So if i got this right the firmware on this one is older than 3.1.6? You can type "version" in CLI to find out what it is btw.

Did you calibrate the escs correctly? Motors not spinning after arming sounds weird, but then again, blheli default min_throttle is 1140 in which case it would be normal...

About dshot not working, maybe the escs need updating too?

PS: a hint for 3.1.7 if you flash that, i think dterm transition default was changed to 1.0 iirc, that might be a bit rough in case things are noisy so maybe keep an eye on that.

I've been studying that frame some more, and a bottom-mounted battery is gonna be tough.  Those two screws holding the legs at the centerline are the main sticking point for me (and potentially "sticking points" for the battery).  Might be best to just stay with the top mount design.

Now having said that - IF I really wanted to do it (and I do prefer my batteries on the bottom), here is the only way I could see it working for that frame (for me).  I would buy an extra bottom plate, and drill out the two centerline holes so that those two screw heads would be recessed within those holes (so as not to protude into the new bottom surface). I'd connect the second plate with the remaining 4 screws (maybe need to be longer), mark and cut away the excess carbon fiber, and then put a non-slip rubber strip on the bottom the size of the battery.  I'd then run the strap between the two bottom plates.  Now all of that will add even more grams below ideal CG, so it may not be worth it - but I think that's what I'd do if I was really set on a bottom-mounted battery.

(Note: I also don't know how those "nut inserts" work, but that might cause additional headaches.)  Anxious to know what you decide - good luck!

(17-Jul-2017, 11:37 PM)fftunes Wrote: So if i got this right the firmware on this one is older than 3.1.6? You can type "version" in CLI to find out what it is btw.
Did you calibrate the escs correctly?...
About dshot not working...
PS: a hint for 3.1.7 if you flash that...

I believe it is. I saw a number outside of CLI but I don't remember what it was because I categorized it in my brain as "less than 3.1.6". I'll check when I get it plugged back back home. 

No calibration on the ESCs so far. When looking up how to calibrate with multishot I ran into a blue falcon video that suggested that it was more about settings than calibration. If I cant get DShot working then I'll go back through that video again and make sure I follow all instructions. If multishot still requires calibration I'll give that a go as well. 

I'll be checking firmware on everything next go of troubleshooting. Crossing my fingers that use of DShot is legit (I know unseen and Ikkuh say its possible but until I see it working it's just a myth in my world with my particular setup, no offense guys.)

As for tune... Once it starts to behave like my other 3 quads on the ground I'll start focusing on tune. I have general settings that I work towards and then tweak for the specific quad, and now with your help set point and transition are part of that equation. 

(18-Jul-2017, 01:48 AM)sloscotty Wrote: I've been studying that frame some more, and a bottom-mounted battery is gonna be tough....

(Note: I also don't know how those "nut inserts" work, but that might cause additional headaches.)  Anxious to know what you decide - good luck!

I really appreciate that feedback Scotty and the help with that particular issue. For now I am not giving up on that one. The martian 3 came with a bottom plate that mounted under the flight stack with some small standoffs. I am thinking about doing similar with what you sent me before. The standoffs would be enough to keep the plate from bumping into the arms. 

As for the nuts. While I have convinced myself to redo the stack (ugh that's not going to be fun, probably have to take everything a part depending on the length of the wires, which may have a touch of slack) those nuts are mostly bad just because they add weight. I had time to think about it and the only thing that they would do differently from typical standoffs is act like metal ones rather than nylon or rubber. On the VTX this is probably not too mch of a problem. The FC however has it's own rubber grommets for soft mount so I am hoping that my assumption about noise is wrong and that it's just related to the other motor communication issues that I am having. I recorded blackbox but didn't look at it yet. 

I am planning to replace the long screws with rubber standoffs that I bought for the previous build. hopefully they'll make things cleaner, and hopefully I can get everything back together if I do that. I'll be measuring first.

Here is a diagram of the current stack mounting. I sort of jerry rigged it and I know it, but everything seemed logical to me. (note diagram doesn't point out rubber grommets on FC)

What's the purpose of the nuts on top of the nylon spacers? One thing that I did that you could try is get some of these.

https://www.readymaderc.com/store/index....ts_id=6306

Get shorter bolts, put the bobbins on top of vtx, maybe a bit underneath depending on how long your bolt is. Then flight controller with nylon nut on top. Then you get a soft mount for flight controller.

(20-Jul-2017, 11:52 PM)Phoenix132 Wrote: What's the purpose of the nuts on top of the nylon spacers? One thing that I did that you could try is get some of these.

https://www.readymaderc.com/store/index....ts_id=6306

Get shorter bolts, put the bobbins on top of vtx, maybe a bit underneath depending on how long your bolt is. Then flight controller with nylon nut on top. Then you get a soft mount for flight controller.

half-space. They're really not needed. 

I have various size bolts. I can probably pick and choose as needed. I also already have some of the rubber ones like the ones you're showing. That is what I am going to do with the revised setup.

Ah I see. I like how the vtx is stackable that's cool. Does it still allow you to switch channels when it's at the bottom of the stack?

(21-Jul-2017, 07:20 PM)Phoenix132 Wrote: Ah I see. I like how the vtx is stackable that's cool. Does it still allow you to switch channels when it's at the bottom of the stack?

yes, and let me tell you... This VTx is well designed and does a great job so far. The fact that it can be part of the stack is great, the buttons and little channel display are on an extended little shelf at the back so it's actually easier to access than any of my other quads. The OSD works well so far (when I don't forget to plug it back into the UART port) and in general I am happy with it even if the price is a bit much ($40usd). 

The only thing that could make a VTx like this better is if it came as part of a package interacting with the stuff that the runcam split is currently doing. For example, rather than the stackable module for recording action cam footage, it should be a combo that does that and has VTx hardware all in one. That would make for an impressive FPV setup. (note: if the FPV equipment manufacturers haven't already been thinking about and working on this PLEASE steal the idea... all I ask is that you make it really well known when it comes out so I know to get one).

Update: BF version was 3.0.1

I flashed the FC to 3.1.7 (this will be my first quad running this version... we shall see how things go!)

After the flash I am able to set up DShot 600 so I am now happy again about protocol. Also it arms and disarms correctly and motors spin up the way that they are supposed to. I still don't have a proper way to mount battery and the gopro and I haven't re-done my flight stack yet. I'll run some blackbox logs this weekend to see how noisy it is or isnt to decide how far I want to go with that part.

Otherwise though I am feeling better about the build. I hope to get it in the air again tomorrow if possible. Proper pictures coming soon. Maiden flight didn't get caught on video but I'll upload some DVR footage later after I get it back in the air.

It's flown through a second battery now and it did much better! I'd upload footage but I kept all the gear in the car except batteries because I am going flying again in the morning.

It's going to be tough for me to remember to turn on air mode... but I think I can do it. Also enabling anti gravity on this one just because... we'll see how that works out.

Roll on the morning..!

So after troubleshooting that I pretty much need to leave airmode on as a default rather than the other way around I am pretty much ready to call this build complete. I will be doing some other modifications like figuring out how to get the battery under it but for now it's flyable and I am going to try to get a feel for it's characteristics.

I've updated the OP with final photos and a flight video:
http://intofpv.com/t-225-ghost-pirat?pid=24522#pid24522

Here is the video:


As for my opinions on the elements
What I am happy with:

• The VTx is great. I like the way the OSD on it works and the picture is a little clearer than my other builds. Some of that may be because of the PDB that is build in with the FC
  
• The FC has a few good elements to it. The first being that I don't seem to have a lot of video noise so I have to assume that it has a built in LC filter. This is pretty common on the diatone PDBs so I figure they must have build it in on this as well. Either that or I am just lucky. The connections to the UARTs and Receiver are a big plus for me as they have JST connectors rather than direct solder, and little connectors that are like JSTs but have little release tabs (I don't know what these are called but the extra reinforcement is great. 
  
• The motors have lots of oomph! it's apparent that this one is faster than the bumblebee so far. I haven't put cyclones on it to compare with same-props yet but there is definitely a "oh crap slow down" feel to the quad
  
• The frame looks good... unfortunately (sorry guys at pirat) it's the only plus I have on the frame
  

What I am not happy with:

• Speaking of the frame... unfortunately I have multiple issues with the frame. It didn't come with some of the hardware that I expected like standoffs for the flight stack. also with only an overslung option to mount the battery and limited options to mount anything below it impeded my ability to build the quad the way that I wanted. While the standoffs are relatively shorter than my other quad the center of gravity is a bit awkward with the battery weight being so high. The compactness is probably half pro half con. The flight stack comes right to the sides of the frame and as a result there isn't really a clean un-kinked way to route the ESC wires on the inside, at least in the front. One other thing that would have been great to have built in that I modified on mine is to have a hole on the top for the VTX antenna. I just widened one of the triangle holes on top to make space. 
  
• The FC ticked me off in a couple of ways. First being that the firmware was so incredibly out of date. I understand that it may be old stock but wow did that throw me off to be on 3.0.1. Luckily I realized it eventually and was able to easily fix it. I don't remember if this one came with a warning about updating firmware but I remember the ARF crusader coming with warnings about warranties being voided or something. They should put clear instructions as to which firmware to update and which version to update to. Preferably a place on the website to go in order to get the latest and greatest info on the topic. 
  

My overall opinion of my second build:
My guess is that this will end up being my 3rd favorite quad out of 4 unfortunately unless I can get the battery underneath. I've learned a ton from building it and someday may put all the components into a Martian 3 frame so that it's characteristics better suit my flying. I feel bad for saying so much negative about the frame because I am happy to have seen a product creator come share with us on the forum but when it all comes down to it almost all of the problems that I've had with this thing that weren't user error are because of the frame :\

A final suggestion on the bottom-mount battery (then I'll quit pestering you)..

You could get a couple of ultra low-head cap screws for the centerline screws on the bottom of the arms, like this:


https://us.misumi-ec.com/vona2/detail/110302280540/

Raise your stack by a couple of millimeters to be able to thread a strap through. Then cut a piece of 4mm foam to glue on the bottom plate between the arms (to bring it level with the arms), slap on a rubberized strip to cover the foam and screw heads.  Looks like you've got enough room to do all that.  OK, I'll quit now.

(31-Jul-2017, 02:34 PM)sloscotty Wrote: A final suggestion on the bottom-mount battery (then I'll quit pestering you)..

You could get a couple of ultra low-head cap screws for the centerline screws on the bottom of the arms, like this:

https://us.misumi-ec.com/vona2/detail/110302280540/

Raise your stack by a couple of millimeters to be able to thread a strap through. Then cut a piece of 4mm foam to glue on the bottom plate between the arms (to bring it level with the arms), slap on a rubberized strip to cover the foam and screw heads.  Looks like you've got enough room to do all that.  OK, I'll quit now.

lol... I think you've now given me like 5 different ways to do it!

I might try something more along this last one but I am not sure. There is part of me that says if I have to redo the flight stack that maybe I should consider putting everything in a new frame :\ so that's 6 ways to do it.