Spektrum DX3C Backlight Mod

[cbp27]

I got into rc heli's last year and ever since I've always noticed that other guys had backlights on their Spektrum DX6i's. I know Spektrum's higher end transmitters have them, but I figured it couldn't be that hard to do.

I'm not an expert on this stuff so please don't bash.
And I am NOT responsible for any damage etc.
And once you open up and play with your TX you void your warranty.


As far as I know, a traditional backlight can be made using an EL panel (electroluminescent) or some form of LEDs. The EL stuff also comes in the form of wire know as glow wire, which is also used in the rc heli/airplane world. EL panels run on AC power so they most often come with a DC inverter to use with batteries. EL panels are very thin and flexible allowing them to fit perfectly in tight spaces, such as behind your TX screens. Some members on here offered backlight kits, but sadly no longer do.

HobbyKing sells an LED backlight that uses a thick piece of lexan with 2 LEDs molded into one end. A chromed film is attached around the edges, preventing light from escaping, and a white film is attached to both faces to allow the light to show up. The LED backlight is nice because you don't need an inverter, it is very cheap, and is simple. However, HobbyKing's is made for a Turnigy/Flysky TX, so you will need to do some modifying. Here is a very good tutorial for a DX6i on HeliFreak.com The downside to HK's LED backlight is that it is very thick (2mm), which is way too thick for the DX3C's space.

Before I tested this mod on my DX6i, I thought I'd used my DX3C as a guinea pig. Plus, I just recently had to crack it open to fix a broken steering wheel tension spring so I'm comfortable playing with it now.

Parts:
EL Panel in Blue/White/Red (inverter included) from Virtual Village (Hong Kong) for $12.50 shipped (mine took 2 weeks for delivery). Also try their own site to buy instead of eBay.
New Polarizing Film for $11.00 shipped from Spectrum Scientifics (optional/read instructions)

Tools:
Small Phillips screwdrivers (I used a precision set)
Needlenose pliers
Exacto knife
glass cleaner
papertowel
scissors
sharpie


First you'll need to take out the batteries, remove the 2 rubber grips, and remove/peel off the back decals to expose 2 screws.
Remove these 10 screws, then gently pull apart the two halves of your TX.



After you stop staring at its guts, remove these 3 screws holding the LCD assembly to the housing.



Carefully pull out the LCD/Radio/Brain assembly.



To begin removing the LCD panel you will have to unclip the ribbon. DO NOT JUST PULL IT OUT! Gently slide out this black bar which basically "sandwiches" the ribbon into it's socket.





Carefully slide out the ribbon.




Now comes the tricky part. The LCD panel is made of 2 thin sheets of glass which has double-sided tape holding it onto the black plastic frame. I used my Exacto knife to cut it out. Just be VERY careful not to cut the ribbon! I wasn't able to cut all of the tape apart, so I gently pryed the glass up and hacked the remaining tape. And because I have already done this, I can't show this step clearly.




Now you should have the LCD panel out by itself. However, yours should have a silver backing on it. Here's how it all works...

On the DX3C's LCD screen assembly you have the outside layer of glass, the actual liquid crystal layer, another layer of glass, polarizing film, and then a silver backing which contrasts against the display making it easier to read. The backlight will essentially replace the silver backing, and provide another contrast effect. The silver backing is very thin and tears easily. You will not need it so don't worry about ruining it. But be careful not to peel off the thicker polarizing film (transparent green). I actually almost peeled that film off. Next, I had the problem of a lot of sticky residue left on the polarizing film. I tried auto window cleaner, windex, goo gone, and it was still there. I got fed up and just ordered a new polarizing film. ($2.50 for two 2" squares, but another $7.00 for shipping).

The polarizing film is really cool. Basically it only allows light to pass through it in a certain direction. And if you have two polarizing films held together at 90* to each other, they block out all light. This film is what allows the LCD to become visible. Check out what happens when I move the film 90*





And the magic trick of 2 films...





Now for the EL panel. Mine was a hair too big, so I just used scissors to cut it to size. As long as you keep the wire leads intact, you can cut them into almost any shape and they will glow. Then I used clear packing tape to seal up the edges. Apparently you can get quite a shock if you touch these the wrong way since they run on a high AC voltage.



Just a test fit. I'm using a 9 volt battery now. It can handle up to 12 volts. The TX only has about 6 volts max so it may just be dimmer.




The LCD assembly originally had double-sided tape holding it to the black frame. With the new EL panel and polarizing film in place, I just layed the LCD on top. So they are only held in by those 3 screws sandwiching them against the front of the TX housing. It's a nice snug fit.

This is the power button board. The black and white wires are power from the batteries. The black and red take that to the rest of the TX. I just soldered in the inverter leads to the latter so the EL panel will only be on when the TX is on.



These wires originally had hot glue covering them. So after soldering I put some on again.



I used double-sided tape to attach the inverter in an open spot and carefully routed the new wires.



Put everything back together and voilà! Only bad news is I somehow broke the little LED next to the power button. Maybe I'll replace it later.



Awesome for night crawling!



Let me know if you have questions.
Good luck and thanks for looking!

[ManxCrawler]

Looks like someones being doing some googling

...I presume you can get other colours

[cbp27]

Originally Posted by ManxCrawler

Looks like someones being doing some googling

...I presume you can get other colours

Haha Yeah like like to make sure everything is right the first time.

If you search "el panel" or "red el panel" on ebay (or whatever color) you'll be able to find them. I've seen them in blue and white too. Maybe green. Just don't overpay for them.

[Taper]

Nice Mod.

I'll try to make it on my DX3R


Will this EL work with my TX?


http://cgi.ebay.es/ws/eBayISAPI.dll?...ht_3259wt_1414

[cbp27]

Originally Posted by Taper

Nice Mod.

I'll try to make it on my DX3R

Will this EL work with my TX?

EL Panel White Neon Back Light Board 12V DC Inverter | eBay

Thanks. That looks like it should work. Looks like a nice deal even with the inverter.

One note on that inverter though. Its input voltage is listed at 12V, however most R/C transmitters use 4 AA batteries which is about 6V. I feel like the EL panel isn't at its full brightness since the transmitter is only supplying half the voltage it needs. I was thinking if the input voltage of the driver is closer to 6V the EL panel should be brighter, but I have no idea if that is true or not.

I found this nice backlight kit on eBay with the option to buy a 6V inverter, but still haven't bought it to test yet.

El Panel Illuminated Backlight for Spektrum DX6i and DX7 May Fit Other Models | eBay

[natskiboy]

Very cool mod!! When I was shopping for a radio I was about to pickup the DX3C but no backlight so I ended up with a 4PL.

[minijoe]

wonder if it will work with the dx 3.0 ,,,,,,,,, has any one tryed that ????

[cbp27]

Originally Posted by natskiboy

Very cool mod!! When I was shopping for a radio I was about to pickup the DX3C but no backlight so I ended up with a 4PL.

Yeah I was disappointed it didn't have a backlight, but it's still a nice radio.

Originally Posted by minijoe

wonder if it will work with the dx 3.0 ,,,,,,,,, has any one tryed that ????

I don't see why not. You just need the courage to crack it open and see what's inside.

[cbp27]

Small update. I bought the EL Panel kit with 6V inverter to test. The 6V inverter is a better match to the transmitter, and provides more light output to the EL panel. However, the new EL panel's power wires were at the corner of the sheet, not the middle like my first one, and would not fit into the LCD panel slot.

I also finally installed a new power indicator LED. Picked up this from Radioshack: Rectangular High-Brightness Blue LED Lamp : LED Lamps | RadioShack.com

Any other rectangular LED should work. They also have red, green, and yellow. This LED is super bright, and the glass/plastic part sticks out of the case so you will have to do some trimming around the soldering points for it to fit right.



And while searching for the link to the LED, I stumbled upon EL panels now sold at Radioshack. Blue, red, green, yellow, and white! You'll still have to source a small 6-12V inverter though.

RadioShack EL Panel 10x10cm (Blue) : LEDs | RadioShack.com

[cbp27]

I picked up my blue EL panel from Radioshack today. I ordered it online and had it shipped to the store for free.


Learning from the first time, I decided to reverse the contrast to make the text easier to read (previously was dark text on light background). This can be done by rotating the front side polarizing film about 45 degrees. I rotated it slightly less than 45* to get a more blue/purple tint to match the blue backlight.




I also installed the new 6V power inverter, which makes more use of the 6V power supply from the radio. The new EL panel glows a little brighter now, even on less than 6V.

It looks much nicer and even in person.


Finally have a matching LED and backlight. I'll call it done!

[Charlie-III]

Has the addition of the EL panels changed TX battery life noticeably?

[cbp27]

Originally Posted by Charlie-III

Has the addition of the EL panels changed TX battery life noticeably?

I haven't noticed a big difference in battery life, but I'm sure there is some difference. Some people choose to add an external switch for the EL panel to control it separately.

[Moore510]

I know this is an old topic however I was wondering if you were going to do a radio for someone else and I also would like to know how you did the steering wheel

[cbp27]

Originally Posted by Moore510

I know this is an old topic however I was wondering if you were going to do a radio for someone else and I also would like to know how you did the steering wheel

I'm sorry, but I do not offer any services. It's simply posted here to help others try it themselves.

The radio wheel is simple though. You pop off the center cap to access a single screw. Remove the wheel and replace it with the correct, included adapter (Spektrum, Futaba, etc.), and mount the wheel with the included screws. I replaced the five wheel screws with RC4WD M2.0x5 scale hex bolts for a more realistic look. The wheels can be found online by searching for "RC radio wheel". Hope that helps!


Sent from my iP6