Glowing Dog Pedant

Summer. Long warm days and late walks with my dog. I let her off leash, we walk, night falls... But where did she go?!

Walking a dog Is fun but stressful at times because I can easily loose track of my dog. I know they sell glowing pedants in pet stores but I am a big fan of orange and my local pet stores don't sell them in orange. I might also have to mention I don't like how they look but fortunately I am a maker and I can make whatever I want!

This Instructable will take you through the process of making custom glowing dog pedant that also functions as name tag and tick repellent all in one! Making one for your dog will let you be comfortable with taking your dog for a walk without leash at any time of day!

And did I mention This Pedant is not exclusively for dogs? Whatever pet can have it! If you are a cat person, don't forget to check the last step because i have a special request for you :)

(Sorry for no proper picture but my camera can't possibly make a decent picture in dark... Vote for me in dog contest and help me get a gopro so I can make my next instructable better :)

Step 1: What You Will Need

In order to make such pedant, you will need:

• An electronic tick repellent ebay (I think this one is th same as mine)
• SMD LEDs (colour of your choice) ebay
• An 100 Ohm resistor [1x]
• A chunk of plexi glass (at least 4mm thick) - ask for scraps at your local hardware store
• Some old keyrings
• Thin wire
• Insulated wire

Aside from that you will also need some basic tools:

• Soldering iron and solder (and get some flux, it will make your life so much easier)
• Saw
• Dremel with engraving bit or hand saw or a file (or all three :)
• An art knife or any other sharp object for engraving plexi glass
• Hot glue

And following things can be omitted but I highly recommend you go find them:

• Tweezers
• Flux
• Sticky tape
• Patience

And finally: a sketch of what you want to make. Draw a sketch of pedant. I used inspiration form this site for my dog motive. Keep in mind that pedant can't be too big and that too many details will ruin the effect - keep it simple.

Step 2: Forming Outer Shape

I knew what I wanted my dog's pedant to look like for a long time: uneven shape, orange LEDs and a cartoony dog as a main motive. I also made a 1:1 sketch and I recommend you do the same. It makes choosing right piece of plexi glass a lot easier - you just place sketch on top of it and you see if it will fit. That is useful if you will try to use scraps.

Once I got started I first roughed out the shape on a saw and brought it to shape on a grinder. If you do not have power tools, you will want to do a good job with saw as grinding plexi glass by hand is a slow process.

Next I drilled the hole. I didn't measure much - I simply eyeballed an appropriate location and slowly drilled through, making sure I held piece firmly against the table to prevent breaking it.

The reason I drilled after sanding is that plexi glass is very brittle material and a hole sitting a couple of millimetres from the edge would greatly increase chance of breakage durng grinding. Another reason is that I wasn't sure where the edge of workpiece would be after grinding it. which could result in uglier product.

Note that I haven't removed plexi glass' protective cover and I didn't do it until it was really necessary to do so. That is to avoid having unwanted scratches all over what I want to be a nice surface.

Step 3: Forming the LED Groove

Next I formed a groove for LEDs. I recommend you clamp work piece in a vise or at least clamp it on a table.

I first marked centre of the groove with file and then formed it with a dremel tool. I made it just wide enough to fit the LEDs in and deep enough for them to fit in with a little bit of extra room. Note that I didn't make the groove over hole because it is not needed there and it would actually just reduce durability of the pedant.

When was satisfied with the groove, I made edges look a little nicer using some fine sandpaper. This wasn't only cosmetic but actually looks better when the LEDs are lidt.

If you Don't have a dremel, you can make the groove entirely with a file or a handsaw. The only major difference between those two and a dremel is in speed.

Step 4: Preparing for Soldering

You might call this step child play but I dare you to stop reading right here and solder 6 0805 SMD LEDs in parallel on two wires without my help. It is a lot harder than you think! But don't worry. Through trial and error I found a relatively fail proof way of doing it.

I started (after failing for 6 hours straight) by taking a piece of tape and rolling it in a tube (sticky side out). The smaller the tube, the better (I could use two sided tape but I didn't have any). Next I stuck it on the table and flattened it. I then got all 6 LEDs out of reel and alligned them all in the same direction. If one of LEDs endsed up soldered the wrong way, it wouldn't glow when I applied voltage because polarity matters with LEDs.

I place first two LEDs on the tape, a little bit less than the groove's length apart. I arrange the remaining 4 LEDs between the first two, first next to the tape and when I was satisfied with theri spacing I moved them over to the tape and pressed all 6 LEDs down firmly.

I did all the handling of LEDs with a pair of tweezers. Not only because it is easier but also because soldering becomes outright impossible if you get grease from your hands on the LEDs...

Step 5: Soldering the LEDs

And now for the real deal. I generously applied flux to each of LEDs and wires as well. I soldered right most LED first and then proceed to solder every second LED (skip one, see images above). That prevented solder on previously soldered LEDs to melt. I did the same on both sides.

The real "fun" starts here. How to solder the remaining LEDs without melting solder on the ones I just soldered? Simply put: can't be done. I found a trick for dealing with this problem though. I used tweezers to press down wire in both sides of LED I was working on and soldered it normally. Solder on both neighbour LEDs melted but because I was pressing the wire down, that wasn't a problem.

Soldering the left most LED was a different as I had to solder next wire onto it. I placed stripped wire under the wire I used to connect LEDs so it lightly touched the last LED. I position it the way I thought it would be easy to solder and pressed it downwards so it stuck to the tape. Once again, I used tweezers to prevent wire from coming, loose and solder everything together.

When I was done, i tested if everything worked (I apply 3V through an 100 Ohm resistor) - it always did with this method - and then gently pried LED strip

Step 6: Engraving and Gluing LEDs to the Pedant

I then moved on to gluing LEDs in place. I first performed "dry fit" to see if I made everything fine. Iturned out one of my LED strips was a little too wide so I skewed them gently (see images above) and that solved the problem. I then applied a thin layer of hot glue in the groove and pressed LED strip in. I waited for glue to cool and applied another layer that covered LEDs. Insulating wires with some more hot glue also turned out to be a good idea. Off to engraving the pedant, I guess!

I noticed I managed to make my chunk of plexi glass smaller than my original sketch anticipated, meaning I had to make a new one. I roughly traced the pedant on a piece of paper and drew a new sketch. Next I placed plexi over new sketch and traced it with a fine permanent marker. This step felt weird because I was tracing 4mm above sketch - not a problem but weirdly interesting.

Next I used an art knife to score plexi glass along the lines I drew. I learned (the hard way) that it is best to engrave small curved lines first and all mistakes with straight and less curvy lines afterwards. Depth of cuts doesn't play much of a role although deeper lines are more visible (but are harder to make).

When I was done I used rubbing alcohol and a tissue to wipe off permanent marker I had the decorational part of my dog's new pedant complete!

Looking back at this procedure I can say this order of operations was a bad idea - what if I made a bad cut? What if I ruined the image? I would've had to do everything all over again... do yourself a favour and engrave first, glue later.

Step 7: Modifying Tick Repeller

I apologise for bad photo documentation of this step. At the time I was making it I didn't know I could find the same tick repellent I had. But here is the sum up:

I started by prying it open and identifying where I can get positive and negative leads from (if you have the same one: on the first picture you will see two golden dots on the right side; left one is - and right one is +). Next I cleaned the contacts and soldered wires onto them. It is very important not to forget wiring a 100 Ohm resistor somewhere. If it is on positive or negative lead is of no importance.

Next I widened the hole in the tick repellent with an M3 drill bit and put wires it. I then soldered everything together (pay attention to polarity as LEDs won't light up if polarity is wrong), put some shrinkwrap on exposed parts of wires to prevent short circuits and closed up the tick repellent.

All that was left to do from now on was to get some keyrings through holes and put this pedant on my dog's pedant!

Step 8: Finishing Up

I put a small keyring through newly crafted pedant and attached to a clip and it was ready to go!

My dog wasn't too amused about the photo shoot that followed as you can see :)

And now I have a special request for you, fellow makers! I have a friend who really wants to have such pedant for her cat. I have no problem making one for her but I don't know what picture to put on it. Please comment your ideas (doesn't have to be orange - a reel of 100 LEDs costs less than just over a euro) I will be very grateful for your cooperation!

Speaking of grateful: I will also be very grateful if you favourited, followed, shared and voted for this Instructable in contests I entered!

And since I know someone will ask:
My dog is 3 years old female schappendoes, her birthday was a month ago.