This looks nice! Is there a public file for this print? Also, where did you get the led combo?
Flitetest DIY Gremlins
- Thread starter CrashRecovery
- Start date
This looks nice! Is there a public file for this print? Also, where did you get the led combo?
Eldowr
Super Nub
Apologies upfront if this is the wrong place to ask this!
For a first 'real' quad, Line of Site to start with, FPV later; Would an FT Gremlin be a good start? I played around with a hubsan x4 back in 2012, but never could get it to behave. Recently got a Taranis QX7 for fixed wing, and want to try getting into drones as well since a chunk of the cost is already sunk.
Thanks!
For a first 'real' quad, Line of Site to start with, FPV later; Would an FT Gremlin be a good start? I played around with a hubsan x4 back in 2012, but never could get it to behave. Recently got a Taranis QX7 for fixed wing, and want to try getting into drones as well since a chunk of the cost is already sunk.
Thanks!
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
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
PsyBorg
Wake up! Time to fly!
Tuning will help your flight times but I suspect something else is going on if you are not getting good flight times at 85g. I have flown mine at 187 g when I first built it for over 6 minutes on a 3s 800 mah pack off an old 200 size heli I had. I will take a guess and say your camera / vtx run off a range of voltages like 5 - 17v and you are wired directly to the battery to power them. If that is the case run them from the 5v regulator on the Femto FC to lower power consumption. Next do not run a vtx over 50 - MAYBE 100 mw that will suck the life out of a battery quick and there will be a lot of sag while that video system is taking that much juice.
Depending on your radio gear you could do like I do and use the throttle percent timer. This works out great as it goes by how much throttle you use so its not always a 1 to 1 ratio of time. Lower throttle say at mid stick will only tick off once every two seconds instead of one second. but when you go full throttle it runs at One to onw. I run 2s and 3s, 450 mah, 45c batteries on mine now and set my timers to ~1:20 and I get like 6 - 8 minutes cruising time or 4-5 minutes faster flying times. My batteries come off and by the time I get back to my charger they start anywhere from 3.5 v per cell to 3.8 v depending how precise I am with the timer and landing.
This is one of my first full pack flights after the maiden at 187g.
Depending on your radio gear you could do like I do and use the throttle percent timer. This works out great as it goes by how much throttle you use so its not always a 1 to 1 ratio of time. Lower throttle say at mid stick will only tick off once every two seconds instead of one second. but when you go full throttle it runs at One to onw. I run 2s and 3s, 450 mah, 45c batteries on mine now and set my timers to ~1:20 and I get like 6 - 8 minutes cruising time or 4-5 minutes faster flying times. My batteries come off and by the time I get back to my charger they start anywhere from 3.5 v per cell to 3.8 v depending how precise I am with the timer and landing.
This is one of my first full pack flights after the maiden at 187g.
Well, after some time away dealing with other projects I'm ready to finally replace my bent motor and rebuild my 3D printed gremlin style quad.
I've kind of put it off because while the PLA frame worked and I never managed to break an arm (though did break the FC mounts several times leading to vibrations that definitely affected flight performance) I really wanted to print this in Nylon. But never got consistent results with Nylon on my printer.
I spent most of the month installing a new Titan extruder my wife got me for Christmas. So of course as soon as it was installed I had to try Nylon as the main reason I wanted the new extruder was my expectation that it would solve my Nylon issues.
And it did! Nylon is now printing wonderfully! It must have been underextruding worse than I realized before too because everything I've printed in Nylon has come out way nicer and stronger than it was before. But Nylon is also lighter than PLA (as well as WAY stronger) so the same frame printed in Nylon at 50% infill is actually 1g lighter than when printed in PLA.
PLA is still stiffer...but at 50% infill the frame is very stiff. It's also crazy strong. The first one I printed I accidentally picked an old revision so tried to do some destructive testing on it. I could (with a lot of effort) bend it until two arms touched - and it snapped back almost perfect. In fact I've yet to manage to break it at all despite a good bit of torture testing. It's a little deformed now and not very flat anymore...but still in once piece.
And Nylon takes dye like a dream as I demonstrated earlier. So let me wife and daughter pick the colors:
The undyed part on the right is for my singlecopter (which I'm currently reprinting in all nylon to save weight and increase strength) just for comparison.
Taulman who makes the Nylon suggests using RIT fabric dye...but at high temps with several hour long soaks...and the colors still aren't that vibrant. This is using my analine egg dyes. The purple frame got about an hour and a half in the dye and the pink camera mount got about half an hour. All at room temperature so no risk of warping or swelling or other issues high heat and long soaks risk!
Hopefully tonight I'll have time to fire up the soldering iron and move my parts over.....
Now to finish that prop guard design I've been putting off for about 9 months
I've kind of put it off because while the PLA frame worked and I never managed to break an arm (though did break the FC mounts several times leading to vibrations that definitely affected flight performance) I really wanted to print this in Nylon. But never got consistent results with Nylon on my printer.
I spent most of the month installing a new Titan extruder my wife got me for Christmas. So of course as soon as it was installed I had to try Nylon as the main reason I wanted the new extruder was my expectation that it would solve my Nylon issues.
And it did! Nylon is now printing wonderfully! It must have been underextruding worse than I realized before too because everything I've printed in Nylon has come out way nicer and stronger than it was before. But Nylon is also lighter than PLA (as well as WAY stronger) so the same frame printed in Nylon at 50% infill is actually 1g lighter than when printed in PLA.
PLA is still stiffer...but at 50% infill the frame is very stiff. It's also crazy strong. The first one I printed I accidentally picked an old revision so tried to do some destructive testing on it. I could (with a lot of effort) bend it until two arms touched - and it snapped back almost perfect. In fact I've yet to manage to break it at all despite a good bit of torture testing. It's a little deformed now and not very flat anymore...but still in once piece.
And Nylon takes dye like a dream as I demonstrated earlier. So let me wife and daughter pick the colors:
The undyed part on the right is for my singlecopter (which I'm currently reprinting in all nylon to save weight and increase strength) just for comparison.
Taulman who makes the Nylon suggests using RIT fabric dye...but at high temps with several hour long soaks...and the colors still aren't that vibrant. This is using my analine egg dyes. The purple frame got about an hour and a half in the dye and the pink camera mount got about half an hour. All at room temperature so no risk of warping or swelling or other issues high heat and long soaks risk!
Hopefully tonight I'll have time to fire up the soldering iron and move my parts over.....
Now to finish that prop guard design I've been putting off for about 9 months
Psyborg and Flying Monkey mentioned the Emax Magnum Mini F3 and I can confirm that it works very well with the Emax 1104 motors. I just finished this build using that setup with an AirBlade Éclair 2.5" frame. The props are the King Kong 2345, which seem to run much smoother than the Emax ones. The motors and Magnum F3 stack are soft mounted using silicone soft mounts:
-Dustin
Hey guys I thought I would share one of my first Gremlin FPV flights. I recorded it from my phones receiver so the quality isn't the best.
https://puu.sh/zd5d7/83674a5b1b.mp4
The Gremlin is the first chance I've gotten to fly and do FPV outside and it's been a blast. It's my second quad in this hobby after my Inductrix and it was the perfect step up. It's fast, easy to fly, and best of all tough. Thanks so much for all the help from the forum and I hope you all enjoy my video!
https://puu.sh/zd5d7/83674a5b1b.mp4
The Gremlin is the first chance I've gotten to fly and do FPV outside and it's been a blast. It's my second quad in this hobby after my Inductrix and it was the perfect step up. It's fast, easy to fly, and best of all tough. Thanks so much for all the help from the forum and I hope you all enjoy my video!
Finally found a bit of time this weekend to get the Nylon frame up and going:
The nylon proved to be plenty stiff! I'm not as happy with the 1.9" HQ tri blades though. I ordered them the day they became available because they were supposed to be the hot new ticket for this size of build. But my tune results show them not giving any better performance than the 60mm super cheap 2 blade props from banggood that I had been running. The tri's do sound nicer, but they just didn't give the expected performance boost and it seemed like the motors were running hotter (hard to say for sure since there isn't much exposed motor to feel - but the screws for the motors felt warm and usually they don't.)
One other nice thing with this new frame leveling modes work well again. So it probably was the broken FC mounts and/or vibrations on the PLA frame that were causing those issues.
I only had time to run a quick pack through it but it felt great to have it back in the air and flying smoother than ever. I have a few other prop options I've been meaning to try so now that the leveling issues are sorted I can run them through the autotune and get some data on them to decide which props I want to stick with long term...though some of what I have are now discontinued so I hope they don't prove to be the best option
The nylon proved to be plenty stiff! I'm not as happy with the 1.9" HQ tri blades though. I ordered them the day they became available because they were supposed to be the hot new ticket for this size of build. But my tune results show them not giving any better performance than the 60mm super cheap 2 blade props from banggood that I had been running. The tri's do sound nicer, but they just didn't give the expected performance boost and it seemed like the motors were running hotter (hard to say for sure since there isn't much exposed motor to feel - but the screws for the motors felt warm and usually they don't.)
One other nice thing with this new frame leveling modes work well again. So it probably was the broken FC mounts and/or vibrations on the PLA frame that were causing those issues.
I only had time to run a quick pack through it but it felt great to have it back in the air and flying smoother than ever. I have a few other prop options I've been meaning to try so now that the leveling issues are sorted I can run them through the autotune and get some data on them to decide which props I want to stick with long term...though some of what I have are now discontinued so I hope they don't prove to be the best option
Like butter Stefan
The Nylon frame does a great job of damping high frequency vibrations but still stiff enough to keep it locked in. I only had time for one pack and my rates were still a little lower than I'd have liked - but it was feeling great. And the tune results back that up with a tau in line with what I saw before. But I suspect with the props I was running before it will improve a bit more since they're lighter and can respond quicker than these HQ's.
They nylon is also practically indestructible:
It took quite a bit of effort to bend it this much:
After releasing:
And after re-bending in the opposite direction a little bit:
I've yet to break that test frame despite doing quite a few torture tests to it with vises, hammers, tossing it at things....
The Nylon is also printed at higher infill than the PLA version was but still weighs less while still being just as stiff. The PLA version would snap long before it bends this much though!
Printing with Nylon is tricky. You need a really good extruder and an all metal hot end that can handle higher temps than normal...plus the Nylon itself is expensive (Like $45 for a 1lb spool or almost $80 for a "normal" 1KG spool) and it's WAY more sensitive to humidity than other filament so it has to be stored in a dehumidifier.
But...I'm so glad I got my printer setup to print with it. Crazy strong, can be dyed any color, and it's lighter. Other than being a serious pain to learn how to use and expensive it's a dream material.
SmokeshowFPV
Member
So I have been flying my Alex frame a ton lately as it seems every time I fly my 5" I break all of it lol. I decided to throw one of my 3S packs that I usually use for my FT Mighty Mini planes on the grem and see how she handled it. Holy crap its like a whole other animal! Lots of jello with these 2345 props, but my Avan 2327 props will be here today and I can't wait to see if that takes care of that. Here is a little DVR footage from yesterday. FYI skip about a min forward when you see the battery get ejected lol, I don't have any video editing software so I have no way to cut out the crashes
One thing I did notice, prop wash or something is much more apparent on 3S. I have never tuned a quad so I am unsure how to get rid of oscillations on tight turns and stuff. You may not be able to hear it in the video (VTX only transmits video) but the motors had an audible.. not really sure how to put this.. chirping or fluttering on tight turns and when flying into my wash. Any info on how I might smooth that out? I am running BF 3.2 with all stock PID and filter settings. I don't really want to upgrade to 3.3 as it flies darn good as it is.
One thing I did notice, prop wash or something is much more apparent on 3S. I have never tuned a quad so I am unsure how to get rid of oscillations on tight turns and stuff. You may not be able to hear it in the video (VTX only transmits video) but the motors had an audible.. not really sure how to put this.. chirping or fluttering on tight turns and when flying into my wash. Any info on how I might smooth that out? I am running BF 3.2 with all stock PID and filter settings. I don't really want to upgrade to 3.3 as it flies darn good as it is.
PsyBorg
Wake up! Time to fly!
I would adjust rates a bit first calm them down a bit. I run mine in the 800 degree per second range. Then I would start by raising P gains for roll 5 points at a time and see what changes that makes. Keep an eye on motor temps as you can fry them easily on stock pids with 3s. Each change fly for 15 -20 seconds and land. Feel the motors. If they are not hot them fly a bit more to see what the changes did. I do not advise you to cookie cutter my pids as I do not have a stock Gremlin. You do not either with them fences around your motors so yours will be a unique tune as well. Just keep an eye on temps and don't feel bad about making changes. What I do is leave profile one as my current best tune. Then I use profiles two and three to make small changes to one thing . on is higher change one is lower change. Then outside in the field it is easy to swap profiles to A/B/c them against each other to see what is best with out a lengthy re-connection to a computer where you lose the feel for the changes. When on the ground and disarmed you can use stick commands to change profiles quickly, rearm and pop right back up in the air. Just watch the blinky lights to see what profile you have switched to.
I think you'll find that the Avan 2327 props are WAY better than the Emax 2345's in terms of jitter, shake, prop wash handling, etc. Let us know how it flies with them.
- Dustin
PsyBorg
Wake up! Time to fly!
I only have recently got a set as well. I have one pack flown on them and they seem more effective. I need to get out and rip a few packs to see but I was liking that first run with them. May have to tweak my tune as the motors were a tad warmer then with the stock props. May be able to drop D gains a bit to help that since these even sound a lot more smooth running.
Grifflyer
WWII fanatic
Hi all quick question, FT just released a new motor for the Gremlin https://store.flitetest.com/gremlin-1104-5250kv-motor/ and I recently broke one of the older motors on my gremlin. So I was wondering is it worth getting four of the new motors or just getting another one of the originals?
I would say just get one of the new ones (if you don't mind it looking different) or get one of the originals. Reading the description of the new version it looks like the performance will probably be pretty close to the original motors since it has the same size and KV, they just made it stronger with better cooling.
- Dustin
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