Go Back  RCU Forums > RC Boats > RC Boats General Discussion
Reload this Page >

Multiple servos, one channel

Notices
RC Boats General Discussion Discuss general rc boating topics here.

Multiple servos, one channel

Old 07-27-2004, 11:58 AM
  #1  
Section 8
Junior Member
Thread Starter
 
Join Date: Jun 2003
Location: Milwaukee, WI
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default Multiple servos, one channel

Hello,

I would like to know how it would be possible to opperate 4 car sized (the ones that are usually included with 2 channel surface radios) servos with a single channel on the reciever. I am assuming that it is not going to be as easy as simply purchasing 3 "Y" adaptors. I have a feeling that the power requirements of the servos is going to be to much for the reciever to handle, and cause it to release the magic smoke.

Is the solution as simple as connecting the signal wires for all of the servos to the reciever and supplying power from a seperate battery pack through the power leads?

Another question is is it possible to reverse the direction of a servo by changing the polarity of the power leads?

Thank you very much,

Greg
Old 07-27-2004, 02:05 PM
  #2  
Ron S
My Feedback: (2)
 
Ron S's Avatar
 
Join Date: Dec 2001
Location: Fort Worth, TX
Posts: 2,202
Received 186 Likes on 114 Posts
Default RE: Multiple servos, one channel

If a series of y-harnesses won't work for you, and you use Futaba compatible equipment, Futaba has come out with a Servo Synchronizer that would work very well here. This box plugs into one channel of your receiver, with up to 4 outputs. All 4 outputs (to servos) can be reversed individually, as well as centering and ATV.

JR has one too, I think, called a Matchbox.

If your transmitter is a higher end programmable type, you could add each servo to, example, 5, 6, 7, 8, then mix the signals... In this case, the above mentioned hardware would not be needed
Old 07-27-2004, 05:38 PM
  #3  
Ron Olson
My Feedback: (1)
 
Ron Olson's Avatar
 
Join Date: May 2002
Location: Kalamazoo, MI
Posts: 18,688
Likes: 0
Received 20 Likes on 17 Posts
Default RE: Multiple servos, one channel

Why do this? Figuring at $15.00 a pop for a standard servo, for $60.00 you can get one that would more than handle the job. Four sevos take up a lot of space unless you have the room.
Most of the newer servos are all pretty much universal now, one of the exceptions being the older Airtronics which now come with a "Z" connector. Yes, it is possible to swap wire leads, I've done it a lot.
Old 07-27-2004, 06:03 PM
  #4  
Section 8
Junior Member
Thread Starter
 
Join Date: Jun 2003
Location: Milwaukee, WI
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

ORIGINAL: Ron S

If a series of y-harnesses won't work for you, and you use Futaba compatible equipment, Futaba has come out with a Servo Synchronizer that would work very well here. This box plugs into one channel of your receiver, with up to 4 outputs. All 4 outputs (to servos) can be reversed individually, as well as centering and ATV.

JR has one too, I think, called a Matchbox.

If your transmitter is a higher end programmable type, you could add each servo to, example, 5, 6, 7, 8, then mix the signals... In this case, the above mentioned hardware would not be needed
Thanks alot. I searched the Servo Synchronizer and the Matchbox. From the look of the wiring on the Matchbox, you can indeed just utilize "Y" harnesses (or solder joints), and splice a new power source into the wires. THanks for mentioning those.


ORIGINAL: Ron Olson

Why do this? Figuring at $15.00 a pop for a standard servo, for $60.00 you can get one that would more than handle the job. Four sevos take up a lot of space unless you have the room.
Most of the newer servos are all pretty much universal now, one of the exceptions being the older Airtronics which now come with a "Z" connector. Yes, it is possible to swap wire leads, I've done it a lot.

It sounds like you know alot more about what I am building that I do. A single servo is completely impractical due to the necesity of haveing numerous bell cranks to do it. It would be easier to use 4 standard servos (of which I have quite a few from buying radios over the years, so there is no cost to them) directly actuating, than 1 heavy duty servo (that I would need to buy) with a complete mess of linkages. Not to mention the headach of finding the percise center of rotation/pitch of the moving parts so as not to introduce unwanted throw at the end point of the linkage. Not to mention the "loose" nature of a set up with many short linkage runs between bellcranks.

Its generally more practical to ask questions instead of making assumptions.

Cheers,

Greg
Old 07-27-2004, 06:25 PM
  #5  
Ron Olson
My Feedback: (1)
 
Ron Olson's Avatar
 
Join Date: May 2002
Location: Kalamazoo, MI
Posts: 18,688
Likes: 0
Received 20 Likes on 17 Posts
Default RE: Multiple servos, one channel

OK, the question that I should have asked you in the first place, what are you installing these in? Even large rudders or a decently sized outboard really don't need a whole lot. Hi-Tec for instance makes standard sized servos that can put out a lot of torque for their size and at a reasonable price.
Old 07-27-2004, 08:01 PM
  #6  
Section 8
Junior Member
Thread Starter
 
Join Date: Jun 2003
Location: Milwaukee, WI
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

Its a scale application. They are going to be running "ambiance". Specifically, elevation of four water gun turrets.

cheeRS,

Greg
Old 07-27-2004, 08:19 PM
  #7  
Umi_Ryuzuki
 
Umi_Ryuzuki's Avatar
 
Join Date: Dec 2003
Location: PDX, OR
Posts: 1,664
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

Fire Monitors,... ooooh.

I'll post a piccy of my boat if you post a piccy of your boat...

Umi
Old 07-28-2004, 08:25 AM
  #8  
Section 8
Junior Member
Thread Starter
 
Join Date: Jun 2003
Location: Milwaukee, WI
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

Hello,

Its not much yet. I am still planning. Here is an 8" x .130" (I have found that not much stock is metric ) and the drawing/s of a transmission plate. The aluminum will be also used for bulkheads. I have not recieved the square tube yet to connect the bulk heads. I am getting alot closer to just floating a small 12 volt battery (lawn mower sized) to run eveything that I keep adding on to what I want to do. [sm=lol.gif]



Cheers,

Greg
Old 07-28-2004, 11:15 AM
  #9  
Umi_Ryuzuki
 
Umi_Ryuzuki's Avatar
 
Join Date: Dec 2003
Location: PDX, OR
Posts: 1,664
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

I can't quite make out the drawing.
You are going to build it out of Metal?
That is a challenge. I can't do welding, especially aluminium, so I glue wood instead.
Do you have plans for your boat?
Here is what I am building.

Umi
Attached Thumbnails Click image for larger version

Name:	Wu61487.jpg
Views:	31
Size:	22.6 KB
ID:	158262  
Old 07-28-2004, 11:53 AM
  #10  
Section 8
Junior Member
Thread Starter
 
Join Date: Jun 2003
Location: Milwaukee, WI
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

There are no plans. Los Angles number 2 looks just like that. I was going to build it simularly as I liked the modern look of it. Less of a tug boat with water cannons on it.

THe drawings are essentially just a couple of plates with a few holes in them. I am using a belt driven RC car for parts. Instead of using gears, I thought that i would use belts since I have a couple of cars lying around.

I haven't decided if I would do the hul out of aluminum or not. I am leaning towards using wood with a thin layer of fiberglass. I am just uning aluminum for the bulkheads and the connecting them together to have it be sturdy while being transported. The deck (and everything above it) will be wood, plastic, or what ever small things such as rope or brass.

Cheers,

Greg
Old 07-28-2004, 12:14 PM
  #11  
Umi_Ryuzuki
 
Umi_Ryuzuki's Avatar
 
Join Date: Dec 2003
Location: PDX, OR
Posts: 1,664
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Multiple servos, one channel

I am building the Fire boat #2, if you need frame plans for the Los Angeles Fire boat #2 I drew them up, and they coordinate with the plans available online.
You might have to modify it a bit for regular propeller drive though.

[8D][8D]

Umi

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.