Articulated Ceiling Lamp

Having good lighting in a workshop is essential, but difficult to achieve. Build this articulated ceiling lamp and see what you've been missing.

The lamp has radius of 1.8m/72" and a vertical range of 1.2m/60". The pivoting lamp holder can point the light in almost any direction. The lamp was so useful in my shop, I made a second one.

The plans were based on the materials I had around. They are a mix of metric and imperial, and I've included rough equivalences throughout the project. I've included a Fusion 360 model of the fixture, and a number of pdf drawings of the part. I also included Amazon links to the air-springs (pistons/struts/shocks) and a number of other components.

Making the "inner hinge" components take the most work, but they can be easily made by hand (though I used a CNC mill). Construction isn't too difficult, but the lamp is large and moving it around (while building) can be ungainly. Enjoy.

Metric:

• 20mm square tubing
• 12mm aluminum plate
• 6mm aluminum plate
• 25mm round tubing with 10mm internal hole, 45cm long
• 10mm steel rod - 60cm long
• (6) M10 shaft collars
• (9) M10 washers
• (24) M5-40mm hex socket head screws
• (24) M5 lock nuts
• (8) M10-45mm socket head screws
• (6) M10 lock nuts
• (16) M10 plastic washers
• (2) M10 internal threaded knobs
• (4) M6-20mm brass thumb screws

Imperial:

• 3/4" square tubing, 1/16th thickness
• 1/2" aluminum plate
• 1/4" aluminum plate
• 1" round tubing with 3/8" internal hole, 18" long
• 3/8" steel rod 24" long
• (6) 3/8" shaft collars
• (9) 3/8" washers
• (24) #10-32, 1.5" hex socket head screws
• (24) #10-32 lock nuts
• (8) 3/8"-16, 1.75" hex socket head screws
• (6) 3/8"-16 lock nuts
• (16) 3/8" plastic washers
• (2) 3/8"-16 internal threaded knobs
• (4) 1/4-20, .75" brass thumb screws

Common parts:

• Light switch
• Lamp socket
• Lamp
• Threaded lamp socket tube
• Power cord
• Zip-ties
• (2) Gas springs
• (2) Screen door springs

You may wish to redesign the following parts based on where/how the lamp will be installed, and the type of fixture you decide to use. The dimensions are only in imperial because that is what was actually constructed. The parts are simple enough that they are easily adapted to the stock you have access to.

• Lamp holder
• 1.5" U-shaped aluminum extrusion or 1.5" square aluminum extrusion. 1/8th" wall thickness.
• 1.25" x 1.25" x .75" aluminum block.
• 3/8" aluminum shaft collar.
• 1/4-20 bolt 1.75" long
• 1/2-20 threaded knob
• Ceiling mount
• 1/4" steel plate
• Lag bolts

Tools:

• Saw for aluminum tubing and steel rod.
• Mill (CNC or manual) or Drill and coping saw to cut aluminum plate into internal hinges.
• Drill and drill bits (M5, M10 or #7
• Taps (M5 and M10 or #10-32 and #1/4-20)
• MIG or TIG welder, or modify the design to use screws.

The 4 inner hinges are cut out of aluminum plate (12mm or 3/8") and aluminum tubing (25mm or 1").

There are 2 pivot holes in the plate which connect to the outer hinges and are used to move the fixture vertically. The aluminum tube is attached to the back of each plate (either by welding, or with screws). The hole that runs through the tube pivots the lamp radially.

The outer hinge plates connect the struts (the long aluminum arms) to the inner hinges. They are cut from aluminum plate (6mm or 1/4").

Cut the hinge plates out. This can be done a number of ways:

• Use a CNC mill
• Use a manual mill
• Manually:
• Glue or layout the hinge plate pattern on the aluminum
• Drill the two pivot holes (10mm or 3/8"). Use a punch and spot drills and clamp to a drill press.
• Drill some holes on the inside cutout of the pattern and use a coping saw to cutout the rest of the material.
• Use a band saw or hack saw to cut out the rest of the pattern.
• Clean and deburr the part. Make sure the back is flat, this is what connects to the pivot tube.

Cut the aluminum tubing to size, this should be slightly longer than the back of the hinge plate.

Attach the aluminum tube to the hinge plate. This also can be done a number of ways:

• Using a mill, flatten one edge of the tube with an end mill until it is the width of the hinge plate (12mm or 1/2").
• Weld the tube to the hinge plate.

OR

• Drill 4 (5mm or 1/4") equally spaced holes through the tube.
• Countersink these holes through one side of the tube and just enough through the far side to seat a button head cap screw.
• Drill and tap the back of the hinge plate to receive these screws.
• Screw the tubes to the hinge plate using 5mm button head cap screws.

The tube should extend slightly above and below the hinge plate. Test to make sure the steel rod (10mm or 3/8") fits through the tube and is able to rotate freely, but without too much wiggle.

Drill a hole through the back, center of the tube (5mm or #7) and tap (M6 or 1/4-20). This is for the brass thumb screw. It is used to keep the arm from swinging radially. Test that the steel rod fits and that the brass thumb screw can keep the rod from rotating.

To make the ceiling mount we need to attach a steel rod (10mm or 3/8") to a circular plate. The plate and rod have to be very strong due to the torque of having a few (Kgs or pounds) of force almost (2m or 6ft) out. I made my ceiling mount out of 1/4" steel plate with a 10mm center hole, and a 10mm rod welded together.

To make the same mount I made, cut out a (150mm or 6") circle out of a (1/4" or 6mm) steel plate. Drill a (10mm or 3/8") hole in the center. Cut a (10mm or 3/8") rod to (140mm or 5.5") and chamfer the edges. Weld the rod into the hole. Make sure the weld is structurally sound.

If you don't have a welder, you can use a thick piece of steel or aluminum and an interference fit - use a lot of force to embed the rod in an undersized hole.

Its a good idea to drill the mounting holes before welding/assembly, so go measure you're ceiling and make sure there is something sturdy to attach to. Everyone's mounting locations are different, so I left out dimensions for holes. Try to keep the holes as widely spaced as possible to increase the stability of the mount.

Cut the square aluminum tubing into 4 equal lengths (74cm or 29"). Clean up the ends with a file or some sandpaper. Drill the 3 holes (5mm or #10 clearance) on each end through the entire height of each tube. These holes should align perfectly with the outer hinge plates. Make sure all of the holes are in the same direction. Deburr the holes.

Attach the outer hinge plates using the (5mm or #10-32) screws. The order should be screw, outer hinge plate, strut, outer hinge plate, (5mm or #10-32) lock nut. Don't overtighten and deform the struts. The large holes on the inner hinge plates should be aligned.

You may be tempted to use standard aluminum T-slot extrusions. Don't. These extrusions resist bending, but are terrible when it comes to torsion (twisting lengthwise). Don't ask me why I know this...

Each arm is made with 2 outer hinges, 2 strut assemblies.

Place one inner hinge facing up and the other facing down - the arm is a parallelogram with pivots. Connect each end of the strut assembly to the inner hinge with:

1. 10mm or 3/8" hex head cap screw
2. Outer hinge plate
3. Plastic washer
4. Inner hinge plate
5. Plastic washer
6. Outer hinge plate
7. Lock nut

For one of the 4 hinge points, replace the lock nut from step 7 with a washer and threaded knob (10mm or 3/8"). The knob is used to adjust the stiffness of the arm, and keep it from drifting up or down.

The plastic washers may be oversized, and can be sanded down to fit. Getting everything snug, but not too snug, is the trick and may take a little time.

There are two arms. They are hinged parallelograms that are pulled down by gravity. We use springs and air pistons to counteract gravity and to equalize the forces.

The upper arm, the one attached to the ceiling mount, holds more weight than the lower arm. It uses two air pistons connected between the bottom and top struts to push itself up. The lower arm uses two springs to pull itself up.

Be careful with springs and air-pistons, they can store lots of energy that can quickly be released and hurt you and damage the lamp.

The Upper Arm:

The air-pistons I bought come with mounting brackets. Drill mounting holes through the struts and mount these brackets on both sides. The pistons are pushing the arm up, so the base of the pistons need to be attached to the lower strut, close to hinge that mounts to the ceiling. The top of the piston attaches to the top strut. To determine the location of the top bracket, push the end (the hinge that will attach to the lower arm) up to its limit. This is where the piston should be attached while fully extended. Mark the location for the bracket, drill the mounting holes, and attach the bracket to the strut.

The Lower Arm:

The springs pull the end of the lower arm up. These are easier to install than the pistons. Its easier to install the springs if the arm is pushed up (the hinge that will attach to the lamp is up). Attach one end of each spring to the top pivot (the M10 or 3/8" screw/nut assembly) of the hinge that connects to the upper arm. Attach the other end to one of the screws that hold the bottom outer hinge plates in place. I swapped out this screw for something a little longer to make it easier.

I chose to build a simple tilting mechanism to hold the socket. While writing this Instructable, I realized that you could eliminate this step and use a lamp socket installed into the inner hinge pivot tube. You can also put a swivel (Satco 77606) into the socket and get the same benefits of the tilting mechanism.

If you chose to build what I made, I attached some drawings, but you might want to design your own based on the materials you have.

You'll need a (5.5" or 140mm) steel rod attached to a "U" bracket. I used a piece of an extrusion I had laying around. You can also bend some steel sheet metal into a similar shape. I welded an aluminum shaft collar to the extrusion and used this to mount the steel rod.

Cut the U bracket to size and drill a through-hole for mounting the aluminum block, and another hole for centering the aluminum shaft collar. Weld the collar to the U bracket.

Cut the aluminum block to size and drill the 2 holes. The offset holes in the block are used to attach the lamp fixture and the other to pivot in the U bracket. Mount the light fixture to the block and mount the block into the U bracket with the screw and threaded knob.

Connect the arms

All of the major components have been built, its assembly time! You need to cut a (250mm or 10") section of metal rod (10mm or 3/8"). This will be the pivot pin between the upper and lower arms. The stack of hardware for connection the arms is:

1. Shaft collar
2. Washer
3. Upper arm inner hinge tube
4. Washer
5. Lower arm inner hinge tube
6. Washer
7. Shaft collar

The assembly should be snug, and should rotate freely. Rotational stiffness can be controlled by tightening the brass thumb screws on the inner hinges.

Connect the lamp holder

The lamp holder assembly is attached in a similar manner. The hardware order is:

1. Shaft collar
2. Washer
3. Lower arm inner hinge tube (the free hinge)
4. Washer
5. Shaft collar
6. Lamp assembly

The lamp assembly should also rotate freely and stiffen when tightening the brass thumb screw.

Wiring

The wiring can either be run through the square tubing or zip-tied to the tubing. I attached it to the outside to make it easier to build and service. Make sure there is slack between the lamp holder and the lower arm, the center pivot between the two arms, and the pivot at the ceiling. All of these components rotate, and need at least one rotation's worth of extra wire to move freely.

Attach the switch wherever you think is comfortable. I chose to mount an inline switch on top of the lower arm, near the lamp holder. I used 3M HVB tape, but you can attach it any way you like.

For the bulb, I used a 3-panel LED lamp that I found on Amazon. I modified it slightly to allow the panel to turn inward, and focus. As shipped, the lamp panels are either flat or point outwards. You can also use remote-controlled bulbs and leave the inline switch out.

Attach the mounting plate to ceiling. I intentionally left mounting holes off of the drawings, you will need to determine where the holes should be. Make sure you have a good, sturdy beam. Drill clearance holes and mount to the ceiling with lag bolts.

The lamp has springs, air-pistons, and lots of pivot points. In order to make it easier to attach to the mounting plate, I recommend wrapping a strap, cord, or something that can hold the lamp parts together. Attach the fixture using:

1. Shaft collar
2. Washer
3. Inner hinge tube
4. Washer
5. Shaft collar.

Ensure that the ceiling plate and the fixture are well attached, and won't fall on your head!

Adjust the tension of the 2 knobs on the arms, the 4 brass thumb screws, and the knob on the lamp assembly until you can easily position the lamp and it doesn't drift around. Even though all of the components are fairly rigid, there are a lot of forces that subtly twist things, this is to be expected with a mechanism that cantilevers so far out.

Plug the lamp in and enjoy!