Newb, various Q's on control & thruster arrangement

[Andrew Leigh]

Morning all, new kid on the block here.

Couple of questions. A mate has just given me an older generation but new Futabo 7 channel radio and receiver (don't physically have it in my grubby mitts yet). There are no servos's attached to the deal. I am planning on building a sophisticated bait boat (for me that is) using the radio as the control. I am a total RC ignoramus so please bear with me.

Question 1 - Is is possible to alter the frequency of the radio as it was used for planes? And from what I have read they have differing bands.

Question 2 - Can one have a receiver control a solenoid type thing rather than to turn a servo. I would like a simple on or off in some cases? e.g. I will have a "bucket at the rear of the boat that will contain the baited hook, once this reaches the destination a solenoid needs to unlatch the "bucket" releasing the cargo. I am hoping a solenoid type solution will be cheaper than a servo.

Question3 - What is the maximum rotation on a standard servo? Can one disable something in the servo which will make it go in circles? The reason for this is that I would like to have "pod" motors to act as thrusters that will allow me to move the boat in all axes, mind you thinking about it one will only need 180° rotation as reverse on the props will give the other 180°.

Question 4 - If I had 4 pod motors, one on each corner of a cat hull will each servo on each motor turn by the same amount or will there need to be some form of equalisation?

Question 5 - Generally what is the average torque of a servo motor?

Question 6 - Regarding displacement would I be correct in saying that for every kg mass of the boat 1 litre of hull would be require for neutral bouyancy? I need to figure out what the size of cat hulls so it does not do a Titanic impersonation.

Last Question - You boys have been around a bit, perhaps the way I am going at this is completely incorrect, advice would be welcome.

Regards
Andrew

[toesup]

Morning all, new kid on the block here.

A mate has just given me an older generation but new Futabo 7 channel radio and receiver

Question 1 - Is is possible to alter the frequency of the radio as it was used for planes? And from what I have read they have differing bands.

Question 2 - Can one have a receiver control a solenoid type thing rather than to turn a servo.

Question3 - What is the maximum rotation on a standard servo?

Question 4 - If I had 4 pod motors, one on each corner of a cat hull will each servo on each motor turn by the same amount or will there need to be some form of equalisation?

Question 5 - Generally what is the average torque of a servo motor?

Question 6 - I need to figure out what the size of cat hulls so it does not do a Titanic impersonation.



Hi Andrew.. and welcome to the forum.

Bait boats have been discussed on here several times before.. Do a search for "Bait Boat" and quite a few of your questions will have been answered before.
My own 'Bait boat' build.. http://www.rcgroups.com/forums/showthread.php?t=869727

Using aircraft (72mhz) radio's for surface (75mhz) vehicles is illegal...
http://rcsource.hobbypeople.net/faqs/freqlist.htm

1/ Yes, you can get them converted by the manufacturer, but the cost will probably be more than buying a new radio system. You only need a 3 channel radio for a bait boat, rudder, throttle and bait release.

2/ Yes, but a servo is probably cheaper and easier to set up.

3/ Standard servo's have a limiting 'switch' built in to them. This can be disabled and the servo made to rotate 360. Some servo's can be bought that will continually rotate (sail winch servo's) as long as the stick on the transmitter is moved.

4/ If you had 4 pod motors, you would need 4 servo's, 4 motors, 4 speed control's... and independant control over each.. That gets very expensive!.

5/ 33 - oz inch @ 4.8v

6/ There are several bait boats out there by 'manufacturers'.. Have a look at their boats to decide on your design.

[Andrew Leigh]

Firstly thanks for the reply,

Awesome boat and great lateral thinking, I am desperately hoping you kept the plans or have them on file somewhere? Can you recall the motor spec's?

Is and air screw a more efficient means of propulsion?

Love the idea, would like to scale mine up a wee bit to be able to drop more ground bait.

Thanks again
Regards
Andrew

[toesup]

Awesome boat and great lateral thinking, I am desperately hoping you kept the plans or have them on file somewhere? Can you recall the motor spec's?

Is and air screw a more efficient means of propulsion?


I drew the plans up myself on CAD... so yes, i still have the plans.
The motor is a standard $25 RC car motor...

The prop isnt more efficient than a water prop.. but its quieter than a water prop scaring the fish.. and allows BD1 to ride over weedy areas.