Low-Cost Research Glove Box

Purpose:

The purpose of this Instructable is to guide in the build of a low-cost research glove box. The overall dimensions of the box are 3’ x 2’ x 2’ ¾” (L x W x H) with a 1’ x 1’ x 1’ pass-through box attached to the side. This box incorporates temperature and humidity control in order to create a controlled environment for experimentation. The approximate build time is 10 days for the main structure and wiring/piping. Some testing of the coding used for this project will have to be incorporated into that time as well, which will vary depending on your level of confidence with Arduino programming. The overall cost of the build is approximately $320 USD in wood, screws, hardware, wiring, piping, PVC, acrylic, paint, sensors, and additional miscellaneous items. A metal cart was used in this build, but is not required. The box can be set up on a table top or workbench.

Tools Required:

· Table saw

· Jig saw

· Router

· Circular Saw

· Power drill

· Straight edge

· Tape measure

· 6” hole saw

· Paint brush

· 6” paint roller and foam sleeves

· 220 grit sandpaper

Materials Used:

· 2 x (8’x4’ x ¾”) cabinet grade birch plywood

· 1 X (36” x 30” x 0.093”) acrylic sheet

· 2 X (24” x 18” x 0.093”) acrylic sheet

· Deck Plus (8 x 1 5/8”) screws (includes bit)

· Gorilla Glue Silicone Sealant, 2.8oz., clear

· Gorilla Glue Epoxy

· PLA for 3D printed parts

· 3 X Gatehouse 1.75” die-cast sliding window sash lift

· 6 X Gatehouse door hardware/hinges 1.5” zinc-plated

· 5 x 1-pint mason jars

· Valspar Duramax satin latex exterior paint, white, 1 quart

· Silicon caulking

· Arduino microcontroller

· Breadboard (or soldering could be used to connect wires)

· 5 different colors of wiring

· 9-volt battery

· Adafruit DHT22 (humidity and temperature sensor)

· 10kΩ resistor

· Stepper motor (28BYJ-48)

· Two relays (JQC-3FF-S-Z)

· CAT 5 wiring

· 2 x 90-degree elbow (copper)

· Plastic hosing

· ½” hose clamp

· Extruded Aluminum panel

· ½” plywood for storage box (used scrap pieces)

· LED strip lights

· Appropriate AC to DC converter for whatever lights used

· 2 x 6" hose clamps

Layout cut lines for all sides of main box and pass-through box on plywood sheet. The cut list is as follows:

· (1x) 36” x 12 ¾” (front where glove holes will go)

· (1x) 36” x 24” (back)

· (2x) 24” x 22 ½” PLUS 45-degree cut from center (12” mark) of 24” side up to 22 ½” side

· (1x) 34 ½” x 22 ½” (bottom)

· (1x) 36” x 11 ¾” (top)

· (1x) 36” x 17 5/8” (front cabinet door)

Make all cuts with a circular saw using a straight edge as a guide, as shown in the photo from Google Images below. Sand all the edges once cut. The top and front face of the box will need to have 45° angle cuts made on the long edges to be flush with the sides which are cut on a 45°angle. Line up and measure these by hand to make the correct cuts. Use a miter saw or a table saw to make these angle edge cuts.

Test fit all sides. In this construction, the bottom of the box is placed “inside” of all of the sides of the box; and the left and right sides are placed “inside” of the front and back of the box. Use a router to trim sides to the appropriate height. In this construction, there was about 1/16” error between the rear side and the left and right sides, so the rear was trimmed to the shorter length to match the sides using a router.

Cut hole for pass-through box in right side. Use a jigsaw to rough cut the hole and a router to straighten up the cuts. This hole needs to be the size of the pass-through box minus two times the thickness of the wood used. In our case, the hole was 10.5” x 10.5” square. You want the bottom of the hole for the pass-through to be flush with the floor of the main box, as seen in the photo.

Cut holes in front face for gloves. A comfortable distance for between the glove holes was obtained from a sand blaster cabinet of 6.5”. Each glove hole was cut using a 6” hole saw. The holes are measured at 3.5” from the bottom of the box. The center of the front face was measured and the holes based off of that rather than the distance from the outer edges.

Screw together all sides to create the box, less the front cabinet door. Mark the centerline of the thickness of the wood (in this case, 3/8” from the edges of the sides which will be screwed to the edges of the adjacent sides). Predrill holes with countersink bit every 2” leaving space at corners for screws from adjacent boards.

Construct pass-through box. This is the 1’ x 1’ x 1’ cube. Cut the 5 sides required to construct the box from the same ¾” plywood as the main box. Remember to incorporate the thickness of the plywood into the cuts. The cut list is as follows:

· (2x) 11 ¼” x 11 ¼” (back and top)

· (1x) 12” x 11 ¼” (front); + about 2/5” slit in side that will attach to box for acrylic “door” to be able to slide through

· (1x) 10 ½” x 11 ¼” (bottom)

· (1x) 12” x 12” (this will be the door of the box on the outermost edge)

Two of these sides (top and front) will need to have viewing windows cut into them. Mark these viewing windows to the desired size. This box has a top window with dimensions 7 ½” x 7 ½” and a front window with dimensions 7 ½” x 8”. Use a jigsaw to rough cut the openings and then a router to finish them. Use a rabbit bit on the openings so that the window will have a surface to adhere to.

For the small slit on the front side, measure about 2/5” off the edge and ¾” in on the top and bottom of this edge. Use a router to cut the 2/5” deep and 10 ½” wide slit on the edge of this side.

Assemble the box in the same manner as the main box as seen in Step 6, leaving off the door on the right side.

Install viewing windows in two openings of pass-through box. Cut acrylic sheet to desired window size + overlap for adhering. Use small screws to attach corners to hold in place in opening and use silicon sealant to completely adhere window to surface from the back side.

Construct sliding window that will separate main box from pass-through box. Cut an acrylic sheet to the desired dimensions. For this box, those dimensions were 14 ¼” x 11”. Attach a small handle made from leftover plywood with small screws so that it can be easily slid by the user. Use felt tape on all edges of the sliding window to help with sealing when it is closed, including an strip at the dimension of the opening of the pass-through box.

Attach pass-through box to main box. Apply construction adhesive to pass-through box edges which will be attached to main box. Then, use 6-12 screws from inside of the main box into the edges of the pass-through to hold together while adhesive dries.

Cut opening in cabinet door for viewing window and install window. Use a jigsaw to rough cut the desired size viewing window. This box has a window with dimensions 30” x 12”. Use a rabbit bit on the opening so that the window will have a surface to adhere to. Cut acrylic sheet to desired window size + overlap for adhering. Use small screws to attach corners to hold in place in opening and use silicon sealant to completely adhere window to surface from the back side.

Use caulking to seal all interior joints of box. Putty all screw holes and paint all components of box with white paint. Do this now before installing any hardware. Use painters tape to tape off installed windows before painting.

Install both cabinet doors to main box and pass-through box. Use small hinges, 4 on the main box cabinet and 2 on the small door for the pass-through box.

Attach sliding window sash lifts to either side of the main box door and one to the door for the pass-through.

Construct storage box for saturated salt solutions. This storage box was built to fit within the confines of the cart that was used. Any storage box that you build is only really needed to store the saturated salt solutions so that they will not fall over. For this application, the measurements of the middle and bottom shelves of the cart used were taken to get an idea for the size of the storage box.

Cut ½” plywood such that the height will fit between the shelves, and attach sides of storage box with 1” wood screws.

Once storage box frame has been assembled, place salt-solution containers (5x pint mason jars) in box, then measure and cut 1” x 3” pine wood for container frame. This needs to be a tight fit so that the jars are not able to move around, but loose enough so that they are easily removable. This box was placed on the middle shelf of the cart for ease of access.

Make holster for heat gun. Place heat gun on a small piece of leftover plywood and trace out the shape.

Cut out the shape with a multi-tool.

Drill a small hole in the bottom of the handle, making sure not to drill into the wires. This small hole is for mounting the heat gun to the cut wood in the previous step.

Attach a small square piece of plywood to the end of the cut wood for a spacer to ensure the gun will mount straight. Next attach a ½” clamp to the end of the small square piece of wood to hold the heating pipe will be attached to the heat gun.

Mount the heat gun to the cut wood with a screw in the hole drilled in the handle. Also put the heating pipe adapter into the clamp and tighten to ensure the fitment is correct. After the fitment has been checked, remove the heat gun and clamp from the cut wood so it can be painted.

Wrap the ½” heating pipe with exhaust wrap to ensure that the pipe does not burn the wood as it is plumbed through the box and also for safety by not allowing the user to get burned by the pipe.

Attach the painted piece of cut wood by screwing it to the main box. Drill a ¾” hole in the rear right hand side of the box in the lower corner to insert the wrapped heat pipe. Insert the heat pipe to the clamp and tighten the clamp to ensure a stable mount.

Secure heat gun to the cut wood by inserting the heating barrel of the heat gun into the heating pipe and then tighten the screw in the handle.

Drill hole in left lower corner of box to insert hose for humidity airflow.

Insert second copper 90-degree elbow into this drilled hole, and the hose into this copper elbow as seen in photo.

Cut extruded aluminum piece to width of interior of main box. This is a spare piece of overhead fluorescent light housing. This one is 34 3/8”. Then, drill 1/16” every couple inches across the length of the aluminum piece in two lines.

Install 3D printed glove flanges into two glove holes for box. The .stl file for these flanges is included here. Attach gloves with 6" hose clamps.

Install mason jars with two holes cut into the lids. One hole will have hose run into it from the air pump, while the other will have hose run out of it and into the box for humidity. The method of humidity control used here is saturated salt solutions. Five different salts are used to control specific humidity conditions, so 5 mason jars are used. The pump used is a standard air mattress pump. The five hoses that run out of the jars and into the box first go through a collector to run the 5 separate hoses into 1 before feeding into the interior of the box. The rotary valve used is run by the stepper motor (28BYJ-48). This system was designed and 3D printed. The .stl files for each part of the rotary valve are included here. The stepper motor needs to be attached to the part b2 as seen in the photo.

Use LED strip lights (the ones used here were spares from another project) and mount to the top of the main chamber. Use epoxy to adhere the strip to the "ceiling" of the box.

a. Sensor hardware: (pins on the sensor are numbered left to right, as viewed from the front of the sensor)

i. Connect a 10kΩ resistor between pin1 and pin2

ii. Connect the pin1 end of the resistor to the 5 Volt pin on the Arduino

iii. Connect the pin2 end of the resistor to digital pin 2

iv. IGNORE pin3. It isn’t needed for anything.

v. Connect pin4 to ground

vi. You MUST download the DHT library or it will not work

b. Motor hardware:

i. Connect the motor wires to the intermediary board

ii. On the intermediary board, connect Vin and GND to a 9-volt battery

iii. Connect IN1, IN2, IN3, and IN4 to digital pins 4, 5, 6, and 7, respectively

c. Relay hardware:

i. Connect VCC to 5V power supply

ii. Connect GND to ground

iii. Connect IN1 and IN2 to digital pins 12 and 13, respectively

Copy or Download Aruino Coding, see operating instructions for files.

Note:

*** You MUST download the library for the sensor you are using, (DHT22 in this case) or the code will not work. In order to obtain the library, go to GitHub (https://github.com/adafruit/DHT-sensor-library) and download the library. Also be sure that the Adafruit Unified Sensor library is downloaded (found at the bottom of the linked page). Once you download these zipped files, unzip and add them to the Arduino Libraries folder (Computer/Documents/Adafruit/Libraries).

A 3D printed GoPro camera mount was made and installed in the front of the main chamber to take video of experiments. A store-bought mount can be used as well.

After additional work on the Low-Cost Research Glove Box, another humidity control option was designed and used. This design does not require a motor or rotary valve in order to choose the saturated salt solution jar that the user desires. Instead, 5 separate valves are mounted with a feed line from the air pump and each valve then feeds into the 5 different saturated salt solution jars. Finally, each jar is fed into a collector and one hose line fed into the main chamber of the box.

Tools Required:

• 5/8" Forstner Bit
• Power Drill

Materials Used:

• 5 x Rain Bird Drip 1/2 in. Barbed On/Off Valve
• 4 x Rain Bird 1/2 in. Barbed Tees
• 11 x Rain Bird 1/2 in. Barbed Elbows
• 1/2" ID Vinyl Tubing
• 1/4" ID Vinyl Tubing
• 6 x 1/2" OD to 1/4" OD splice
• 1 x 1/4" ID to 1/4" ID barbed tee
• 10 x 1/2" Two Hole Strap
• Imagitarium Air Pump, 4W
• 20 x 1/2" screws
• 4 x 1" bolts
• Spare 3/4" x 7" solid oak wood board
• Rotary Valve from other humidity option used as collector
• Gorilla Glue 5 minute epoxy

Steps:

1. Mate each of the 5 valves on both sides with the barbed elbows using the 1/2" ID vinyl tubing as seen in the photos.
2. Construct the air intake setup using 4 of the barbed tees and 1 barbed elbow as seen in the photos.
3. Measure the distance from center to center of the opening of the tee valves to determine the spacing for the valves when mounted to the wood board. We mated the tees as close to touching as possible so our distance was 3".
4. A spare piece of solid oak was used to mount the valves to. The spare piece we had was about 1.5' long so we centered our valve system on that. The valves needed to be a horizontal distance of 3" (as found in previous step) from each other in order to mate with the air intake assembly. Use a speed square to mark 5 45-degree lines spaced 3" from each other. Measure the center to center distance of the openings on the elbows mated with the valves. We measured about 6 1/4". Mark the board on the 45-degree lines where you would like to drill out for the elbows to sit through to mate on the backside with the air intake assembly.
5. Use a Forstner bit (5/8" was a usable size we had on hand) to drill out the 10 holes marked in the previous step.
6. Mount the valves to the board using 10 two hole straps as used in running conduit (see photos).
7. Use the 1/2" ID vinyl tubing to mate the air intake system to the bottom row of elbows mated to the valves. (These were mated to the bottom row because of the end orientation of the air pump and the saturated salt solutions.)
8. Mate 5 1/2" OD to 1/4" OD splices to the top row of elbows mated to the valves using the 1/2" ID vinyl tubing.
9. Mount valve board in a convenient place for the user. This board was mounted to the right-upper corner of the cart. Measure and predrill 4 holes into the board and the cart. Use 1" bolts to attach the board to the cart.
10. Set saturated salt solutions in designated locations and run 1/4" ID tubing from the splices into the bottoms of the jars. The length of tubing required will depend on your setup. These were test fit and then cut, so no measurements were made. (See photos)
11. Finally, use a 1/4" ID to 1/4" ID tee to mate the two output tubes from the air pump to a 1/4" OD to 1/2" OD splice and mate this to the air intake system on the back of the board.
12. The rotary valve from the previous humidity control solution was used as a collector in this design. Five minute epoxy was used to seal the valve.
13. Run 1/4" ID tubing from each saturated salt solution jar to the "rotary valve" collector. Use the same tubing from original design to feed the collector to the interior of the chamber.