Tag Archives: LED

LED Bridge Lamp Shades

The lamp shades were a part of this project I agonized over. In the end it was a fun engineering challenge.

Challenge #1 Color

The first challenge was to figure out what color to make the shades.  I printed out a few sample shades that I tested out with a simple rig on a breadboard that would run through a series of animations on a small NeoPixel stick from Adafruit. This allowed me to see how each of those sample shades would look as the colors on the strip changed.

Test rig to see how various colors and materials would look as a lamp shade/diffuser on this project
Test rig to see how various colors and materials would look as a lamp shade/diffuser on this project

First I tried Village Plastics and PolyLite White PLA — it was not bad but seemed to look like a warmer color (See photo below) which while not bad was not the look I wanted.

Testing Village Plastics White PLA
Testing Village Plastics White PLA

Next I tried PolyLite PLA Translucent Blue (the same as the the bridge superstructure) but I felt that color skewed everything blue. (Left side of image below)

Testing Translucent Blue and White PLA shades
Testing Translucent Blue and White PLA shades

Next up I tried nGen clear filament — which prints a lot slower than PLA but also is more resistant to heat —  and I really liked the results.  The colors were clearly transmitted through that material and could be seen from the sides. For me this lamp is not really used for downlighting, it’s more of a novelty to been seen from all angles so I thought this was the best solution.

NOTE: My friend and co-worker Chris also printed out test shades in  PolyLite Translucent Red, Yellow and T-Glase Red — and much like my experiments seemed to skew the colors too much to look like whatever color the filament was.

I had the demo rig below on my desk for a few weeks and solicited feedback from friends and we all seemed to land on the clear nGen

Translucent Blue PLA, White PLA, and nGen Clear shades
Translucent Blue PLA, White PLA, and nGen Clear shades

 

Challenge #2 Glare and Drooping

In the original LED Bridge Lamp (Universal Segment) by my friend Janis Jakaitis (Opossums) I noticed in one of the photos the LED strip was sagging a bit (See below).  This is a common problem as the adhesive on the back of these LED strips is not all that good or strong and doesn’t stick well to plastic. If you go with a more aggressive glue it makes it harder to repair/move/replace anything that fails in the future.

Original LED Bridge Lamp (Universal Segment) by Janis Jakaitis (Opossums)
Original LED Bridge Lamp (Universal Segment) by Janis Jakaitis (Opossums)

After working with my test rig I also found that these LEDs can cause glare and be rough on the eyes if you look directly at them so I figured some sort of diffuser would be a worthwhile addition.

I spent some time trying to come up with an elegant solution — maybe printing each shade vertically and creating a channel for the LED strips — but I felt that orientation would weaken the shades and likely result in rougher prints. Other ideas were too complex — such as screwing on diffusers etc.

In the end I came up with a solution I am happy with — I modified the light channels to be deep enough to enclose the LED light strips and created a dovetailed channel that would capture a flat printed thin diffusers. (See photo below)

My Enhanced Lamp Shade/Light Diffuser Model Rendering (Straight Section)
My Enhanced Lamp Shade/Light Diffuser Model Rendering (Straight Section)

3D Printing Tips 

I printed these light channels WITHOUT any sorts of brim as the object is flat with a lot of surface area and didn’t require any real cleanup.

I printed my lamp shades with 20% infill.

You’ll want to make sure your printer is really dialed in and well calibrated. If you find the diffuser cover is too tight, I provided a ‘loose’ cover LightChannelDiffuserCoverLoose.stl which is the same diffuser cover but 2% narrower.  I believe this is what I used as the basis of the covers included in the curved shade sections — so those already include a loose diffuser cover. If after printing you find yours are still too tight you can break up any of the diffuser sets and scale the diffuser cover another percent or two narrower.

Straight section of lamp shade
Straight section of lamp shade

Assembly Notes: 

When trying to slide the diffuser covers into the diffuser I found it was sometimes easier to slide in if I spread the diffuser a bit in my hands as I slid in the cover.

Make sure the diffuser cover is oriented the right way (the same way it was printed)– with the tapered side down before trying to insert it into the diffuser channel.

For the curved sections of bridge lamp there are two sections — an ‘A’ and a ‘B’ section each with a diffuser channel and a cover. All parts print with a letter in/on them. The ‘A’ in the cover should be oriented the same as the ‘A’ in the diffuser channel. The same logic applies to the B section. Section A and B are not identical mirror images, just like the original channels.

My Enhanced Lamp Shade/Light Diffuser Model Rendering (Curved Section) NOTE: Sections A and B have matching raised letters in shade and in diffuser covers
My Enhanced Lamp Shade/Light Diffuser Model Rendering (Curved Section) NOTE: Sections A and B have matching raised letters in shade and in diffuser covers

After removing the lamp shade prints from the printer I would assemble the lamp shade section (slide in the cover) and file the ends flat with a flat mill file. They didn’t need much filing but I wanted nice smooth mating surfaces. I would have an assembled super structure assembly in hand and could use that to test and make sure the ends were co-planer with the ends of the bridge superstructure section.

I would assemble the 3 blue superstructure sections using the nice glue up jig provided by Janis’ original model. I didn’t bother to modify the jig to fit the lamp shade diffusers — as my shades have a deeper channel. Instead I would take the assembled (and dried) superstructure, line the edges with a small bead of LocTite 401 CA glue and then slide in the shade  (Above the glue lip and then slide it down into place to not disturb the glue and more than needed. This allowed me to squish/twist the superstructure if needed to really square up the now fully assembled section. You’ll want to take extra care to make sure the channels of one section really line up well with the next one.

For curved sections I’d glue the A and B sections to each other (make sure to file and test fit that A and B mate cleanly). With an assembled A and B section I’d then follow the process described in the paragraph above to glue it into a completed curved superstructure assembly.

A and B Sections in completed bridge
A and B Sections in completed bridge

In the image above you can see how the A and B sections are mated in a curved section of the completed bridge lamp.

My bridge lamp is broken up into 3 assembled sections — 90 degrees of the arc, 2 straight sections to support the billboard and another 90s degrees of arc.  I built my lamp in a modular fashion so it would be easier to change if I have a different job or workspace in the future and don’t want to rebuild this lamp from scratch.

With a completed section of bridge (superstructure + lamp shade/diffuser) in hand I would test fit it with the next piece of the bridge. This meant testing to make sure the tabs locked well into each other — usually filing meant flattening any edges/corners that were rounded and likely squaring up the clips a bit to fit tightly. Squaring up the clips meant filing out a bit of the underside the tab which was triangular in profile to better mate with the square edge of the adjoining piece of superstructure.

With all the individual bridge sections completed I would glue each of the fitted sections of bridge to the other to add additional rigidity to the lamp. (If you don’t do this each of the sections can twist a bit which makes it even harder to fish the LED strip through the diffuser channels.)

The photo below shows one of the 90 degree assembled sections. In order to fish the LED strip through the channel I soldered a long piece of wire (longer than the assembled section) to one of the pads on the LED strip and then used electrical tape to further secure the wire to the LED strip and protect the pad — as they are really easy to pull off — and likely after this you’ll want to sacrifice/cut off that first LED. I then pushed the wire through the channel. Now for the dancing….

Assembled light diffusers and bridge sections ready for the LED light strips
Assembled light diffusers and bridge sections ready for the LED light strips

Getting the LED strip through the channels was a time consuming and sometimes quite frustrating ordeal. I would push the strip in from one side and GENTLY pull the wire from the other side. This is where the pains taken to keep things aligned will hopefully pay off for you. Keep feeling where things get stuck (usually an LED on a junction between sections). Usually I could press the thin diffuser cover a bit and push or pull to get it past that catch point and keep feeding the LED strip into the assembled section. This dance will take a fair amount of time and patience — but the result is worth the trouble.

NOTE: Wire Cutouts

If you plan to make sure bridge lamp in modular sections as I did you’ll want to use the diffuser section ‘A’ with wire cutouts (shown below) for any place where you want to mate two sections of lamp.  These sections have a place for wires to get out of the channel and allow for modular wire connectors — I used JST connectors — to be placed inside of the bridge superstructure.

Curved section lamp shade diffuser with reliefs for wire connections
Curved section lamp shade diffuser with reliefs for wire connections

In the post on electronics I’ll talk about the JST connections etc.

You can navigate back to the Enhanced LED Bridge Lamp Summary here. 

Take care,
-Bill Rainford
@TinWhiskerzBlog
@TheRainford

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LED Bridge Lamp Base

As I worked out the details of my version of the LED Bridge Lamp by my friend Janis (Opossums) Jakaitis, one of the things I wanted to tweak was the base.

The modifications I focused on were:

  1. Lower the risk — the original base was a very large piece that would take about 25 hours to print and if something failed that would be a lot of time and material to lose so I broke my version of the model into pieces
  2. The slots/vents were slightly asymmetrical so I made my own variant of that so I could print on the side and keep the lines clean compared to printing them vertically
  3. I needed a way to handle height differences in the surface where I’d install the light * *

** The location in my cubicle at work where I wanted to to install this light has two different heights — the metal wall is about 1.5 inches higher than the top of bookcase so I needed a way to compensate for that. My solution will allow you to handle any reasonable height difference you want to tackle.

Here is a finished and an exploded view of the bases: 

Figure 1: All the parts that make up an Enhanced LED Bridge Lamp base
Figure 1: All the parts that make up an Enhanced LED Bridge Lamp base

While my bases look very similar to Janis’ models they were created from scratch but designed to emulate the originals and add a few new features you’ll see as we walk through this post. I also eliminated a few design details like the screw holes (replaced by my magnet solution) and the transition to the cap piece.

Print Details

What did you wind up printing? (Quantities are for what I built, you may need to change them to meet your needs) 

  • Qty 2: Side (side.stl)
  • Qty 2: Side with Power Outlet (SideWithPowerOutlet.stl)
  • Qty 2: Electronics Tray (Electronics_Tray.stl)
  • Qty 1: Base Height Spacer (Base_Height_SpacerV2.stl)
  • Qty 1: Base Height Spacer Tall  (Base_Height_Spacer_TallV2.stl)
  • Qty 2: Magnet Space Filler Block (Magnet_Space_Filler_Block.stl)
  • Qty 2: Center — the core of the base (Center.stl)
  • Qty 2: Cap (cap.stl)
  • Qty 2: Baseplates (BasePlateMamaWithCableHoleV2.stl)
  • Qty 3: Clips (ClipV2Loose.stl)
  • Qty 2: Foot Height Extensions (This STL can be found in Janis’ lamp here)

Material Used: Polymaker Polylite PLA in ‘True Grey’ 

Print Settings:

  • I printed all the side parts with a brim to decrease the likelihood of warping
  • 20% infill, 0.25mm layer height
  • 210C Nozzle Temp

Additional Supplies: 

  • Qty 4: 90lb Neodymium Cup Magnets
  • Qty 4: M4 Flathead Machine Screws
  • Qty 8: M4 Machine Screws (double up the nuts so they don’t back off — or add a lock nut)
  • Qty 8: Hex Button Head Machine Screws to secure base sections to each other
  • Loctite 401 Glue

Build Details / Notes: 

Printing a side of the base
Printing a side of the base

When printing the pieces called out in the print details section above I printed all my pieces with a brim to help reduce or eliminate warping.

Printing the electronics tray with a brim
Printing the electronics tray with a brim

The elements of an assembled base (1 regular side, 1 side with power outlet hole, center, cap, riser and base plate) are designed to fit inside/on top of this electronics tray. The tray is designed to also secure an Adafruit 1/2 size Perma-Proto board which is what I used to house the electronics that control this project. (More details on that in an upcoming post) The tray also provides supports for the height spacer which keeps the magnets in the proper location.

NOTE: You may want to print the tray 1-2% larger in the X and Y dimensions. Otherwise you may find yourself using a fixed belt sander to thin things out a bit. Guess how I know that? 😉 And my machine is really pretty well dialed in.

Electronics Tray Rendering
Electronics Tray Rendering

The height spacers below were designed to align themselves under the electronics tray via the little standoffs you can see in the image below. The height spacer also keeps the magnets secured as the base gets moved around.

Height Spacer
Height Spacer

The height spacer can be extruded to make it as tall or short as you want.  The spacer above is the minimum height as it is the same thickness as the 90lb strength magnets.

Height Spacer (Tall)
Height Spacer (Tall)

As you can see above, extruding this model to make it taller is straightforward. (You can do it by editing the model or in a pinch you can scale the z axis as needed and trim the alignment tabs if they get too tall as a result of the Z scaling)

Magnet Spacer
Magnet Spacer

For taller spacers I also designed a filler block to make up the space between the magnet and the bottom of the electronics tray. The model can also be scaled in the Z axis to adjust the height.

Assembling the base
Assembling the base

The electronics tray also makes a helpful aligner as you glue up the base pieces. I used some small clamps to hold the sides and center together as the glue dries — only takes about 1 minute to dry enough.

NOTE: Be careful that you don’t glue your base into the electronics tray.

In the lower half of the picture above you’ll see the baseplate sitting upside down in the height riser so that I could glue the blue clips in place. Once the clips are secure I flipped the plate over and glued it on top of the height riser block.

Base plate with clips glued in place and glued to the height riser block
Base plate with clips glued in place and glued to the height riser block

NOTE: The base plate on one side does NOT require the clips.

Be sure to test fit your bridge section and the two plates and file as needed to make sure you have a good snug fit. Filing usually meant squaring up the underside of the clip to make sure it squarely engages with the bridge superstructure section.

Testing out the base
Testing out the base

The base plate is glued to the top of the height riser. That assembly is glued to the cap piece (it has a nice indent in there to make alignment easy) and that second assembly is glued to the top of the base (center, side and side with power outlet hole)

Completed base pieces (angle)
Completed base pieces (angle)

You can insert M3 button head screws into the holes shown below to secure the top section of the base to the electronics tray. The screws tap themselves into the plastic and hold well.

Completed base pieces (side)
Completed base pieces (side)

Examining the underside of an assembled base section you can see how well the magnets fit.

NOTE: Use two nuts on top of the screw securing each magnet so they don’t get loose.

I installed the electronics into the taller of the bases and drilled a small hole to allow the USB cable to pass through so I could flash new firmware onto the micro controller after the lamp was installed.

Assembled base with button head screws installed and testing the wiring
Assembled base with button head screws installed and testing the wiring

If you have any questions about building the base, please let me know in the comments section  below.

You can navigate back to the Enhanced LED Bridge Lamp Summary here. 

Take care,
-Bill Rainford
@TinWhiskerzBlog
@TheRainford