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FoamyDM - Gremlin Build- Please help

FoamyDM

Building Fool-Flying Noob
#1
This Forum has had me VERY excited to get into and build one of these Gremlins.

The Thursday before two weekends ago it came in however, I was finishing prep and cleanup on a DND event for that weekend, and most of this week involved late family and friend nights. so Last night was my first real night to build.

During the week I had printed LB's gremlin frame. and had one night to work on the getting the ESC connected and the power lead attached. Last night I almost finished it up. I love how it's come together so far. The AIO make some of this much easier than the RoboCAT build

I need your help.

After I calibrated the ESCs, I spooled up the motors to find the low throttle point, I found the front right motor (motor 2), wouldn't spool at all, then I saw one of the leads had not been soldered. I soldered and double checked the others on that arm, I thought they looked good. When they spooled up, that motor was twitchy.

So I read that as a short circuit. Is that Correct?

Any advice on this? Should I remove and re-solder that whole arm assemblage? (would that help?)
 

PsyBorg

Wake up! Time to fly!
Mentor
#4
Seems the combination of the Femto and the esc's that come with the kit have some funky tendencies when working with certain protocols. If the esc's are flashed to a XX.0 firmware they are happy with one shots. If they are flashed with XX.5 firmware they are for multishot. If you try Dshot motor 4's signal wire has to go to the ppm pad not motor 4 pad. In some cases it has to go to the led pad and get configured to a different address in CLI.

Start by checking what they are flashed to using Blheli configurator. make sure the esc's are all read and are at the same revision. I was in blheli configurator changing motor direction and decided while I was in there to flash them to latest. That's when I had twitchy motors and lucked out and tried Multi shot while troubleshooting. It was after all that I learned the above information in a post by Airkaos here in another thread.
 

FoamyDM

Building Fool-Flying Noob
#5
@cranialrectosis - Thanks for the Advice, Brake light bulbs (socket too), and check the versions. of everything.

@ PsyBorg - Everything is Stock right now. I changed NOTHING. Thanks for letting me know about the funky-ness. I'll see if one ESC is diferent.

I may not get to this until Sunday as the rest of this week is STUPID busy. But I AM eager to try these and get this flying! :D

until then
-FoamyDM
 

FoamyDM

Building Fool-Flying Noob
#6
This shouldn't have taken this long... but so those who can sympathize, I'm writing down all the BS I go through to get what seems a simple fix done. Maybe you'll get some enjoyment out of it... As I understand this is normal. It never feels that way while doing it.

I had brought my quad into work on Thursday 6/1 to try and trouble shoot (as I have betaflight on the work chrome browser) the compatibility issues PsyBorg spoke of. I wasn't having success connecting when the intern came in and began asking questions.

After asking explaining the problem I was having with the Gremlin build to an our electrical engineering intern who was programming code and had built a working robotic arm. I had him look at the solder joints. He, Ok'd them. He suggested to directly power the motor to see if it's the problem. He suggested I hook the 7.4V 500mAh battery leads to the red and black lead on the motor. If it didn't spin, then a new motor was in order. Good sound trouble shooting logic except for the unbridled current flowing through the tiny motor windings... He assured me it would be fine, and I did it anyway (against my better judgement).

This was the first time I've seen the magic smoke exit a motor housing. :eek:

I'll chalk this up to a lesson learned. Listen to your better judgement, if you don't think it's right, it probably isn't. :black_eyed: As he was wafting the smoke away and apologizing / explaining how stepper motors must work differently. I went and ordered a new motor. almost panicked when these seem to only come in a kit. and I found it on progressiverc.

Thank you Progressive RC for helping me get a motor Pronto!


Last night it the motor arrived. And after getting the kiddos to bed (11pm) I went to work building a 1157 light bulb smoke stopper. Thank you Cranialrectosis Then I hooked up the motor (this is going faster now) calibrated the ESC, Got them all to spin at 1041 throttle and they were all spinning backwards. When was solder the motors up I figured they will either be all perfect or backwards. No biggie. Open BL Heli chrome app and fixed it all. Connected everything up and tested the motors, then the remote.
  • Throttle - check
  • Roll- check
  • Pitch-check
  • Yaw-check
:cool:
Started putting the frame together and found out that my Tx03 AIO camera isn't sending signal my VR-007 goggles seem to understand? (maybe a NTSC/PAL thing) I swapped out the TX03 camera with one I know works. While getting it in the frame, I somehow broke a power lead off a the black gunk on the camera. re-soldered that on. (2pm now). Then I modified the frame to accommodate the antenna tab. Assembled it, checked the motors and video one last, then added propellers. put in two screws each prop.... and forgot to tighten the prop bolts down. hmm. Either way - IT WORKS.
Hoping to maiden at lunch today.

GremlinBuildFoamyDM.JPG
 

PsyBorg

Wake up! Time to fly!
Mentor
#8
Good job on that.. That frame came out better then I thought it would. Should have no problems LOS with that red color either. Best of all that WILL stand out in the grass after you crash and make it much easier to find.

You said that intern had an electronics degree and told you to apply DC to a motor like that? That's elt 101 level stuff and he is an engineer? I would seriously talk to your boss and have his qualifications questioned before he destroys something far more valuable or gets someone killed.

I am on round four with my Gremlins video. I took it all apart last evening and put the receiver in the frame and moved the VTX to the top to get it away from the bird nest of wires all pulsing a magnetic field inside the frame. Hopefully my video signal clears up and it does not record with anything green being rust colored or totally washed out in bright sunshine and looking silver. Batteries are on the charger as we speak.
 

FoamyDM

Building Fool-Flying Noob
#9
Frames

@ French & PsyBorg - Thanks The Frame is linked in my first post here, It was the first one I was excited about.

...You said that intern had an electronics degree and told you to apply DC to a motor like that? That's elt 101 level stuff and he is an engineer? I would seriously talk to your boss and have his qualifications questioned before he destroys something far more valuable or gets someone killed.
he is studying to be a electrical power/utility engineer, he likes computers and can write code. playing with electronics w/motors is new and I think he didn't understand the diff. in motor types. his main run-in has been the stepper motors for his school project and the fans in his computers. I give him a small pass on this. He's smart and picks things up quick and a willingly hard worker... I'll take it.

I am on round four with my Gremlins video. I took it all apart last evening and put the receiver in the frame and moved the VTX to the top to get it away from the bird nest of wires all pulsing a magnetic field inside the frame. Hopefully my video signal clears up and it does not record with anything green being rust colored or totally washed out in bright sunshine and looking silver. Batteries are on the charger as we speak.
.

I'm excited to maiden - I got too hungry and opted to eat at lunch which was more involved. The Weather lately as been like Florida in the afternoon, Each individual cloud holds it's own bucket of water to dump. Should be OK this evening though.

Thanks for the help and the encouragement!
 
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FoamyDM

Building Fool-Flying Noob
#11
Thank you for the Share PsyBorg. I looks a lot like the flying I did, without the flips. (I tried at the end of the maiden, and in the wrong mode that is a crash. :) )
Here's the Maiden:


and flight 2:


When we left to do them I mis-poke and said we were going to the park...My sons insisted I make good on it.
So we when to the Softball park during softball season just after dinner. Fortunately the back half cleared out after a while and I was able to do the maiden. I just didn't want a bunch of young-uns running under it while my new-piloting self was unable to control an untested craft.

I'm pleased. It went well. While my boys played a gave a neighbor kid a "ride" with the goggles as I managed fairly smooth level coordinated turns and figure eights. I'm really excited!

-FoamyDM
 

FoamyDM

Building Fool-Flying Noob
#12
Can anyone help me understand what three motor twitches and a beep mean" (Escs with BL heli 16.6 flashed.) Where do I go for all the coding for the escs?

I flew this last time in rate mode. That was a LOT of fun. I had a very successful flight at the local park and it had a weird ending. One of the Screws holding the motor on (I used only two short screws each motor) got dislodged, and the motor was running fine by listing... I brought it home, switched out the screws for the long ones, made sure the screws weren't touching windings, and tested it out. it was twitching... ug. I had the problem described above. any ideas?

I've spent the end of last week and some of a kid birthday filled weekend, trying to fix this fail.

I swear this is like trying to trouble-shoot my power mac in college. :confused:
 

FoamyDM

Building Fool-Flying Noob
#13
Lastly, while goofing around trying to re-solder, I started back in without de-powering from a test hookup and I think I fried the board. :black_eyed:

I should have had FT just build the dang thing for me. I would've been flying instead of trouble shooting. I guess I wouldn't be learning though. ;)

I'm taking stock: So far I a Fried motor, and board because of twitchy crud/ bad Solder? I'm now at 150% +100% budget to get it/them to work. I have a new board on the way and a complete kit. If I get this right, I'll have two Gremlins. The second will be built on a different frame. If this doesn't get the first working I'm cannibalizing it for micro plane parts. :D or some Micro Sea Duck, or my dragonfly scratch build or something.

Hmm Micro Sea Duck.... 15"-ish wing span? Foam Formers + spar, 2.5g escs, paper/plastic skin. I'll tuck that under my hat for now.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#14
You've probably seen this before, but if you are tired of frying your kit, use a smokestopper EVERY time you connect a lipo after touching your electronics with a soldering iron. Take it from me, I blew up 8 (yes 8) brand new 12A KISS ESCs and two motors when KISS first came out.

It was heartbreaking and expensive. Since that month in 2014 I have NEVER blown another ESC or motor due to a short or bad solder or bad ESC or whatever. I have received bad ESCs in the mail but if they aren't blown and don't work you can usually send them back.
 
#15
You've probably seen this before, but if you are tired of frying your kit, use a smokestopper EVERY time you connect a lipo after touching your electronics with a soldering iron. Take it from me, I blew up 8 (yes 8) brand new 12A KISS ESCs and two motors when KISS first came out.

It was heartbreaking and expensive. Since that month in 2014 I have NEVER blown another ESC or motor due to a short or bad solder or bad ESC or whatever. I have received bad ESCs in the mail but if they aren't blown and don't work you can usually send them back.
That is a really neat idea, Never thought about that. I think that is something worth putting in your flight kit! Not only will it give you practice soldering its actually useful!
 

PsyBorg

Wake up! Time to fly!
Mentor
#16
OMG just saw the maiden video... "Dude!!! I'm Filming!!" Classically awesome!! Gratz on a good first flight. That printed frame really sticks out well and should be great for LOS.

Smoke stopper GOOOOOOODDDDDD!!!! BEST most valued tool in your kit if you are doing any type of electronics work.

Sadly in our hobby replacing things is a constant. If you are not replacing damage you are replacing worn parts specially in the motor / esc departments as with quads we are constantly hammering both. THEN add in UPGRADES !!!. yup forever fiddling.. It truly is an addiction.

I think you have gone the right way though as you have a head start on the skills needed to be effective in the hobby. The only thing having someone else build your quad would have gotten you is maybe some additional flight time. You would still have to do the set up for your radio gear and then there is tuning to YOUR style of flying. At least now you have the build knowledge to put to use in the repair aspect.

Don't worry about some of the beginner mistakes you have made we ALL have done some or all of them ourselves at some point.
 

FoamyDM

Building Fool-Flying Noob
#17
That smoke stopper has already paid for itself.

I have the aikons 20A for the RoboCAT build that would have smoked I bet without them. Still two twitchy motors there. I'm gonna look to see if it's ESC protocol/cleanflight protocol settings... I just don't get it. Honestly tempted to take the motors and ESC off the FC and connect them up like they were a plane and see how they work... I always thought if the Quad didn't work, I've got 4 f-pack plane motors. Some nights I can barely look at this stuff anymore, it's just sad. I hope I can turn that around soon though :)

Thanks for the Encouragement PsyBorg. Some days I need it. :black_eyed: I picked up the banggood V-tail 210 (whose arms will break) and can't connect that to Cleanflight to change the receiver mode to SBUS to even try and break it. Man, I can't catch a break. I suppose if I did, I just see it as, "that's the way it oughta be."

I'm such an a$$ sometimes. :D

I have bright blue filament I want to print a second gremlin frame with...Maybe V-tail smurf or maybe a RoboMouse?!? Or a Trash Panda :p

-Matt
 

FoamyDM

Building Fool-Flying Noob
#18
That smoke stopper has already paid for itself.

I have the aikons 20A for the RoboCAT build that would have smoked I bet without them. Still two twitchy motors there. I'm gonna look to see if it's ESC protocol/cleanflight protocol settings... I just don't get it. Honestly tempted to take the motors and ESC off the FC and connect them up like they were a plane and see how they work... I always thought if the Quad didn't work, I've got 4 f-pack plane motors. Some nights I can barely look at this stuff anymore, it's just sad. I hope I can turn that around soon though :)

Thanks for the Encouragement PsyBorg. Some days I need it. :black_eyed: I picked up the banggood V-tail 210 (whose arms will break) and can't connect that to Cleanflight to change the receiver mode to SBUS to even try and break it. Man, I can't catch a break. I suppose if I did, I just see it as, "that's the way it oughta be."

I'm such an a$$ sometimes. :D

I have bright blue filament I want to print a second gremlin frame with...Maybe V-tail smurf or maybe a RoboMouse?!? Or a Trash Panda :p

-Matt
 

PsyBorg

Wake up! Time to fly!
Mentor
#19
Welcome to the club mate. When things go good they go REALLY good.. when they don't they hurt like heck and WILL drive you batty. I am in frustration mode myself with the Video section on my Gremlin. Three cameras. two VTX. and now my eleventh antenna I believe and I STILL can't go thirty feet without signal loss. I moved my receiver antenna last night to a horizontal plane out of the path of the VTX antenna to see what that gets me.

Sadly Bills Law WILL dictate that I get perfect video signals and exchange that for fail safes at thirty feet.. At least that is my prediction for todays test as soon as my battery gets done charging..