Forward / Reverse Control Needed For Electric Motor
 

Hello!

First off, I am brand new to this site. If I make mistakes in using this site......, please forgive my "ineptness!"

Anyway, I am constructing an R C Rescue Boat / Airboat to take along with me when I fly my Flyzone Beaver DHC-2 on floats, just in case of a water mishap with the airplane.

I want to have both forward and reverse control of the "PowerUp 480 1000KV Outrunner Brushless motor that I am installing on the airboat. That would make maneuvering the airboat a whole lot simpler - if needed - when approaching a stricken aircraft. I will be using an 11.1V 2200 MAH Lipo battery with a 40A ESC for power and speed control.

My question is this: Does anyone know of / or a way to "Add Reverse" to this motor problem portion of this project? All help and ideas are appreciated!

Thank you very much.

Use an ESC with forward and reverse. Just a question of finding one with the appropriate power handling. You will need to look in other places than aircraft and fast boat sites.
Just how well an airboat will respond to reverse, anybody's guess. If the water is weed free, a more conventional boat like a Springer (simple basic tug/workboat type)might work better. It can easily tow a line with floats to make pulling in easy.

Car ESCs will have reverse and *some* boat ESCs have reverse. The car ESCs won't be water cooled, so they will need some air movement to stay cool. Boat ESCs are sometimes water cooled, but you would probably want an air cooled model.

Simply swap the airplane esc for a car esc :

http://dynamiterc.com/Products/Defau...rodID=DYNS2400

Thank you for responding to my request for help mfr02!!
I had not thought about an ESC with both forward and reverse, but I will l look for one. My original thought line was of an electrical way to switch between the two directions, perhaps some type of a switch that could be activated with another servo. Anyway, I am now intrigued by the Springer Tug Boat and shall Google it to see what I can find out about it.
But your astute mention of weeds is what has me concerned to some extent and that is why I came up with this airboat idea......, for now anyway. So time will tell.
And if you have any other ideas too, I would be interested in them also. As the water here is all ice now, I do have a ways to go before spring time float flying, but a winter project is always nice to do too.
Thank you again.
Jim

Thank you very much for your reply.
In this case, I do not think that cooling would be an issue with the ESC.
Anyway, I seem to be getting a consensus on what could be done to take care of my problem. It seems like an ESC With Reverse will work for my needs.
As I am an airplane guy..........lol......., it never even dawned on me about a car ESC with reverse.
I do wonder though......., that it would need to be paired with a "Surface Only" receiver. If that is the case, then I wonder if I would need a "Surface Only Transmitter."
But these days, "Surface Only" Equipment is relatively inexpensive.
Thank you again.
Jim

Thank you - very much for the reply.
Your answer certainly coincides with the other ones that I have received. As I am into airplanes only, it did not occur to me to contemplate a car ESC. I looked at the one that you attached the link to and it is intriguing.
I am wondering what the cost would be with out the included motor.
Also, I am wondering if I would need to also purchase a "Surface Only" transmitter for this........, as I do not know how an "Air Only" transmitter would work for Reverse. I do know that "Surface Only" transmitters have some internal way of going from forward to reverse, but I do not know of any way that an "Air Only" transmitter could be made to do that!
But I may contact Horizon Hobby to ask them a few questions about this ESC.
I want to thank you for your time in replying to my dilemma.
Jim

With earlier conventional radios, various bands were allocated for surface or air use. At best, it was bad manners to use the wrong one. At worse, illegal and dangerous.
Not a problem with 2.4GHz, the only problems are that "park flyer" radios often lack the range required, and, since aircraft dominate the market, much of the control labeling is inappropriate. The instructions for my set say that used in air, range is about 1K, on surface, about half that. This assumes that the RX antenna has been sensibly sited.
To reverse a brushless motor it just needs two of the wires to be reversed (any two). A DPDT relay worked by a switcher would do the job, but it would need some sort of interlock to prevent the possibility of just slamming it into reverse. A "proper" ESC that changes the phase order for reverse is a much neater idea, and they are available. Being for a smaller market, they do tend to cost more than a similar power forward only type.

Most surface esc's need to see 50% throttle to be in neutral, zero is full reverse and 100% is forward. If your transmitter allows, you could enable the spring ,release the ratchet and center the throttle stick. Then calibrate the esc for forward and reverse. You may have to adjust the throttle endpoints as well. Center throttle would be off/idle, any forward stick movement above center/50% would rotate the motor forward and any stick movement below center/50% would rotate the motor i reverse.
Other option would be to program a throttle curve.

Once again thank you - very much - for your response as it is very much appreciated here!!
Anywway, here is what I came up with - last night - before falling asleep.
First off, I did not want to go to a "Surface" transmitter, and as you pointed out and are well aware of also, I was very concerned about the range of those systems. I have built and flown R C aircraft for over 30 years, so I wanted to use my aircraft system to keep the range at its max.
Here is what I came up with. When I first started to consider this project, one of my parameters was to use vectored thrust for steering - instead of using air rudders. I have now developed a way to do that and it now works so I can literally rotate the motor 180 degrees. When the motor rotates 180 degrees from forward, it will be sitting "Backward" and will then be able to pull the airboat backwards.
All I actually need is a little "maneuvering ability" if the airboat is not where I want it when it contacts the stricken plane. I will now have forward, sideways and reverse control of the airboat.
This will now eliminate any need for anything electrical and will be a mechanical solution to my dilemma.
I have placed an order with "Santa" for some needed "parts" to complete this project and I am expecting that they will arrive via "airmail"..... Ho ho ho....., on the 24th : - )
So, thank you - again - and enjoy what you like to do!!!!!

Once again thank you - very much - for your response as it is very much appreciated here!!
Anywway, here is what I came up with - last night - before falling asleep.
When I first started to consider this project, one of my parameters was to use vectored thrust for steering - instead of using air rudders. I have now developed a way to do that and it now works so I can literally rotate the motor 180 degrees. When the motor rotates 180 degrees from forward, it will be sitting "Backward" and will then be able to pull the airboat backwards.
All I actually need is a little "maneuvering ability" if the airboat is not where I want it when it contacts the stricken plane. I will now have forward, sideways and reverse control of the airboat.
This will now eliminate any need for anything electrical and will be a mechanical solution to my dilemma.
I have placed an order with "Santa" for some needed "parts" to complete this project and I am expecting that they will arrive via "airmail"..... Ho ho ho....., on the 24th : - )
So, thank you - again - and all of your help is greatly appreciated!!!!!
Now, if I could only figure out how to place an Avatar into my profile here, as that has me stumped!!!!!....

Planemann, I know this is getting to be an old thread, but I was hoping I could get some insight on your vectored thrust idea. I built a regular air boat and would like to change it to have reverse. I have thought of vectored thrust by using a servo, but that only turns 45 degrees or so. Did you modify a servo to rotate farther?

Hello tictac80.
My idea for vectored thrust needs more work! The way it "works" is by connecting a series of gears together. The gears are connected to the servo output shaft, which as you said rotates only about 45 degrees. Through a gearing process, (gears and accessories are available from Hobbymasters.com plus a whole variety of other distributors on the Internet) one can get the motor, which is mounted on a vertical rod within a vertical tube, to rotate. However............, and this is where more work is needed. The wires from the ESC are pretty stiff........, and this whole process is still a work in progress. It is extremely putsy and time consuming to get to work correctly. There is so much "play or slop." So my idea does work, but not real well.
Another idea I had was to wrap a cord several times around the motor rod and then wrap the other end around the output shaft on the servo. The servo shaft would need to be lengthened to accommodate the cord and then, similar to "gearing," the same effect could be obtained.
Then I had the idea of considering trying to develop some sort of "wiper system" whereby I could eliminate the stiffness from the wires from the motor and the esc and then eliminate that issue....... OR, maybe I just need a whole lot bigger servo with a lot more torque to overcome the wire stiffness issue!
And finally, I may just try to not "reinvent the wheel here anmore" and look at the "reversible esc's" for the r c cars and boats.
I am wishing you the very best and I hope that it all works out good for you!!