Joining servo leads

[Darran]

Hi

I foolishly brought a Durafly BF110 kit, and I am trying to assemble it. I am sure for some of you out there this is a fairly simple assembly, but I have found it much more difficult than I expected.

I have been following a few build threads on here and another forum to try and assemble the model.

I have a couple of questions, the first is that in the tail there are two servos driving the rudders, but there is a third servo to drive the tail wheel which is in the fus. Normally the tail wheel would be connected to the rudder. This sounds stupid I know but does this mean I need to join all three servos together and connect to one receiver port.

Secondly, the servo wires for the rudder come together right on the joining point to the fus, I cannot use connectors here as there is no room, the only option I think I have is to splice an extension on to them.

Given that the two questions relate to the same circuit, is it a better option to create a harness to join the three servos together, especially as space in this model is tight.

Edited By Darran on 29/04/2017 20:31:52

Edited By Darran on 29/04/2017 20:32:17

[Hamish]

Are you sure you mean rudders? Suggest it could be split elevator.

The third servo would be to operate the rudder.

Each servo will connect to Rx in separate ports. (Advice from expert as elevator servos can be power from one port with a Y lead )

Edited By Hamish on 29/04/2017 21:20:40

[Former Member]

[This posting has been removed]

[Darran]

Posted by Hamish on 29/04/2017 21:17:56:

Are you sure you mean rudders? Suggest it could be split elevator.

The third servo would be to operate the rudder.

Each servo will connect to Rx in separate ports. (Advice from expert as elevator servos can be power from one port with a Y lead )

Edited By Hamish on 29/04/2017 21:20:40

Yes I mean rudders, the Bf110 has two of them.

The elevator is controlled from a seperate servo with a linkage that looks like a tuning fork.

[ChrisB]

Y lead the rudders then mix the tail wheel channel in with the Y lead rudder channel.

[Hamish]

Thanks Percy as I could not find specific model. Same suggestion of a Y lead would still stand?

[Darran]

Thanks guys, that makes more sense.

What are your thoughts on splicing extensions on the servo leads to get round the tail joining obstruction.

[Hamish]

No problem splicing. Have you soldered before? 

Edit.  Would use heat shrink at joint.

Edited By Hamish on 29/04/2017 21:40:08

[Tim A]

The tailwheel servo is connected to the two rudder servos by a three way servo lead. W? lead? However on one flight with it after a nice take off & left turn in circuit it sailed on with no response! Found undamaged hanging on a fence by its props after glancing off the tree line - no damage everything seemed to work. Back in the pits found tailwheel no go. Left sitting with power on while checking over, smoke started to appear from rear of fuse. Turns out tailwheel servo had seized & shorted. Causing it to go into failsafe. So cut servo wiring to tailwheel, centred wheel and flew without.

Found takeoffs & landings were better without it, so unless you have a sealed runway (ours is v. short grass) I wouldn't bother with tailwheel control. Rudder control is good on takeoff & the tail lifts quickly anyway making tailwheel superfluous.

[Darran]

Maybe fixing the tail wheel is a viable option, on this model would certainly make the limited space problem easier. When fun is joined together then space and access to the tail wheel servo is very limited.

 

Edited By Darran on 29/04/2017 23:31:54

Edited By Darran on 29/04/2017 23:33:29

[Jonathan M]

Or, rather than fix the tail-wheel, let it rotate freely within a limited arc? That way you'll have more rudder authority when taxiing.

[Peter Miller]

Tip for joining wires when making up leads.

Slide heat shrink up one wire on each joint (obvioius)

Make a groove in a piece of balsa the same size as the wire. Hold the two pieces of wire together in the groove with pins. Apply solder to the joint. The groove keeps the solder the same size as the wires and makes a neat joint/ Repeat for all three wires.

[mightypeesh]

Top tip on the grooved balsa Peter, I will try that next time Cheers, Simon

[Tim A]

The other thing to do with DF BF110 is throw the supplied props away and fit Master Airscrew 9X6 three blade props. The HK ones are hopelessly out of balance and will shake the motors off their mountings! They will fit the existing adaptors and spinners with only a little modification.

[Simon Chaddock]

Splicing servo leads?

If you are a dedicated lightweight flyer you always splice them if only to save the weight of the connectors! In addition a good soldered joint is physically more reliable and with a lower electrical resistance than a connector.