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.
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 (firstname.lastname@example.org) 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.
- Solid $75 radio that I really like for buddy boxing (wireless)TTX404 4-Ch 2.4GHz Tx/Rx No Servos
- 6 channel version of the above, assume it is as good for $15 more. You get dual rates which
means that you can make the controls have less throw with a switch which in turn can make it easier to fly if you are a beginner. We call it granny mode. TTX600 6-Ch 2.4GHz Tx/Rx No Servos
- Optic 5 5-Ch 2.4GHz Transmitter, Minima6E Receiver Solid well made radio that will last for years. Currently unavailable probably because I bought them all for the Maker Shed kit–sorry.
- Old standby radio that is NO LONGER RECOMMENDED. Hong Kong HK-T6A v2 for less than $25 but high shipping. They are rarely in stock now and I have been noticing quality issues. The transmitter requires programming cable that is only available from Hong Kong. Programming information here–read before you buy!
- Ok radio if they are in stock. HK6DF from the Hobby King Hong Kong warehouse for $28.
You will need two servos per towel. But they can break/strip so ordering a few spares is not a bad idea.
- The standard HXT900 at Hobby King for $3. Amazon Link for the same servo HexTronik HXT900 Micro Servo 9g / 1.6kg
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).
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.
- Slow Flyer Propeller,10 x 4.7 SF
. $2 each. Has large prop hole.
- Propeller: PS/PJ3 (10×4.7)
. $1.50 each, get at least six. They break easily. Has small prop hole.
Motor/Speed Control Connectors
You will want at least two batteries. 6-10 minutes flight time per battery.
- $8 1750 mAh. Needs Male battery connectors, the package is enough for 5 speed controllers.
- Alternatively a $9 US warehouse 1800 mAh pack is an option. Needs same connector as above.
- Spendy at $30 but solid pack–make sure charger fits the balance connector. E-Flite 1800mAh 2S 7.4V 20C LiPo Battery, 13AWG EC3. Will need E-Flite EC3 Device & Battery Connector, Male/Female
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.
- Cheap, runs off of household current, 1.5 hrs to charge. $12.
- Same one as Hobby King but probably higher quality at $24. 2-Cell& 3-Cell Lipo Battery Balance Charger
- At $33 A decent looking multi-pack charger should be considered by groups building towels. You will need to get a separate 12-15 volt power supply or you can run it off of a car battery with a trickle charger.
There are tons of alternatives for charging. I have identified the easiest/cheapest solutions. Ping me if you need to know more.
You will also need
- 4mm/5mm heat shrink or electrical tape
- 30 small zip ties
- 2 wire coat hangers
- 3mm or 1/4 inch coroplast 16 x 11 –suggest you look for an old sign etc.
- 1 sheet 1/4 inch DOW fan foldHigh Performance Underlayment (HPU) insulation with plastic bonded to both sides (Plastic/Plastic (P/P)). Alternatively a big sheet of cardboard, presentation board, be creative
- 8 inches sticky sided velcro tape (3/4 inch wide)
A few tools are required for a reasonably easy build. They include:
- Razor blade/razor knife
- Felt tipped pen
- Soldering iron
- 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)