The Tale of a DIY CW Paddle Key

My first DIY Paddle Key 

Way back in 2014 I built a two paddle cw key from basically trash; an empty Tic-Tac box, piece of phone cord, a bunch of popsicle sticks, 3 screws, 3 nuts and a 3.5mm Stereo phone plug. 

With this I attempted to practice morse code sending with the Ham Gadgets Pico-Keyer.

The popsicles sticks levers proved to be too stiff and I swapped them for some FR4 PCB material cut into paddle shapes.

Fast forward eight years and the PCB levers were getting too limber. Squeezing the paddles together cause the PCB levers to curve around the center bolt contact without touching.

In replacing the PCB paddles with a couple pieces of spring steel, I decided to do a redesign and ditch the Tic-Tac box for an open frame key. 

Old PCB levers, trial fit of steel levers
decided to get rid of Tic-Tac box

I used a scrap piece of 1/2 inch plywood for a wood base and a wooden lever mount. I glued and stapled the two pieces of wood together, drilled holes and added a ring terminal and more hardware to the center bolt. I attached the steel levers with a bolt, ring terminal and washer on each paddle. Soldered the three ring terminals to the phone cord, Secured the phone cord with zip ties and placed heat shrink tubing over the paddle ends.   

Finished (?) Two Paddle CW Key

The action is a little stiff, I might have to bevel the sides on the forward end of the wooden level mount to allow the levers to easily touch the center bolt.

As I have the $12 Chinese Paddle as my main paddle this key will serve as a backup.

05 Mar 2022

CW Key - Double Paddles - eBay $12

Made in China 

My G90 has a CW decoder with the built keyer if needed. I tried DIY paddles with some varying success. These were build using all sorts of rubbish, spring clothes pins, biner clips, broken hacksaw blades, an old 2 switch wired computer mouse, popsicles sticks, scraps of copper clad PCB material. etc. I even made a couple touch pad triggered FET switches in an altoid tin. They are not very appealing and tend to break easy and fall to bits. 

On eBay there is a dozen sites that offer what looks like CW paddles off the pages of thingiverse. These are from China and run around $12 as a kit and $25 assembled.

CW Paddles Kit Parts List

3.5mm stereo M-M cable (~4 Feet / 1.5 Meters) 

Plastic Box (6.5cm x 4cm x 3cm) in two parts; box cover and base.

Plastic Paddles (1 left & 1 right)

Red Wire (2.5 inches / 6.4 cm) 2 pcs

Black Wire (2.5 inches / 6.4 cm) 1 pc

Black Heat Shrink Tube (2.5 inches / 6.4 cm) 1 pc

3.5mm Stereo Jack w/ Nut

Brass Ring Terminals - Brass 3 pcs

Brass Bolt 1 cm -  2 pcs

Brass Bolt 2 cm -  1 pc w/ washer brass 2 pc

Brass Nuts - 2 pcs

Steel Bolt 2.5 cm - 2 pcs

Steel Spring 1.5 cm - 1 pc

Magnets - 4 pcs

Steel screws black 1 cm - 4 pcs 

CW Paddle Kit 

Tools I Used:

Soldering Iron w/ rosin core solder

Tip Cleaner

Continuity Checker

Wire stripper 

Hobby knife

Needle nosed Pliers

Flush Diagonal Cutter

Small Phillips screwdriver

Wire Crimper

"Helping Hands"

3X reader glasses

Tools I Used

Build Instructions:

Note: In fitting the Stereo Jack into the Base of the Paddle. I had to clean out the hole and flanges in the base of any excess material with my hobby knife.  Lightly sanding the plastic sides of the jack that sit next to the flanges would improve the fit. I had to gently scrape around the top of all the bolt holes to get the bolts started. Be sure all bolts are square to the part they will thread into.

1. Strip the three wires back 3.5mm/ 0.125" one side only.

2. Crimp ring terminals on wires,  solder ring terminal.

Soldering the crimp connection on ring terminal

3. Cut Heat Shrink into 6 pieces 1cm long. Shrink 1 piece of tubing over each ring terminal shaft. Hold on to remaining 3 pieces for later.

4. On the jack determine which solder terminals are the tip, ring and sleeve with continuity checker or ohmmeter. 

5. Check for fit by placing jack into the flanged hole in base. Sleeve solder lug should  be down. Use hobby knife, drill bit, sandpaper, etc to clear any material obstructing the jack placement. Keep clearing material until jack is a snug fit.

6. On jack gently bend the tip solder lug to the left side of jack and bend the ring solder lug to the right side of jack. (Standard set-up for right handed paddle operators)

Jack wires soldered and jack mounted to flange in base.
(notice I left the black sleeve wire  25mm/1.0" too long.)

7. Check for correct length of black wire to be connect to jack sleeve, place ring thru slit in base and fit into keyhole underside of base.  Black wire only needs to be long enough to reach past the sleeve solder lug.

8. Remove jack from base. Trim off excess black wire leaving enough to strip back 3.5mm/ 0.125". Trim both red wire back 3.5mm/ 0.125".

9. Place remaining cut pieces of heat shrink tube from step 3 on over each wire. Solder red wires to tip and ring. Solder black wire to sleeve.

10. Reinsert jack into flange and orient the jack so the sleeve lug is down be sure ring terminal goes thru slot to underside of base. Secure jack with nut provided.

Underside of base with sleeve ring terminal secured

11. The sleeve ring terminal on black wire is positioned so the ring terminal will fit into the keyhole over screw hole. Place one brass washer under ring terminal. Secure with the 2 cm brass bolt and second washer. The bolt is screwed all the way thru the base to form a post contact between the paddle positions on top of base. Don't over tighten.

12. Take one of the 1 cm brass bolts, place a brass nut halfway down the bolt. Position the tip terminal on red wire outside the left paddle over the screw hole, turn the bolt and washer into the screw hole. The terminal should be captured on the bolt between the nut and the paddle. Set aside for now.

13. Repeat step 12 for the terminal with the red wire connecting the ring of stereo jack and the right paddle. 

14. Use the 2.5mm steel bolts to attach paddles to the base. Do NOT over tighten. Just snug down enough so paddles swing without being lose.

15. Install the steel spring between the paddles, placing ends of spring into the indentation in each paddle. (May want to use a loop of string loosely around paddles to keep spring in place until paddle is adjusted and cover is on)

Adjusting the gaps between the paddle bolts and post contact.
(Notice I used the cover upside down to limit outward paddle travel
and keep from losing the spring, you could also use a loop of string.)

16. Adjust brass bolt in each paddle by screwing in or out to maintain an equal gap between each paddle with the center bolt. Once adjusted tighten brass nuts to keep wires in place next to paddle lever and lock the adjustment.

17. Install a magnet on the underside of each corner of the base by starting  a black steel screw into each magnet hole. 

18. Place cover over the base and secure by fully tightening the black steel screws.

(You may now remove loop of string from paddles as cover opening limits the paddle outward travel and keeps the steel spring secure.

Congrats,

 your $12 Chinese CW double paddle key is now complete. 

Let's celebrate by ordering a big dish of beef chow mein.