WN-2 Winch Kit

WN 2.2 Winch Kit
$365.00* ** ***
*Plus Actual UPS Ground Shipping
**Price Subject to Change About Pricing
***$345.00 If you were on the WN2.2 notification list prior to 6/4/2008

Page updated 6/04/2008 with lots of new information
(This page is in the process of being updated so there might be some errors)

WN2 Mounted on Cart Photos WN2 Photos Assembly Drawing PDF updated 2/18/2007

A reliable, rugged, compact and affordable winch based on the popular Ford Longshaft starter motor (FLS) designed to launch open class TD sailplanes. The WN2 has become the "Standard Winch" with 100's in use including most major R/C sailplane competitions. The frame is constructed of formed steel welded to form a rigid "box" structure with provisions for dual solenoids for safety and a variety of battery connectors and foot switch configurations. The objective is to supply the major winch components (frames and drums) with the motor and electrical components supplied by the user/builder reducing the entry cost for a "full power" winch. Because the machine tools required to produce drums and frames are larger than those usually found in most hobby work shops, it has been difficult for a hobbyist to build a quality winch without expensive custom machine work. The WN-2 Winch kit can be assembled with home work shop tools and customized to fit different needs and mountings.
Don't Get Stuck With an Orphan - WN2 Compatible with Ford and Injoy Motors
The WN2 can use Ford long shaft motors including motors equipped with "Real Balls" AND Injoy motors with the optional adapter kit . Switching motors is quick and easy with no change to power cables. Scroll down to the motor section for more information.

Cutoff Switch

Academy of Model Aeronautics 2002-2004 Competition Regulations 9.1.
"All motor powered winches will have a disconnect switch installed in the positive cable to the electric motor or a disconnect in the ignition circuit of a combustion engine."

Machined 1/4" thick steel motor mounting plate. Cutaway design provides maximum drum width and simplifies motor installation. The painted frame has no exotic coatings or plating and can be easily disassembled, stripped and repainted if necessary. Powder coating is not used to better facilitate builder modifications.

Competition Proven V Belt Anti Backlash Brake

The brake arm is machined from a solid piece of wear resistant 304 stainless steel. The brake arm is one of the most challenging pieces of the WN2 system to build because 304 stainless steel is difficult to machine.Welded and fabricated arms were tried and rejected because they eventually failed. Only a solid piece of machined, formed stainless steel is durable enough for serious competition use.This is the same brake arm assembly used by the CVRC Visalia club home of the largest sailplane meet in the World launching thousands of sailplanes in two days and at the AMA Flying site in Muncie home of the AMA Nationals along with many other large meets. The V belt ends are terminated with injection molded polyethylene ends.

Integrated Flange/Sheave Design

A V-belt provides the positive predictable braking action required for competition use. The groove for the "A" size V belt is machined in a solid piece of aluminum forming the inner flange and sheave reducing weight, maximizing drum width and increasing line capacity. The integrated flange/sheave design increases reliability by eliminating sheave mounting and drive hardware.

The drum is machined of 6061T6 aluminum with a 2" dia. core and 6" dia. flanges. A 2" core provides the best energy match to the Ford Longshaft Motor with torque to pull 3 meter + open class TD ships and the speed for zoom launches and downwind conditions. Experience has shown a larger core diameter often results in poor performance and battery life. It's important to keep the rotating mass of a winch drum as low as possible to reduce stress on the brake components and the starting electrical current so a flange diameter of 6" was chosen.

The drum is first rough machined, mounted in a lathe on a precision steel mandrel that duplicates the 5/8" shaft of a longshaft motor then finish machined resulting in a drum with near zero runout.

The end plate is tapered from 3/8" to 1/4" to reduce towline wear and dissipate and withstand pressure from monofilament line that can cause deformation. The drum is driven with a 1/4-20 bolt or a 1/4" tension pin though the existing hole in the shaft. Pin drive provides for quick and easy drum installation and removal without removing winch line. A set screw should never be used because they eventually spin or deform the shaft making the drum almost impossible to remove.

Handle Design
By Popular demand, a parachute hook was added to the handle.

Annealed Copper Buss Bar

There's no point in having a powerful motor and puny copper. The power supply is only as good as the weakest link. The WN2 copper buss bars have a cross section 102% of 1/0 welding cable assuring minimum power loss. Buss bar is formed in a hydraulic press then annealed in a heat treat oven and can be easily shaped to match solenoid spacing.

Review and Construction Article by Paul Ferradas WN2.0 Review

Winch Line
White braided nylon seine twine is most popular for thermal soaring available from Memphis Net and Twine (888) 674-7638 toll free.
TWB #18 170 Lb test 1080 ft./lb for general sport flying.
TWB #21 200 Lb test 840 ft./lb for 3 meter sailplanes and light contest use.
TWB #24 250 Lb test 720 ft./lb for aggressive zoom launching and heavy contest use.

Winch Line Storage Capacity
Drum shown with 32oz of #21 200 lb (1720 ft. measured) braided nylon line. When filled to the edge of the flange, the drum can hold 48oz of line which translates approximately to the following line lengths.
#18 170lb 3200 ft*
#21 200lb 2500 ft*
#24 250lb 2100 ft.

It's good practice to not put more line on the drum than your flying field can accommodate. At the time of launch, there should only be a couple of layers of line on the core. Storing unused line increases the drum diameter and degrades motor performance and battery life.

*AMA and LSF rules limit the distance to the turnaround to 984 ft. (300 meters) so normally no more than 2000 ft. line should be used.

Wiring and Cables Instructions for building cables and electrical part numbers are included

Foot Switches

McMaster Carr Industrial Supply Enter 7024K11 (Linemaster Clipper) or 7377K2 in the search bar. I've used a switch similar to the 7377K2 for years however there are many switches to choose from. Also check out Line Master

Solenoids
Current rating of the contacts is the most important consideration when selecting a solenoid to avoid welding the contacts and a "runaway winch". Contacts should be rated at AT LEAST 750 AMPS. This is especially important when using a 3110/12volt set up or Injoy TB1248 which can draw more than 500 amps CONTINUOUS DUTY usually only means the coil can be energized continually however continuous duty solenoids often have a low contact current rating making them unsuitable for sailplane winch use. Two solenoids should always be connected in series so if one shorts the other will break the circuit.

For added insurance against shorted solenoids check out Cal Posthuma's LED Kit that indicates a shorted solenoid. The switch bracket of the WN2.2 is pre-drilled for easy LED installation.

Here's a short video demonstrating the LED circuit in operation. Click Here to download (224kb)

Motors
About Ford Long Shaft Motors
There are two Ford long shaft motors (FLS) usually designated by the electrical parts industry "Lester" number. Lester 3110 and 3115 are identical except the gauge of the wire in the field coils which can be seen by removing cover over the brushes. The 3110 is a 6 volt motor in service in Ford pickup and industrial trucks from 1954 to 1955 identified by .078" field coil wire. The 3115 is a 12 volt motor in service in cars and trucks from 1955 through 1962 identified by .035" field coil wire. Click here for more Motor Identification info. Be wary of any discussion that refers to FLS without designating which one, 3110 or 3115.

3110 or 3115
It's common now to use a 6 volt 3110 motor with 12 volts which is Very Powerful and may not be appropriate for everyone. Brush and solenoid life is reduced and the extra current increases the possibility of battery failure or hydrogen explosion. In addition, the possibility of an airframe failure during launch is greatly increased. A 3110/12volt setup should be used only by the most experienced. Note: Large molded F3J planes designed to be hand towed by two 300 lb. linebackers are capable of stalling a 3110/12volt set up resulting in burned brushes and damage to the commutator.

A 3115 with a 12 volt battery provides plenty of power for most sailplanes and is probably the best choice for sport flyers. 3115's are easier to find because they were in production longer and more recently. Back in the old days we used 3115's with a 6 volt battery to gently launch all wood sailplanes and should be considered for fragile nostalgia ships like the Airtronics Grand Esprit. (It may be necessary to use 6 volt solenoids)

Motor Shopping
New 3110 and 3115 motors are manufactured in India and available in mass quantity but the armatures are different from the OEM design using a 25 segment commutator instead of OEM 23 segment which is a problem if you want to add after market ball bearing end plates. The new "Indian" motors also have short studs protruding on the front end that will have to be hacksawed off. The power is slightly less than 23 segment OEM motor and the shaft is 1/16" short but they are very affordable and may be acceptable for sport flying. The field coils and housing of the new India motor is identical to OEM and could be used with a 23 segment armature and after market ball bearing end plates. Search Ebay for "Ford 3110" or "Ford 3115" or Check with local starter shop. Check Arrowhead Electrical Products for more reference material.

Rebuilt Long shaft motors are getting harder to find but may be superior to a new "off shore" motor. It's my experience that small independent automotive parts suppliers and automotive electric shops are more likely to stock a 3110 or 3115 motor than the large chain stores. BE SURE TO MEASURE THE SHAFT LENGTH. It should be 5.75" long. Some tractor starter motors have a 5" shaft and are frequently mixed in with 3110's

Injoy Motors
Injoy Lure Coursing offers high quality new longshaft ball bearing, four pole motors that can be used on the the WN2 winch with the optional adapter kit. The adapter kit is currently only available with the purchase of a winch kit however if there is sufficient interest they will likely be available individually allowing both WN1 and WN2 series to retrofitted to use Injoy motors. Email for more information.

The Builder is responsible for insuring safe operation
Part numbers are suggestions. Check with other modelers for additional suggestions and safety considerations
Individual Components
I don't normally sell individual winch components (unless it is a replacement) because it complicates my production schedule. I usually make the components in sets (10drums, 10 frames, 10 brake arms etc) and if I sell one piece then I have an incomplete winch kit.

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