New Developments in the Desert

The Desert Star flower harvesting/restoration in the Desert diorama has been productive. The tiny flowers were completely remodeled with new flowerettes and new (hairy) leaves. We finished about 200 flowers, with about 4 leaves per flower. IMG_0002IMG_0004Collin and I opened the diorama this morning and “planted” the flowers back into the foreground. The new flowers added a lot more color into the bland landscape. We also harvested a couple of cactus flowers that we will restore. IMG_0092

IMG_0091Secondly, we are getting great results with the 3D printing of the scorpions and centipede. Chelsea Graham has opened up her office at West Campus to us, specifically her Artec Space Spider scanner, for Collin to use for this project. Collin is learning the ins and outs of the scanner and we are both salivating to get one of our own for our lab. Dante Archangeli is helping us print them at CEID with the Objet printer. The results are amazing!

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This is the smallest scorpion at 4cm

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The next step is to paint them! I always like to use living specimens as color references if possible. It turns out, my volunteer Stefan Hurlburt can get us live scorpions-even ones of the exact species we are trying to replicate. Just this morning, I gave him the go-ahead to order a couple of each species!

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More on the Scorpions

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Printed scorpion coated with Krylon spray paint. Excellent adherence

After the sodium hydroxide bath and power-washing at the CEID, the spray paint adhered beautifully to the printed scorpion and will provide a secure foundation for oil or acrylic paint. Note: Stratasys has a website that covers how to paint these prints: http://www.stratasys.com/solutions/finishing-processes/painting

The next step is to remove the actual specimens from the Desert diorama, which we did yesterday.

New specimens were replaced in the diorama in the mid-1990s. They are still in fairly good shape though there is some evidence of dermestid damage. Several of the distal segments on the centipede are gone. A couple of the scorpions are also missing distal segments and claws. Someone asked why we don’t try to get rid of the dermestids from the diorama and the answer is that it is difficult to find a pesticide that works, doesn’t degrade the display (or me!), and lasts more than six months. It isn’t feasible to open all the dioramas every year to keep a pesticide regimen active. So, we have decided to live with it. Old no-pest strips from the 1970’s are evidence that Ralph Morrill and Dave Parson’s made attempts to mitigate bug damage, but Ralph told me while he was still alive that it wasn’t worth his time to keep up with it either.

As for the preparation for the digital work, the over-riding concern I have is that the specimens are very fragile. I have been very careful, but I have already knocked off several of the legs on the centipede and I accidentally dropped the smallest scorpion. It’s tail and one of it’s legs broke off. The tail on the larger scorpion fell off without even being bumped!

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Note the small tail-less scorpion and its missing leg. The larger scorpion’s tail also broke off, but was repaired and strengthened with an internal dowel.

I started using crazy glue to glue back legs, but I have found that the conservation-grade white glue works better. I quickly realized that our method of spraying white poster paint on the specimens won’t work on these fragile specimens, so I am reinforcing all the leg and antennae with white glue.

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Reinforcing joints with white glue

It is not clear whether they will survive the ultrasonic water bath, so I may need to prepare myself for removing the poster paint manually with a brush and lightly soapy water.

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Children’s poster paint applied. Specimens ready for scanning!

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Some Success with Small Specimens

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Actual scorpion specimen on the left. Printed copy on the right.

Collin and I set up an appointment with Chelsea Graham at West Campus to try out her Artec scanner. We were told that this is the next level scanner up from the David scanner we already have and it might be the best for scanning something small like the scorpion. We took over two specimens to West Campus, a 9.5cm scorpion and an 11cm centipede. The scorpion was sprayed with white children’s poster paint first. The centipede was already a light color, so we thought we’d try it without the poster paint. It turned out that we didn’t have enough time to work on the centipede, but Chelsea was able to get a pretty good scan of the scorpion.

A pretty good scan is made up of many scans stitched together. Each scan was assessed before saved and then, if it made the grade, it was included. The scanning took several hours and some experimenting to get the scorpion in 3D. Chelsea worked further to clean up the scan file after we left and later sent us what appears to be the best scan we have been able to get to date. Collin immediately set to work sending the scan to the Taz printer. Again, we got the best print we have ever been able to get. Both filament printers (Taz 6 and Dremel) leaves a visible contour even at a high resolution print setting, which makes the prints hard to use without sanding or covering with wax or putting them into an acetone gas chamber (all clunky-especially with small things).img_1082.jpg

By coincidence I ran into Joe Zinter and Dante Archangeli from CEID (Yale Center for Engineering Innovation and Design) on my lunch break. This was on the very day that Collin pulled a couple of fair to middling prints from our filament printers. I asked Joe if he had a laser/resin printer at CEID. He said they didn’t have one, but that we should try their Fused Deposition Modeling Printer manufactured by ObJet. He told me the quality is as good as the laser/resin printers. Within an hour, I had the scan on a thumb drive over to CEID and they had it loaded and printing by the time I left. The scorpion print was scheduled to take 3 hours and 30 minutes, so I told him I would pick it up the next day.

I was back at CEID in the morning and the prints were done and still in the printer. Dante scraped it off the printing table and handed it to me. I wasn’t impressed!

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Hot off the presses!

It looked like something you get from a schlocky halloween store. But Dante told me that most of what I was seeing was matrix that all comes off. You can literally pick it off with your fingernails. The cleaning appealed to my obsessive nature. I was supposed to get a display of taxidermied birds set up for this weekend’s Fiesta Latina celebration and I couldn’t stop picking away at the matrix and uncovering what appeared to be a very nice print. (I got the birds done later!)

I used ethanol to do the final cleaning, though I’m not sure it clears the matrix from the print. I went over and over the print removing more of the matrix each time. I finally got it as clean as I could and here’s the results. I think this print is ready to paint without any further work on my part.IMG_1079IMG_1080

I wanted to throw in one more issue that has come up with the ObJet print. The matrix is very difficult to remove completely. I spray painted the scorpion with Krylon matte white paint after going over it four times with a stainless steel dental pick. The paint adhered, but after it dried, I could remove it with a toothbrush. Dante and Joe from CEID said that sodium hydroxide (NaOH) was suggested as a cleaner by the company who sold the printer. First, I removed the spray paint with acetone, which seemed to have no effect on the printed plastic whatsoever, and took the paint-free scorpion back to CEID. Dante put it into a solution of NaOH. It was left there for about three hours. The solution seemed to loosen the remaining matrix, but it still felt greasy to the touch, almost like there was vaseline on the surface. Dante then gave it a high pressure power wash. After that, the print no longer felt greasy and I felt hopeful that I could paint it now. Unfortunately, I decided to check it with the dental pick again and here is the result:IMG_1087I’m going to spray it anyway and see how it works…Stay tuned. Also, Dante is contacting the company to see if they have any further suggestions for clearing the matrix.

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Printing Insects, Printing Small

I am beginning to think about the next new horizon with which to use our 3D scanning/printing station. The bird models for the Connecticut Bird Hall are getting close to being completed and I will shift my focus to the North American Mammal diorama hall. Collin and I looked closely at each diorama to note where we might improve them. The mammal taxidermy in many of these dioramas need repair and recoloring, but there will be some need for creation of new leaves, installing new snow, and coloring groundcover and epiphytes.

Additionally, in the Desert diorama, there are dried specimens of scorpions and centipedes that periodically disappear as a result of living populations of carpet beetles inside the dioramas. Therefore, I would like to create 3D models of some of these invertebrate specimens. The sizes of the specimens pose a problem. We are looking into whether our scans are good enough or whether our printers are precise enough to pick up minute detail like legs and antennae. Also, the scanner doesn’t like dark, shiny surfaces (mostly what we have to scan) and the scans tend to go haywire.

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Rhinoceros Beetle-Just the kind of surface that presents problems.

To see if it is possible to scan and print small bodies with small appendages, we have to experiment with testing removable surface materials.

 

We had to get specimens of less importance on which to practice. My colleague, Maishe Dickman is an avid insect collector with a special interest in giant Titan Beetles from the neotropics. The smaller specimens are not as important to Maishe, so he agreed to bring in several of the smaller ones for us to work on. He had them in the freezer, so they had to be thawed, pinned and dried.

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Believe it or not, this is a smaller specimen!

Just the drying alone takes several days. In the meantime, Nicole Palffy-Muhoray, representing the Entomology Department, told me that we could use specimens from the Entomology study collection so long as we can wash off the surfacing materials we apply. I asked her how to wash a beetle and she brought over an ultrasonic jewelry cleaner! I was floored that this is how specimens are cleaned in the Entomology collection.

 

We picked out several beetles, scorpions, and centipedes from the study collection and began to experiment. I wondered how dusting might work. Collin sanded several sticks of chalk to dust and I have whiting that I use in mache, which also turns out to be chalk dust! I have confectioners sugar, which I have used in the past on my silicone castings and Kremer dry white pigment. I went online because I figure others have run into this problem and must have found a solution. The solution I found is to adjust the settings of the scanner and to use an opaque, matte “developer” aerosol called Spotcheck. Spotcheck is very expensive, so we will continue our experiments…

It took about five minutes to realize that dusting won’t work because the surfaces of the bugs are too smooth for the dust to grab on to. Gum Arabic, a water-soluble tree sap, was suggested at an art supply house as a reversible medium in which to add the dusting powders to create a paintable surface. This basically creates watercolor pigment and can be built up over several layers to coat the insects. Nicole went to Michael’s craft store and picked up some reversible children’s poster paints and a spray can of chalk dust as additional materials to experiment with.

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Children’s poster paint-Paintbrush application is clunky

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Spray chalk-Better application, though this is too heavy

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Watercolor-Maybe not dense enough?

We will try scanning these three test subjects to see if the scans work and if the surfacing material can be easily removed. More to come soon.

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3D Update

The 3D work on the birds for the Connecticut Bird Hall continues to move forward. I thought I would write up an update on the latest work and post some photos.

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Female Merlin falcon in process

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Finished Merlin ready for installation

We are scanning study skins from the Ornithology collection. This is a male Ruddy Duck in breeding plumage. The study skins can give me accurate wing measurements and some sense of the body shape, but it mostly gives me a solid armature on which to sculpt the body.

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Sculpted Ruddy Duck from the study skin scan

In the case of the Ruddy Duck, the head and tail of the 3D print were cut off on the band saw. The head was re-positioned on top of the body using a wooden dowel and epoxy. Clay was sculpted over it and a cast bill was added. A tail was carved in wood and the feather detail added with a wood burning tool. The clay model will then be scanned, printed at 97%, and coated with a thin layer of wax. Feather patterns will be sculpted over the wax surface and finally painted using the original study skin as a reference for color. Collin is exploring software (Sculptris and Meshmixer) to manipulate the scans on the computer screen rather than on the band saw.

We are also creating scanned models of extinct birds. I have almost finished the sculpting on the passenger pigeon.

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Passenger Pigeon and Heath Hen (both extinct) at a preliminary stage

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Passenger Pigeon almost ready to paint (it needs sculpted feet!)

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Black-necked Stilt. We scanned a larger-sized Avocet and printed it at 80% to get the right size for this model.

The following photos are bird models ready for paint or in process with paint.IMG_0881

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Long-billed Curlew (note the study skin from which the scan was made.)

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Hudsonian Godwit, Red Knot, and Long-billed Dowatcher models ready for paint.

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Digital Project Accomplished!

The final four digital sandpipers were approved and installed this past Tuesday, April 11.

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Breeding plumage Western Sandpiper model installed next to the taxidermied non-breeding Western Sandpiper

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R-L Two White-rumped Sandpipers, Baird’s Sandpiper, Semipalmated Sandpiper, and Western Sandpiper on permanent display in the CT Bird hall

Also, the Merlin carving is finished and awaits paint (and feet!).

Merlin carved

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Three D Experiments

Collin and I are wrapping up our Blended Realities grant proposal to produce four different species of sandpipers from one scan of a taxidermied bird. Today, he is painting the final touches on the last one, the White-rumped Sandpiper. When painting is completed, we will have our ornithology collections manager, Kristof Zyskowski, critique them, after which we will install them in the Connecticut Bird Hall alongside the previously approved, Baird’s Sandpiper. With four models produced from one digital scan of a taxidermied Baird’s Sandpiper, we had to print the models at varying percentages from the original. With each model that was reduced from the original, I made sure the wing and leg lengths were accurate for the specific bird. Each unique bill was cast in epoxy and attached to the models. All defining field marks were painted and the local color of the feathers was ascertained by matching it to a study skin from the collections. (see the previous blog post, “The First Digital Bird Lands”)

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From L-R: Western Sandpiper, Semipalmated Sandpiper, and White-rumped Sandpiper

New Horizons:

With the Blended Realities project well on its way, we are looking to other ways to use the SPROUT workstation. Recently, I sculpted a “gestural” model of a Merlin falcon in clay. I didn’t have a taxidermied mount to scan, so I am sculpting a clay model in the position I want for the Bird Hall. I have started with clay sculptures before and typically, I would make a 2 part plaster mold of the clay sculpture and cast a copy in wax. This would usually take eight to ten hours of my time.

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Merlin Falcon “gestural” sculpture

In this case, Collin scanned the clay sculpture and it is now being printed out in plastic.

IMG_0534I will coat the 3D print with wax tomorrow and start work on the final model for installation.

Once the feather detail is carved into the wax, we will paint directly on the wax.  The 3D plastic sculpture covered with a thin layer of wax, painted to look realistic, is robust enough to install directly without having to make another rubber mold and cast. This is another big time and money saver

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Taxidermy mount of a male Merlin falcon (note the perch hole for the missing female bird)

Another experiment came about when I discovered that the Long-tailed Weasel in the Forest Margin diorama had received a serious case of insect damage. We removed it from the diorama and decided to try scanning and printing it as is. You can easily patch the areas decimated by bugs with wax and there were other areas where the model had to be sanded using the original taxidermy mount as a guide. I know how to sculpt bird feathers, but I don’t have a lot of experience sculpting mammal fur. I’m going to get a lesson with Dorcas MacClintock and see if I can get something good enough to install in the diorama.

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The taxidermy mount and the 3D print

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Wax covered model awaiting fur sculpting, glass eyes, and fore and rear claws!

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