Laser Cut Lepidoptera Spreading Board

This Instructable will show you how to make regular, oversized, and micro Lepidoptera spreading boards with a laser cutter and a few other basic tools. The top surfaces of the boards are made from basswood, which is soft enough to hold a pin, but still durable enough to last for years of heavy use. The regular and oversized boards are designed to be adjustable to accommodate moths and butterflies of varying sizes. Lepidoptera with bodies up to 20mm thick and wingspans up to 130 mm can be spread with the regular board. Lepidoptera with bodies up to 48 mm thick and wingspans up to 297 mm can be spread with the oversized board. Micro Lepidoptera that are too small to fit on a #1 size pin can be pinned with a minutin pin instead and spread on the micro sized board. Nearly every moth an entomologist is likely to encounter will fit on the regular or micro boards, so I don't recommend making the oversized board unless you think you will be collecting very large moths. I designed these boards in Fusion 360 for use in my personal insect collection and the Essig Museum at UC Berkeley uses them as well. I am hoping that students and researchers at other universities will be able to use campus laser cutters to make their own entomological supplies from this and my other Instructables posts.

• 1/4" or 6 mm thick MDF
• 1/8" or 3 mm thick basswood (It really has to be basswood, not balsa or any other wood)
• Wood Glue (The brand doesn't really matter, even Elmers would work)
• This carriage bolt (Do not substitute! 2 bolts are required per spreading board except the micro which doesn't use hardware)
• Washers (Substitution with a similar size is ok. 2 washers are required per spreading board except the micro which doesn't use hardware)
• Wing Nuts (Substitution with another 8-32 threaded wing nut is ok. 2 wing nuts are required per spreading board except the micro which doesn't use hardware)
• Shop towels or paper towels
• High density foam. This one is tricky because I'm using Bioquip foam and they have gone out of business. For the regular sized board, you will need a strip of high density foam that is 270 mm long and 20 mm wide. The oversized board foam strip should be 270 mm long and 48 mm wide. Both sizes of foam strip should be 12-17 mm thick. It's ok to glue two thinner strips together to make a strip that's thick enough. This foam looks promising, but since I haven't used it myself, I can't guarantee that it will work. DO NOT be tempted to use Styrofoam. It is not durable enough.

Tools:

• Laser Cutter with a minimum bed size of 300 mm x 200 mm.
• Calipers
• X-Acto knife or other sharp cutting tool
• Extra large binder clips (8 clips are needed)
• Small sliding clamps (8 clamps is ideal, but don't go below 6)
• Long ruler or straight edge
• Cutting mat (not essential, but helpful)
• Glue brush (not essential, but helpful)

The following files and instructions are for the regular sized spreading board. Additional files and instructions for the other two board sizes are included in their own sections at the end of this Instructable.

1. Measure the thickness of your MDF. I will include files for this project in 0.1 mm increments from 5.5 to 6.5 mm. Round up to the nearest mm when selecting the appropriate files. For instance, if you measure your MDF to be 6.04 mm thick, use the 6.1 mm file.
2. When importing dxf files for your laser, be sure that the units are in mm.
3. Cut the basswood with the Basswood Pieces.dxf file. Slight variations in the thickness of the basswood don't matter, so there is just one file that will work with all sheets that are nominally 1/8" or 3 mm thick. In the photo, I cut three of the pieces because I'm making multiple spreading boards. Only two pieces are needed for each board.
4. Cut the MDF with the MDF file of the appropriate thickness.

There are engravings of my name and the version number on the pieces in the photos, but these are not included in the files.

I recommend following the steps below without glue once to familiarize yourself with the process and to make sure that all of the pieces fit properly. Lasers cut at a slight angle instead of directly perpendicular to the sheet they cut, so if a given piece isn't fitting well, try flipping it over. Most of the pieces in this design are bilaterally symmetric and can be flipped this way. If there are still pieces that don't fit, you can try to trim them with an X-Acto blade, but depending on how bad it is you might want to select a different thickness of file and try cutting new pieces. If your pieces are too tight to fit, choose a larger number, like 6.2 instead of 6.1. If they are too loose, choose a smaller number. After each of the following steps involving glue, wipe away any excess with a shop towel.

1. Remove the pieces from the bed of the laser and spread them out on a cutting mat. Make sure that you have all 14 MDF pieces and the 2 basswood ones. See photo 1.
2. Find the three pieces shown in photo 2 and set aside the rest.
3. Apply glue to both ends of the rectangular piece as shown in photo 3.
4. Press one glue covered end into the rectangular hole in the irregular shaped piece as shown in photos 4-5.
5. Press the other end into the other irregular shaped piece as shown in photo 6. Make sure that both sides are symmetrical.
6. Flip the assembly over as shown in photo 7. Find the long thin piece shown in photo 8.
7. Apply glue to the long thin piece as shown in photo 9.
8. Press the long thin piece into the assembly as shown in photo 10.
9. Flip the assembly back over and find the large notched piece shown in photo 11.
10. Apply glue to one end of the assembly and the large notched piece as shown in photo 12. Repeat for the other side.
11. Press the large notched piece into the assembly as shown in photo 13.
12. Orient the assembly and find the thin notched piece as shown in photo 14.
13. Apply glue as shown in photo 15.
14. Press the thin notched piece into the assembly as shown in photo 16.
15. Orient the assembly and find one of the two large rectangular pieces as shown in photo 17.
16. Apply glue to both ends of the assembly as shown in photo 18.
17. Press the large rectangular piece into the assembly as shown in photo 19.
18. Orient the assembly and find the medium rectangular piece as shown in photo 20.
19. Apply glue to the assembly as shown in photo 21.
20. Press the medium rectangular piece into the assembly as shown in photo 22.
21. Set the assembly aside while keeping it upside down.
22. Find two of the carriage bolts, two of the wing nuts, and the two small triangular pieces shown in photo 23.
23. Apply glue near the head of one of the bolts as shown in photo 24.
24. Push the bolt all the way through one of the triangular pieces as shown in photo 25.
25. Thread a wing nut onto the bolt as shown in photo 26.
26. Repeat steps 23-25 for the other small triangular piece, but be careful to assemble it so that the two small triangular pieces are mirror images of each other. Find the large rectangular piece as shown in photo 27.
27. Apply glue to the small triangular pieces as shown in photo 28.
28. Put the large rectangular piece onto the triangular ones as shown in photos 29-30.
29. Find the long thin piece shown in photo 31.
30. Apply glue to the long thin piece as shown in photo 32.
31. Press the long thin piece into the backs of the triangular pieces as shown in photo 33.
32. Set aside the smaller assembly that you just made from the last four pieces and pick up the larger assembly.
33. Apply glue to all of the interior seams of the larger assembly as shown in photo 34. A glue brush is especially helpful for this step.
34. Set aside the larger assembly while keeping it upside down.
35. Wait 5 minutes for the glue on the smaller assembly to become somewhat tacky, then flip it over. Apply glue to all of the internal seams as shown in photo 35. Leave the smaller assembly upside down to dry.
36. Wait at least 45 minutes before continuing to the next step.

Do not proceed unless the glue has been drying for at least 45 minutes, preferably an hour.

1. Place the larger assembly right side up next to one of the two basswood pieces as shown in photo 1.
2. Apply a thin and even layer of glue to the higher of the two flat platforms on the larger assembly. See photo 2.
3. Press the basswood piece onto the glue and align it so that the edges line up with the MDF below it. Find a piece of scrap hardwood/plywood/MDF that is about the same size as the basswood. An extra of the large rectangular pieces is ideal. See photo 3.
4. Place the scrap piece over the basswood. This will prevent clips and clamps from damaging the soft basswood. See photo 4.
5. Use four of the extra large binder clips to hold the scrap piece and basswood flat against the top of the larger assembly as shown in photo 5.
6. Recheck the alignment of the basswood and make adjustments as necessary. See photo 6.
7. Use small clamps on the other side of the scrap piece to hold it down. See photo 7. Check the basswood alignment a third time.
8. Repeat steps 3-7 with the other piece of basswood and the smaller assembly as shown in photos 8-10.
9. Wait at least 45 minutes before continuing to the next step.

Do not proceed unless the glue has been drying for at least 45 minutes, preferably an hour.

1. Put the larger and smaller assemblies next to each other, right side up. Remove the wing nuts from the smaller assembly. See photo 1.
2. Put the smaller assembly on the flat surface of the larger assembly as shown in photo 2.
3. Find one of the two square pieces as shown in photo 3.
4. Apply a thin layer of glue to the piece between the edge of the rectangular hole and the edge of the piece as shown in photos 4-5. Do not apply glue beyond the red line, because if glue gets past the blue line, the smaller assembly will not be able to slide across the larger assembly. If that happens, the spreading board will no longer be adjustable. The space between the lines accounts for a small amount of glue squeeze out. Don't apply too much glue or it will squeeze past the blue line.
5. Press the square piece onto the side of the two assemblies, with the bolt sticking through the rounded slot as shown in photo 6.
6. Repeat steps 3-5 with the other square piece on the other side of the spreading board.
7. Slide the small assembly so that the spreading board is fully open as shown in photo 7.
8. Cut two pieces of foam, 270 mm x 20 mm. (If you have just one piece of thicker foam, use that instead of two thin strips.)
9. Apply a thin, even layer of glue to one side of each of the pieces of foam as shown in photo 8. Stack the two pieces of on top of each other so that the top surface of the top piece of foam has glue on it. See photo 9.
10. Flip the double layer of foam over and press the glue side down onto the MDF platform between the two pieces of basswood as shown in photo 10.
11. Wait at least 45 minutes before continuing.
12. Place washers and then wing nuts on the ends of the bolts as shown in photos 11-12.
13. You're done!

If you make this board and find a moth big enough to spread on it, please comment on this Instructable with a photo.

The assembly for the oversized version is almost the same as for the regular board. The main differences are that there are an additional three long support pieces and the foam should be 270 mm x 48 mm. I will include photos of the assembly process, but not step by step instructions since they are so similar to the the regular instructions. Additional clamps are helpful, but not absolutely necessary for the oversized board.

The micro sized boards are very simple and non-adjustable. They have no interlocking pieces, so the exact thicknesses of the materials are not important as long as the MDF is nominally 6mm/(1/4") and the basswood is nominally 3mm/(1/8"). The thickness of the foam for this board isn't very important as long as it's at least 5 mm thick. Since the micro boards are not adjustable, they come in two sizes. One has a gap between the pinning plates of 1.5 mm and the other has a gap of 2.5 mm. Any moth with a body size larger than 2.5 mm should be pinned on the regular sized board.

1. Cut the basswood with the "Basswood Pieces..." file. Choose the MDF file that corresponds with the size that you prefer and cut it from MDF. See photo 1.
2. Cut out a piece of foam that is the same size as the piece of MDF. The easiest way to do this is is by using the MDF piece to set the position of the straight edge which then guides the X-Acto knife. See photos 2-8.
3. Apply an even coat of glue to the MDF piece and then press the foam on top of it. Make sure that it is properly aligned, but do not clamp it. See photos 9-10.
4. After the glue has dried for at least 30 minutes, apply a thin and even coat of glue to the two basswood pieces. See photo 11. Don't try to combine steps 4 and 5 into a single step because it will be difficult to keep all of the pieces aligned while clamping.
5. Press the basswood pieces onto the top of the foam so that the outer edges of the basswood pieces align with the edges of the foam and there is a gap in the middle. See photos 11-13.
6. Place a piece of scrap or an extra MDF piece over the basswood as shown in photo 14. Double check the alignment and then use four clamps to prevent the basswood from curling up away from the foam. Don't squash the foam excessively. See photo 15.
7. Wait 30 minutes and then remove the clamps. If there is excessive glue squeeze out in the gap between the basswood, remove as much as possible with the X-Acto blade.
8. You're done!