News:



  • May 26, 2024, 06:00:45 AM

Login with username, password and session length

« previous next »
Pages: [1]   Go Down

Author Topic: Single battery, two ESC's  (Read 1001 times)

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Single battery, two ESC's
« on: October 21, 2011, 06:46:03 PM »
Guys:

I am building a scale ship that is a twin that will have two electric motors and two ESC's. I intend to use a single Lipo battery in the fuselage for power. The part that I am struggling with is how to do the "Y" connection for power from the battery to the two ESC's. I am using 20 ga. silicone wires and just simply soldering those three wires together seems that it will be a very bulky connection. Do you think that this is the best way to create this connection or is there some other sort of "slick" connection that I am missing?

Jim Fruit
Logged

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12822
Re: Single battery, two ESC's
« Reply #1 on: October 21, 2011, 06:56:16 PM »
Strip off about 3/4 of an inch of insulation from the middle of a wire.  Strip off a like amount from the end of another.  Wrap the free end around the 'in the middle' wire and solder.  Then cover with heat shrink.  It shouldn't be too bad.

Alternately, since you should be using honkin' big connectors for this anyway, solder both pairs of ESC wires onto your battery connector, so that it 'Y's off there.
Logged
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #2 on: October 21, 2011, 07:49:32 PM »
Tim:

I really like your second suggestion. The only concern I might have would be the amount of heat that it will take to solder the connection. Do you think it will distort the plastic in the connector?

JHF
Logged

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12822
Re: Single battery, two ESC's
« Reply #3 on: October 21, 2011, 08:13:43 PM »
You should be using a connector that's suitable for the full current of both motors; if the ESC wire is 20 gauge then two wires add up to a wire area that falls between 18 and 16 gauge.  So as long as the connector is hefty enough to work with 16 gauge wire then you should be just fine.  If it isn't, then I would question whether it has the current-carrying capacity for your motor combination.

The way I'd do this would be to strip both black wires a bit longer than the usual amount for connecting one wire to a battery terminal.  Then I'd comb the strands out straight, put the wires together, and twist.  I always pre-tin stranded wire, so I'd do that next.  Then I'd shrink a small (maybe 1/4" long) collar of tubing around both wires to hold the mess together when the solder melts, string on a slightly extra-long tube, solder, and shrink.  Then I'd repeat for the red wire.

If the mass of wire is too much for the connector, then it's a good sign that your connector is just too small.
Logged
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #4 on: October 21, 2011, 09:35:06 PM »
No, the connectors are not too small, Tim. Thanks for the suggestion about a collar to hold everything together. These are the sort of neat suggestions that I was inquiring about. Thanks again.

JHF
Logged

Offline Dennis Adamisin

  • 2019 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4344
Re: Single battery, two ESC's
« Reply #5 on: October 22, 2011, 08:26:20 AM »
Jim:
Attached are some pix of the harness I did for a Pathfinder Twin awhile back.  I PRESUME (dangerous word!) that you will also be controlling the throttles together?  If so you will actually need TWO Y-harnesses - one for power, one for control.

Like Tim said the power harness needs to be substantial, I used 12 ga.  I removed a bit of material from the middle of the wire and soldered in the wrap around joint.  These were tape wrapped & staggered so as not to rub against each other.  I then soldered Deans Ultra connectors at the appropriate places so I could plug in the ESC's at the ends and the batteries in the middle.  Because of the way the installation was made the harness is actually slightly longer on one side than the other - could not be helped.

The signal harness was a regular RC Y-harness with the exception that ONE of the power wires needs to be disconnected (edit) on one connector only.  I simply pulled the middle pin on one connector and taped it back.

The two harnesses were taped together and installed as a unit.

 
« Last Edit: October 22, 2011, 02:07:38 PM by Dennis Adamisin »
Logged
Denny Adamisin
Fort Wayne, IN

As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #6 on: October 22, 2011, 02:58:27 PM »
Dennis:

Thanks for the response. The pictures are very helpful.

Yes, I am aware of the need for the two Y-harnesses. I also have had discussions with others about the need to drop one of the power wires to one of the ESC's. Actually, I am using one of Clancy Arnold's systems, and Clancy has been very helpful in that respect. My plan is to run each motor on a separate potentiometer mounted side by side sort of like the throttle quadrant in the real plane. Clancy is not too excited about this due to a bad experience he had in the past with an IC twin turning in on him. My hope is that the ability to start each engine independently will be worth impression points for the judges. Otherwise the throttles will be controlled in consort with each other.

Thanks again for your help.

JHF
Logged

Offline Dennis Adamisin

  • 2019 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4344
Re: Single battery, two ESC's
« Reply #7 on: October 22, 2011, 04:58:10 PM »
Hmmm, if you hade SLIDE style pots you could advance one, advance the other, then hold them together to adjust throttle in flight.   8)
Logged
Denny Adamisin
Fort Wayne, IN

As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline John Rist

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2952
Re: Single battery, two ESC's
« Reply #8 on: October 22, 2011, 05:02:41 PM »
Quote from: Jim Fruit on October 22, 2011, 02:58:27 PM
Dennis:

Thanks for the response. The pictures are very helpful.

Yes, I am aware of the need for the two Y-harnesses. I also have had discussions with others about the need to drop one of the power wires to one of the ESC's. Actually, I am using one of Clancy Arnold's systems, and Clancy has been very helpful in that respect. My plan is to run each motor on a separate potentiometer mounted side by side sort of like the throttle quadrant in the real plane. Clancy is not too excited about this due to a bad experience he had in the past with an IC twin turning in on him. My hope is that the ability to start each engine independently will be worth impression points for the judges. Otherwise the throttles will be controlled in consort with each other.

Thanks again for your help.

JHF

If you use linear pots side by side you could rig them to lock together once they are side by side.  With helper holdind bring up the inboard to idle first - then run it up and back to idle.  Bring outboard up to idle - run it up and back to idle.  Then lock the two pots together.
Logged
John Rist
AMA 56277

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #9 on: October 22, 2011, 05:52:16 PM »
You guys are reading my mind. Yes, I AM using slide pots. I also don't think I will need anyone to hold the plane. Using Clancy's system and Maxx Products combination motors and ESC's, in the past, I have been able to spool up the motor to idle with no one holding the plane. I then advance the slide pots and take off. There won't be much thrust from the motors at idle, they are a substitute for .25 IC engines. Yes, I am having too much fun.

Jim
Logged

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12822
Re: Single battery, two ESC's
« Reply #10 on: October 22, 2011, 07:19:23 PM »
Quote from: Jim Fruit on October 22, 2011, 02:58:27 PM
My hope is that the ability to start each engine independently will be worth impression points for the judges. Otherwise the throttles will be controlled in consort with each other

Isn't it possible to declare "one engine out" running to be a scale maneuver?  If you can get an ESC with a strong enough brake you may be able to get a prop to stop in flight just by dropping the throttle.
Logged
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #11 on: October 22, 2011, 08:31:28 PM »
Quote from: Tim Wescott on October 22, 2011, 07:19:23 PM
Isn't it possible to declare "one engine out" running to be a scale maneuver?  If you can get an ESC with a strong enough brake you may be able to get a prop to stop in flight just by dropping the throttle.

Tim:

I believe under the current rules, to get maximum points for "multi-engine" (one of the allowed options), all engines must remain running throughout the flight. I suppose that could be waived if one were to declare it as an option. I don't know if the other competitors might challenge the validity. The other question would be if the plane could maintain safe flight on only one engine. As I noted before, my motors are each rated as a substitution for a .25 IC engine. I believe the plane is going to weigh a little more than four pounds with a 48", tapered wing. I have plenty of options available to me to complete the six options, however: Retract gear (2 options); Flaps (1 option); Multi-engine (1); Touch & go (2); Taxi (1); Throttle control (1);Overshoot (1). As you can see, I can pick and choose based upon conditions. I don't believe that I will even try High-flight with this plane. The six options are required if I enter the plane in Sport Scale. If I enter it in F4b, there are fewer options required. Thanks for the thought, however.

Jim Fruit
Logged

Offline Dennis Adamisin

  • 2019 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4344
Re: Single battery, two ESC's
« Reply #12 on: October 22, 2011, 08:51:33 PM »
Quote from: Tim Wescott on October 22, 2011, 07:19:23 PM
Isn't it possible to declare "one engine out" running to be a scale maneuver?  If you can get an ESC with a strong enough brake you may be able to get a prop to stop in flight just by dropping the throttle.

This story is kind of in line with Tim's idea:

I understand Jack Sheeks was flying in a scale meet with a Hellcat(?) with the gear retracted.   Apparently there was a malfunction and the gear would not extend.  Story is Jack was quick to improvise; he announced his next manuver would be "Crash Landing"!
 8)
Logged
Denny Adamisin
Fort Wayne, IN

As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline John Rist

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2952
Re: Single battery, two ESC's
« Reply #13 on: October 22, 2011, 09:31:09 PM »
Quote from: Tim Wescott on October 22, 2011, 07:19:23 PM
Isn't it possible to declare "one engine out" running to be a scale maneuver?  If you can get an ESC with a strong enough brake you may be able to get a prop to stop in flight just by dropping the throttle.

I think this would be a great manever.  However to be really cool - one would need a variable pitch prop that could be feathered.  The magnets should cause the prop to stop turning.  After a couple of laps or perhaps a touch and go declare an air restart.  What fun that would be!

 #^
Logged
John Rist
AMA 56277

Offline Jim Fruit

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 316
Re: Single battery, two ESC's
« Reply #14 on: October 22, 2011, 09:39:27 PM »
Quote from: Dennis Adamisin on October 22, 2011, 08:51:33 PM
This story is kind of in line with Tim's idea:

I understand Jack Sheeks was flying in a scale meet with a Hellcat(?) with the gear retracted.   Apparently there was a malfunction and the gear would not extend.  Story is Jack was quick to improvise; he announced his next manuver would be "Crash Landing"!
 8)


Dennis:

I had heard that one before. On a related note, on my C-45 the gear retracts into the wing, but not all of the way. If I have a similar problem to what Jack had, I will be able to land on the retracted wheels. The props will probably be a mess, but the bottom of the airplane should be O.K.

JHF
Logged

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12822
Re: Single battery, two ESC's
« Reply #15 on: October 22, 2011, 09:47:31 PM »
Quote from: John Rist on October 22, 2011, 09:31:09 PM
I think this would be a great manever.  However to be really cool - one would need a variable pitch prop that could be feathered.  The magnets should cause the prop to stop turning.  After a couple of laps or perhaps a touch and go declare an air restart.  What fun that would be!
I have some doubt that a motor would stop without an ESC brake.  But yes, variable pitch props would be cool.  Some of the smaller 3D planes had them for a while -- I don't know if they still do.
Logged
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Advertise Here
Pages: [1]   Go Up
« previous next »
Tags:
 


Advertise Here