- Casting the gel
- Applying an electric field across the gel
- Viewing the results
This system has been specially constructed with the scientists ease of use in mind. The trays are very cheap to build, which allows users to own several. This means they can be pre-cast in parallel and stored in a refrigerator, saving time. The system is also very compact, at only 5.5"x5.5", saving bench space. And the whole system is inexpensive, which means it is perfect for teaching. I intend to sell a kit for around $200 for the entire package, while similar commercial systems sell just the box (no power supply or illuminator) for $600.
Read more about the development on my blog!
Beta test the kit here!!! It can be expensive and difficult to get all the parts, but if you want you can just buy them!
Step 1: Gather the Materials
Laser Cut Plastic:
- Top and Bottom plates from .118" orange acrylic (orange, picture 1)
- Shelf from .118" clear acrylic (clear, picture 1)
- Safety walls from .118" clear acrylic (clear, picture 2)
- Gel box walls from .177" clear acrylic (picture 3)
- Gel box floor from .118" white translucent acrylic (picture 3)
- 2x Switches
- 1x 2.1x5.5mm female barrel connector to terminal block
- 1x Voltmeter (0-99v readout, 12v power)
- 1x blue LED panel
- 1x 12-30v input 60-100v output high voltage boost converter
- 1x 12v power supply with male 2.1x5.5mm barrel connector out
- 6x 2" long black oxide 4-40 bolt
- 2x 7/16" long 18-8 stainless steel pan head 4-40 bolt
- 2x 3/8" long 18-8 stainless steel truss head 4-40 bolt
- 8x 1" long nylon pan head 4-40 bolt
- 10x black nylon acorn nut 4-40 thread
- 10x black nylon hex nut 4-40 thread
- 10x stainless steel hex nut 4-40 thread
- 16x 316 stainless steel washer
- 2x 1/8" long 1/4" OD 6/6 nylon spacer for 4-40 screw
- 12x .75" long 1/4" OD 6/6 nylon spacer for 4-40 screw
- 10" .016" diameter 316 stainless steel wire
Step 2: Top Plate Electronics Assembly
Using two 1" long 4-40 nylon bolts and two 4-40 nylon hex nuts fasten the voltmeter to the top panel. Then use the two round nuts that came with the switches to fasten the switches to the top panel. When you are done, it should look like this picture.
Step 3: Bottom Plate Electronics Assembly
First, remove the backing from the LED panel and stick it in the middle of the bottom half of the bottom plate. This should be on the side near the semicircle cutout. Make sure the cables point in the same direction as the picture.
Then add the binding posts in the upper right hand part of the image. They are 4-40 nylon screws attached to the plate with 4-40 nylon hex nuts.
Attach the high voltage boost converter to the upper left corner. Make sure the terminal blocks are pointed towards the binding posts you just added. It should be attached with two more 1" nylon 4-40 screws and nylon hex nuts.
When you are done, you should have something that looks like the picture.
Step 4: Start Wiring
Put the terminal block into the right hand wall. Put one stainless washer on each of the binding posts. Screw one end of the pre-stripped wires into the terminal block and the other side onto the binding posts.
Step 5: Finish Wiring
The next step is to finish wiring. The wiring diagram is shown above- as long as you follow that diagram you should be fine. Basically, between the high voltage boost converter and the positive terminal you want to attach a switch and between the positive terminal of the LED panel and the positive terminal you want a switch as well.
To do this, you need to take the stripped ends of the wires for all the electronics and attach them to the binding posts so that they are attached to each other electrically. This is done by wrapping the ends of the wire around the binding posts, and sandwiching them between stainless steel hardware. Always put washers between wires, and always put washers on the end of stacks of fasteners.
For the post closest to the edge, you will want to connect the positive wire from the terminal (It should be marked with a ) to both of the switches, and the power for the voltmeter. The exact stack from bottom to top is:
wire to the positive terminal of the barrel connector block
red wire from voltmeter
For the other binding post, you will need two separate areas of conductivity. You will also need to be careful to hook up the right switch so that switch near the voltmeter turns on the power, not the leds. From top to bottom, this stack is:
wire to negative terminal block
wire to -in of the boost converter (see last image)
black wire from LED panel
switch wire from the lower switch (not next to the voltmeter)
red wire from LED panel
Now that that is all done, you can test the led panel. Plug in the power- the LEDs should light up when you press the button!
There are two more connections to make- the connections that conduct power to the gel tray. These come from the out and - out of the boost converter. These are made to the clear piece of plastic shown in picture 4. With the notch facing away from you, the blue wire from the voltmeter should be bolted to the out wire on the right side, and the - out wire should be bolted to the left. Look at picture 4 if you are confused- it is much easier to explain with a picture.
That's it for wiring! Lets close it up!
Step 6: Assemble the Back
Now it is time to assemble the structure of the box. There are only two pieces you need to find now. One is a large rectangular clear piece with no holes in it, and the other looks just like the plate in picture 4, only it has no cutout for the terminal block in it. combined with the backslash, which has the blue voltmeter wire bolted to it, and the wall with the terminal block in it, these four pieces make the four side walls of the electrical compartment. The backsplash goes in the middle groove, while the back (large rectangular piece) goes in the groove closest to the power supply. The side wall with the adapter goes close to the binding posts, and the last side wall is opposite that. Check out picture 2 for a view of the side wall without the hole.
Once the pieces are in, fit the tops of the four pieces into the top orange plate. The box is almost done! Now the next step is to add the spacers and bolts. Grab two .75" long spacers and one .125" spacer. These support the very back of the box. You can see this in picture four. Both of the back boltholes use this stack of spacers. Put them under the mounting hole and let a 2" black oxide finish 4-40 drop through them. Then cap the screw with an acorn nut. Make sure the nut is on the bottom of the box-it acts as a foot for the box.
The front four stacks of spacers are slightly different, because they do not have .125" spacers in them. To install these spacers first slot in the saftey walls and place the shelf on top of them. See pictures 2 and 3 for reference. Then a spacer goes on the top and bottom of the shelf, and a 2" long 4-40 screw drops through the spacers. All of these bolts screw into acorn nuts. At the point, the box is finished!
Step 7: Tray Assembly
- A tray wall
- a tray bottom
- 2x 7/16 pan head 18-8 stainless steel screw
- 2x 7/16 pan head nylon screw
- 4x nylon acorn nut
- 10" of 316 stainless steel wire
The stainless steel bolts should be on the same side of the tray. Make sure the notch on the outside of the tray is on the left when the steel bolts are facing away from you (picture 2)
Install nylon screws on the opposite side, and put acorn nuts on all the exposed screw threads.
Fourth Prize in the
Build My Lab Contest