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Gremlin Idea, would like suggestions.

Jason of Gaming

Gravity is heartless...
#1
View attachment 98117 View attachment 98119

If I did this right, there should be two pictures somewhere on this post.

I would really like a miniquad that I could just (literally) throw into a car and fly, and that was reliable. I have access to a PCNC Milling Machine, and some common plastic used for it, i found out, is actually somewhat bullet proof... Anyway, I figured that tuff-ness could be used in a quad frame. If I deigned it right, that would take care of making this really strong. I also wanted something that would be reliable and powerful. I saw FT's video here: https://www.youtube.com/watch?v=KqMXWXhfGxc and thought that would be a good electronics set. Here is what I will probably need help with:

Specific parts: I am not an expert on how some of these electronics go together or finding the parts online, this is my second real quad.

RX: I use FlySky. Their RXs aren't as common as FrSky and DSMX, and I have very little experience on how receivers connect to other components.

Aerodynamics: I'm not quite sure how aerodynamic my design is, somewhere on this post I have a SS from tinker CAD where I was brainstorming. I have the general idea of having two plates of plastic (UHMWPE) bolted together and nearly indestructible "whoop style" prop guards. I included a picture of a larger quad with wraparound carbon fiber. I want that idea, but plastic, microbrushless, and full guards instead of just two plates. I would like to fit the "FT Baby Redbottom" setup (https://www.youtube.com/watch?v=KqMXWXhfGxc) into my frame, as it seems really powerful and the plastic will be somewhat heavy. I also think I'll just velcrostrap a 3s I already have to the bottom or get a bit smaller 3s.

If you have an idea, please tell me, if I am wrong, please tell me, if my pictures don't work for you, please tell me. Thanks for reading this long post, and all help appreciated!

EDIT: The tinkerCAD design is not final, and I will make the final one using Autodesk Fusion 360.
 
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rockyboy

Skill Collector
Mentor
#2
The attachments say 'invalid format' so something went sideways there. If you can make sure the pictures are in JPG PNG or BMP format they should work OK

Generally speaking, aerodynamics aren't much of a concern with quads until you're really reaching for the 100pmh crazy speeds side of things - the thrust to weight ratios on these things are just so crazy high it overpowers whatever air resistance the frame provides at lower speeds.

The Flite Test power packs are great for getting started as all the electronics are matched up and there are plenty of support options here on the forum, or through TJ at Flite Test for any questions. Those baby red bottoms look pretty wicked too :)

And there are some folks on here using FlySky or can at least provide support for using FlySky satellite receivers - unfortunately I'm not one of them - I only used FlySky briefly about three years ago for fixed wing, and never went to the serial setups with those.
 

Jason of Gaming

Gravity is heartless...
#3
Ok, thats what I figured about the power to weight ratio, I just want hangtime. I think I actually might buy the parts seperate because FT doesn't seem to sell the red bottoms or gremlins without the frames. Thanks, I'll fix the pictures when I have more time!
 

LitterBug

Troll Spammer
#4
You can buy the frames and all the pieces parts separate. May not be the most cost effective approach, but I managed to get most of my parts for my 2nd gremlin on sale. My first FT gremlin is JT's frame with the stock gremlin power/fc kit. My 2nd I'm building up from just Alex's frame, modifying the frame for 20x20 FC mount pattern, and using DYS motors, LittleBee ESCs, and a Omnibus F3 Nano V2. Think the layout of Alex's frame is much better than JT's as it fit's the long EMAX escs better. You can also easily leave the center 4 top plate standoffs off of that frame, as they are there more for looks than function.

Cheers!
LitterBug

GremlinBuddies.jpg
 
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PsyBorg

Wake up! Time to fly!
Mentor
#5
Couple things to think about mate. I have talked two people who tried the red bottoms for the Gremlin and have been underwhelmed with the performance over the stock ones. This is more to do with props then the motors as there are very limited options for them. Second these are very light and will not carry the inertia in a punch out like say a 5 incher will. They slow down fast and they fall fast. Hang time with these will not be so much a hang as you might expect.
 

LitterBug

Troll Spammer
#7
Grnd Flyr, You would need to re-drill the motor mount holes for 13xx/14xx motors.... The Gremlins have a smaller bolt circle for 11xx motors.... 13xx/14xx motors are for 3-4" props also. Gremlins are 2".


Cheers!
LitterBUg
 
#8
Don't think so... on the BG page it says:

Specification:
Brand name: Brotherhobby
Item name: Returner 1402 8100KV 9500KV motor
Configuration: 9N12P
No.of Cells(Lipo): 1-2s
Rotor: N52H arc magnets
Stator: 0.15mm Nippon silicon steel
Bearing: NSK 5X2X2.5
Casing Material: Al 7075
Wire AWG: 26AWG
Weight: 6G
Mounting: T-Mount (M2 holes, 5mm eye to eye)

...and on the RCGroups page he said:

Frame I used for 9500kv with some emax 1106 on it. 1402 have same mounting as 1106 size motors and don't fit tooth fairy 3in frame mounting made for 1407 motors

just take smaller 2" props tho? I don't know...
 

LitterBug

Troll Spammer
#9
Ahh.... Sorry Grand Flyr, Maybe I should have looked at the actual specs rather than assuming they were standard 14XX motors. "Mounting: T-Mount (M2 holes, 5mm eye to eye)"

Cheers!
LitterBug
 

Jason of Gaming

Gravity is heartless...
#10
Psy, I didn't get that idea from this video, but I could be wrong: https://www.youtube.com/watch?v=KqMXWXhfGxc

I am also not quite sure what FC to get, I'd love suggestions and I'm not choosy about FCs. (I also will probably need instruction on what goes where, and an output for a tiny fpv cam)

I also want to fly this on a 3s, so please don't send me anything I could set on fire. (The Brotherhobby motors seemed rated for 2s, whereas the redbottoms could go 4s.)

What kind of ESC should I buy? (I'm trying to make a parts list)

Thanks to all that responded!

grnd, are these good props? https://www.banggood.com/2-Pairs-Ge...Country=US&currency=USD&createTmp=1&value_ids[]=24&utm_source=googleshopping&utm_medium=cpc_ods&utm_content=heath&utm_campaign=pla-multi-us-pc&gclid=EAIaIQobChMIs9v3rLXG1wIVxrbACh0vvQc4EAQYASABEgJhHvD_BwE&ID=224&cur_warehouse=CN
 
#11
Ahh.... Sorry Grand Flyr, Maybe I should have looked at the actual specs rather than assuming they were standard 14XX motors. "Mounting: T-Mount (M2 holes, 5mm eye to eye)"

Cheers!
LitterBug
Dude, don't make my head pop... if grand and anything to do with flying is concerned call me grand crasher... was thinking ground... hahaha :D
 
#12
Psy, I didn't get that idea from this video, but I could be wrong: https://www.youtube.com/watch?v=KqMXWXhfGxc

I am also not quite sure what FC to get, I'd love suggestions and I'm not choosy about FCs. (I also will probably need instruction on what goes where, and an output for a tiny fpv cam)

I also want to fly this on a 3s, so please don't send me anything I could set on fire. (The Brotherhobby motors seemed rated for 2s, whereas the redbottoms could go 4s.)

What kind of ESC should I buy? (I'm trying to make a parts list)

Thanks to all that responded!

grnd, are these good props? https://www.banggood.com/2-Pairs-Ge...Country=US&currency=USD&createTmp=1&value_ids[]=24&utm_source=googleshopping&utm_medium=cpc_ods&utm_content=heath&utm_campaign=pla-multi-us-pc&gclid=EAIaIQobChMIs9v3rLXG1wIVxrbACh0vvQc4EAQYASABEgJhHvD_BwE&ID=224&cur_warehouse=CN
I'm not able to view your pics but thought it was a 2" frame?

I've used those gemfan 3025 props on a RCX 1304 powered Minimalist128 3" frame before and loved them.

If your frame is a 3" and have high octane T-mount motors, maybe your best bet is using RX3044TX props. Ought to really scoot!
 

Jason of Gaming

Gravity is heartless...
#13
Well, I was going to do a 2"... Basically I'm going for a really small 3s drone, but I'm going to custom PCNC my own frame from UHMWPE plastic so its "indestructible." The thing is, I need the size of all the things and the voltage of all my electronics to match up. These motors look like they are for a 4s-5s: https://www.getfpv.com/rotorx-rx110...MIo5yVs4jH1wIVgRCBCh2sJQUKEAkYAiABEgKCk_D_BwE I saw the baby red bottom video, and I really want to make a gremlin that acts like that, but with my own custom frame. Basically I want the fastest gremlin electronics that I can find, and put them in an indestructible frame with full prop guards so I won't break it. (Immediately)

The thing is, I've gotten a ton of good suggestions, but I don't know how well they all fit together...

Thanks again!

EDIT: This is the general idea I'm going for, but Full of plastic and not just two plates of carbon: http://www.lapdrone.com/images/H250 Frame.jpg
 
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#14
Like you said... "Gravity is heartless..." and that's where your battle lays in the end.

Did you just get a Tormach or access to one? Reason I ask is maybe you're looking for a project?... I dunno, but the main problem as I see it, is weight.

Look at what Armattan did for another idea along this line: http://www.armattanquads.com/bumper-frame/

Look at the Owl that Litterbug has built.

Just my 2 cents but instead of trying to find the ultimate combination of parts to make the elusive best/lightest/strongest/fastest/fill-in-the-blank quad... go out and break some stuff, it's waaaay more fun. But that's me.

Seriously, like you said Gravity is heartless, and in the end there's your conundrum...
 

LitterBug

Troll Spammer
#15
That looks similar to a FlexRC owl frame. I have 3 of the full size 118mm 3" prop owls. They are well designed and very durable carbon frames. NOTHING is indestructable, but I'd take carbon over plastic any day. I run 1306 4000kv motors on them which makes them usable from 2S to 4S depending on how much punch I want.

Cheers!
LitterBug
 

Jason of Gaming

Gravity is heartless...
#16
Thanks guys! grnd, my dad has a tormach, and I don't need a project, but thanks. I actually was trying to replicate the bumper out of UHMWPE plastic. It would be heavier, but I feel like that foam would eventually get torn up. I would go buy and test some stuff, but I have a serious budget. Speaking of budget my Eachine 007s reciever seems all screwed up and now I'm looking for a new pair of goggles...

I think that might have been a flexrc frame. Armatten's bumber is basically what I want to mill from plastic. I'm thinking a 3s with, thanks!
 

PsyBorg

Wake up! Time to fly!
Mentor
#17
You stated in the original post you would be using various size 3s batteries. That FT video was done with 4s which is a HUGE step up in power on that size quad motor. If you want to fly 4s with those motors then rock on the performance will be great. On 3s as I stated I have had people tell me they are lacking. Also be aware that they would need to step up to 12 amp esc's not stock 6 amps.
 

Jason of Gaming

Gravity is heartless...
#18
Ok, I believe that half of the video was 3s, half 4s, with the lighter 3s working better. What do you think of me just getting a lizard 95 and moving the electronics to my own frame?
 

PsyBorg

Wake up! Time to fly!
Mentor
#19
Personally I think there is nothing wrong with the stock Emax power pack FT puts out for the Gremlins. Works fine on 2s or 3s, is small, very agile and can be easily tameable for indoor flight too. Pretty much everything you want. Size range near same as a tiny whoop, powerful enough for outside flight (have put mine up in 12-15 mph winds with zero issues.) and scale-able for indoor. Cant ask for much more then that. Frame design doesn't really matter other then strength weight and noise conduction so you can fly on anything from Popsicle sticks to full on tooled aluminum if ya want.

I maidened mine at 187g all up weight and now fly full time at 147g and have a blast. Others rock theirs out around the 100g area with lesser video systems then I use and smaller batteries. Plenty of wiggle room to play with design wise.

I been puttin a lot of time on mine recently so there are plenty examples up on my yt page to see and my build thread has all the information I have as I progressed since I first bought it to look thru and see what I found works and what doesn't.

At the end of the day its your time and money so you have to make the choice. Plenty of info on everything you have mentions in the interwebs and forums to make an informed decision mate.
 

Jason of Gaming

Gravity is heartless...
#20
Thanks a lot Psy, when I have a bit more time I'll go check out your channel, I think I'll get the lizard 95, replace the camera with a mullet modded one, and put it into my machined plastic frame. Thank you all! One more thing: What's your opinion on a cheap "fatshark style" goggle for my second pair, my Eachine VR007s have broken. I need something preferably under $200, thanks.