Model Boat Mayhem

Mess Deck: General Section => Beginners start here...! => Topic started by: robbievanl on November 04, 2009, 11:14:30 am

Title: Jet Drive Reversing with 2ch Radio
Post by: robbievanl on November 04, 2009, 11:14:30 am
Hi all,

Just discovered this great site and the amazing wealth of information in contains for boating beginners like me  :-))

I am currently undertaking an RC boat project with a jet drive propulsion system and was wondering whether it is possible to control this boat with a 2 channel radio controller. Obviously one channel has to be dedicated to steering the jet nozzle, and another to the speed of the motor powering the jet drive. However is it possible connect a servo to the same channel as the speed control so that when the throttle is pushed down (in reverse) on the radio controller, this servo also lowers the steering bucket, thus allowing the boat to reverse?

If anyone has any ideas or alternate suggestions I'd love to know!

Thanks,
Robbie

P.S. I've attached some images I rendered in CAD  :}
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: HMS Invisible on November 04, 2009, 12:33:00 pm
For a brushed motor like a Graupner 700,Torpedo 850 or Graupner 820
In stock

Click on the Pibber silhoette on the top left of my homepage for specification and email me for ordering
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: Martin (Admin) on November 04, 2009, 05:46:13 pm
For a brushed motor like a Graupner 700,Torpedo 850 or Graupner 820
Click on the Pibber silhoette on the top left of my homepage for specification and email me for ordering

Interesting Item!
So you plug your speed controller into the throttle channel and set up forward speed.....
How do you set up reverse speed (which is still forwards in reality)?
Where does the reversing bucket servo plug in and is there any electronic adjustment for this servo?
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: Sub driver on November 04, 2009, 06:26:50 pm
 Hi Guys.

Just a thought.

Put a Y lead in the Throttle socket on the receiver,  servo into one of the ends, speedo into the other now both will work with the throttle stick, if you limit the full throttle by setting the speedo so the stick is at 1/2 way and set the bucket so it wont cover the jets output but when go to full throttle stick the bucket will drop covereing the jets output and give reverse, a lot of playing with the linkages but it might work .  O0

Regards Sub. :-))
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: HMS Invisible on November 04, 2009, 07:10:24 pm
Interesting Item!
So you plug your speed controller into the throttle channel and set up forward speed.....
How do you set up reverse speed (which is still forwards in reality)?
the throttle profile is mirror image with the option of different gains.


To set 100% THROTTLE  point
(http://homepage.ntlworld.com/microgyros/jet_fwd_only_files/uP.gif)
   1. deflect throttle to maximum
   2. ensure radio failure is OFF
   3. press the  SETUP button

repeat in reverse direction


Quote
Where does the reversing bucket servo plug in and is there any electronic adjustment for this servo?

The speed controller has a servo connector.


Servo Position Adjustment

   1.   Hold the setup button...                                            
   2.  After two seconds one pair of lights flash alternately
   3.  Move the throttle so the servo opens the reverse mechanism
   4.  Release the setup button...          

Repeat the above with the throttle lever reversed and the reverse bucket mechanism closed

I didn't really answer the question :  
Quote
how :- set up forward speed
Here:-
You may wish to reduce the throttle in one or both directions
The throttle power can be reduced independently which is
particularly important in a streamlined speedboat hull

Deflect the lever in one direction
Press the SETUP button twice
Repeat until full throttle is acceptably low
It is all here
Jet bucket speed control instructions (http://homepage.ntlworld.com/microgyros/jet_fwd_only.htm)




Notice two of my loyal speed control punters offering up a sellotape alternative when they know the prices I charge.
This thing actually works you know!  <*<
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: Martin (Admin) on November 04, 2009, 07:37:23 pm
My post   wasn't   a criticism!  {:-{
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: HMS Invisible on November 04, 2009, 07:49:07 pm
My post   wasn't   a criticism!  {:-{
It wasn't taken that way for a moment :-)) I'm encouraged by your interest,Martin.

Title: Re: Jet Drive Reversing with 2ch Radio
Post by: Martin (Admin) on November 04, 2009, 07:55:09 pm
OK.  :-)) 

Any video around?
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: HMS Invisible on November 04, 2009, 09:07:42 pm
OK.  :-))  

Any video around?
I have only just started experiments with animated gif editing, so.....Nope!
See the submarine that will appear below.It was my first attempt and took all afternoon.
It shows the action required of a submarine pitch-control/auto leveller

I've noticed quite a few of my stuff in sub videos and pictures here on mayhem.
Video editing is one helpful aid that is beyond me unfortunately as I havn't tried :((
I have exchanged emails with two Mayhemmers,all day today,telling them of my video transfer woes and asking how much it will be to edit and upload raw footage.
I'm going to cough up $$ for youtube microgyros presentations like this (http://www.youtube.com/watch_private?v=0zodqVly2bk&sharing_token=lF0kQTIzrOdN1_v1mu7Xaw)
But most of the sub meeting videos have got my equipment in them but as you can see from another variant of that speed controller (with its servo operating an air-release valve) , it is pretty difficult to shaw the internal workings in a sub.
 (http://img.photobucket.com/albums/v293/subculture84/th_DSCN1038.jpg) (http://img.photobucket.com/albums/v293/subculture84/DSCN1038.jpg) here is the yellow rectangular gadget thing in action   youtube link  (http://www.youtube.com/watch?v=XN_UB2D_rVw)

That is the third variant,used in subs where there is an air release servo.
The picture is of Alan Poole's excellent HMS Ocelot and there are videos of that doing lengths in a swimming pool.
Much more interesting,don't you agree?

Don't know if any customers of the bucket reversing controller made any.
Graeme was a videotape engineer to trade I wonder if he's got one.
Failing that I will do an unedited one myself but my video card has packed in so it will be a few days.
There are plenty mayhemmers here who have used the fast electric variant so it will be captured somewhere : exact same hardware, just different software and an additional servo connector.

(http://homepage.ntlworld.com/microgyros/xxi-pitching.gif)




Title: Re: Jet Drive Reversing with 2ch Radio
Post by: HMS Invisible on November 04, 2009, 11:24:00 pm
OK I will put an animated gif in the updated html instructions (http://homepage.ntlworld.com/microgyros/jet_fwd_only.htm) of the jet bucket speed controller
Give it a week for the change.I'm already on the case...............



Here is the only product that merits an actual video.
http://www.youtube.com/watch?v=0zodqVly2bk
 (http://www.youtube.com/watch?v=0zodqVly2bk)
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: timsenecal on November 05, 2009, 12:28:27 am
microgyros....

the jetboat throttle/bucket controller is fantastic.... I would love to have one to play with...

but my jetboats use brushless motors  :(


anybody have any suggestions for that small issue?
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: robbievanl on November 05, 2009, 01:34:54 am
sounds like a great idea microgyros!
just a quick question, does it matter if the jet nozzle is above or below water (or a combination of both- i.e. half under half over???)
thanks guys  :}
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: Martin (Admin) on November 05, 2009, 01:40:07 am
I think you'll find most will start under water but the forward motion of the hull will soon leave the jet above water!
Title: Re: Jet Drive Reversing with 2ch Radio
Post by: robbievanl on November 05, 2009, 02:28:29 am
thanks martin  :-))