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Jtrjr

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I have been flying my new X-Ray build sucessfully for a few weeks now. I really love this bird and it flies beautifully. When I was building it I was forced to use a somewhat cheap Eachine VTX because my Tramp HV's have been on backorder for months. I finally got my hands on a Tramp HV and decided to swap out the Eachine for the Tramp.

I went to fly it yesterday and noticed a lot of video noise with the Tramp. The only difference on the install was that I put the new SMA pigtail connector on a pre-drilled hole in the CF frame. I pulled the Tramp VTX from the bird and plugged it in outside the frame and the video noise was gone.

Doing a resistance test with my DMM revealed a slight short between the CF frame and the negative battery lead. I tried to do an extremely clean soldering job on my BetaFlight F3 AIO flight controller and I mounted it to the frame using nylon standoffs so I was pretty sure it wasn't a short on the FC. I also heat-shrinked the ESC's and put some double stick mounting tape under each one.

Doing further research on RCG it was mentioned that my motor screws could be shorting on the motor windings. I didn't believe this was the case because I thought I had been very careful on selecting the right screws. I decided to pull the screws anyway and with them removed the short was gone. I replaced the screws with some slightly shorter screws, no more short and the video noise is gone.

I don't know why the noise didn't show on the Eachine VTX and I only discovered this underlying issue because I swapped the VTX. So as part of any future building process I will always do a resistance test between the CF frame and the negative battery lead. I hope this helps some other new builders out there.

Jerry
 

Danny Z

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I guess it depends if your PDB is insulated from your frame (at least the "negative" side of the PDB.

I can only speak to the KISS PDB, because it's underside (which is negative) is in direct contact with my CF arms, so if a short developed anywhere in the system that would allow a "positive" connection to the CF, then yes, you would create a "short circuit" condition, it sounds like you got lucky, and had what we call a "high resistance" short, that only affected your VTX, once the resistance of the "short" gets to a point of enough current flow...................POOF !!!!.......all the magic smoke that makes you quad fly......... is gone !!................and gravity takes over.........

The outer casing of the SMA, the part that you touch with your hands is the negative side, so it is ok for that to touch the CF.......UNLESS, as you found out with your motor screw being a tad too long, allowed enough current to flow to jam the VTX signal.

Good catch Jerry.........................

Danny Z
 
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theGreenOrange

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Jerry,

Not sure It is related at all, but it seems the TrampHV is a bit picky when it comes to supply voltage. They recommend running it straight off unfiltered lipo voltage but list compatibility as something like 5V-16V. When I read that I thought, what the heck are they talking about, I am running it off my fancy 5V BEC. Well, it would not even turn on, even though I tested the 5V supply and it was 5V. Long story short, you may want to run it off of unfiltered lipo voltage like they say on the manual.
 
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Jtrjr

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Green,

Yeah, I'm running it off the Lipo. Once I isolated everything all was good. Hoping to fly it again tomorrow.

Jerry
 

Reaper71

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Hey Guy's, Im starting my first build.
I am using Lumenier LUX V2 fc and 4 in 1 20A esc
I have the motor wires ran to the esc, power to the board (bat) The part that is confusing to me is the + and - wires for the esc where am I supposed to solder this to?
I still need to wire up the signal wires,camera vtx etc. (also using the Tramp)
any help would be great!
Thank's
Mark
 

Jtrjr

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Mark,

Wish I could help but I'm not familiar enough with those components. Good luck!

Jerry
 

theGreenOrange

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Hey Guy's, Im starting my first build.
I am using Lumenier LUX V2 fc and 4 in 1 20A esc
I have the motor wires ran to the esc, power to the board (bat) The part that is confusing to me is the + and - wires for the esc where am I supposed to solder this to?
I still need to wire up the signal wires,camera vtx etc. (also using the Tramp)
any help would be great!
Thank's
Mark
For the 4-in-1, you need:
2 large power wires
4 ESC signal wires
1 ESC signal ground (maybe? I did this on mine but may not be needed)

The other small + (red) wire is not needed unless you want to power your FC from the ESC.
 
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theGreenOrange

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When you wire them up, make sure the FC signal pad 1 goes to the back right motor (ESC signal 4?) and FC pad 2 goes to the front right (ESC signal 3?) and so on.

Alternatively, you could wire it up FC signal pad 1 to ESC signal 1, and hope there is a layout that matches in betaflight. I have never tried it, but I know there are several other layouts and there probably is one in there that would match up.
 
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Jtrjr

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Raymon,

I was getting 'video noise' like this:


It seems to be totally related to the SMA connector going through the hole in the backplate you made on the frame (the little CF plate with the two holes in it). Whenever I remove the SMA from the hole it goes away and my meter shows no resistance. When I put it in the hole and put the nut on the SMA I get the noise and resistance on the entire frame. I have now heat shrinked the SMA and put a few o-rings on the SMA before I put on the nut and it appears to be gone. I'm going to try to fly with it in a few hours.

I also had a really tough time fitting everything into the frame. I'm using the BFF3 on nylon standoffs, a FrSky XSR, the HS177 and the Tramp HV and it's super tight. The tramp HV really screws things up because of the pigtail. Maybe you could post some pics of how you have everything put in your frame.

Jerry
 

Reaper71

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Thank's for the help guys
I was able to get most of it all wired up, motors,esc's and flight controller. Now I'm having some fitment issues with the remaining components, so going over my options.
I didn't see all these posts till just now! I did however speak to Doug @ xframes fpv and he helped guide mr through the issues I was having.
That being said I am having a blast building my first drone I will get some pics up as I start to finish it up

Mark
 
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