1st Cat Build: Delta Force Explorer 36" - Some Basic Questions

[c_michael_72]

xxx

[100 mph jet boat]

Im no expert

take a round dowl lay on flat table and set the boat on the dowl (seesaw) and set COG around 30% from back of sponsons

put some tape on bottom and side and mark 30% on tape then line up marks with dowl

measure from back of sponson to tip Not the overhang then set cog from rear of sponsons


strut.... set boat flat on table and bottom of strut flat on table

[c_michael_72]

xxx

[Fluid]

1) The best way to do this is to float test the boat. It is just too difficult to try to balance the hull on an axial pivot. It is best to be just a bit heavy on the left side to counteract prop torque.

2) This will depend on the weight and speed of the boat. Be able to move the packs to get from 30% to 33% forward of the sponson transoms, NOT the extreme aft end of the hull.

3) I mount all my transom hardware first, then place all the components (including shaft and prop) in the hull to get the balance where I want it. I mark where everything goes and install each piece - motor/stuffing tube first.

4) This will depend on the weight and speed of the boat. The default position is with the hull flat on a table and the strut bottom resting flat on the table. However, after running most find that the strut will need to be a bit higher than this and perhaps angled up a bit at the prop end. You will need some adjustment capability.

5) I like your component tray idea as long as it has very little standoff from the tunnel floor - keep the vertical CG as low as you can. It will have to be very well attached to the hull, as a high speed flip will try to tear it out of the boat.

I like the OSE hardware, although I wish it had a longer rudder. You choice of motor is not what I'd choose, the Kv is pretty high for 6S, limiting your choice of props and raising the danger of over-amping. I'd have chosen one with a Kv between 1300 and 1500. With your high Kv motor props with ~2.5" of pitch will get you into the 60s in theory. The m445x447 come to mind, as do the Prather p225/P230. Be careful on your first trials, don't run for more than one minute (use a timer!) before bringing it in to check motor/ESC/pack temps and to look for water inside. And use plenty of floatation!


.

[c_michael_72]

xxx

[100 mph jet boat]

1) The best way to do this is to float test the boat. It is just too difficult to try to balance the hull on an axial pivot. It is best to be just a bit heavy on the left side to counteract prop torque.

2) This will depend on the weight and speed of the boat. Be able to move the packs to get from 30% to 33% forward of the sponson transoms, NOT the extreme aft end of the hull.

3) I mount all my transom hardware first, then place all the components (including shaft and prop) in the hull to get the balance where I want it. I mark where everything goes and install each piece - motor/stuffing tube first.

4) This will depend on the weight and speed of the boat. The default position is with the hull flat on a table and the strut bottom resting flat on the table. However, after running most find that the strut will need to be a bit higher than this and perhaps angled up a bit at the prop end. You will need some adjustment capability.

5) I like your component tray idea as long as it has very little standoff from the tunnel floor - keep the vertical CG as low as you can. It will have to be very well attached to the hull, as a high speed flip will try to tear it out of the boat.

I like the OSE hardware, although I wish it had a longer rudder. You choice of motor is not what I'd choose, the Kv is pretty high for 6S, limiting your choice of props and raising the danger of over-amping. I'd have chosen one with a Kv between 1300 and 1500. With your high Kv motor props with ~2.5" of pitch will get you into the 60s in theory. The m445x447 come to mind, as do the Prather p225/P230. Be careful on your first trials, don't run for more than one minute (use a timer!) before bringing it in to check motor/ESC/pack temps and to look for water inside. And use plenty of floatation!


.

what is this float test???? Im still a noob and learning.

[c_michael_72]

xxx

[100 mph jet boat]

Thanks that make sense now for setting port and starboard

[siberianhusky]

Level at speed when you have torque acting on the hull is what's really important.
Keep the build as simple as possible, don't over think or over complicate things it will probably come back to bite you at a later date. There is a reason 99% of the boats are built almost exactly the same way, it works, is simple and reliable. Nothing but the batteries should ever have to be moved once the boat is built.
First rule of RC boats K.I.S.S. - Keep It Simple Stupid. (not inferring anything just the way the saying goes )
2nd - Cheap, fast or reliable - choose 2

[c_michael_72]

xxx

[siberianhusky]

Innovation or copying old ideas? Sorry but your idea has been tried many, many times over the years, In the 30 years I've been into RC boating I've seen people trying to reinvent the wheel hundreds of times, I'm guilty of it myself.
Every couple months on here I read about a "new" old idea.

[c_michael_72]

xxx

[siberianhusky]

LOL I'm only 43 started when I was 13.
LOL in my previous post I was going to ask if you were a gear, only people who can complicate a stick!
Just out of curiosity what is having everything in the boat movable going to accomplish? Not sure how you can move a motor without a major overhaul to the stuffing tube as you can't have too much exposed flex shaft and the angle of the stuffing tube is fixed. You can't move the rudder servo without making up a new pushrod. My Rx's never move as they have to be near the antennae hole in the hull.
About the only thing that should ever move is the batteries, and you can already buy premade battery trays if you want to go that route.
You want everything mounted as low as possible in the hull to lower the CG, that usually means mounting directly to the bottom of the hull.

[c_michael_72]

xxx

[keithbradley]

I don't mean to be a stick in your spokes here, but do you already have the parts or are they just consideration? What you have listed there doesn't look like a bad setup, but if it were me I would go with a different ESC/motor combo. For a similar cost to the 240 ICE, you could run the Castle ICE 200HV and go with a lower kv motor (900kv-1000kv). 70mph requires a fair amount of power.

Also, if you make a plate to go in the boat, I would use carbon fiber, not aluminum. The Delta Force hull is quite thick and already heavy before you start, so keep weight into consideration. The lighter you keep this hull the better it's going to handle.