Last year, I purchased the CWMouse paddles from KN6FQM, and they have seen some heavy use in the field. They have become my go-to paddles for portable use. Starting in 2026, Mike made an improvement in the material he uses for 3D printing, so I added a second set of CWMouse paddles to my arsenal. … Continue reading "Another Mouse in the House" Go to Source

(Microcwmouse and Cwmouse) I embarked on sharing my CWMouse Iambic Paddle with others a year ago. I finalized the design, manufactured 100 units and sold all of them during 2025. The reviews on ebay, eham and amazon are overwhelmingly positive. I had only two “warranty” repairs - both due to exceeding PLA storage temperatures (both in locked vehicles in summer heat). ### Lessons #### Material Science The biggest lesson is that I should have used PETG instead of PLA from the beginning. Having temperature warnings is not enough and I suspect a few more units have “melted”1, but their owners didn’t contact me for a replacement. After calibrating my 3d printer for PETG, I made a few special-order units in PETG. I learned that despite using same printer and optimal settings, there were dimensional changes making PLA-designed, but PETG-printed, paddles in need of tweaks to assemble correctly. Parameterizing the model for different materials, or maintaining a PETG fork, is more overhead than just switching all production to PETG. A surprising finding was that while PETG **does** print slowly, it is much less significant impact on overall print time than that suggested by extrusion speed. A lot of time during a large bulk print is spent traveling between pieces and with Delta Printers it is very fast. Mechanical strength, temperature resistance and (in my opinion) nicer surface finish are some of the PETG advantages over PLA. #### Commerce Different stores have very different reach and costs. **Ebay** is very popular with Ham Radio Amateurs and provides not only a store, but also a search/advertising service. They have the best international shipping logistics and prices. I sold many CWMouse units to hams around the world! Ebay services are reflected by their high fees. The down side of Ebay is that they are very protective of their position and punish sellers for sharing their web site or email address - they want ebay exclusive lock-in. **Etsy** sold only two units. It has lower fees, but does not appear to have many Hams frequenting it. **Amazon** is painful. First I tried FBM2 which had a few downsides and later switched to FBA3 which had ever more downsides. FBM cannot offer prime shipping, as I’m responsible for packaging, dropping off at USPS and logistics. Amazon very aggressively nags about shipping within 24h and keeps a scoreboard. Even when shipment is delivered late due to USPS, they count it against the seller. FBA requires sending bulk package of a dozen+ units, which is a lot of work at-once, but no more per-unit effort than when I make small batches on-demand. Disappointingly, all of my FBA bulk shipments were delayed in warehouses for well over A MONTH, before Amazon started selling them. Offering Prime is convenient for customers, but all of this is reflected in high fees to Sellers. My last FBA shipment was lost. This was extremely disappointing, as a large part of my motivation is knowing Hams are using my paddles. To add salt to the wound, Amazon offered to reimburse me for only a THIRD of my price for the units they lost. There is still a small chance that after the holiday rush, 12 units of CWMouse will be found and offered for sale. Suffice to say, once this situation runs its course, I’m stopping sales via Amazon. **Stripe** is the best experience for a small operation like me. They are an online payment processor with a small fixed fee per transaction and very easy to integrate with web sites. CWMouse is already “out there” and I rely on search engines and word of mouth for sales via Stripe from my web page. All prices reflect middle-man fees, as cost of my time is fixed. If customers find CWMouse via search engines and purchase using Stripe link on cwmouse.com, they’ll save as much as $10 per unit compared to other stores. ### New Products (Qrp Radio Cover) In 2025 I built a QRP-Labs QCX-mini and bought an assembled QMX. I designed a protective magnetic cover that works with both. The cover doubles as an angled stand during operation which improves screen readability. I added this product to my web page and priced it competitively. The production of the original CWMouse is coming to an end. I have enough components to build at most half a dozen more units in PETG. Separately, if Amazon finds my bulk shipment, a dozen more PLA units will be made available. After that, I’m switching to uCWMouse4. (New Ucwmouse Half Case Model) **uCWMouse** is the outcome of my CWMouse experience. It is designed to be printed in PETG only. It is based on the same switches and the same paddle geometry as CWMouse. It has the same finger-feel as CWMouse. What is different, is that I further reduced parts count, optimized it for easier+faster assembly and it is even smaller and lighter than the original. It will be available in 2026. CWMouse has its own web site at cwmouse.com! * * * 1. melted: PLA deforms at 140F which is easily reached in a locked car on a summer day - see post ↩︎ 2. FBM: Fulfilment by Merchant - stock is managed, packaged and mailed by the Merchant -> me. ↩︎ 3. FBA: Fulfilment by Amazon - prepackaged and pre-labeled units are sent in bulk to Amazon which ships them on-demand from their warehouses. ↩︎ 4. u: micro: as in - an even smaller CWMouse :) ↩︎

(Melted Cwmouse) CWMouse is printed in PLA material. Since mid-2025, I’ve been including in packaging a note with storage temperatures reminder. PLA softens at 140F, which is easily exceeded in a locked vehicle (or Pelican case) in direct sun on a hot summer day. (Card Reminder) Through experimentation, I determined that on a hot 100F day, in free-air, sitting on a bench or in a breathable backpack, the temperatures are very unlikely to reach 140F and CWMouse will be unaffected. One of my customers left his CWMouse inside a locked RV on a hot 100F summer day and found it melted, twisted and no longer functioning as the storage temperature was exceeded. I am working towards offering a paddle printed in PETG, which is a more expensive material, which prints slower, but does not soften until 180F. (Twisted Lid and Arms) (Lid Deformation) (Bowed Arms and Base)

(Cwmouse Available on Amazon Prime) I’m still producing CWMouse Iambic Keys based on mouse micro-switches and pivots supported by four ball bearing for exceptional precision and smoothness. The process of on-boarding Amazon took much more time and patience than anticipated, and almost two months!! Since I had to send out a large batch to get started, all my stock at this time is on Amazon. Until it mostly sells, I’m not motivated to make more, hence eBay may be out of stock for a while. Do note that Amazon price is very competitive, as Prime members get free shipping! I hope you try it and share a review with #cwmouse tag :) 73!

(Cwmouse Available on Amazon Prime) I’m still producing CWMouse Iambic Keys based on mouse micro-switches and pivots supported by four ball bearing for exceptional precision and smoothness. The process of on-boarding Amazon took much more time and patience than anticipated, and almost two months!! Since I had to send out a large batch to get started, all my stock at this time is on Amazon. Until it mostly sells, I’m not motivated to make more, hence eBay may be out of stock for a while. Do note that Amazon price is very competitive, as Prime members get free shipping! I hope you try it and share a review with #cwmouse tag :) 73!

(Cwmouse Available on Amazon Prime) I’m still producing CWMouse Iambic Keys based on mouse micro-switches and pivots supported by four ball bearing for exceptional precision and smoothness. The process of on-boarding Amazon took much more time and patience than anticipated, and almost two months!! Since I had to send out a large batch to get started, all my stock at this time is on Amazon. Until it mostly sells, I’m not motivated to make more, hence eBay may be out of stock for a while. Do note that Amazon price is very competitive, as Prime members get free shipping! I hope you try it and share a review with #cwmouse tag :) 73!

(Parts for 24 Cwmice) (Simplified Front Face) (Cwmouse on the Underside) (Optional Callsign) (Business Card Front) (Business Card Back) CWMouse is a precise, lightweight, micro-switch based and affordable Iambic CW Paddle. In previous posts Refining CWMouse and Coverage and E-Commerce Changes, I explored design changes to ease assembly, keeping costs down and noted efforts to diversity Sales. Below I share what worked, what didn’t and provide project updates. ### Design Changes Explored * Design a through-hole PCB - alternative found. * This was to ease soldering of wires to audio-jacks. * Instead, I experimented with a different jack designs and found one which allows easy direct soldering. * Design will be updated once I run out of my stock of audio-jacks. * Offer unassembled kits - not taken. * There is 0 interest in this option. * Switch parts suppliers - completed. * I made orders in bulk and saved on unit costs. * Switch bearings from 14mm to smaller units - not taken. * Competitively priced, high quality bearings could not be found in sizes below 14mm OD. All units I located were either more expensive or lower quality. One area identified for improvement was less than 100% yield on printed parts. It was completely solved by: * a) Refining my print plate preparation process. * Involves strict clean, degrease and application of adhesion agent. * This eliminated lifting of corners preventing deformed and unusable parts. * b) Refining the design of lettering on the CWMouse. * The small below surface lettering was a source of print failures. * The solution was to move the `"CWMOUSE"` text to the back and use a larger bolder font. * Any print deviations are now minor, on the back and less noticeable. Two areas of limited value and high time commitment were identified: * i) Lids printed with **custom callsign** required printing after customer placed an order. * This is very inefficient from production point of view, as it requires 3d printer-time ON-DEMAND for printing just one lid. * I switched to making a small plate with the callsign which prints reliably in 2min. * The custom callsign is offered only via ‘Stripe direct payment’ option. * ii) Personalized notes overhead. * Cannot be done for Amazon. * Many customers don’t care. * My handwriting is not the most legible. * The note doesn’t make a good “leaflet” to hand to a friend. * Solution: I designed a business card with all necessary information. ### E-Commerce Changes Today I offer CWMouse through four stores: * Stripe direct payment * Lowest fees. * **Custom callsign** is available with this option * Make sure to provide your callsign on the order form! * Includes a personalized “Thank You” note. * Amazon * Reasonable fees. * Bulk fulfillment - no possibility of personalization. * Ebay * Highest fees. * Very popular option with lots of reviews. * This is the only option with **international shipping**. * Etsy * I tried - but haven’t yet made a sale on Etsy :) Every box now includes a business card with a big “Thank You”, contact info, QR code, a picture of CWMouse and an ask to please leave a review. Handing this card to your friends is another way to support CWMouse. ### Future work I’m exploring 3d printing in PETG, considering color options, including translucent paddles and wood-fiber, but I need your input (link in bottom-right of this post) to know what folks will buy. ### Summary CWMouse taught me a lot how to run a (very) small business and how to refine a product with customer, and manufacturer in mind. If you are an existing customer, please drop a review on the site where you purchased your CWMouse and consider reviewing on eHam.net. Thank You again, 73 KN6FQM :)

(Parts for 24 Cwmice) (Simplified Front Face) (Cwmouse on the Underside) (Optional Callsign) (Business Card Front) (Business Card Back) CWMouse is a precise, lightweight, micro-switch based and affordable Iambic CW Paddle. In previous posts Refining CWMouse and Coverage and E-Commerce Changes, I explored design changes to ease assembly, keeping costs down and noted efforts to diversity Sales. Below I share what worked, what didn’t and provide project updates. ### Design Changes Explored * Design a through-hole PCB - alternative found. * This was to ease soldering of wires to audio-jacks. * Instead, I experimented with a different jack designs and found one which allows easy direct soldering. * Design will be updated once I run out of my stock of audio-jacks. * Offer unassembled kits - not taken. * There is 0 interest in this option. * Switch parts suppliers - completed. * I made orders in bulk and saved on unit costs. * Switch bearings from 14mm to smaller units - not taken. * Competitively priced, high quality bearings could not be found in sizes below 14mm OD. All units I located were either more expensive or lower quality. One area identified for improvement was less than 100% yield on printed parts. It was completely solved by: * a) Refining my print plate preparation process. * Involves strict clean, degrease and application of adhesion agent. * This eliminated lifting of corners preventing deformed and unusable parts. * b) Refining the design of lettering on the CWMouse. * The small below surface lettering was a source of print failures. * The solution was to move the `"CWMOUSE"` text to the back and use a larger bolder font. * Any print deviations are now minor, on the back and less noticeable. Two areas of limited value and high time commitment were identified: * i) Lids printed with **custom callsign** required printing after customer placed an order. * This is very inefficient from production point of view, as it requires 3d printer-time ON-DEMAND for printing just one lid. * I switched to making a small plate with the callsign which prints reliably in 2min. * The custom callsign is offered only via ‘Stripe direct payment’ option. * ii) Personalized notes overhead. * Cannot be done for Amazon. * Many customers don’t care. * My handwriting is not the most legible. * The note doesn’t make a good “leaflet” to hand to a friend. * Solution: I designed a business card with all necessary information. ### E-Commerce Changes Today I offer CWMouse through four stores: * Stripe direct payment * Lowest fees. * **Custom callsign** is available with this option * Just email me with your callsign after placing an order!! * Includes a personalized “Thank You” note. * Amazon * Reasonable fees. * Bulk fulfillment - no possibility of personalization. * Ebay * Highest fees. * Very popular option with lots of reviews. * Etsy * I tried - but haven’t yet made a sale on Etsy :) Every box now includes a business card with a big “Thank You”, contact info, QR code, a picture of CWMouse and an ask to please leave a review. Handing this card to your friends is another way to support CWMouse. ### Future work I’m exploring 3d printing in PETG, considering color options, including translucent paddles and wood-fiber, but I need your input (link in bottom-right of this post) to know what folks will buy. ### Summary CWMouse taught me a lot how to run a (very) small business and how to refine a product with customer, and manufacturer in mind. If you are an existing customer, please drop a review on the site where your purchased your CWMouse and consider reviewing on eHam.net. Thank You again, 73 KN6FQM :)

(Stock Image: Online Store) The online store where I sold the CWMouse Iambic Paddle blocked my listing this Sunday morning. They didn’t like that I was answering questions from a potential buyer and interpreted our conversation using their own messaging system as me funnelling people to a competing online store. ### Problem There was not a single problem in sight. Due to a family travel I suspended sales by reducing the number of units to 0. One of the potential customers watching CWMouse on this site, asked when I’ll have more in stock. I responded that I will contact him when I make more units available. (Cwmouse With Penny) Today I reached out with a note that more units are available and edited the listing. The conversation was plain and simple. No links, no phone numbers, nor email addresses were exchanged. Within minutes, I received a _violation_ and my listing was suspended. Vague language noted no sharing of contact info. As I didn’t share any contact info via site’s messaging system, I eventually reasoned that they took offense to my listing having `cwmouse.com` in plain text. I removed the `.com` and got my listing re-instated. My own web site http://cwmouse.com/order/ previously ALWAYS linked to this very large and popular four-letter online store whose logo is red-blue-yellow-green. ### Solution Diversify, diversify, diversify. Same answer for investing, media presence and for commercial endeavors. While this online store had somewhat high fees, it was effective, convenient and worked for me - at least until they got in my way. I was content to just cruise-control and sell exclusively via their site. Now I have Etsy, I am working on setting up Amazon Marketplace but will keep the former store listing active. May the market decide which of them will win most middleman fees. (Preview: Etsy Listing for CWMouse)

(Stock Image: Online Store) The online store where I sold the CWMouse Iambic Paddle blocked my listing this Sunday morning. They didn’t like that I was answering questions from a potential buyer and interpreted our conversation using their own messaging system as me funnelling people to a competing online store. ### Problem There was not a single problem in sight. Due to a family travel I suspended sales by reducing the number of units to 0. One of the potential customers watching CWMouse on this site, asked when I’ll have more in stock. I responded that I will contact him when I make more units available. (Cwmouse With Penny) Today I reached out with a note that more units are available and edited the listing. The conversation was plain and simple. No links, no phone numbers, nor email addresses were exchanged. Within minutes, I received a _violation_ and my listing was suspended. Vague language noted no sharing of contact info. As I didn’t share any contact info via site’s messaging system, I eventually reasoned that they took offense to my listing having `cwmouse.com` in plain text. I removed the `.com` and got my listing re-instated. My own web site http://cwmouse.com/order/ previously ALWAYS linked to this very large and popular four-letter online store whose logo is red-blue-yellow-green. ### Solution Diversify, diversify, diversity. Same answer for investing, media presence and for commercial endeavors. While this online store had somewhat high fees, it was effective, convenient and worked for me - at least until they got in my way. I was content to just cruise-control and sell exclusively via their site. Now I have Etsy, I am working on setting up Amazon Marketplace but will keep the former store listing active. May the market decide which of them will win most middleman fees. (Preview: Etsy Listing for CWMouse)

(3d Printing Batch Smooth) (3d Printing Batch Textured) (Wiring Work) (Assembly Desk) (Two Units Nearing Completion) (Assembled Paddle Before Buttoned Up) Since Jan 2025 when I started CWMouse, I sold enough units to print and manufacture a number of batches. The reviews are good and folks are starting to post YouTube videos mentioning it! 😁 Now I’m exploring how to reduce my time needed to assemble CWMice and making them even more price competitive. ### CWMouse media coverage I reached out to a number of hamradio bloggers, podcasters and youtubers, if they would like to take a look at CWMouse. Jim “Ham on a Bike” **N4JAW** responded and was the first to review it on his blog and shared a YouTube video of CWMouse in action. (Youtube Video) Yesterday I found a YouTube video review by Bruce **AA7AR** who discovered CWMouse via eBay, bought his own and was kind enough to post a review. (Youtube Video) ### Design: existing time saving features * printing in batches * 8 hours of print time is needed for six units * completed in two steps: a) textured parts, b) smooth parts * printed parts require no supports and no post processing * soldering in batches * cutting and pre-tinning all jumper wires * soldering audio-jacks to micro-switches * epoxying in batches * micro-switches to switch-trays * audio-jacks into cases * using only three bolts for assembly * fewer bolts1 means less assembly time * using electric screwdriver * no inserts or nuts, all holes are engineered for one-time self-tapping by machine bolts ### Design: more changes * create through-hole PCB for audio-jacks * solder pads on PCB will be much faster to solder wires to than pins * offer unassembled kits at a discount * Q. is there a demand? * let me know via **`Comment on this page`** link below * switching parts suppliers from Amazon to DigiKey * lower prices * switching bearings from 14mm to smaller units * 14mm x 8mm x 4mm is a common RC car size * unnecessarily heavy, $$$ and strong for paddle use * smaller ~10mm bearing will be cheaper and functionally equivalent ### Summary I already consider CWMouse a success. I created it for myself and it works well for me, but it turns out others also appreciate it and have kind words to say about it. Lets see how long it takes to sell 100 units!! * * * 1. Note: only one bolt holds the case together, while remaining two bolts are used to prevent inter-layer shearing of paddles at bearing pivot area. ↩︎

(3d Printing Batch Smooth) (3d Printing Batch Textured) (Wiring Work) (Assembly Desk) (Two Units Nearing Completion) (Assembled Paddle Before Buttoned Up) Since Jan 2025 when I started CWMouse, I sold enough units to print and manufacture a number of batches. The reviews are good and folks are starting to post YouTube videos mentioning it! 😁 Now I’m exploring how to reduce my time needed to assemble CWMice and making them even more price competitive. ### CWMouse media coverage I reached out to a number of hamradio bloggers, podcasters and youtubers, if they would like to take a look at CWMouse. Jim “Ham on a Bike” **N4JAW** responded and was the first to review it on his blog and shared a YouTube video of CWMouse in action. (Youtube Video) Yesterday I found a YouTube video review by Bruce **AA7AR** who discovered CWMouse via eBay, bought his own and was kind enough to post a review. (Youtube Video) ### Design: existing time saving features * printing in batches * 8 hours of print time is needed for six units * completed in two steps: a) textured parts, b) smooth parts * printed parts require no supports and no post processing * soldering in batches * cutting and pre-tinning all jumper wires * soldering audio-jacks to micro-switches * epoxying in batches * micro-switches to switch-trays * audio-jacks into cases * using only three bolts for assembly * fewer bolts1 means less assembly time * using electric screwdriver * no inserts or nuts, all holes are engineered for one-time self-tapping by machine bolts ### Design: more changes * create through-hole PCB for audio-jacks * solder pads on PCB will be much faster to solder wires to than pins * offer unassembled kits at a discount * Q. is there a demand? * let me know via **`Comment on this page`** link below * switching parts suppliers from Amazon to DigiKey * lower prices * switching bearings from 14mm to smaller units * 14mm x 8mm x 4mm is a common RC car size * unnecessarily heavy, $$$ and strong for paddle use * smaller ~10mm bearing will be cheaper and functionally equivalent ### Summary I already consider CWMouse a success. I created it for myself and it works well for me, but it turns out others also appreciate it and have kind words to say about it. Lets see how long it takes to sell 100 units!! * * * 1. Note: only one bolt holds the case together, while remaining two bolts are used to prevent inter-layer shearing of paddles at bearing pivot area. ↩︎

(3d Printing Batch Smooth) (3d Printing Batch Textured) (Wiring Work) (Assembly Desk) (Two Units Nearing Completion) (Assembled Paddle Before Buttoned Up) Since Jan 2025 when I started CWMouse, I sold enough units to print and manufacture a number of batches. The reviews are good and folks are starting to post YouTube videos mentioning it! 😁 Now I’m exploring how to reduce my time needed to assemble CWMice and making them even more price competitive. ### CWMouse media coverage I reached out to a number of hamradio bloggers, podcasters and youtubers, if they would like to take a look at CWMouse. Jim “Ham on a Bike” **N4JAW** responded and was the first to review it on his blog and shared a YouTube video of CWMouse in action. Yesterday I found a YouTube video review by Bruce **AA7AR** who discovered CWMouse via eBay, bought his own and was kind enough to post a review. ### Design: existing time saving features * printing in batches * 8 hours of print time is needed for six units * completed in two steps: a) textured parts, b) smooth parts * printed parts require no supports and no post processing * soldering in batches * cutting and pre-tinning all jumper wires * soldering audio-jacks to micro-switches * epoxying in batches * micro-switches to switch-trays * audio-jacks into cases * using only three bolts for assembly * fewer bolts1 means less assembly time * using electric screwdriver * no inserts or nuts, all holes are engineered for one-time self-tapping by machine bolts ### Design: more changes * create through-hole PCB for audio-jacks * solder pads on PCB will be much faster to solder wires to than pins * offer unassembled kits at a discount * Q. is there a demand? * let me know via **`Comment on this page`** link below * switching parts suppliers from Amazon to DigiKey * lower prices * switching bearings from 14mm to smaller units * 14mm x 8mm x 4mm is a common RC car size * unnecessarily heavy, $$$ and strong for paddle use * smaller ~10mm bearing will be cheaper and functionally equivalent ### Summary I already consider CWMouse a success. I created it for myself and it works well for me, but it turns out others also appreciate it and have kind words to say about it. Lets see how long it takes to can sell 100 units!! * * * 1. Note: only one bolt holds the case together, while remaining two bolts are used to prevent inter-layer shearing of paddles at bearing pivot area. ↩︎