How to build a 2S pepperFIISH pocket rocket — Shopping list & Recommendations

By | July 28, 2017

Recently I have been asked for my recommendation for a super lightweight pocket rocket. At the time of writing there are no stock lightweight RTF 2S copters I can recommend. You will have to assemble it on your own, luckily you can buy all the needed parts, there is no need to assemble circuit boards on your own. In the end you end up with ~280g thrust on a 27g + 17g (battery) = 45g quadcopter (6.3:1 thrust to weight ratio).

For a decent flying and durable copter I would recommend BR1103 motors. I have used the old racerstar motor design in the past, but unfortunately it looks like it is not in stock anymore… I have updated my frame design to the newer BR1103B motor mounts. The 070x motors I have tested in the bast used brass bushings instead of real ball bearings. In combination with poorly balanced flange you will end up with a short lifetime and maximum vibrations :-\ This is why I recommend 1103 motors.

The other parts are quite obvious, use a tinyFISH FC (or clone), a 2S ESC from furiousFPV (based on my tinyPEPPER2 design), 56mm props, a frame of your choice and Turnigy nano 2S 300mAh batteries:

Shopping List

UPDATE: changed the regulator to a step-up/down. This way this build can run on 1S and 2S! Thanks for the recommendation nwbb!

3D printed parts

Due to changes to the mounting pattern this frame design is only for BR1003B motors!
With this new design you can save some weight by using foam and rubber bands for battery fixation instead of the 3d printed holder. In case you want to use different motors I have a similar design for you: One for 070x motors (with rubber tabs) and one for the older BR1103 motor design.

Assembly

Start by soldering the power cables to the FC input pads. Next, add power and signal connections between the FC and ESC. Connect the input pads of the stepdown to the Lipo Vout pads of the FC and connect the 3.3V output to the camera/vtx combo. I had to add a 47uF capacitor to the 3.3V pads of the step down in order to get the camera to work. You can use any 47uF  capacitor rated for at least 10V for this, I used a SMD multilayer capacitor in the 0805 size.

Use a M2 drill bit and cut the thread into the camera holder. Next, take four screws, the spacers, the FC, the ESC, and the camera holder. The 2mm spacers go between frame and ESC, the 3mm ones belong between ESC and FC. Screw everything together.

Take the motors and mount them to the frame. Make sure to use screws with the right length, they should not touch the motor coils! I used some nice and lightweight titanium screws instead of the ones that came with the motors. Add some low strength threadlocker to the motor screws (I use the purple Loctite 222).

Cut the motor wires to the appropriate length (keep some extra) and solder them to the ESC tabs. Those motor wires are really fragile. The best way to strip the isolation is to cut the wire a bit longer, overstretch/expand the isolation, cut the isolation and apply some heat to it. The isolation is made from heatshrink tubing and will shrink on heat exposure. This exposes the wire you want to solder. Do not use wire stripper/cutter tools as they might leave cut marks on the thin motor wire which cause it to break on vibrations.

Insert the camera into the holder and add a shortened zip tie as protector cage. Now finish up the quad by adding sticky foam on the bottom and mount the battery using some rubber bands.

Setup

Start by binding your TX to the receiver by pressing the bind button during powerup. Do the normal bind procedure you are used to. Now it’s time to proceed with the configuration — Fire up the betaflight configurator. Please note that the FC will not run on USB power, you will have to connect the battery as well. Do not let it run on the lipo for long time, the camera will drain a fully charged battery within less than 40 minutes…

The most important thing you will have to do is to set the FC orientation to the right value! Depending on how you mounted the FC, it is +/-45° or +/- 135°  rotated (yaw axis)! Set and doublecheck it by viewing the 3d model of your copter, it should follow all your turning motion. If you screw this up the copter will end up in your ceiling on the first arming — been there, done that…

Check your motor ordering and fix it by using resource remapping. Verify the receiver functions properly in the input tab. That’s it. For me the copter flies quite good with the stock PID settings.

Just in case you want to use a buzzer on this FC with bf 3.1.7 make sure to apply the appropriate fix.

You finished your 2S pepperFIISH? I would be happy to see and share a picture on my blog!

Happy flying!

50 thoughts on “How to build a 2S pepperFIISH pocket rocket — Shopping list & Recommendations

  1. Curtis Ruin

    Today I unfortunately get rid of the RX antenna of my BoldClash Tinyfish incl. the solder pad!
    Maybe you guys have an idea if I could connect the antenna somewhere else.
    Much appreciate your comments.
    Thank you in advance.
    Regards,
    CR
    PS: Thats how I managed it! 😉
    https://youtu.be/1Z6FlwOb5YA

    Reply
    1. fishpepper Post author

      You can solder the antenna to the smd components that connect to the trace. See the tinyFISH FC assembly blog post.

      Reply
  2. Russell L

    Thanks so much for the build write up. I’ve finally gotten my pepperFiish build finished, and while I went with a different frame, everything else is as indicated in your super helpful guide. I’ve got some photos on my build page at https://rotorbuilds.com/build/8061

    I set up a switch on my taranis to make it easy to fly on 1S, 2S with a reduced throttle curve for indoors, and full power 2S for outside. You can use these settings if you’d like to do the same: https://imgur.com/a/Ves00

    Reply
  3. Joost van Rossum

    I am so close to completion… I got it out, but when I throttle, right as the quad starts to hover, it wobbles uncontrollably. Thoughts on what the issue could be?

    Reply
    1. fishpepper Post author

      This happens when you forget to set the board rotation to 45°. Open up the bf configurator and set a 45° yaw rotation for the board.
      These wobbles and the resulting pid windup to full throttle look really scary, I do not want to see what happens if you do this to a powerful racing quad…

      Reply
      1. Joost

        Sweet this worked! another issue,… trying to add an frsky xm to the fishpepper 2s design you made. I added the receivers sbus wire to uart3 rx. Bound it to my receiver (D16) en set the receiver to serial and sbus in betaflight + turned on serial in the ports tab for uart3. However, i am still not seeing a connecting in betaflight. Has anyone here added a seperate receiver to uart3? If so, what im i missing..

        Reply
        1. fishpepper Post author

          You might have to enable sbus inversion. This can be done via software using the betaflight cli.

          Reply
          1. J

            thanks again! Everything works now. Got two of these and they are both great

  4. Curtis Ruin

    Hello Simon,
    I m so happy with my PepperFIISH build as you can easily see…
    https://youtu.be/APbO6hJJ5bY
    Do you or anybody else have suggestions regarding adjusting the rates & PIDs?
    Any recommendations are more then welcome.
    Thanks in advance.
    Viele Grüße,
    CR

    Reply
    1. fishpepper Post author

      Thanks for sharing this! The flying does not look like a micro copter! I should definitely get more stick time instead of building stuff *g*

      Reply
  5. lac

    Are you actually using the balance leads to power the quad?

    I mean even the “big” JST plugs are insufficient no? 1103b-s pull easy around 5A each on full throttle with smaller but more bladed props. Are the 58mm 2blades that much different? Would it make sense to go with xt30? i know they are like 1.7g but if I understand it correctly you will be compensated by a lot more power.

    Reply
    1. fishpepper Post author

      I really do not like the alternatives. I think I should design a XT15 and let China steal my design *g*
      Due to the lack of alternatives my new design will probably use XT30… 🙁

      Reply
  6. JJ

    Hi! Great work!

    I am almost ready. I accidently ruined the antenna solder pad. Is there another component i can solder it to?

    Best wishes,

    JJ

    Reply
    1. fishpepper Post author

      Have a look at this picture. You can use one of the capacitor/inductance pads that are connected to the round antenna pad 🙂

      Reply
    1. fishpepper Post author

      I think for 1S and 2S the 1103 are the best compromise. But I did not do any 0806 tests on my own. So it might work out as well. Stay away from 070x, those really suck.

      Reply
  7. Yannic

    Same as many others couldn’t resist and started building a 2S !
    Cannot wait for it to be airborne..

    Thanks for the great work on the FC and ESC Simon, really much appreciated!
    I will use a slightly different version of the carbon fiber frame which I would like to share with you before I put them on Thingiverse. Can you please send me a email so I can send them to you ?

    Keep up the good work,
    Cheers!

    Reply
    1. fishpepper Post author

      Cool! I would really like to see your frame idea. I also have a new frame in the works, it will feature a runcam micro 🙂
      You can reach me at fishpepper AT gmail.com

      Reply
  8. Curtis Ruin

    Hi,
    do I have rto add the 47uF capacitor also if I use Pololu S7V7F5?
    Please advice.

    Thanks in advance.

    Regards,

    Curtis

    Reply
    1. fishpepper Post author

      Just give it a test. If the cam starts up just fine you can skip the capacitor.

      Reply
    1. fishpepper Post author

      The latest 83mm version for the BR1103B weights 2.5g at 1mm thickness.

      Reply
    1. fishpepper Post author

      You will need to hook up a FlySky receiver to the fc or modify your Evolution to run OpenGround.

      Reply
  9. JihadPoo

    Can lower kv motors be used to extend flight time? Would the props need to change? Also what is the flight time even?

    Reply
    1. fishpepper Post author

      As usual flight time depends on how much you push it 😉 I would say 4-5 minutes cruising.
      Lower KV motors and matching props would increase flight time, of course 🙂

      Reply
  10. Wes

    Hey all, got the components to build one of these incoming. Just confirming – the 24AWG silicon wire is for power and the 30AWG is for everything else(i.e. connecting the FC to the ESC)?

    Reply
    1. fishpepper Post author

      Correct! Make sure to get the thinner 30AWG ones. Aliexpress lists some 1.2mm outer diameter and some 0.8mm outer diameter. The thinner look much better on a micro build 😉

      Reply
  11. Sini

    Hi,
    i got two questions regarding the shopping list and the assembly instructions:
    In the parts list you recommend the Pololu 5V 0.5A Stepd-down, but later in the text you seem to be talking about a 3.3V Step-down, which one is correct? The VM275t should theoretically be working with both. Also you recommend M2x12mm screws, but in the text you talk about 14mm long screws. I can’t find m2 nylon screws longer than 12mm anywhere.

    Reply
    1. fishpepper Post author

      Thanks for pointing this out, it has been corrected in the text. You can use a 5V or 3.3V stepdown. The 12mm screws will do, I thought I removed all wrong references to the 14mm version. Did I miss one somewhere?

      Reply
  12. Victor Johansen

    I wasn’t sure where to put this I couldn’t find a comment section on the tinyfish page. This just happened to me and I have heard of others having the same problem. After using the USB port on the tinyfish a few times it comes off. This is just feedback. I have ordered a new one and I intend to put a small dab of hot glue on the USB connector to help strengthen it. In examining the board it seems the USB connector was only soldered on one side. The pad lifted and the little pins were no match for the pressure of plugging in. While it was obvious that it should have been soldered on both sides the solder didn’t stick to the connector. Maybe you can make the manufactures aware of the problem. I suspect those that build there own board, don’t have this problem. As always thanks so much for your work.

    Reply
    1. fishpepper Post author

      This should not happen. If soldered properly this should withstand normal use. Was it a racerstar clone? They seem to have the worst quality.
      You could try this adapter or an angled usb cable. This would remove some of the stress.
      I doubt the hotglue will help. Maybe adding some 2K epoxy to the sides can help.

      Reply
  13. Pingback: DIY : 2S pepperFIISH pocket rocket | HelicoMicro.com

  14. Jaapp

    Great! This tipped me over the edge. Definitely building this.

    I’m having a hard time sourcing the M2x14mm screws thought. Even the link you provided doesn’t have them larger than 12mm. Any tips where I can get a hold of there 14mm once’s?

    Thanks for this great blog!

    Reply
    1. Curtis

      Hey Jaap,
      watched your vids yesterday, congratualtions! Where did you find the M2x14 finally ?
      Would be much appreciated because I m building my one at the moment….
      @Simon Many thanx for your hard work and sharing the passion!
      Many happy landings.
      So long,
      Curtis

      Reply
  15. Firlefanz

    Such a wonderful quad! Can’t wait to find a solution to get the esc in Europe (Germany) without huge shipping costs.

    Reply
    1. Curtis

      Hey Firle,

      go and check out Redbee.de! They sell the Furious version!

      Many happy landings.

      Regards,

      Curtis

      Reply
  16. Shane

    I have been having problems getting my transmitter (Taranis Plus) to work with my Pepperf1sh. I suspect in my initial setup (first time using betaflight) I might have messed up some settings. Could you send me the proper settings for the configuration, port and receiver screens? Screenshots would be fine.
    Thanks.
    Shane

    Reply
    1. fishpepper Post author

      Just flash it again and set full erase. This will restore the stock settings which should work 😉

      Reply

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