LED Mod

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sohjsolwin
Posts: 6
Joined: Mon Oct 01, 2018 9:25 am

LED Mod

Post by sohjsolwin » Fri Oct 26, 2018 12:06 pm

Utilizing a strip of these cheap, 5$ LED lights, and some hot glue, you can add custom lighting to your Promega.

Example:
Promega LED.gif
Promega LED.gif (5.09 MiB) Viewed 587 times
Promega LED.gif
Promega LED.gif (5.09 MiB) Viewed 587 times
Tool List:

1 x LED strip (https://www.walmart.com/ip/Monster-Inc- ... /209681674 or similar will work fine)
Some wire (I used some left over speaker wire I had)
Hot Glue
Soldering Iron (and solder)
Wax Paper/Parchment Paper
x-acto knife
Scissors or Side Cutters

Step 1:

Unpackage the LED strip and go ahead and measure out how many segments you'll need per side.
On the strip of LEDs that I had, each segment was approximately 1 1/4" or 32mm long.
I used 13 on the left and right sides, and 14 on the front and back sides.
Take a look at the strip and you'll see contacts in between the segments. Those are where you will be cutting.
When measuring, go ahead and cut off the first segment with the control adapter. You'll be soldering on some wires in place of that later.

Step 2:
Once you've measured your strips, it's time to cut. You want to make sure the control end of the strip is on the right hand side strip, at the back just in front of the limit switches.
Once your strips are cut, be sure to line them up on top of the printer to gauge the placement.
The left and right sides will go int he top edges above the rivets.
The back will go on the bottom, back edge of the "floppy carry handle*".
The front will go in the highest part of the curve in the front.

Step 3:
Trim a small amount of the plastic shell away from the LED segment ends in order to expose the contacts. I found it easiest to pry a little bit up at the edge and then use a pair of side snips to cut the clear plastic. Scissors should work fine too.

Step 4:
Get ready to solder.
After placing each of the LED strips on the top of the printer to size them up and position them correctly, get your wire out and snip off a few pieces that are just long enough to make the 90 degree turns.
For the two connections going to the front piece, you may need to get creative, or remove one more LED from the left and right strips.
IMG_20181028_171628.jpg
Front Right corner connection
IMG_20181028_171633.jpg
Front Left corner connection
On mine, I had the two front connection meet at a T and curved the connecting wires to fit.
IMG_20181028_171650.jpg
Back Right corner connection
IMG_20181028_171643.jpg
Back Left corner connection
The back left is a standard 90 degree connection, and the back right is just straight through wires routed behind the limit switches.

For the back right connection (the connector side), I recommend soldering on about 20" or more so you have plenty of room to route it wherever you need.

Step 5:
Prepare your joint factory.
Once you have the corners soldered, you can encase the wires in some hot glue to help it keep shape and reduce any stresses on the
Using the parchment paper, place a glob of hot glue down on the paper, then press the wires for the corner you're making into the glue.
You want to make sure the glue goes in between the wires and holds it well.
Next, you can place more hot glue on the top to completely encase your wires and the ends of the LED strips.
You're essentially trying to recreate the casing that the LEDs were already in.
Once you've put more hot glue on the top, then take the parchment paper and fold it over on top of the hot glue and use your fingers to mold it into a shape resembling the LED's clear coating. The glue won't stick to the parchment paper, so you can give it a nice rounded shape.

Once the glue has cooled down, you can use the xacto knife to trim it up a little and make it nice and clean.

Repeat this for the back left, front left, and front right corners.

Step 6:
Using more hot glue, go ahead and attach the LED strips in place in the frame of the Promega. There's no trick to it, it just takes time and patience.

Step 7:
Now, for powering the LED strip, you have a few options.
I went the route of soldering some pins to the end of the wires I routed in the Promega so that I could plug the wires into the same USB control board the LEDs came with.
You can also go the route of setting the up with an arduino or similar and controlling the LEDs that way.

Eventually, I would like to be able to connect the LEDs to the Maestro and control them along with the print for visual feedback.
For now, it's just a manually controlled, handy built in light that looks cools while printing.


*Do not attempt to carry the printer by that piece of metal. It's not actually a handle.

User avatar
Shep
Posts: 62
Joined: Tue Sep 11, 2018 4:18 pm
Location: Cleveland, OH
Discord Handle: @Shep
Owned M3D Printers: Original Micro, Pro, ProMega, Crane
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Re: LED Mod

Post by Shep » Fri Nov 02, 2018 2:30 am

Excellent write-up, fancy pics! I think I had one of these cheap from eBay but damn not even $5 and that's a TON of length from WalMart available nearby. Nice! Need to grab some now :D

Mounting the LED strips, my thought has always been to tap into the enclosure bolts, and/or even the side bolts since those sit above the rails. A good 3D print should hold it plenty fine. Failing that there's always a cable tie mount, which can be simply adhered to the ceiling:

ctmb-350-adhesive-mount-base-attached-to-metal-bar[1].jpg
[source]

sohjsolwin wrote:
Fri Oct 26, 2018 12:06 pm
Now, for powering the LED strip, you have a few options.
I went the route of soldering some pins to the end of the wires I routed in the Promega so that I could plug the wires into the same USB control board the LEDs came with.
You can also go the route of setting the up with an arduino or similar and controlling the LEDs that way.
Arduino's only really nice if you plan on feeding it data for the Arduino to decode, i.e. the colors would mean something. Otherwise, if it's just a simple on/off with a specific color in mind (or a specific effect), I'd try to stick with the USB remote guy and simply not use the remote once you set it the way you want it.

I've had a few of the USB remotes "forget" where they were once unplugged, so if that happens, I can at least recommend [these] mini-controllers, though it terminates with a barrel jack, so you may have to source a good 5V 1A+ wall wart for it.
sohjsolwin wrote:
Fri Oct 26, 2018 12:06 pm
Eventually, I would like to be able to connect the LEDs to the Maestro and control them along with the print for visual feedback.
Honestly this is my intended use case. I got a fancy pulsing controller for about $5 from SuperBrightLEDs.com (seriously not plugging them -- they just have easy-to-find stuff) and it would look fantastic under the bed for red LED's, but until I can figure out how to make the printer control it, there's not much point.

Once we figure out the pins in question, then for actual board control, this is a flawless use case for a MOSFET. The most basic of circuits is found [here], outlining the difference between NPN and PNP:


Image

Image

Where "load" is the LED strip you want to switch on/off (or controller should you want to use an RGB strip -- MOSFET's are basically light switches, not dimmers). There is typically only one sufficient use case per type -- NPN is switched based on supplied voltage, where PNP is switched based on an open path to GND. With the amount of raw power, a MOSFET is required, but circuit design typically does not change much, if at all, for that given we are using LED's here. So basically, which one you would use would highly depend on which pins the Duet has available and how they function. I tend to stick with the TO-220 footprint because it's insanely plentiful and typically comes with a hole the tab to make mounting easier -- though be sure to find one where that tab isn't electrically connected to be on the safe side. On occasion I've used breadboard pins to connect to the TO-220 footprint without a proper circuitboard, which is a bonus as they're cheap and readily available. The wires are literally the most expensive part of a MOSFET setup! :lol:

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