OK I need some advice from some experience zephyr II builders. I've studied the various blogs here and youtube builds but I want to see the best way to position all the equipment and I guess every build is a bit unique so here are my details. I will paint it yellow and then laminate it.

Here's what I need to put in but the question is where is the best placement?

APM1 with mag and gps and airspeed sensor.

Ritewing Zephyr II came with 150gr 1300 kv motor 60A esc

came with plastic gopro mount. I would prefer the wood case I saw at blacksheep but this will do for now.

I will use the gopro with this RMRC-600XV 600TVL WDR CCD (NTSC)

ImmersionRC 600mW 5.8GHz A/V Transmitter with  5.8 GHz Bluebeam Whip Antenna Set (RHCP)

EZUHF 8 Channel Diversity Receiver

XBee-PRO 900 extended range module w/ wire antenna

2 of Turnigy nano-tech 3300mah 4S 35~70C Lipo Pack

Remzibi OSD with it's own GPS

Castle Creations 10A BEC

Turnigy Voltage Protector 550000uf (1.4sec) (for BEC 5v line)

So my questions are:

Where to best position for the equipment?? If I embed anything in the wing, I want to be able to see the equipment from the top of the wing for status lights and maybe use a clear hinged cover for protection or just use the laminate and cut if off when necessary. Also will have to consider cooling for the components that get hot like the OSD, ESC, BEC.

I think it's impossible to use the battery bay in the center because I will need that space for the APM or can I put the APM embedded in the wing with a clear cover? Does it need to be over the COG or can it be to the side. Is the Zephyr more stable with the batteries in the front like I have in the picture?

I think I prefer the idea of mounting the batteries on the front. This gives me the center battery bay for APM, BEC and maybe Remzibi OSD. I will gorilla glue down a piece of 3mm plywood to help reinforce the center or can I use similar thickness balsa to save weight? I hear this is the weak point in the zephyr II according to blacksheep and I don't have their battery box.

Do I need to have a cooling channel for these two center compartments? The ESC will go by itself in the back compartment.

Or can I put the APM to the side of the battery compartment and use the original battery compartment for the batteries. Does the APM need to be near the center?

Do I need to mount the ezUHF receiver out near the wing tip. I'm going to be dealing with 900MHz xBee, 400Mhz UHF, 2 x GPS, 5.8GHz video. I think what is going to have the most bulky cable is the ezUHF depending on how many channels I will use. If I can just use the signal wires and one power connection from the APM to the ezUHF then it wouldn't be so bad but I dread digging too many long distance cable channels in this sleek airfoil :) If I can put the ezUHF with the APM in the standard battery bay then that would make for less cable clutter but I don't want to create any interference problems.

The vTx should be on the wing tip?

What about shielding? Do I need to shield any of the wires or will twisting them and / or use ferrite rings deal with any noise? I know xBees can cause interference.

I've laid out all the equipment and also laid a roll of laminate to get an idea of the weight and it came in at 2.1 kilos which seems lighter than my similarly equipped soon to retire skywalker. It still should be hair raising to launch, especially considering it's my first wing.

I'm not seeing a parameter file for the zephyr. Anyone have some good PIDs for it?

Found some parameters here from İlhan Başçuhadar. Maybe I will start with those.

Where should the center of gravity be so I can make sure the placement doesn't unbalance it.

I'm going to have an experienced pilot do the initial trimming in manual mode but what is the best way to launch them using the APM? Stabilize mode (that is what I use on the skywalker) or FBW A or FBW B or Alt Hold? I launch into a valley so the ground isn't a problem right away :)

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Lots of questions and lots of options.

Launching the ZII in FBW mode works out great (I do not have an airspeed sensor). Apply fullish throttle, full elevator up, and do a Frisbee like toss. It climbs out very controlled.

Parameters, default ones worked great for a start. Minor adjustments so far: reduced cruise speed, increased max climb angle.

CG, As ritewing recommends: CG is located on the bottom 9 3/8'' to 9 1/2'' from the nose back.  Of course that is before you cut off the nose ;)

I put my video transmitter close to the wingtip, the Vee andtenna on the winglet. RC receiver/antenna is in the middle of the other wing. 3DR radio module is on the midsection, close to the APM (did not make a longer cable yet). The GPS is under clear wrap just off the main compartment (so I can see the blue light).

On the first flight I had the ESC inside the back compartment. It melted the foam. Now I strap it on top of the cover and it gets cooled by the airflow.

I would recommend building a plywood box for the main compartment. The nose is a weak spot, especially when you cut the nose for the camera.

Thanks Andreas. I'm installing things today so will post pictures soon.

I'm getting stuck on how to wire up the APM1.4 to the EzUHF Rx.

I'm using a JR9503 and have ch1 going to Throttle pin3 on AP Inputs

ch2 not used

ch3 going to pin1 Roll/Aileron

Do I also need to set switch 4 on the oilcan like it says here? 

And does anyone know how to set the mixing on the JR9503 so I have proper manual mode.

OK I think I might have manual mode working. At least it looks like the flaperons are responding correctly but it's my first wing, so not sure.

I have wingtype set to Flaperon and have

ch1 of ezUHF going to Throttle on AP input 3

ch2 of ezUHF going to Roll Aileron on AP input 1

ch6 of ezUHF going to Pitch Elevator on AP input 2

autopilot I will put on combo gear / flap channel and connect to AP input 8

Do I need to do any special mixing? I know that APM will handle it in stable mode but I want to have manual mode fall back working first and for initial trimming / balancing.

How can I check if I have it right?

It seems so few cables compared to my arducopter so the simplicity is causing me doubts :)

Ferrite rings. Where do I need them before I start laying down the wires.

I'm not using the BEC in the ESC so I will not have any noise coming from that. Do I need one on the castle 10A BEC or is it clean? What about the vTx power line? What about the OSD power line? I don't want to over do it with ferrite rings so need to understand WHERE to put them.

Final doubts!

I think this is the placement I will settle on. I put the vTx on the left. I don't need to go to the tip right? I prefer to run all cables inside the foam so don't want to go long distances if I can avoid it. I hate cables so will avoid all sight of them and tighten up as much as possible.

ezUHF I put on the opposite side. Also ok to not go all the way to the tip?

xBee 900MHz I really can't decide on. I don't want it close to anything because I hear it can be loud in the RF band. Am I being to paranoid? ANYONE see a good placement for it before I grab the xacto knife??? :)

GPS on either side of middle bay and will be visible so I can see any status light. I installed super caps on them to keep GPS for a few days. If I can find room in the main bay is there any reason to keep the two GPS away from APM or other components in main bay? I'd prefer to not go to the trouble of burying them if there is no reason.

The rest that will go in main bay -- AttoPilot voltage sensor, Remzibi OSD, Castle BEC, 550000uf capacitor bank for 5V line will all go with APM in main bay.

I cut my 4s 4000s into the wings, parallel with the line of flight.

Line the front interior edge and floor of the battery bay with ply.

I have survived multiple nasty crashes and I have been very happy with battery placement.

APM1 right where you have it.

I think a nasty crash would rip those batteries right out of the leading edge.

My .02.


I'm glad I saw your message before I cut 8-) Good tip about the batteries. I've seen blacksheep put them their but I guess that was the zephyr I and maybe is ok there. So you put them in line with flight. I think that will be stronger and I will put wood on the bottom of the battery compartments also. I've already put 3mm ply with gorilla glue on the main bay and embedded 3 nylon standoffs to receive the APM which fits perfectly there now. Can you look at this picture and see if I have the batteries right now. I'm thinking to cut them last so I can figure out the COG first. I'm using 3300 but I will try some 4000's also. You think it would lift 2x50004S? With 2x3300-4S I'm at 2.1kg. Now to decide where to put the xBee. 

What would be most sensitive to xBee noise? I also want to get good xBee reception so don't want anything interfering with it also. I'm just not sure what to stay far from and if I need to shield it's cable also. I've heard they are noisy but with my quadcopter I've never noticed a problem. With this I will be going further distance so don't want to mess up my 5.8GHz 600mW vTx. 900Mhz should effect that or is there a harmonic there that can cause trouble?

I taped a tube to the bottom at 9.5" from the nose to see how the COG was going to be. I had to put the batteries this far back to get the COG at 9.5". I wonder why they need to be so far back or is that about where you have your 4S4000s? It's 3" further back than the standard battery bay. I know I'm adding weight to the nose with the gopro and cmoscam and APM, OSD, etc but should they need to go back that far? JC can you post a picture of your setup? I will cut the battery bays last once I have everything else fixed in but wanted to make sure this is about where they will need to go. I will put a ply base to in their compartments also so I can hold down the battery velcro tie.

Tonight I will cut the compartments so if anyone sees something really wrong, this is how it will be.

Still trying to figure out how to get flaperon's working in manual mode. I'm almost ready to cut out the battery bays but am in doubt if this is where they should be. The COG is suppose to be 9 3/8 to 9 1/2 from front nose. I marked that before cutting out the gopro and for it to balance, the batteries need to go here. The only thing not in the equation is the flaps but that shouldn't add much weight. 

As a comparison, I put the batteries on top of the APM where the normally would go and I had to move the COG 1 inch forward for it to balance. 

JohnC did you cut your bays to the side of the original or did you have to move back some in the direction of the motor to get a good COG?

not sure if you need'to bother with flaperons. the zii can be flown quit slow and it stops on a dime when landing.

i'm a bit surprised that you can have the batteries that far back and get the right cg. i had to move all the weight to the very front. my batteries are in the bay and hence 2-3 inches more forward. just be sure to double check everything

I thought I had to set up the transmitter so it could fly in manual mode? I thought that could only be done by using flaperons but should I choose delta? I've never set up a wing before. With my skywalker I just set it up normally but the wing only has to surfaces to control so what does the mixing so I have pitch control? When I move the stock forward both flaps should go down in manual mode but they are not.

Chris at ritewing said the motor was supposed to be mounted so it's nose would have been over the spar so I think that is what shifted the cog. He said just balance at 9 3/8 and put the batteries where they need to be to get that cog.

But I need to find some instructions on setting up the radio so i can fly in manual mode if necessary. Looked everywhere for that but not finding anything for my transmitter.

Your motor mount should have been mounted so its nose would have been over the spar.

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