LEGO_lamp_2_complete_dark   This is the assembled LEGOlamp.  It will be mounted as a ceiling fixture, with an internal bulb.  To light it for this picture, I used a desklamp to project light into the tube.

One idea I tried after the previous post, was slicing the tube into 16 rings.  The idea was to glue the bricks to the tube, with the bricks stacked vertically, then offset the rings after the bricks were attached.  That approach failed.  I was unable to cut the rings smoothly, resulting in large gaps between them.  When stacked, they looked horrible.

In the end, a simple change of adhesive and application made the difference.  First, I abandoned both hot glue and epoxy.  I discovered gel super glue has sufficient open time to position the bricks, but also sets quickly enough that clamping and supporting the bricks was unnecessary.  I addition, I realized the important joint is between the bricks.  If the bricks are firmly cemented to each other, the connection to the tube can be a series of comparatively weak joins.  Less glue on the end-face means less glue to smear, and less chance of accidentally gluing the template in place.


drillpress_dremel_saw  Many people have asked how I cut the LEGO bricks.  Initially, I used a sharp chisel.  That was tedious, as each brick had to be clamped.  After that, I switched to a rotary-tool held in a fixture, with a standard abrasive cut-off disk.  That worked well enough.  Finally, I hit on chucking a Dremel-sized circular saw blade into a drill press.  That provided a rock-solid platform.  Better still, once the height was set it didn’t vary.  Unlike the abrasive disk, the bricks weren’t heated by the saw blade.  No molten plastic flying around.  Using this method, the bricks required little-or-no touch-up work with a sharp knife.

LegoLamp follow-up

There are some issues . . .

It’s not going so well . . .

In a previous post, I outlined the plan for constructing the LegoLamp.  It was good theory, but not really workable.  This post will be a “what I learned,” rather than “look at what I built.”  The picture tells the story.

Legos are rectilinear, the cylinder is not.  Which means the contact between them is a line.  That’s not a lot of gluing surface.  Ideally, I would have cut the brick-end to match the curve of the cylinder.  But Lego are hollow.  Removing that much material would have removed the end of the brick.  I counted on the relatively thick hot-glue adhesive to smoosh, expanding the area of the joint.

The laser-cut template has very tight tolerances.  This was deliberate.  Making the template tight allowed it to serve, in theory, as a substrate for the next layer of bricks.  The tight fit to the current layer of bricks would hold the template perpendicular to the cylinder.

In the background, you can see the hot-glue gun has been retired.  There is a yellow, plastic-razor-holder next to it.  Hot glue was not the proper adhesive for this job.   I installed, removed, and scraped, 3 layers of bricks — twice — before abandoning the hot glue.  The template is so tight, it leaves no room for adhesive.  The glue gets scraped-off and smeared onto the cylinder as the brick is fit.  After the first layer, placing a brick is not merely a matter of fitting it into the template.  The template must be aligned with the lower layer of bricks so that the new brick will snap onto the one beneath it.  The glue is not-so-hot by the time the template is properly aligned and the brick is inserted.  The resulting joint is weak.

I switched to two-part epoxy, to gain a longer working time.  In short, it still wasn’t sufficient.  Five minutes was long enough to place the persnickety first brick of a row, plus 3 more.  Then the epoxy became unworkable, and I had to dispense more.  I wasted a lot of epoxy.  Adding insult to injury, the working time was 5 minutes but the minimum set time was 20.  That means 30 minutes per layer.  Sixteen layers is 8 hours of gluing.  That’s too long.  And, the epoxy had the same smearing and small-contact-surface issues as the hot glue.  Some of the epoxy joints are no stronger than the hot-glue joints (i.e., they fall apart if touched).

The template works as a substrate for the next layer of bricks.  But the etched outline is not sufficient to accurately place that next layer.  When the template is rotated & raised to lock onto the 2nd layer, it doesn’t fit.  The bricks are not placed within the tolerance of the template.  I can’t use the template to support the new layer as the glue sets.  Without that support, the bricks tend to fall out of parallel as the adhesive sets.  This makes the next layer even more difficult to place, stresses the lower layer’s joint in the process, and results in collapses like the one in the photo.  I created support structures from other pieces of Lego.  These work for the initial layers.  But they add to the difficulty of placing a brick.  They can’t be used after the first 5 layers, because there’s no space for them.

Clearly, it’s time to back away from the project and rethink it.



  • Clear acrylic tube, 3″ O.D.
  • 4×2 LEGO bricks, 6 per layer
  • Ceiling-mount shade holder (like this one)
  • Hot glue or specialty adhesive (e.g., Weld-On #1802)
  • Template material (flat, at least 6″ square, 5/16″ thick)

Initial considerations:

3″ O.D./2.75″ I.D. tube is appropriate for a ceiling-mount shade holder.  That greatly simplifies the wiring and allows a standard bulb to be used.  Incandescent bulbs get much hotter than CFL bulbs.  Airflow around the bulb is likely to be restricted.  Cooler bulb is better.  Distorted or discolored acrylic is not pretty.

Acrylic tube is not the only option.  Transparent PVC and polycarbonate are also viable.

Spacing between “vanes” is important.  Because the light-source is inside the bricks, they will cast dramatic shadows and restrict the amount of light projecting into the room.  The 3 screws attaching the tube to the shade holder require equidistant holes.  Space must be left for them.

A child may not understand the difference between decor and toy.  A ceiling mount places it out of reach.  The 3-screw attachment should be easily adaptable to other mounts, should they be desired later.

Template illustration

Each brick hinges on the corner nub of the brick below & behind it.  Thus each one is half a brick ahead of the one below & behind it.  Brick edges are straight, so the ends will only touch the tube at their centers.  A triangle, formed by the center of the tube and the centers of connected bricks, has a vertex of 12° (see illustration).

Use a template to ensure the bricks are glued in the correct orientation and spacing around the tube.  The template has brick-shaped holes for already-attached bricks, and indicator-lines showing where the next brick should be placed.

Correct thickness of template




The thickness & rigidity of the template material are important.  In this illustration, the template rests on the red layer of bricks, is held in the correct orientation by the yellow bricks, and supports the new, green, bricks while the glue sets.  If the template is too thin, the leading edge of the new bricks will drop.  Instead of stair-stepping up the side of the tube, the “vanes” will droop and level-off.  If the template isn’t rigid (say, cardboard), it will flex under the new bricks with the same result.  (I used sheet acrylic.)

The correct thickness of the template is equal to the distance from the bottom of the new layer of bricks to the top of the nubs on which it rests.  Note that this is not the same as the thickness of a brick!  It’s the thickness of a brick, minus the height of its nubs, then minus the height of the nubs on which the template rests.  7/16″-1/16″-1/16″=5/16″.


The Tube:  How long should it be?  As long as you want.  In my case, I noticed that 6 inches is an even multiple of the brick-height (3/8″ per brick * 16 bricks = 6″).  So my tube is 6 1/2″ long.  The extra half-inch is to accommodate the nubs on the topmost layer of bricks and provide clearance for the shade-holder.  I cut the tubing on a table saw.  The technique recommended by the manufacturer is to raise the saw blade to just above the thickness of the tubing, then rotate the tubing, in place, on the blade.  In my case, I used a cross-cut sled to ensure the cut was perpendicular all the way around the tubing.

The LEGOs:  16 bricks per “vane” * 6 vanes = 96 bricks.  I decided to use equal numbers of each color, so I needed 24 bricks each of red, yellow, green, and blue.  I purchased used bricks and a large LEGO plate in an on-line marketplace.

Don’t cut the red ones!

Because each brick must rotate 12° relative to the brick on which it sits, 3 of the 4 nubs must be removed from one side of each brick.  Important: Decide which way your bricks will rotate before you remove the nubs, and remove the same 3 nubs from each brick!  In the illustration, the red nubs are closest to the tube.  Do not cut those!  Those are the pivots for the bricks that will attach to them.  If you want the bricks to spiral clockwise up the tube, remove the blue nubs.  If you want counter-clockwise, remove the green nubs.  Note: you don’t need to remove the nubs from the top-most 6 bricks.  In fact, it will probably look better (from the ceiling, anyway :~) if you don’t.

My set-up for removing the nubs







I used a rotary tool, fixed in a stand, to remove the nubs.  I used a standard cut-off disc.  I adjusted the height of the tool so that the bottom of the disc was at the bottom of the nubs.  I used a big, green LEGO plate to hold the bricks in place, while I cut them.  The plate allowed me to keep my fingers well-away from the spinning blade, but still manipulate the brick being cut.  I left a gap between the pivot end of one brick and the next brick.  This made it easier to avoid accidentally removing the pivot nubs.  (Note: molten plastic is hot.)  After cutting, the bricks required some touch-up work with a knife, to remove the plastic still attached to the edges.  Also, the nubs are discs that sit atop holes in the brick.  Removing the nub reveals the hole.

Laser-Cut template

The Template:I found some scrap acrylic of the correct thickness. Shane was kind enough to redraw my template sketch as a vector, and show me how to use the Makerspace’s laser-cutter (Thanks, Shane!).  We cut the template in multiple passes.  The first pass included the outline for the “next-up” brick.  Subsequent passes did not.  That produced the desired through-cut with adjacent guidelines.

Template test-fit






This image shows the template, a short length of tube, and a pair of test bricks (3 nubs have been removed from the red brick).  Notice how the template aligns the red brick, and how the guidelines show correct placement of the blue brick.  Note: The template is resting on the table, not on a lower layer of bricks.  That’s why the blue brick doesn’t rest on the template.)

That’s as far as I’ve gotten.  I’ll post again when the project is completed.


A microtome is a device for slicing very thin cross-sections of stuff, in order to view them under a microscope.  Commercial ones are available, but they cost upwards of $50.  There is a classic DIY solution, but it involves a piece of old technology — a wooden spool for thread.  Outside of antique stores, those aren’t common.  Plastic ones tend to be hollow, meaning there’s no guide surface for the razor blade; and the razor is likely to shave the plastic instead of slide across it.  Gluing a washer to the plastic spool would address both of those problems.  But there is very little gluing surface on the end of a hollow plastic spool.



Lacking a wooden spool, I cut a cube off the end of some scrap 2×2 and bored a slightly-oversize hole through it.  Using Gorilla Glue, I attached a flanged nut and a flat washer to opposite ends of the hole.  Before the glue set, I used the bolt to center and clamp them over the hole.  Gorilla Glue expands 30% as it sets.  To avoid permanently gluing the bolt into the body, I carefully removed it after a few minutes.  You can see glue in the threads adjacent to the bolt, in the image at right.  A few minutes with a wire brush cleaned the bolt threads.






Lastly, I flattened and polished the washer on a lapping plate.  The edge of the washer-hole was rough, and glue had expanded out of the hole and onto the surface.

The nut & bolt are 1/4 x 20.  One complete turn is 1/20″.  So a quarter-turn should be 0.0125″ thin.  That, and a fresh razor blade, should make slices thin-enough for a microscope.