Introduction: Desk Shield for Teachers
I was wanting to build some sort of desk shield for my wife's elementary school classroom and was browsing Instructables for ideas. I came across a fantastic project by ebanzai called "DIY Teacher Desk Shield for Writing Conferences" that seemed like the perfect solution. The problem was that the design involved woodwork and I have zero woodworking tools or skills. I took his general idea and re-worked it to be build-able using the tools I had available.
The general idea of this project is to build a transparent shield that can sit on a table top between a teacher and student to allow them to collaborate more safely at close distances. Discussing an assignment generally requires teacher and student to be much closer together than social distancing allows (it's hard to read a paper from 2m away, much less point to things or write on the paper). The shield must:
- Ensure that teacher and student aren't breathing directly on each other
- Allow both sides to see and hear each other without difficulty
- Allow papers to be passed back and forth
- Allow the teacher to easily point to or write on the paper
- Be easy to transport from one table to another
- Be easy to clean
This is certainly not a replacement for wearing a mask or other basic health precautions, but it adds an extra layer of safety to moments where close proximity is unavoidable.
- Plexiglas/acrylic panel
- PVC pipe
- Pipe fittings
- 90° elbow (x2)
- T-joint (x1)
- "Side-out elbow" (x1)
- End cap (x4)
- Zip ties (6-10)
These are all fairly common materials and should be available at most local hardware stores. An alternate source for the acrylic panel is craft stores as they're often used to replace glass in picture frames.
The panel itself can be whatever size you want. Mine was 18" x 24" and is a good size for small to medium sized desks. You don't need a thick panel, the 0.08" thickness panels work fine and are the least expensive.
The size of the PVC pipe doesn't matter too much. I used pipe with a 0.5" inner diameter because I had some on hand. I don't recommend going too much smaller than that or it may not be rigid enough to hold its shape.
The zip ties should be on the thinner side. Mine were about 3/32" wide. Go too much wider than that and you might make things more difficult later.
The shield I built has one right-angled foot so that it can sit in the corner of the table and run diagonally. If you'd prefer, you can omit that feature and use a standard T-shaped foot instead. To do that, substitute the "Side-out elbow" above for a second T-joint. For a truly flexible design, get both and swap between the two feet as needed.
Step 1: Cut Pipe
Cut your pipe into seven pieces: one horizontal bar that goes across the top, two vertical posts, and four feet. The specific lengths will depend on the size of your acrylic panel.
My panel was 18" tall and 24" wide. The outside of your frame should be as wide as your pane. I made my horizontal bar 22" long, which makes the outside of the frame 24" wide once you account for the width of the corner fittings. You may have to experiment a bit to get the size just right. Cut the horizontal bar a little bit on the long side if in doubt, you can always trim a bit off later.
I cut the vertical pieces 20" long. After accounting for the size of the fittings, this gives a gap of about 3" between the bottom of the panel and the table surface (in hindsight, a 2" gap might be more appropriate). Make sure that both vertical pieces are as close to the exact same length as you can get them.
The feet were cut to lengths of 3". This seemed like a good balance between stability and the amount of table space they occupied. 2" is probably the bare minimum. It's okay if the feet aren't exactly the same length.
Step 2: Mark Panel and Drill Mounting Holes
You will need to drill several mounting holes along the edges of the acrylic panel. I recommend one every 8-10" along the top in order to ensure the weight of the panel is adequately distributed. The holes along the sides won't support any weight, they're only there to prevent the panel from swinging.
Drilling too close to the edge of the panel can cause the material to crack. My holes were 1" away from the edges.
Leave the protective film on the panel for now. Mark the location of the holes with a marker. Any stray marks will come off later when you remove the film.
Place something underneath the panel before you drill the mounting holes. A piece of scrap wood works, or I used a stack of scrap cardboard that I pulled out of the recycle bin. This will help the drill's "exit wound" stay clean and avoid splintering.
You can drill the holes with a regular drill or with a rotary tool (like a Dremel). I used the latter. Your drill bit should be slightly larger than the width of the zip ties. My zip ties were 3/32" wide so I used a 1/8" bit. Small holes are easier to drill in Acrylic than large ones, so this is where it helps to have thinner zip ties.
Acrylic will shatter, so the key is to go slowly and don't try to drill the hole all at once. I drilled about 1/3 of the way through the material, backed the drill out, drilled the next 1/3, etc. You don't want to risk generating too much heat through friction and causing the material to melt. You should end up with a nice, clean hole with smooth edges.
Step 3: Assemble Frame
Take your pipe and fittings and assemble the frame. Don't fit things together too tightly at this stage. You should still be able to pull the pieces apart without much trouble, but the parts should be tight enough that they don't fall apart on their own.
Start with the long horizontal bar (red in the model above). Place the right-angle fittings on either end and then attach the vertical support posts (blue) to the fittings. Make sure the vertical supports are as close to parallel as you can get them.
Build the feet by placing two of the small pipe segments (green) into each of the remaining two fittings, and then add the end caps to the exposed ends. Attach the feet to the bottom of the vertical supports. You should end up with feet that look like the image above.
Step 4: Attach Panel and Make Final Adjustments
Use the zip ties to hang the panel on the frame, but leave the ties relatively loose for now.
There are two methods for attaching the panel. You can leave the frame standing upright and attach the top zip ties first to support the panel's weight while you attach the others. You can also remove the feet, lay the frame flat, and set the panel on top of the frame. The first method is a bit easier if you have a helper that can hold things in place, but I recommend the second if you're working solo.
Once the panel is hung, stand the frame upright and inspect the unit. Everything should look square, the vertical supports should be parallel with each other and perpendicular with the ground, and the horizontal support should appear level. The amount of pipe showing on each side of the panel should be roughly equal.
This is the time to make final adjustments. Nothing is connected too securely just yet, so you should still be able to disassemble the frame, make any additional cuts as needed, and then thread the pipe back through the existing zip ties to re-assemble it.
If the legs appear to bow inward at the bottom, your horizontal support piece is likely too long. Trim it down in 1/2" increments until the legs sit vertical.
If the horizontal support piece doesn't sit level, one leg is likely longer than the other. Remove both legs and trim down the longer of the two. This can also be caused by a poor cut that left the end of the leg at an angle.
If the entire frame wobbles, lay the entire unit flat and double-check that the vertical posts are parallel with each other. This can also be caused by the end caps on the feet. Some end caps aren't completely round and have a small bump or ridge on one side that makes it easier to grip with a wrench. Make sure these are all facing upwards (away from the table surface).
Step 5: Clean Up
Finish off your desk shield by press-fitting the pipe components together as tightly as you can. Tighten the zip ties along the top edge of the panel so that they hold the panel securely. Tighten the zip ties along the outside edges as well, but leave them slightly loose. The panel has no stretch to it, so tightening the side ties too tight can cause the legs to bow inward and the frame to wobble.
Remove the protective film from both sides of the acrylic panel. Cut the excess length off of the tail of the zip ties. If this leaves sharp edges, you can use a metal nail file to round off the corners and avoid cutting your hands later.
Step 6: Maintenance
Glass/window cleaner will leave the acrylic panel looking nice but is not sufficient to sanitize it. Check the data provided by the manufacturer of your panel to see which cleaning chemicals can and cannot be used on it. For my particular panel, harsh cleaning agents like ammonia or hydrogen peroxide will damage the material but weaker acids will not. Your safest bet is always old-fashioned soap and water.
Some formulations of acrylic can yellow over time when exposed to ultraviolet light. When not in use, store the shield out of direct sunlight.
My shield has worked well with everything press-fit together but if you'd like a little extra structural reinforcement, you can permanently join the pipe components using PVC cement or superglue. If you go this route, I recommend not permanently attaching the feet to the rest of the frame. The shield is easier to store when you can remove the feet and lay it flat.
Step 7: Conclusion
Parts for this project cost me just under $25. More than half of that was the cost of the acrylic panel. Panel costs can vary quite a bit based on size, thickness, and extra features like impact or UV resistance. The PVC components get cheaper as you buy them in larger quantities, so you can probably hit the $20 price point if you're building a bunch of these.
Total build time was around half an hour, with most of that time going towards cutting the pipe by hand. If you have access to a bandsaw, you can probably build this in around 10 minutes.
The snap-together style of this design makes it easy to build assembly-line style. If you're a member of a makerspace, scout troop, or shop class, consider building a bunch of these for your local schoolteachers.
Here are a few other resources that you might find helpful:
- The original design on which this project was based, and which deserves most of the credit
- audreyobscura's excellent PVC class, full of useful tips about working with PVC
- PVC-101 by trevormates, another great source of PVC information
- How to remove lettering from PVC pipe
- Cutting PVC without tools
- Fabrication guide for my specific acrylic panel, full of info on how to work with the material without damaging it