Frankinsten

After some requests for more information about my boat I decided to start this thread


Hi again

Just some new information about the boat/racing

After a long 7 months of building the boat(from scratch) and 3 weeks of testing ,I was ready to our big race of this year. When we got there, I took my boat out on to the lake to check everything was running well. Since I have not tested the boat with the new Hitec HFX esc, I had been worrying about how it will perform. Needless to say, the boat performed better than ever and running really well at 3/4 throttle.(Video Included). The night before, I played around with the boats balance after how baddly balanced it was in the last test(pompebled: "hillariously out of balance"). On the water it was much better. There is still room to improvements however. After pulling in at our pits and setting up the boat(with the better cells) for the race. Then problems arose.

7 sec to the race the Mg16(The ak47 of all servos) desided to stop working. With no stering, we had to pull out of the race.

To make the raceday even better, I managed to flip the old electric boat and managed to fill it up to the motor with water.(pic included(Last Pic))

Anyway, the batboat is not in bad condition and can be fixed pretty easy. Anyone know a good reliable and fast servo for stearing which is under £20

Also, if anyone can see any improvements I can make (even if it is minor), It would be greatly accepted.

Tom

Edit: Surface Piercing Prop


[youtube]http://www.youtube.com/watch?v=xKQFAKnvsmA[/youtube]
Running at 3/4 throttle with the smallest prop I could get to the drive (think it is 40mm)

verado

Very nice!

ryanwilson277

maby trimtabs , looks like u could use them. also why did u want a small prop becuz when u said that i thought it was an inboard (subsurface) untill i saw the pics. so prolly bigger prop. idk.

Frankinsten

I am going to buy a load of props soon. Its only a 19t 540 motor and is rather expensive. Don't know about trimtabs however.

pompebled

Hi Tom,

Thanks for the video and the pictures, I'll get back to you when I've studied them more closely.
Did the video come without sound? Being able to hear how the motor performs/revs out, or not, can be of help.

Regards, Jan.

Frankinsten

Hi Jan

The video was filmed on a mobile phone and sound quailty is very poor. Since the event was so busy, all you can hear is lots of voices and not the boat.

Small update on the boat

I removed the deck of the boat and the servo still isn't working but is very stiff. Futher more, I forgot I supersteeled the servo in place so I will have to cutout a new tray. Also moved the weight a touch forward to get a better COG. Still looking for a good servo however.

Should be able to give it a run next weekend (if I can order some battreys from the vapatech store) so I will bring my Video recorder(with good sound quality)

Tom

pompebled

Hi Tom,

Having slept on it, I think the porpoising may be because the keel line of the hull is only straight for a short distance.
This effectively makes it a 'Kyosho style' hull like the Blue Streak or the Twin Drizzle (err, Storm that is...), which all have a rocker in the keel line, making the hull undrivable beyond a certain speed.

See what shifting the CoG forward will do about the handling, the next step would be to stretch the straight part of the keel line, by adding trimtabs, like ryanwilson277 suggested, trimmed neutral it should make a difference

I can see the extra arm on the rudder might cause binding, if you have room for it, or can make room for it, go for a single rod, straight from the servo to the rudder arm.
A Hitec HS 81 MG should have no problems with a rudder that size.

Regards, Jan.

Frankinsten

Hi Jan,

The weight has been moved a inc forwards form the previous location which should improve the balance. I have spents a few hour doing this today. I will try the trim tabs after a test run at the usual testing place.

The extra arm is there to help the boat turn left. Without it, the boat would only turn right but this may of been a servo issue so i will see if I can put it back on with the new servo (I do perfere the orignal way(Included Pic)). Also, what do mean by binding?

I am going to order the servo tonight.

http://cgi.ebay.co.uk/Hitec-HS-82-MG...QQcmdZViewItem

Thanks

Tom

Midget

Hay, Nice boat.
I would use Trim tabs as a last resort...
From the video, once the boat gets on a plan it starts to hop. From looking at the pictures
your prop is already angled down quite a bit, so i would move the batt/s forwards.

I know it's really hard designing an building a boat from scratch. I personaly would have designed
the boats rails differently - I would of made them opposite to how you have made them - so the rails
were taller towards the back of the boat, than they got small towards the front, this would give the hull
something to rest on when it's on a plan, and make it more stable.
If i were to make the hull like you have, i would have mounted the prop a bit higher, so there is more hull
in the water - I believe this would stop the nose from hopping as well.

But, who am i to know - thats just my 2 cents.
Good luck.

Frankinsten

Hi Midget, Thanks for your response

The battreys used in the video were the 2200mAh which are much lighter than the 3700mAh or 4300mAh I use in the races. I only have one 2200mAh pack which is very rarely used.


This was the first boat I have designed and built from scratch. I was inspired by the batboat, but there are alot of differences between them. After building the boat, I have discoved things which can make life just a bit easier. From the 'wings' at the side making installing a servo a pain (even a micro servo), to the fitting of a rudder on the back of the boat.

At the moment, I am exploring way of making it easier to use, along with bringing new ideas to the table which have yet, not been explored.


Tom

Edit: Just Ordered Servo

Frankinsten

Just a quick news update:

Me and a freind have changed the servo to the new Hitec Servo and had a onland test quickly. Everything it working smothly apart from the motor which dosn't sound too good so I am costing up the price of a decent brushless motor and esc. Any suggests for this would be helpful. Apart from this everything else is fine. Since it is now the summer holidays for me, I should have alot of time for running the boat. Got another pack of Nimh on it way so should get some good runtime.

Anyway I have left you a few pictures of the batboat next to our Teams race winning Nitro. Any suggestion like I said would be helpful (Feigao 540S??)?

Tom