My 3d-printed morse key didn't allow me to adjust the throw of the paddle, and I had to move my hand way too far when sending. It was tiring, and I kept occasionally missing a dit or a dah. I swapped out the 12mm M3 screws for 16mm and added a nut. I adjusted the throw to be shorter, then held the screw in place while tightening the nut on the ring terminal to lock it in place.
Then I ran some 400 grit sandpaper against the screws to contour them a bit to fit the screw head they connect to.
Suddenly a lot of the problems I had sending before went away. I still have trouble copying at 10WPM, but sending a sample QSO from paper (so I didn't have to think about spelling while sending) I can now send with this key with few errors at 20WPM...
I hadn't used this key since my nicer Putikeeg arrived. But now I want to do CW #POTA (as my skills increase) so I thought it would be interesting to try strapping this key to my leg... 1/2
Michael K Johnson
in reply to Michael K Johnson • • •I used an infinitely adjustable synthetic belt that fit through the sides to strap it to my leg and practiced sending that way. I found that I could relax my leg while not sending, and then tense my leg while sending to hold the key more firmly in place. The main problem is that if I move, sometimes I activate the paddle, so I need to disable break-in on my transmitter while I'm not actively sending.
I practiced responding to a POTA activation a few times with break-in disabled, and finally decided to take the plunge and actually hunt. It was a very very small hunt (only one QSO) but WG8X took my call from US-3516 in OH.
I suspect that I'll only hunt and not activate for a while, because copying morse code is still really hard. But maybe I can take this to parks and hunt park-to-park as I practice. Or just hunt portable from parks that don't count for POTA because they are municipal or county parks... 2/2
Jason, Human, Average
in reply to Michael K Johnson • • •That is a thing of beauty.
Michael K Johnson
in reply to Jason, Human, Average • • •I might actually finish it and post it with a few more changes.
If I did that, would you (or anyone else here) print it?
I did start my new design strongly influenced by an "ND" design, but that doesn't prevent me from posting a new and somewhat different model, as far as I can tell. I'd also share the FreeCAD model so that others could make their own changes, and I would use a permissive license for it.
#HamRadio #AmateurRadio #CW
Jason, Human, Average
in reply to Michael K Johnson • • •Sure, I'd print it. Sadly I don't have much time for radio these days, and my code is rusty (and that's being generous), so I'm not sure I'd get much use. But printing it is the easy part (how weird we live in a time where I can make that statement).
Seems like this would be a good piece to electroplate. As cool as it looks, it might look even cooler with a smooth nickel plating. 😀
Michael K Johnson
in reply to Jason, Human, Average • • •Here's where I got so far with modeling a similar key based on the approximate dimensions of the model I started with. I set it up with approximately the same mounting holes (what existing thing uses 15mm x 19mm hole spacing that this is set up for?), but with a very different spring mechanism, fillets, chamfers, and cable routing holes.
My hope is that this spring hinge design will self-damp better; the key I printed had such a strong spring action that it could spring all the way across and hit the other contact. I plan to iterate on this design, probably tweaking the spring design until it feels good.
I think that the cable routing holes are a bit big. Mine has a huge cable routing hole because I grabbed a thick wire, but really this should use cheap earbud wires (like they hand out on planes) instead. Much more convenient!
Haven't yet looked at cover, baseplate, sanding jig, or longer slots yet from my punch list, and I suspect that I could add even more fillets.
I might have to make the spring hinge a bit parametric, because I expect that the right wal
... show moreHere's where I got so far with modeling a similar key based on the approximate dimensions of the model I started with. I set it up with approximately the same mounting holes (what existing thing uses 15mm x 19mm hole spacing that this is set up for?), but with a very different spring mechanism, fillets, chamfers, and cable routing holes.
My hope is that this spring hinge design will self-damp better; the key I printed had such a strong spring action that it could spring all the way across and hit the other contact. I plan to iterate on this design, probably tweaking the spring design until it feels good.
I think that the cable routing holes are a bit big. Mine has a huge cable routing hole because I grabbed a thick wire, but really this should use cheap earbud wires (like they hand out on planes) instead. Much more convenient!
Haven't yet looked at cover, baseplate, sanding jig, or longer slots yet from my punch list, and I suspect that I could add even more fillets.
I might have to make the spring hinge a bit parametric, because I expect that the right wall thickness will depend on the type of plastic you use. Probably want thicker walls with PETG than ABS; I'll be printing ABS.
Michael K Johnson
in reply to Michael K Johnson • • •OK, finally got around to printing the design, and that spring was too stiff by far, at least for my taste. I'm trying a new design.
I found some thumb nuts that were originally bed adjustment nuts on my first-ever 3D printer to use to lock in the adjustments for the contacts. This style has a shoulder and is available cheaply online.
I'm also experimenting with putting the body of a 1/8" stereo jack into the hole in the back, so that it can be connected with any 1/8" stereo patch cord rather than having to have a cable permanently connected. That might take some careful soldering, through.
If this design is still too stiff, I'll have to decide between just making it thinner and making a symmetric serpentine shape. I was avoiding a serpentine shape to avoid sloppy contact from the spring stretching, but maybe I'm over-thinking that part.
Michael K Johnson
in reply to Michael K Johnson • • •That spring design was still too stiff, so the symmetric serpentine was indeed the approach I took. To make enough space, I started over completely from scratch again.
This time, I built up as much as possible as only half the part, then mirrored everything across and added the couple of centered features. I also have a groove cutting through a fillet. This meant that I had to put "dress-up features" (fillets and chamfers) all through the design instead of all at the end. This makes a parametric design more fragile. To combat this, I placed all sketches on base planes and offset them by parametric amounts instead of putting them on faces.
This key is working, but it wants some accessories. The groove down the side is to intersect with a cover/handle, a belt mount, a desk mount that puts the lever off the table, or whatever else one wants... I haven't designed those yet, but they are coming soon.
When I'm done, I will distribute all off this under a license that allows derivatives.
Michael K Johnson
in reply to Michael K Johnson • • •For example, here's a cover that slides over the key to give a bit longer grip, protect the wiring, and elevate the key off the table if it's set on a table. I'm still working on making the sliding fit perfect by getting the right amount of interference. I'm printing my 4th iteration now as I approach
perfectiongood enough. 😀Next, I'm thinking of a belt mount with a locking swivel so you can attach it to your leg at a comfortable angle for you.
Michael K Johnson
in reply to Michael K Johnson • • •My #3DPrinted #MorseCode key design is coming along.
The cover/handle works really well, I think. I printed it just long enough to be comfortable in my hand. Someone else might want it shorter or longer.
Meanwhile, I've also designed a belt mount. The belt goes through slots in a base that goes under the key, and it goes over the key to make it a solid fit. I could have done one where the belt goes underneath, but this seems like it would be more solid. Then the key slides into a block that swivels, and a few more thumb nuts lock it into any location you like within 40° left or right of center.
This is extremely parametric. The height of the block, the allowed degrees of swing, how thick and wide the belt are, how wide the whole thing is; most of the dimensions are derived from parameters.
This is the second revision of the base and swivel. The first version didn't swivel far enough, the key wasn't raise up far enou
... show moreMy #3DPrinted #MorseCode key design is coming along.
The cover/handle works really well, I think. I printed it just long enough to be comfortable in my hand. Someone else might want it shorter or longer.
Meanwhile, I've also designed a belt mount. The belt goes through slots in a base that goes under the key, and it goes over the key to make it a solid fit. I could have done one where the belt goes underneath, but this seems like it would be more solid. Then the key slides into a block that swivels, and a few more thumb nuts lock it into any location you like within 40° left or right of center.
This is extremely parametric. The height of the block, the allowed degrees of swing, how thick and wide the belt are, how wide the whole thing is; most of the dimensions are derived from parameters.
This is the second revision of the base and swivel. The first version didn't swivel far enough, the key wasn't raise up far enough above my leg, and the whole thing was too wide. If the key isn't high enough, I inadvertently TX from my pants leg fabric brushing the key. This is because I have the key set to maybe 0.5mm travel to each side; it's quite sensitive. On this iteration, it's slightly too narrow; I can only fit a thin belt through it because the thumb nuts that lock the swivel in place interfere. The next version will be just a little wider.
I think I'm ready for some beta testers! Folks who don't mind running FreeCAD to adjust parameters and print multiple copies to adjust for the filament they are using could help make this good for others. Any #HamRadio #AmateurRadio CW enthusiasts also enjoy 3d printing and want to try this?
field94Mop
in reply to Michael K Johnson • • •Michael K Johnson
in reply to field94Mop • • •I've been using STEP files instead of STL as outputs, but really one of the values of this one is the parameterization available using FreeCAD. For example, the hole in the back can be smaller if you want to just run a wire into it, or you can choose the diameter to fit a 1/8" stereo jack, and print it that way.
But I can send you STLs.
What type of plastic will you print in?
Do you like a light touch or heavy touch for your keys?
Do you have an m3 tap to cut threads in the plastic?
Hardware required to complete the key:
Hardware for the swivel base:
Michael K Johnson
in reply to field94Mop • • •@field94Mop I've done a lot of updates. See the README and all the STEP and STL files I built in the project releases.
Please let me know how it goes!
README.md · main · Michael K Johnson / Single-Paddle-Key · GitLab
GitLabfield94Mop
in reply to Michael K Johnson • • •Michael K Johnson
in reply to field94Mop • • •@field94Mop Ah, always either fun or "fun" fixing the broken printer, depending on whether part of the 3d printing hobby is the fiddling with the printers themselves...
(I have one nearly-stock printer, and one that is my playground for trying out new 3d printer ideas on, which is currently about 90% repaired from a redesign of the head after a giant blob of death.)
field94Mop
in reply to Michael K Johnson • • •Michael K Johnson
in reply to Michael K Johnson • • •VBand - Ham Radio Solutions
hamradio.solutionsStu Gott
in reply to Michael K Johnson • • •Michael K Johnson
in reply to Stu Gott • • •Stu Gott
in reply to Michael K Johnson • • •Michael K Johnson
in reply to Stu Gott • • •@stu I first tried FreeCAD in January 2016. I was so confused. I went straight to OpenSCAD, which made lots of sense to me.
Simple fillets and chamfers were what eventually won me over to FreeCAD four or five years ago. But also my machining hobby and making technical drawings, which FreeCAD is good for
FreeCAD can actually integrate OpenSCAD, and I've used that a few times.
Michael K Johnson
in reply to Michael K Johnson • • •I have created a public repository with the FreeCAD file and a fairly detailed README about the parameters and build process:
gitlab.com/mcdanlj/Single-Padd…
If anyone needs STLs or STEPs, send me a private message with any parameters you need set differently from the default, and your email address and I can send you the files with those parameters set.
Or just download FreeCAD and set them yourself; I included instructions in the README for how to do that.
Michael K Johnson / Single-Paddle-Key · GitLab
GitLabMichael K Johnson
in reply to Michael K Johnson • • •This design is ready for you to test!
I printed out keys with six different variations on spring strength, four different sizes of covers, two different heights of swivel bases, and brought them all to my local club monthly show-and-tell. A few others club members have also printed them. I took some feedback, and have now updated the documentation and released STEP and STL files for multiple configurations.
The ones I printed were ABS. One club member printed in PLA, and another in PETG, so it looks like this design can work well across multiple types of filament. One club member screwed down what I had meant as a belt swivel mount to a board that you rest your wrist/forearm on and it's a very clever addition! Picture attached.
I
... show moreThis design is ready for you to test!
I printed out keys with six different variations on spring strength, four different sizes of covers, two different heights of swivel bases, and brought them all to my local club monthly show-and-tell. A few others club members have also printed them. I took some feedback, and have now updated the documentation and released STEP and STL files for multiple configurations.
The ones I printed were ABS. One club member printed in PLA, and another in PETG, so it looks like this design can work well across multiple types of filament. One club member screwed down what I had meant as a belt swivel mount to a board that you rest your wrist/forearm on and it's a very clever addition! Picture attached.
I would like lots of detailed feedback! If you are interested in a single-paddle morse key, it doesn't matter whether you want a very light or extremely stiff spring or anything in between, this design can meet your needs. It's not expensive. You may be able to use random hardware lying around the house, especially if you have spare parts for 3d printers, but I also have links in the documentation for various hardware you can use with it.
Lots of options and possibilities, and if you need help, please don't hesitate to speak up!
#AmateurRadio #HamRadio #CW #MorseCode
The Raleigh Amateur Radio Society
rars.orgMichael K Johnson reshared this.
Kris Mitka
in reply to Michael K Johnson • • •so while my local club sits around and talks about how one of the key contributors to WiFi and spread spectrum had great tits, Raleigh is out there creating new things!
Nice!
Michael K Johnson
in reply to Kris Mitka • • •@mitka At the same gathering, KO4HUI Rob was showing off his latest open source Spooltenna work, another group was characterizing an old switchable signal attenuation box rescued from scrap, someone was showing off a homebrew regenerative receiver made manhattan-style on un-etched copper-clad, someone else demonstrated a new battery box setup with lots of different power options, another member was showing a QRP POTA setup with an amazingly cute little metal iambic key, and I didn't even get around to talk to everyone because I was talking about my key with a bunch of interested folks. It was quite a buzzing convocation!
This is the club that runs RARSfest, which is happening the weekend after next, and as a baby ham I'm really looking forward to being a volunteer at my first-ever hamfest. 🎉
Spooltenna Store
SPOOLTENNAKris Mitka
in reply to Michael K Johnson • • •Thanks.
I am going to try your 3d print out.
Which files do you recommend for a beginner? I noticed you have varying weights and sizes at gitlab.com/mcdanlj/Single-Padd…
Michael K Johnson
in reply to Kris Mitka • • •@mitka I prefer the lightest springs, the "feather" or "light" configurations. I am also a beginner, but I adjust my adjustable keys with minimal tension and close contact, like a tenth of a millimeter or even less.
The heaviest springs are because I'm told that some people like really high tension, but I wouldn't start there. If you haven't developed those habits, start light and your wrist will thank you. 😀
If you find it's too light, it's just a few grams of plastic, and I designed them to print without supports to minimize waste otherwise.
Daniel Marks
in reply to Michael K Johnson • • •I tried a design using an undulating Z spring made out of the printed material so the key is all one piece. There are also FreeCAD files available as well.
github.com/profdc9/RFBitBanger…
github.com/profdc9/RFBitBanger…
RFBitBanger/CAD/PaddlesKey-PaddlesKeyBody.stl at main · profdc9/RFBitBanger
GitHubMichael K Johnson
in reply to Daniel Marks • • •@profdc9 This also is a single-piece print of the key proper, including a symmetric undulating S spring (curved to avoid concentrating stress), but a single-paddle key instead of iambic.
I've attached a bottom view showing the printed-in spring.
The other parts in my design are accessories. It's possible to use this key without any of them, though when I hold it I prefer a longer handle to make it more comfortable in the hand. I have used it more often strapped to my leg, practicing to get comfortable for POTA operations. ☺
Daniel Marks
in reply to Michael K Johnson • • •Michael K Johnson
in reply to Daniel Marks • • •@profdc9 That is why I tried to avoid stress risers, though I did run into problems getting FEM set up to work in FreeCAD and so haven't done a formal stress analysis. There's absolutely plenty of room to make the spring plan form area larger.
In this first formal release, I actually made the spring smaller than the initial prototypes, but the thickness of the spring elements, the radius of the bends, and the width of the area the spring is in (and thus the length of the spring legs) are all parametric. That width could go up close to the width of the body, and the radius can be increased a bit. But the thinner the spring, the less stress to the spring from flexing, which was why with thinner springs I use a smaller radius for the configurations that I exported.
Additionally, the amount of gap between the sides of the lever and the body is parametric. I meant it to be small enough that the springs are always in the elastic region, but without analysis I don't kno
... show more@profdc9 That is why I tried to avoid stress risers, though I did run into problems getting FEM set up to work in FreeCAD and so haven't done a formal stress analysis. There's absolutely plenty of room to make the spring plan form area larger.
In this first formal release, I actually made the spring smaller than the initial prototypes, but the thickness of the spring elements, the radius of the bends, and the width of the area the spring is in (and thus the length of the spring legs) are all parametric. That width could go up close to the width of the body, and the radius can be increased a bit. But the thinner the spring, the less stress to the spring from flexing, which was why with thinner springs I use a smaller radius for the configurations that I exported.
Additionally, the amount of gap between the sides of the lever and the body is parametric. I meant it to be small enough that the springs are always in the elastic region, but without analysis I don't know whether that's correct for the thickest springs. On the other hand, the stiffest springs are so stiff that they are unlikely to move a lot. I personally can't imagine using the heaviest configurations at all. But I created extra configurations because I want to hear back from hams with other preferences.
My own preference is for minimal key movement, so I initially adjusted the contacts so close that just sliding the cover on closed both contacts from lightly squeezing the body together. I backed it off just far enough that I can put the cover on, or put it on the leg strap holder, without sending both dit and dah!
sergio_101
in reply to Michael K Johnson • • •Michael K Johnson
in reply to sergio_101 • • •sergio_101
in reply to Michael K Johnson • • •SKCC has lots and lots of people giving out QSO points.. and the SST is a great place to make a ton of contacts in an hour.
Michael K Johnson
in reply to sergio_101 • • •@sergio_101 My experience so far as a baby ham is that some SKCC operators have beautiful, easy-to-copy fists, and others are wildly syncopated and jazzy, or send dahs that are 10-12 dit-lengths, and break my brain. I'm sure when I've had a few years of experience that will all feel like just fun different accents, but for now I try to find ragchews with good fists to help build an intuition of what a clean fist should sound like, and practice my head copy.
One of my first CW ops was responding to K1USN on SST. Though last Sunday was my first Sunday since DST looking for SST and I couldn't find anyone calling CQ SST, not even K1USN. Thought that was weird and started calling CQ SST. Someone finally kindly came back to me to point out that it didn't start until 0Z and it wasn't time yet. 🤦
sergio_101
in reply to Michael K Johnson • • •OMG!
I got my radio tuned up.. and got on deck for SST on on friday.. and the bands were 100% DEAD..
Then, i looked at the calendar and realized we were in EDT now.. an hour later, and the bands were full.
I am an old timer, so i usually work super hard to work the unsteady fists, just in case it's someone new. but there is no way i could have done that when i was newer to CW..
Michael K Johnson
in reply to Michael K Johnson • • •If you have a local ham club with several people interested in this key, you can buy brass hardware, and with the links in the README can buy enough to make 5 keys for $50 (with a bunch left over because of different multiples, of course). I did this because I intend to make several of these keys for testing and display.
But it works fine with far cheaper stainless hardware; brass just looks nicer. As far as I can tell, most hardware stores even in the US have M3 metric hex socket screws in bins, so you don't have to buy 10-packs or 50-packs of hardware. This works perfectly fine. You just need a hex wrench and a small box-end wrench or needle nose pliers or forceps/hemostats or something to tighten the nuts when you adjust spacing.
My goal here is to help make it cheap and easy to have a really usable key.
And if you run into any problems, please please ask for help! The whole point of the beta release is to get feedback so I can improve both the models and the instructions before posting this more widely.
#AmateurRadio #HamRadio #CW #MorseCode
Ĝan Ŭesli Starling, KY8D
in reply to Michael K Johnson • • •Michael K Johnson
in reply to Ĝan Ŭesli Starling, KY8D • • •@Aplonis Oh sorry, I'm used to a Mastodon client that shows the whole thread just by scrolling up. Here are a few pictures, and if you like, you can look at the thread starting here for more pictures as I worked on this over the past few weeks. 🎉
I also plan to add images to the README during the beta period, including assembly instructions with pictures. Or maybe break out a separate assembly guide. Something like that...
@Aplonis Oh sorry, I'm used to a Mastodon client that shows the whole thread just by scrolling up. Here are a few pictures, and if you like, you can look at the thread starting here for more pictures as I worked on this over the past few weeks. 🎉
I also plan to add images to the README during the beta period, including assembly instructions with pictures. Or maybe break out a separate assembly guide. Something like that...
Michael K Johnson
2025-03-10 22:28:51
Michael K Johnson
in reply to Michael K Johnson • • •@Aplonis Also this separate post to the FreeCAD community about how I used FreeCAD to do the design has a few pictures as well.
Michael K Johnson
2025-03-28 11:30:45
Michael K Johnson
in reply to Michael K Johnson • • •The
secondthird beta release of my #HamRadio #MorseCode single-paddle key is out. The spring weights have been adjusted based on some feedback. Each key has an identifier associated with the weight on the bottom to make it easy to tell them apart. There is now a separate mounting plate for a clipboard or forearm plate like Dan WY3O brought to the RARS meetup.It's not actually necessary to use ring terminals, especially while experimenting. You might want them on a final version, but while testing, bare wires under the lock nuts and center screw are probably good enough. If I were carrying this POTA or SOTA, though, I'd want the ring terminals for durability.
I'm eager for feedback, and if I get time to print off a new batch tomorrow, I might bring a set to RARSfest Saturday.
#AmateurRadio #CW
0.3 Beta · Michael K Johnson / Single-Paddle-Key · GitLab
GitLabMichael K Johnson
in reply to Michael K Johnson • • •Looks like the labels were too big, resulting in some corner lifting in my test print, which will make them not interface with with the holders. Oops.
So I made the labels a little smaller and made a new beta release. I also put some example hold-down screws in the assembly showing the new mount.
Hopefully that print goes better. I hate creating waste. 🤞
Seb DA6SEB
in reply to Michael K Johnson • • •love that design with the print-in-place spring!
I've been using magnets in my attempts to make a decent paddle but that comes with its own challenges - mostly around adjusting the force. So now I'm making another one that will put them onto adjustment screws but that feels very over-engineered.
I also want to add the option to print a heavy base as I've been lugging around a piece of steel to put the mag paddle on ...
Michael K Johnson
in reply to Seb DA6SEB • • •@DA6SEB@darc.de Thank you!
Further down thread, you can see that one of my beta testers came up with the idea of screwing it down to a board that rests under your arm, and as a result I made a swivel fitting just for that. Maybe something like that would be an option for you?
Seb DA6SEB
in reply to Michael K Johnson • • •I like the swiveling leg-strap version but I think eventually I'll make something that attaches directly to the radio by incorporating a dovetail in a fitting that screws to the radios front side corner.
But it would be nice to have that then swivel around instead of being at a fixed angle!
I also saw a kind of clipboard-like setup in a YouTube video (that I can't find now) where everything - radio, paper notebook, mobile phone and CW paddle - is attached to it.
Michael K Johnson
in reply to Seb DA6SEB • • •@DA6SEB I've thought about making a swivel mount designed for clipboards, but my ideas for that haven't gelled yet; still letting that roll around in my head.
I have the Elecraft built-in front-mounted iambic paddle, but I like the single lever better and am thinking about designing a 3d-printed single-paddle key for my KX3. But I'd try to make it smaller, and haven't worked out a design I like. Meanwhile I'm just using my paddle, held in my left hand, alternating poking on phone and operating the paddle with my right.
Michael K Johnson
Unknown parent • • •@cad_viewer Have you thought about making that a clickable link? At least in your profile, where you have the option to link to a web site?
Do you have examples of integrating info a gitlab page?
Michael K Johnson
Unknown parent • • •Michael K Johnson
Unknown parent • • •Michael K Johnson
Unknown parent • • •@cad_viewer Ok, while I'm on a roll, a few more questions! 😁
Not being Open Source / Libre software, how do you distinguish your project from GrabCad?
How is this different in practice from making an OnShape project with some STEP/IGES files imported into it, as an alternative gratis part display with assemblies?
With respect to embedding as a proprietary service within open source projects as a display engine, what would differentiate it for them from using open source STEP web display built from OpenCASCADE and wasm? (Because, having a choice, who uses IGES over STEP? I was originally introduced to IGES as "I guess...")
Michael K Johnson
Unknown parent • • •@cad_viewer Well, that's "how you wonder if someone else will distinguish you from GrabCAD" and I'll let you do your own market research.
But I've also seen open source web-based STEP model visualization that honored colors at least; don't remember whether what I saw included a representation of the tree, since when i care about that i have it open in FreeCAD anyway. 🙂
Michael K Johnson
Unknown parent • • •@cad_viewer Right, my questions are only somewhat related to "what is your market?" and were really started by your opening suggestion that I would have a reason to use your services for my Morse code key design, then more generally what a community hobbyist would want, since you started this with an assumption of community outreach.
I still don't grok why a commercial entity is operating from a .org domain; that sets up weird expectations.