Up To Date Parts List for Flack (Flying Hack)


Below is the current parts list as of Oct, 2012. Often parts are on back order so I have attempted to provide substitutes. Hobby King is officially in the dog house because several folks are reporting problems with getting orders. We, of course, do not know if the problems are with Hobby King or not but be warned.

A Freshly Built Flack

A Flack built by Bethany

I fear that the days of a $100 Towel are gone due to chronic back order issues but I am still working on it. Kits are now available from Maker Shed for $249. Spendy but the gear is way better than the cheap stuff for the $100 version. We are sourcing the kits so I know.

Home page for the project that is a good starting place.

Folks have started their own build blogs. They are doing a good job of reporting on where to get gear etc. Email me (breck@brooklynaerodrome.com) if you want your blog listed here.

We are starting build sessions in October for folks that want some help with the build and flying.

I have provided a bunch of links to Amazon sources. I have not confirmed the vendors integrity or tried to see how much shipping is etc. Someone noted that a $3 part had $8 shipping and handling. It would be nice to have a single good vendor for the parts–I am working on that.



You will need two servos per towel. But they can break/strip so ordering a few spares is not a bad idea.

Speed Control/Motor combos

I prefer combo packs because you know that the motor/speed control are appropriate for each other. But you can buy them separately as well.

  • This combo is my current go-to setup for $18. Has motor connectors. Get GWS props. You want the 18amp speed control and 1800kv (means how many rpm you get per volt).

The propeller

Get at least 3. Be mindful that the prop fits the motor. The grey APC props have a bigger hole than the
GWS style props.

Motor/Speed Control Connectors


You will want at least two batteries. 6-10 minutes flight time per battery.

Any of the LiPo packs with 2 cells in parallel (2S1P), a 10c or greater rating (max discharge is 10 times the capacity of the pack) in the 1500 to 2200 mAh range.

Charging Options

There are tons of alternatives for charging. I have identified the easiest/cheapest solutions. Ping me if you need to know more.

Misc parts

You will also need

A few tools are required for a reasonably easy build. They include:

    • Razor blade/razor knife
    • Ruler
    • Felt tipped pen
    • Soldering iron
    • Solder
    • Needle nose pliers with wire cutter
    • Soldering station helping hands
    • Small philips head screw driver
    • Drill with various small bits (1/8 inch, 1/16 inch)

99 Responses to “Up To Date Parts List for Flack (Flying Hack)”

  1. Georgi Todorov Says:

    The towel uses 4 channels, right? I have a Spectrum DX6i radio and was wondering if one of these will be enough:
    OrangeRx R410 Spektrum DSM2 Compatible 4Ch 2.4Ghz Receiver

  2. Michael Gonzaga Says:

    I met you at the Maker Faire this weekend. Great show. I looked at all the parts from you list and there are a couple of parts on backorder.
    Speedcontroller: Is the Hobbyking SS Series 18-20A ESC (card programmable) an ok substitute?
    Battery Charger: can you suggest an alternative?

    Thanks, Mike

    • brooklynaerodrome Says:

      Back ordered stuff is a big hassle with Hobby King. The esc should be fine, as for chargers there are lots on the site, but
      not at the price point of the one I suggest. They just need to have a JST connector and handle 2 cells. Problem is that
      you need a 12 volt supply too if you don’t have a car–btw don’t charge in the car unattended. LIPO’s can catch fire and
      burn the car up–or anything else around for that matter.


  3. Saleem Banatwala Says:

    I saw you guys at Maker Faire New York and now I am dying to build The Towel. I am filling my cart at HobbyKing with all of the parts and unfortunately the motor controller is on back order. Is this alternative acceptable:


  4. Scott Says:

    What’s the best covering material to use for a Towel made from foam?

    I made my first towel from a sheet of Depron that I reinforced with carbon fiber rod along the leading edges and from side to side.

    The thing flies so great and is such an easy build, I’m building a bunch more

    My next build is on the table and I figured I’d skip the carbon and sheet the foam with tape or sticky backed paper.

    From what I recall of your squadron at the Maker Faire, your Towels were all covered.

    • brooklynaerodrome Says:

      I have not tried a depron plane. The stiffness from the carbon must be nice.

      At Maker Faire we had both covered and uncovered towels. I tend to skip the deck for the
      covered ones to save weight. They fly really well because the covering stiffens the plane


    • Andy B. Says:


      What thickness Depron did you use for your towel? Did you make a Coroplast deck to mount equipment or did you just mount it all on the Depron?

      • Scott Says:

        For my first towel I used 6mm White Depron, 3mm Carbon fiber rod, and a coroplast deck. It is my best flier so far, I love it.

        I also made one using 6mm Black Depron, no Carbon fiber, but covered one side with strips of packing tape. Also used a coroplast deck. This one flies ok but its flexibility reduces its performance compared to my first.

        My third attemp I went with vertical stabalizers on top and bottom and added rudder control to the top sufaces for yaw control. It’s fun to fly but I don’t think I’ll do it again.

      • Andy B. Says:

        Thanks for the info! I’ll probably not get to building this until after the holidays and will post my results.

  5. andy Says:

    Seems like HK is out of the recommended motor – what do you think of this one
    FC2822 – FC 28-22 Brushless Outrunner 1200kv
    with a 9050 prop?

  6. stephen Says:

    is this a fine subtitute? all the Hobby King ones are backordered.


    And what about this for the motors instead?


    • brooklynaerodrome Says:

      Motor looks too small. Just updated parts list on blog. Check out what is there.


    • brooklynaerodrome Says:

      The radio is the same thing as the Hobbky King HKT6a V2 from the parts list. A real pain to program. If you have the patience then go for it. I use them all the time.

      Motor looks to be too small. No real specs offered but I don’t think it will swing a 10×4.7 prop with out burning out.

      Suggested motors are in stock now. Revisit the parts list.


  7. Andrew Says:

    I found this combo on HobbyPartz.com. I’m wondering if this would be a good substitution for the motor, ESC, and servos? And if so, what batteries should I used with this motor? Thanks


    • brooklynaerodrome Says:

      It looks pretty good. You will need to use a 3 cell LiPo instead of a 2 cell. At 810kv it will turn to slowly with two cell (7.4 volts). Breck

  8. Greg Says:

    If I get the 2200 KV motor on the recommended motor/esc combo page, how will i have to compensate?

    • brooklynaerodrome Says:

      You will want a smaller prop. I am guessing a bit but an 8″ prop is what I would consider. They can restock pretty quickly so you might want to inquire when they think the 1400kv will be ready.

      • Greg Says:

        Thanks, what will happen if i use the bigger prop? Are there any power consumption concerns? I went ahead and got it with the 40 amp esc, I hope it wasn’t a mistake.

      • brooklynaerodrome Says:

        I am not aware of any issues around using a bigger ESC that needed other than efficiency losses
        and extra weight.

        Bigger prop will draw more current because it take more energy to swing it. You can fry the motor from too much heat on the windings which melts the insulation and you smoke the motor if it is too small for the prop.


    • brooklynaerodrome Says:

      Smaller prop will be called for. Go with a 9″x 4.7 or 9″ x 3.8 (the pitch of the prop is not
      that critical).

  9. Mark Says:

    Found a site where parts seem to be in stock. What do you think to the motor


    as a alternative? I see that the Max Pull (Approx.): 550g is less than that detailed in your parts list. Is the pull based on the size of propeller? It describes it as Suitable Propeller: 8×6 / 7×4.5

    • brooklynaerodrome Says:

      I am guessing a but but I would get a 9″ and 10″ prop and try them both. The 8 and 7 inch props are for a 3 cell pack and we use two cells. So a bigger prop can be driven if the voltage is lower.


  10. Chad Says:

    I was trying to build a towel by cannabalizing an old Parkzone plane I had but it is a not going to work (the motor is not powerful enough and the servos are trashed). Do you know if I can still use the transmitter from this with the other parts above? It is a 3 channel transmitter that operates on Channel 1.


    • brooklynaerodrome Says:

      You will likely need an onboard elevon mixer unless the plane you pulled the gear out of is a flying wing. Might work. You can also achieve the same result with hacking the transmitter or holding the transmitter at a 45 degree angle to get the right mixing.

      Good luck.


      • Chad Says:

        Great – thanks – the plane did have an elevon configuration so hopefully it will work.

    • Nicholas Larkin Says:

      I used the same PZ 3ch radio with my build, but it was from a normal plane. There are 3 switches on the bottom left of the Tx, 2 are for reversing your control stick (not the servos) and the 3rd is marked T/V (I think) which will switch it between tail/rudder and elevon.

  11. varun Says:

    can i buy from dealxtreame i find cheaper




    plz confirm brooklynaerodrome i am waiting

    • brooklynaerodrome Says:

      The deal extreme setup is too small for the Towel as designed. It would be
      more appropriate if you scaled the Towel down to 18 inches wing span I am guessing.
      A coroplast deck would be too heavy.

      The battery is way to big for the above gear. You would want a 300 Mah (I am guessing here)
      at most.

      The charger looks good. I don’t know much about it but check that it has the
      correct balance charge leads for the battery you get.

      Good luck


  12. Sean D. Coston Says:

    I love my Make magazine subscription and I’ve made 10 or so Arduino projects. My boys (10 and 12) and I knew immediately when we saw the cover with the Towel, that we were going to make some of these. We never have entered into the R/C realm before this other than some robots that were Arduino controlled … so I went online and started buying stuff. I ended up buying only two R/C transmitter/receivers — the HiTec Optic ones recommended here, and they are very nice and are easy to use and program. We spent last weekend building the three Towels (I wanted to play too!) I made my boys practice on a computer simulator every day this week, and now we are going out.
    For MY Towel, I built a Transmitter/receiver from a small arduino microprocessor and a pair of XBee-Pro radios I have been playing with. for the controller, I used a Logitech Cordless Rumblepad game controller made for PCs. I wrote a Processing program to take data from the controller and convert them into commands sent by XBee to the Arduino on my Towel. I’ve found that it was fairly easy to develop the logic for the proper control of the servos, and as an added benefit I have several left over Arduino pins that I can use to control LEDs or whatever on the airframe. I’m only limited by my imagination!

    I can post pictures and programs if anyone is interested, but I don’t know how to upload pictures to this site.


    • brooklynaerodrome Says:

      Yikes and away! Most excellent.

      Maybe after I approve the post you can put pix up. I am not sure how wordpress handles this.
      In any case please feel free to send them to me and I will post.


    • Hollister Says:

      Very cool! I’ve done a few Arduino projects, most recently a semi-portable g-meter using a Bosch BMA180 accelerometer that I’ve thrown into various locations ranging from my car (doesn’t pull that many gs) to my washer on the spin cycle (> 16g). Next up is to see how many gs a towel pulls in a hard turn. Or, more likely, a crash right after that hard turn.


    • MaxL Says:

      I would love to see/hear this Arduino controller project; any progress?

      • Sean D. Coston Says:

        I finished the project and the programming some time ago, and it behaved exactly as I wished on the ground. Took some time to figure out serial buffer management. Even got the elevon mixing just right. But I could never get the Arduino towel to fly very well. The Logitech rumble pad (in my hands) was just too sensitive or there was too much latency in my system. Meanwhile my boys were using regular RC transmitters and flying their towels all over the place… so I got frustrated and just bought a extra receiver for mine and used their transmitters.

        I’ve programmed a robot with four motors and two steering servos with the arduino and it works perfectly had, so not sure what the problem was with my Arduino towel. It was fun writing the code and engineering it all though.

      • brooklynaerodrome Says:

        This sounds amazing. Please put up a post or share what you did. If you need a venue I am happy to send you a login to the Brooklyn Aerodrome blog.


  13. Paul Says:

    There is an “economy” version of the recommended motor/ESC combo on the same site that is in stock.


    Both versions link to the same spec sheet so I’m not sure what the difference is but I ordered one to give it a shot.

    Does anyone know of a source for the 1/4 in DOW insulation in central New Jersey? The closest thing I’ve been able to find is “Pactiv” 1/4 in fan-fold from Lowes, but it doesn’t have a “skin” so much as it has a loose wrapper.


  14. Vijay Says:

    When my first issue of Make magazine showed up with the towel on the front, I knew I had to build it. I’ve finally got all the parts ordered and they’re slowly trickling in. I am having trouble with the airframe material though. My current choice is 3mm thick foam core, but I’m worried it’s too heavy. I can’t find quarter inch fan foam here in Ontario. I’ve worked out that the combined weight of the whole plane will be about 20 ounces if I use foam core. Is this too heavy for the 18A 1400kv motor suggested in the parts list? How heavy can it get and still fly with the 1400kv motor and a 2 cell battery?


    • brooklynaerodrome Says:

      The motor should easily tolerate a 20oz airplane. Let me know if there are issues.

      • Vijay Says:

        Hi Breck,
        I’ve got it all assembled and you were right, it looks like the motor has the power to keep it in the air. One problem though, is that I have the battery as far forward as physically possible, but the CG is still too far back(11.5 inches vs. 10 inches). This is a consequence of using a heavier material I guess. I’m going to try adding an extra counter weight to front. I have tried flying it, but I haven’t been able to keep it in the air yet.

        As a separate issue, I’ve found that I have to use the invert switches on all my control channels, even the throttle. I’m using the cheapy Hobby King controller. Is this normally necessary? I’m fairly certain I have everything connected right.


  15. Carl Plossl Says:

    The foam is a bit of a problem finding. How does this foam look:


    Owens Corning Foamular 1/4 in. x 48 in. x 50 ft. Fanfold
    “Tough fi lm facers for added damage-resistance”


    • brooklynaerodrome Says:

      I have used the 3/8″ version of that without film I think. Give it a go if you don’t mind risking the cost of a bundle. We are having tons of hassles around getting foam so if there was a CA source it would be huge.

  16. Todd Jones Says:

    Saw you flying around by the stomp rockets at the Faire this weekend… I’ll admit I was inspired to build one. What about an e-flite park 450 motor(870kv) with a 10×5 or 10×7 prop? i already have the 450 motor and esc…

    • brooklynaerodrome Says:

      You will need a 3 cell pack to drive that. Otherwise seems fine with either prop. Let us know how it goes.


      • Todd Jones Says:

        Yes, have 3cell… (coroplast wing). Tried it out Sunday and it ripped! It IS a bit heavy and did seem to have trouble keeping the nose up in tighter turns. I’m thinking this may just be a trim issue… I also made a foam wing out of two pieces of Dow 1/4 inch single plastic faced (laminated w/spray glue). It seems much lighter and rigid than the coroplast… I was sacared to go single 1/4″ thickness because it felt fluttery and fragile(I.M.O.)

      • brooklynaerodrome Says:

        Glad you got if flying. You can add wrapping paper to the non plastic side and it should stiffen up considerably. Both sides even better. Sounds like you got a hot motor so might as well minimize the possibility of flutter. Breck

  17. Todd Jones Says:

    Wish i would have came over at the Faire… We are both ‘Dromers- I working at the Fun Bike Unicorn Club/Whiskeydrome all weekend . I would have bought your kit! I found some of the Dow single plastic faced in SF for $55 a bundle(slightly damaged outer sheets, but at least 15 good ones)

    If anyone around the Bay Area is looking for foam- i would sell for reasonable price (maybe $5-2×4 sheet?)

    • Jim Says:

      Todd, which part of the Bay Area are you at? I’m in San Jose so if you’re not too far, I’d be happy take a few of those off your hands. My 13 year old wants to build this so I’m starting to collect materials.


      • Rick Says:


        How have the Towel builds gone? I’m in San Jose and built two with Breck. Been having a blast with them. Let me know and maybe we can have a fly session.

        – Rick

    • Victor Reinoso Says:

      Todd– also be interested in some, if you’ve still got it.


    • Tim Says:

      Todd, I would be interested in a couple of sheets too. Please let me know if you still have some available.

      • Jim Says:

        I was not able to find suitable foam boards at any of the local home improvement stores. I ended up getting a 40x60x3/16 foam board from University Art in San Jose. They’re about $17 after tax. The lady at the store referred to them as “clay-backed foam board”. To my untrained eye, the backings (both sides) look like cardboard. I should be able to get 3 full airframes out of this plus some scrap pieces for repairs.

      • brooklynaerodrome Says:

        That sounds interesting. I need alternative materials. Did your foam board come with a part number or manufacturer?


  18. Mark Molberg Says:

    Has anyone made a simulated model of a Towel that can be flown on Aerofly or FMS? I am trying to find the DOW siding insulation in the Denver CO area.

  19. Victor Reinoso Says:

    Everyone seems to be out of the servos you recommend. Any thoughts on alternatives?

    http://www.hobbypartz.com/60p-dy-1007.html offers a 9g Detrum for $3.95 [similar pricing to HXT900]

    http://www.servocity.com/html/hs-55_sub-micro.html has an 8g HiTec HS-55 for $9.99. Servocity also has a bigger 16g HiTec HS-81 for $12.69.

    Do you get what you pay for here or are we good to go w/ the less expensive Detrums?

    Also, your videos suggest that we will lose servos in the line of duty. How many do you recommend having in contingency?

    • brooklynaerodrome Says:

      The Detrum looks ok and the HS-55’s are a better version. HS-81’s are more than you need and
      in my experience tend to strip gears.

      I would have at least one spare servo and just to be sure go ahead and get two. They do strip on
      hard crashes. My approach has been to get cheap servos and plenty of spares.


  20. Alex Wu Says:

    they only have the 20A ESC for the motor. Do I choose that one?

    • brooklynaerodrome Says:

      That should be fine for the standard motors. Breck

      • Alex Wu Says:

        I mean for the motor you guys suggested.

      • brooklynaerodrome Says:

        We have recommended all sorts of different motors. Just take a look at it and
        figure out how to get it attached to the aluminum. You can see from the build videos
        various ways of doing it.

        Good luck


  21. Alex Wu Says:

    how do I mount the motor you suggested?

  22. Alex Wu Says:

    would a Max18ABrushless Motor ESC for planes(2A BEC, 2-3 cell Li-Poly) work as well?

  23. Alex Wu Says:

    does the ESC’s BEC has to be 2A for the plane to work?

    Please reply soon!


    • brooklynaerodrome Says:

      You will probably want at least 1Amp for the BEC. It is the part that powers
      the radio and servos. Most any speed controller with a BEC should be sufficient.


  24. Jim Says:

    The Optic 5 seems to be out of stock everywhere. Do you have a recommendation for another radio? The only manufacturer that I recognize from my youth is Futaba but they are pretty pricey.


  25. Joe Says:

    Can you tell me where to get: 2 wire coat hangers and 8 inches sticky sided velcro tape (3/4 inch wide)? I really like the idea of the Towel.

    • brooklynaerodrome Says:

      Dry cleaners have wire coat hangers and most hardware stores have velcro tape.


  26. s p e x Says:

    I mistakenly bought a 3-cell 11.7 V battery as a second battery for my makershed kit. I looked at the docs for the speed controller and it said it would work. However, when I plugged in the battery, I wasn’t able to get a link.

    I think I fried my receiver because I was supposed to program the speed controller first. (?)

    Should I even try to use this 11.7V battery? Or should I get another 7.4V 2-cell?

    Do you think I also fried my speed controller?

    • brooklynaerodrome Says:

      You can try to fly with 3 cells on the 10″ prop but you cannot use full power. I would guess half throttle is all it will stand before either the motor or speed control will burn out. Gauge how much power you use by what thrust of the motor at full throttle on the two cell pack.

      The right thing to do is get a smaller prop. 7″ prop is my guess.

      The three cell pack should not have fried the receiver. There is no programming required to switch the BEC from two to three cells.


  27. ggunners Says:

    Hello all, as a request from another Towel flyer, I have created an FMS model of the Towel. I am told it flies close to the real thing and you can edit the .bmp file with Win Paint to make it look just like your own Towel. http://gunnerson.homestead.com/files/towel.zip. Happy Flying! — ggunners

    • brooklynaerodrome Says:

      Thank you so much for creating a model of the Towel. We used it in the last class for sim training in FMS and it was great.


  28. Carl Plossl Says:

    Any Flight Simulator recommendations?
    For instance: HobbyKing –

    My son and I tried your simulator at the workshop and it was decent. You suggested that we remind you to opine on this subject.


  29. DEB Says:

    Hi. this is my first time making anything like this and I was wondering if you could give me some plane explanations or recommend a website to read up on RC planes.

    • brooklynaerodrome Says:

      I just did a search for introductory materials on RC and was not happy with what I found. I am in
      the process of writing a book and the next chapter will be on the basics of RC airplanes as we
      build them at the Brooklyn Aerodrome. Can you wait a week? I will send you a draft if you email me

      The Make Magazine Volume 30 issue has our intro to the Towel, our started airplane and it lays out
      the basics. http://makeprojects.com/Wiki/30

      Anyone else find good introductory resources for RC?


  30. Jim Says:

    I have a question about the ESC placement. Most of the build photos I’ve seen place the ESC to the right of the centerline. Is there a reason for this?

    Thanks in advance.

    • brooklynaerodrome Says:

      Sorry for the late reply on this. I don’t get alerts for some reason unless you are a new poster.

      No reason at all for the placement of the ESC. Just keeping it neat and out of harms way on crashes.


  31. Jim Says:

    Breck, there was no manufacturer info on the clay-backed foam board. However, a cursory search on uline produced this:


    My daughter and I will likely finish the build this weekend so I’ll send you some photos in the next few days.


  32. Jim Says:

    I have a question about the CG. We completed our build last weekend but noticed that our center of gravity is about 11.5″ from the tip. We followed the Make Magazine instructions so our prop opening is 11″ from the front. The Make Magazine article suggested that the CG should be about 10″ from the tip. I can think of two significant deviation in our build:

    1. material: we used 3/16″ clay-coated foam. The final plane weighs 1 lb 2.7 oz. How does this compare against the reference build? Is it possible that ours is heavier and that’s why the CG is further back?

    2. battery placement: we mounted our battery in a transverse-fashion so as to lessen the shock on the battery in the even of a front-end impact. Therefore, our battery probably isn’t as forward as it could be. We used the e-flite battery and I don’t know if that is lighter than the other recommended battery.

    • brooklynaerodrome Says:

      The build weight looks manageable. All up build with blue foam is around 16 oz. The clay coated board is definitely the reason you have an aft CG. I fly the planes about .5 inch ahead of the prop hole so get it there by adding weight to the nose and/or removing one stabilizer–Towel flies fine with just one stab.

      If you fly with too aft a CG you end up with a very squirrelly airplane.

      Lets us know how it turns out and send a picture.


      • Jim Says:

        Thanks for the clarification — so the clay-coated foam is heavier despite of it being thinner. We’ll add some weight to the nose after we complete the repairs. The first flights didn’t go so well because our controls were unknowingly reversed. 😦

        Will try again this weekend…

  33. jacob Says:

    my browser said that the links on this page our untrustworthy

  34. joe Says:

    I accidentally purchased batteries 11.1V rather than 7.4v…am I going to have a problem burning anything out? Or will it just run faster?

    • brooklynaerodrome Says:

      You can use that battery but a smaller prop should be used. I would think either a 6 or 7″ prop would be better. You
      can cut down a larger prop. Be sure to balance it though.


  35. Jorge Says:

    Can i use a HXt500 servo instead of the HXT900 since its backorder


    • brooklynaerodrome Says:

      Yes, we have used the HXT500 before. The HXT900 is available in the USA warehouse now I think.

  36. sam Says:

    Can I replace the dow board with 1/2 inch thermocol , I am unable to get the dow board equivalent in India.


    • brooklynaerodrome Says:

      You will have to experiment with what you can get in India. If thermocol can be gotten thinner that 1/2 inch then try that. The 1/2 inch may work fine–I have built with materials that thick before.

      Good luck and send pictures if you get flying.


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