3D printing the things.

I bought a very cheap Yaesu VX1-R dual band handy last year, it's a cute little thing that covers 2 and 70 but unfortunately it came without the battery.

No problem, if it works I'll just buy a replacement, simple.

But WOW, the FNB-52 battery is *expensive*, more than three times what I paid for the radio and I could not find one in stock anywhere (I have since found them)...

I did find out that the battery pack is a standard 14650 Li-Ion cell in a molded plastic case (presumably including a battery management circuit) and a quick search of everyone's favourite tat bazaar eBay found a pack of two for a not expensive £9 so I ordered some and waited.

When they arrived I gave them a few hours on charge and then tried one in the handy, it worked but of course it rattles about and runs the risk of being damaged or, worse, exploding if charged incorrectly as the cell isn't 'protected'.


Now I do have a charger but it meant I'd have to remove the cell to charge it which isn't particularly convenient, especially as the VX1-R has a power socket on the side which can be used to charge the cell 'in situ'.

Now, as you know (you have been reading right?) I've got a 3D printer so it seems logical to print a replacement enclosure for the cell and to include a protection board so it can be charged properly without exploding.
 
By taking the radio apart, looking at the few pictures of the battery I could find on the 'net and making some educated guesses (it's a 14650 cell so it has to be at least 65mm long and 14mm diameter) I threw a CAD model together and got close but the first attempts were just a little too snug, needing to be removed with needle nose pliers which is less than ideal so I asked for measurements on the RSGB tech forums and got replies from two helpful people who have the same radio complete with battery.

Rather pleasingly it turned out that I was very close to the correct dimensions but with their measurements the first new version of my Designspark Mechanical CAD model fitted just fine and seems to have plenty of space for the protection board. 
CAD Model, almost there.

Freshly printed, I love the smell of PLA in the evening

First attempt without negative terminal cutout and second attempt with

In the radio, fits easily.
Now I'm satisfied the pack will work I can get on with finding the bag full of protection boards and some nickel strip to finish off the build and I'll post back when I've done more.

Comments

  1. Unknown28 July 2019 at 01:21

    Hello M0UAW. I'm trying to get my old VX1R working and the battery case you have designed and printed looks just the job. Any chance that you could make me a couple? Let me know if possible and how much. Thanks. 73's de Phil G4MKW contact info is also good in QRZ.com

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