Many of you know that I tend to extol the use BONDIC as an adhesive for affixing LEDs inside loco shells. Rather than a CA or other glues / epoxies, it is a UV-cured "liquid plastic" which seals to the surfaces it is in contact with when hit with UV light. Unfortunately, the curing lamp which comes with the kits is a bit clunky to use, so I finally decided to make my own. The first photo shows both: the upper item is the purchased BONDIC (the liquid is in the black tube), with the included lamp on the right. The light is a basic UV LED, with its leads sandwiching two 1.5V Li button batteries (for 3V total). The little orange slide switch literally pushes the lead under it down onto the battery to complete the circuit. You have to slide the orange switch back towards you, and with 1-inch batteries, it is sometimes difficult to get the apparatus and fingers into the area where you want to bond (like SMD LEDs on the inside front of an N-scale loco). I came up with the lower item: it consists of an 0603 UV emitter (i.e. UV SMD LED), mounted at the end of a 4-inch piece of 1/8" styrene tubing. I used a small surface contact switch, in line with the ground leg of the circuit, mounted about halfway along the tube (the silver button in the blue holder. And of course, the button and the UV emitter are bonded to the tube....using BONDIC. This photo shows the whole unit. I put a micro connector on the far end of the wires, using shrink wrap tubing to provide strain relief both at the top of the styrene tube and at the connector. I have a 12V 500ma wall wart, with mating plug, which I use for my bench work electronics power when testing. (yes, there is a 1Kohm current-limiting resistor in line with the wire under the green shrink wrap). This last photo shows the emitter at the tip (have to look carefully). Being much lighter and much smaller, the control of the area being exposed to the UV is amazing, and much simpler and easier to use.
Very nice!! Can you give me more info on the switch. I'm not familiar with what you used. Also is the UV LED like this one... https://www.ebay.com/itm/20-x-LED-0603-UV-Purple-SMD-LEDs-SMT-Lights-Super-Ultra-Bright-Xbox-Car-Models-R/161258807647?_trkparms=aid=555018&algo=PL.SIM&ao=1&asc=20131003132420&meid=e1c08f80430a434b8ba9fbc84084bd64&pid=100005&rk=1&rkt=12&mehot=pf&sd=112080106492&itm=161258807647&pmt=1&noa=0&pg=2047675&_trksid=p2047675.c100005.m1851 Would this light work with one of the refills such as this one..... https://www.napaonline.com/en/p/NCB...U3o6uJ44gozRkRQb3WwvnB_zqgDAJZ5MaAqKVEALw_wcB Thanks for the useful post, Sumner
I used this emitter, from DigiKey https://www.digikey.com/products/en?keywords=492-1949-1-ND yes, it will work with any UV cure items. As to the switch, I got a bunch of them, years ago, from some electronics clearing house and thought I would use them on the panels for the JACALAR. You can search for small (under 1cm x 1cm) tactile switches (you want off-momentary action) at any of your favorite places.
Thanks, I think I'll put one together and give it a try. For how much I'd use it I'm thinking of using a 9 volt battery and the appropriate resistor as a power source. Do you see a problem with that? Sumner
Nope, that is a good alternative; solder a 9V connector pad to the ends of the wires. Just make sure you make them “long enough” so that you can easily work with the tool without pulling on the wires and battery.
For anyone looking for the exact tactile switch I used, it is https://www.goldmine-elec-products.com/prodinfo.asp?number=G22753
