Below is the current parts list as of January 9, 2011. Often parts are on back order so I have attempted to provide substitutes. I have used the Hobby King Hong Kong warehouse and for some items provided gear from the US warehouse. If you want to make a single order with all relevant parts then it has to be from the Hong Kong warehouse because the US warehouse does not stock everything. With shipping an complete towel order will be around $100 USD.
Shipping from Hong Kong is very expensive. Between 30-50% of the cost of the order and it can be very slow. Customer service can be spotty but for us the cost savings is worth it. A towel would cost two to three times as much if we used US distributors–all the gear is manufactured in asia in any case.
This parts list is optimized for price at tolerable quality and convenience. I will provide alternative links for higher quality/speed of delivery as well if there is demand.
Transmitter/Receiver
HK-T6A v2: A good news/bad news situation:
Good News: Our workhorse setup is the very good value for money HK-T6Av2 transmitter. It is an amazing transmitter for the money and is perfect for large groups since learning to deal with its foibles is better motivated.
Bad News: The transmitter is often out of stock, a real hassle to program which is a requirement to fly the towel and it burns through batteries very quickly. Occasionally, also, there is a dud.
You can get the
Hong Kong HK-T6A v2 for less than $25 but high shipping.
You can also get the HKT6A v2 from the US warehouse. Shipping is faster, cheaper but the transmitter is around $30. Which source will likely depend on which site has them in stock.
The transmitter requires programming cable that is only available from Hong Kong. Programming information here–read before you buy!
Alternative Transmitter/Receivers
I don’t recommend that the lone hobbiest take on the hassle of programming the HK T6A v2 unless they are very comfortable with computers and glitchy software. What to buy then?
You can easily drop more than $1000 on a radio but I don’t recommend that because those radios are very complicated to program. What you want is a simple radio to get you flying without frustration. The Towel is a flying wing that requires elevon mixing. This in turn requires that the transmitter have mixing capability or that there is a mixing capability on board the aircraft. The perfect choice, which I would buy lots of if spare receivers were available is the HK6DF from the Hobby King Hong Kong warehouse for $28.
Prop Saver
For almost the same price you can get 10 prop savers.
Servos
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.
As an alternative we have had good luck with TG9e
The propellor
Get at least 5 props per towel, they break all the time.
You can also get a 6 pack. Choose based on what is in stock.
Speed Control
The motor/prop/battery combo draws around 14 amps. So A solid 15-18 amp speed control is what you want.
Alternatively the 18-20 amp speed control from the US warehouse is a good choice.
Yet another option is the more expensive Turnigy speed control
Motor
The classic Tower Pro Outrunner. This motor is often back ordered. I am looking for alternatives.
Alternative Motor
We have used the earlier versions of these motor/speed controls back in the day and they were great. Get the 1400kv model. Note that they come with motor/speed control connectors installed!
Motor/Speed Control Connectors
The standard 3.5mm connector Enough for 3 planes with one spare connector–you need 3 male/female per plane.
Another version is 3.5 mm gold connectors.
Battery
You will want at least two batteries. 6-10 minutes flight time per battery.
Alternatively a US warehouse 1800 mAh pack is an option.
Any of the LiPo packs with 2 cells in parallel (2S1P), a 10c rating (max discharge is 10 times the capacity of the pack), jst charge connectors, XT60 speed control connector should be fine in the 1500 to 2200 mAh range. The 1750′s are chosen because they are a good value and 7 minutes in the air is plenty of time.
Battery to Speed Controller Connector
Male battery connectors, enough for 5 speed controllers.
Charging Options
Cheap, runs off of household current, 1.5 hrs to charge
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.
Misc parts
You will aslo need
- 4mm/5mm heat shrink or electrical tape
- 30 small zip ties
- 2 wire coat hangers
- Credit card
- 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
- 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)
September 19, 2011 at 3:13 pm |
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
September 19, 2011 at 5:59 pm |
The plane is 3 channels. The Spectrum 6 channel should be fine.
Breck
September 20, 2011 at 8:21 pm |
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
September 23, 2011 at 11:54 pm |
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.
Breck
September 24, 2011 at 12:07 am |
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:
http://www.hobbyking.com/hobbyking/store/__656__TowerPro_w18A_Brushless_Speed_Controller.html
September 24, 2011 at 9:15 pm |
Yep, that one is fine.
Breck
October 6, 2011 at 7:03 pm |
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.
October 6, 2011 at 9:16 pm |
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
considerably.
Breck
December 13, 2011 at 4:01 am |
Scott,
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?
December 14, 2011 at 6:07 pm
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.
December 14, 2011 at 6:32 pm
Thanks for the info! I’ll probably not get to building this until after the holidays and will post my results.
November 18, 2011 at 5:28 pm |
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?
November 18, 2011 at 9:54 pm |
It might work just fine but I would stick with a 10×4.7 prop if you are
going to go with a 2 cell pack. If you get a 3 cell, what they recommend, then
go with a 9″ prop.
Alternatively we have used the combo packs from RC hot deals with success:
http://www.rchotdeals.com/Products/rc/Brushless_Motors_ESC/B2212_18a_combo.html
Get the 1400kv from them.