SpARF - The modular strip fixture

[YYCannabis]

Sp.A.R.F. -Spine-And-Rib Fixture

Thought I would share my light fixture build. My goal is to make a fixture that can be adjusted more than just turning a potentiometer. I wanted something that I can adjust physically to meet different growing needs (ie mixed stages of growth/plant size/space utilization) and be able to easily change/add strips and add mono color (UV or IR etc) to exactly which areas need a specific coverage.

Meet SpARF. The Spine And Rib Fixture. Cheap. Easy. Modifiable.

[YYCannabis]

SpARF is a work in progress but I am excited about the options it presents. Designed with aluminum U-channels and flat bar, this strip fixture presents a solution to everything I was aiming to achieve.

The strips I will be using are the 3000k 90cri and the Optisolis 5000k 97cri from Cutter. I will be driving 20 of these strips in groups of 5 by using 4 drivers (ELG-150-48B) w/external potentiometers. I like the idea of keeping lights close to the canopy, so I will be running these strips cool at 700mA (approx 30w/strip). These are to cover a 4x4 tent.

The tools and materials for this build is fairly basic:
THE SPINE:
19mm (3/4”) aluminum u-channel. The spine can be any length needed to suit individual design.

SpARF spine 3/4” channel

THE RIBS:
-aluminum flat bar: I chose to use 31mm (1 1/4”) wide flat bar that is 3mm (1/8”) thick and approx 6mm (1/4”) longer than the strips.
-aluminum u-channel: 26mm (1”)

SpARF rib 1

SpARF rib2

Tools:
-saw
-file
-sand paper and block
-drill
-pliers or side-cutters
-stainless steel wire brush
-torch (propane or MAP gas)
-gloves
-safety glasses
-dust mask

Other Materials:
-aluminum brazing rods (find on Amazon)
-felt pads with sticky adhesive.

[YYCannabis]

Assembly:
**This assembly includes the use of power tools and extremely high heat. Use all safety precautions to avoid injury or death, or damage to property **

First up let’s start with building a rib. The rib is made from the flat bar and a piece of the 26mm u-channel. Simply cut a piece of the u-channel to match the width of the flat bar. In my case that is 31mm. Use a metal file to chamfer the ends where you cut. *SHARP EDGES* will cut you so please wear gloves when handling any cut pieces of aluminum.

Center and square the piece of u-channel across the flat bar so it is exactly perpendicular and fix in place. Do this by heating the flat bar and the u-channel with a torch. Then apply the brazing only to the outside edge of where the u-channel meets the flat bar. Try to avoid getting the brazing melt into the inside of the channel opening. Search “Aluminum brazing” on YouTube to see examples of how it’s done.

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At this point I ran into a small problem. The height of the spine was approx 1mm too tall to fit through the rib. So I decided to use some sandpaper and block to sand away the excess material along the length of the spine. (Your access to tools might be better.) Sanding wasn’t the easiest way to do it, but no matter, I had to remove the material somehow.

Once the spine was reduced enough, grab the file and chamfer all the edges so there are no sharp edges anywhere. Remember to also gently round-over all corners so nothing pokes a hole in the tent.

I don’t know if there is a structural difference to how the rib is oriented, but I feel it’s more rigid when the u-channel has the legs down and the flat up. Then slide the ribs onto the spine.

As you can see in the picture, there is a lot of empty space along the side of the spine.

[YYCannabis]

One of the small issues I’ve run into is that the width of the spine leaves too much latter wiggle space when in the rib passage. To fill this space I decided to try using felt strips. I found some felt pieces that were close enough in size to fill the space. I cut and trimmed the pieces and stuck it onto *one* of the inside walls of the rib passage. This helps to fill the space and keep the rib close to perpendicular to the spine.

[YYCannabis]

Next challenge will be how to hang it. But that’s for tomorrow.

Cheers
YYC

[0 to 220]

That's awesome dude! Really inspiring. Great pictures and write-up
I like the felt... hope it doesn't wear & tear too much from the friction, I think it should be fine. easy to replace anyway
Looks like you could drill holes in the spine (before welding) and the ribs and add some bolts or whatever to be able to lock them in place if you wanted to. But then you can't simply slide them left or right.
I think perphaps with 3m VHB tape you could attach those 'connectors' ribs, instead of welding them? (I can't weld for shit, obviously you did a great job and this is superior)

How about the wire management? I guess you will be using flexible stranded wires. Any tricks up your sleeve?

edit: I meant brazing when I say welding

[YYCannabis]

Thanks 0to220.

The felt should almost never wear out unless I decide to start sliding the ribs back and forth daily...which is a totally unreasonable practice. The pieces of felt could be replaced with whatever a person has on hand to use.

The brazing is something new to me. Never done it before this build. It really is stupid easy when following the makers directions (stainless steel brush is super important). I guess a person could use some type of tape, or even epoxy for making each rib since it’s not holding a lot of weight. I just wanted to help people see what’s done and they can modify construction to suit their needs.

[0 to 220]

Nice, it's truly inspiring, thanks for posting it! On one hand I would like to cover an area with strips, on the other hand, I do have to save space for other equipment. Something like this where I can possibly angle bars slightly would be perfect. I guess I'll investigate brazing, a useful skill, especially if it is easier than it seems.

[YYCannabis]

Here’s a YouTube video from the guys that made the brazing rods I bought from Amazon.



And here is the rods from Amazon. I only have used 3/4 of one rod so far. So I have tons left over for future projects.

Blue Demon BDTP-125-01T Triple...