Was gonna go with 34-35mm.

[Panchothedog]

That is certainly in the ballpark for that size hull.

[eehess81]

Do I need to do some kind of inlay inside the hull before mounting all the electronics? Does it add rigidity or just protect the boat?

[ray schrauwen]

No.It's such a small hull and laid up so well it doesn't need it. a simple motor mount will add lots of strength and rigidity

[ray schrauwen]

pics

[ray schrauwen]

.....

[eehess81]

Thanks for the advice Ray. Where do you mount your battery in that setup? Not sure if I'm gonna mount on the left side or in the center with motor mounted towards rear.

[Suriabiantara Tjahaja]

Hi Ray, can I find out where did you buy the stinger and trim tabs. Thanks

[ray schrauwen]

Directly from Delta Force however they do not make or stock it anymore. I do have a rudder for my present build but I am using the TFL black 4mm stinger drilled out to 1/4" and made like speedmaster. It's maybe 50-55mm long. The trim tabs are small TFL the I took a Dremel to one side to make the sides angled to look like DF tab if you can understand that???

I used the smallest turn fins I could find and they seem thicker than the old ones pictured. Things change...

Kind wish I tried to mount a Speedmaster rudder on there... Oh well, if the one I have gets trashed I'll go Speedmaster like Tony did in his build.

[Suriabiantara Tjahaja]

Thank you Ray for the explanations.

[eehess81]

I got all the parts and have installed most of the hardware on the transom. Going to epoxy in the motor mount next, gotta see if I need to bend the stuffing tube. When I cut the flex cable should I solder it first or just tape it? I'll post more as I go.IMG_20210629_220814549.jpg

[eehess81]

Installing a 90 amp flycolor esc, 2862 2800kv outrunner, and going to start with 2p3s 2200 ma lipos.

[ray schrauwen]

Looks good and sounds good. 3S 11.1Volts right?

[properchopper]

Here's one I built for a customer a while ago. Cool little boat

https://forums.offshoreelectrics.com...ht=mini+sniper

[eehess81]

Yes I'm going to start with 3s batteries. Nice build on that mini sniper! I checked out your thread when I started, helped a lot. I have an issue, I installed the rudder a little too close to the strut and the prop might hit the rudder if I don't bring it out past the rudder a bit. Is this a problem?
Got the motor mount epoxied in.

[eehess81]

IMG_20210701_191353171.jpgIMG_20210630_192956873.jpg

[properchopper]

Eric,

There's not a whole lot of real estate on that transom for hardware. When I do a build I'll mock up the strut & rudder with some double-side gooey tape and hang the biggest prop likely to be used to determine clearance before drilling. In your case, based on examining your picture you're a little tight but remember that these rigs don't call for much in the way of prop diameter. Since I'm pretty much (as many of my customers are) in the realm of oval racing, the only criteria for clearance is right turns. Most radios allow for independent R and L endpoint adjustment which you could set to keep the left turn rudder range of motion restricted somewhat in case the L rudder can hit. Then get used to R turns

[eehess81]

I'm gonna check out my clearance tomorrow and will get back to ya. I was just wondering if it's a problem for the prop to be further back than the rudder.

[properchopper]

I'm gonna check out my clearance tomorrow and will get back to ya. I was just wondering if it's a problem for the prop to be further back than the rudder.

Conventional Wisdom (eeek) states that the front of the rudder blade should be about where the drive dog lives. I wouldn't worry if you're a tad further back.

[eehess81]

So I hope going against conventional wisdom doesn't make my boat undrivable. The prop is going to have to be kinda far back behind rudder. Problem was I couldn't put the rudder any further to the right due to the trim tabs. Had to notch it as is. IMG_20210702_181850564.jpg
IMG_20210702_181822115.jpg
IMG_20210702_181815115.jpg

[properchopper]

I'd just make an extension for the rudder - easier and more sensible to do as I see it. If you just assemble as is (and restrict L rudder with radio endpoint adjustment) t won't make the boat undriveable.