Servo setup: EPA, current, and linkages

[cwojcik]

Another option is to add a second receiver if you have another 6208 kicking around. Put the rudder and throttle servo on one receiver and the ignition on the other, use two batteries with two switches, and two or three leads into each receiver. You will have as much current capacity as a power expander but it will be lighter, and if you lose a receiver you can still kill the engine and have some control over the airplane (not that this is likely).

I have been doing this on my giant scale stuff up until this point and love it. Simple, robust, cheap, redundant, and light.

 

[m0dest]

Another option is to add a second receiver if you have another 6208 kicking around. Put the rudder and throttle servo on one receiver and the ignition on the other, use two batteries with two switches, and two or three leads into each receiver. You will have as much current capacity as a power expander but it will be lighter, and if you lose a receiver you can still kill the engine and have some control over the airplane (not that this is likely).

I have been doing this on my giant scale stuff up until this point and love it. Simple, robust, cheap, redundant, and light.

Actually that seems like a great idea.

I do happen to have another 6208.

SO the game plan is to Make room for the RX.

2 TP RX packs into the WOlverine(2 switches)
JR Leads from the TP packs, one into each receiver.
Wolverine leads one to each Receiver.

Sort of ironic you mentioned it. It has to be about the safest route to go.

Is there anything I need to know about running the 2 receivers. Binding? Maybe I could bust out the manual.
8FGsuper

 

[cwojcik]

Just bind up the second receiver like the first one. It will work fine. With two-way receivers like the Hitecs range is usually reduced when running dual receivers but it makes no difference with the 6208's. If you ever feel like you want more redundancy and less resistance, you can go to two switches that each have two outputs. No you guys are seeing why I love dual receivers so much.

 

[wedoitall]

So all you have I do is bind the 2nd one also. How does it work with hooking up servos? Try to out all on the same Rx? Is there anything linking the two Rx's? Sorry for the questions just this is interesting never heard of seperate dual Rx

 

[wedoitall]

Oh never mind reread above

So you should keep them the same model of Rx, 2 of the same. I'm glad you posted this. I'll be maiden my first gas plane on New Years snow or shine. This will be much cheaper than buying a power expander. Just need to get another switch.

 

[URAGANO23]

Returning to the topic of servo setup i have some questions, since i have learned something new reading the Joe Smith posts about MAX EPA and Amp draw.

In a new plane:
1- Set the control horn almost at 90° from servo and linkage for a better geometry. To do so if some sub-trim is needed how do you setup your max and min servo travel (or both sides as you want to call them). With subtrim i will have some more travel to one side than the other of course. Do you reach for example 45° on both side using different EPA each side? Is it correct?

2- for dual servo elevators (one each side) the above setting will introduce some errors in the throws for example when i'm at 50% stick travel will i have 20° on both elevators or easily for example 20° on one and 22° on other?
This assuming that linkages are the same lenght and the points of attach are at the same distance.

I hope you understand the meaning, for me is a bit difficult to explain the concept in english...

Thanks
Adriano (Italy)

 

[gyro]

Returning to the topic of servo setup i have some questions, since i have learned something new reading the Joe Smith posts about MAX EPA and Amp draw.

In a new plane:
1- Set the control horn almost at 90° from servo and linkage for a better geometry. To do so if some sub-trim is needed how do you setup your max and min servo travel (or both sides as you want to call them). With subtrim i will have some more travel to one side than the other of course. Do you reach for example 45° on both side using different EPA each side? Is it correct?

2- for dual servo elevators (one each side) the above setting will introduce some errors in the throws for example when i'm at 50% stick travel will i have 20° on both elevators or easily for example 20° on one and 22° on other?
This assuming that linkages are the same lenght and the points of attach are at the same distance.

I hope you understand the meaning, for me is a bit difficult to explain the concept in english...

Thanks
Adriano (Italy)

I think it was [MENTION=699]3dbandit[/MENTION] who reminded me that the arms should be perpendicular (90 degrees) from the HINGE LINE not the servo. This will give you the best geometry.

Use your radio's EPA (End Point Adjustment) or Travel Adjust to adjust the max points of deflection, so that both sides match and move the same amount/correctly.

Use a programmable curve if the elevators don't move in sync after this is done.

 

[3dbandit]

I think it was [MENTION=699]3dbandit[/MENTION] who reminded me that the arms should be perpendicular (90 degrees) from the HINGE LINE not the servo. This will give you the best geometry.

Use your radio's EPA (End Point Adjustment) or Travel Adjust to adjust the max points of deflection, so that both sides match and move the same amount/correctly.

Use a programmable curve if the elevators don't move in sync after this is done.

Perpendicular to push-rod and parallel to the hinge-line....

I would definitely use a match or balance feature to match surfaces. I have noticed a difference in performance by matching points of travel in all directions.

 

[URAGANO23]

Perpendicular to push-rod and parallel to the hinge-line....

I would definitely use a match or balance feature to match surfaces. I have noticed a difference in performance by matching points of travel in all directions.

Ok Thanks as i did. To be more clear for match or balance feature do you mean a special feature of the radio so that if i give some subtrim it will auto correct the two limits so that both sides have equal throw?

I have the Frsky Taranis and it has this feature but it is more suited if you have for example two aileron servos each wing.

 

[3dbandit]

Ok Thanks as i did. To be more clear for match or balance feature do you mean a special feature of the radio so that if i give some subtrim it will auto correct the two limits so that both sides have equal throw?

I have the Frsky Taranis and it has this feature but it is more suited if you have for example two aileron servos each wing.

Similar to mixing a dual servo wing. It ensures equal movement of say your elevators at all points of deflection.

Some times, even with good geometry, elevator halves may deflect a little different at various points of stick movement.(just a degree or two usually)