My first Gremlin build
Hi All,
I'm new here but wanted to share my build.
As I'm from the UK I struggle to get any of the delrin or carbon frames posted.
However, I have a cheap 3D printer (Anet A8) that does a reasonable job.
My initial build was based on the QAV-M frame from thingiverse (
https://www.thingiverse.com/thing:2300936) I did my first LOS flights with this while my FPV camera was in the post. My runcam micro swift took so long to arrive that I got impatient and bought a runcam nano and vtx from a UK store. Only for both the swift and the nano to then turn up on the same day.
This turned out to be a blessing though as I could not find a way of mounting the micro swift in that frame. It was too big in almost every dimension. I therefore printed a quick runcam nano mount and hot glued it to the frame. This served me well for my first fpv flights but I really wanted to use the swift. The swift means I can change the camera setting based on conditions and monitor my battery voltages, etc...
I went back to thingiverse and saw that SPONZ had published the Josh Bixler frame. This meant I could fit the bigger runcam micro swift on the front with the included bracket. 3 hours of printing later and I had the frame assembled and moved my electronics across. Here are some photos in it's current form.
I hot glued some foam to the top and bottom to help with battery mounting. The foam is from an Emax 2204 motor box and works really well. It is taller than the screws so stops the battery from touching. I was worried that when underslung, a hard landing might cause one of the bolts to dig into the battery.
I created these D shaped camera protectors after I landed upside down and snapped the dipole off my Runcam tx25 and lost it. I didn't have a spare so swapped to the Runcam tx200 and added this protection. The two pieces are separate and have a little tab that can be glued down to the arm. I added a small cable tie for extra strength. It's taken a few crashes now and seems to be holding up well.
I've been using a few different batteries:
- Turnigy Bolt LiHV 500mah 2s
- Turnigy nano-tech 300mah 2s
- Turnigy graphene 950mah 2s
My favourite by far is the bolt as it is so light and still punches. The graphene battery needs at least half throttle just to maintain altitude and doesn't provide much longer flight times.
My flight times aren't great at the moment. Without a battery my gremlin comes in at 85grams so not super heavy having read other posts. However, I haven't done any tuning yet. This is my first quad so don't really know where to begin, or what I should be looking for in terms of flight characteristics. If anyone has some suggestions I'm all ears...
I also monitor my battery voltages through the runcams OSD but the sag is horrendous. Sometimes even in the first 30 seconds of flight a small punch will drop the voltage below the threshold yet once landed it recovers to a reasonable voltage. How do other people manage their flight times? Do you use a timer? I've tried a lipo alarm but that typically triggers earlier than necessary as well. I'd be interested in what other people find works best.
Many Thanks