New Stitch and stack rig design

perdu34 · Post by **perdu34** » Sun Mar 18, 2018 9:06 am

A few weeks ago I posted my first image here https://www.photomacrography.net/forum/ ... hp?t=36645 after a LONG time playing with lighting and got asked about my lighting set up. That got me thinking about how I choose to light my subjects and what kind of aesthetics I want to produce. I then took a long hard look at my rig and thought I could do better.

Like most people here my current rig is held together with sellotape and bits BlueTack. It wobbles and it's not easy to move and I can never get the lights into the right place. Worst of all I always knock it when changing batteries.

So with that In mind I set about designing my ideal stitch and stack rig.

I use a Canon 5Diii, a Canon MP-E 65mm and a Canon MT-24XE flash and I want to make sure that my images have a clear and crisp separation between the subject and a totally black background. To get a totally black background I want to block as much light from hitting whatever is there. I also wanted to have a little back lighting so that the edges of my subject "glow" giving me the separation I am looking for.

The design I came up with is a 3D printed diffuser in the rough shape of a beetle that I can aim different flashes at to give me the lighting I want. I then attached a shade with a narrow aperture that exactly fits outside the field of view of the MP-E at 5x. The inner side of the shade is coated in silver foil and acts as a reflector giving me the "glow" I want, the other surfaces are painted in Black 2.0 to block out as much light as possible.

The two parts of the diffuser are held together with magnets which allows good assess to the subject. The size is pretty even all around for a 30-45mm long beetle, which will make lighting more even.

Next I looked at the rig as a whole. I want to be able to use step sizes around 10um which means having less than 38um of wobble in the system (DOF at 5X =48um) so that my images always overlap by at least 1/3 in Z. I looked at what others had done and thought I couldn't cut a block of wood straight to save my life. I needed something idiot proof. Thats when I found OpenBuilds.

All the parts for together in logical ways that appeal to me and it's really simple. SO I grabbed the drawings and planned out a table. The table needed to be hollow so that I can get lights around the subject. it needed to be sufficiently big so that I could fit my lens in. I also use a Pentax 200mm and a 10X Olympus from time to time so it needed to fit those too. I made the table 50x50x50cm as that seemed a good size from my mock ups.

Finally I looked at how I adjust my subject in X, Y and Z. Currently I have a Mauzhouser micromanipulator as my main X&Y movement and a StackShot for Z. I want to keep this as it allows me to have the subject about 20cm away from the movement (helping me keep the background black). BUT I also want more than the 30mm travel this offered. So I bought a standard Ebay XYZ stage and designed plates to attache it to the V-slot table and the micromanipulator. For now these are to be 3D printed in ABS+ but I will be ordering then in Aluminium as soon as I am happy with the design.

As this is an ongoing project I will be posting here again soon. Comments, ideas and criticisms welcome.

perdu34 · Post by **perdu34** » Wed Mar 21, 2018 11:06 am

I got home from work today and found that the postman had been and delivered the parts I ordered from Ooznest.co.uk. I had tried to get all black extrusions but they were out of them when I ordered. The silver parts will get painted in sure course.

Thanks to my not paying attention to the bolts I ordered 24 of the wrong size and they are way too big to fit the corner brackets. I'm going to have to source some locally this weekend so I can put the whole thing together.

This image gives you an idea of how it will fit together.

I did get the attachment for the StackShot sorted properly. The two Arca Swiss type brackets fit nicely under the StackShot and into the extrusions.

The blue part is a VERY handy 3D printed part designed by Jason Canning (
https://www.thingiverse.com/thing:2778361) that correctly aligned my StackShot and my MP-E 65mm.

Next up is to get the right sized bolts, then to print some feet for the table as I don't want to scratch the wood floors or my desk for that matter.

Then I need to re-print the diffuser and shade. I got some very weak neodymium magnets that were meant to hold the two parts together. But they are so weak they can't even hold their own weight. Plan B is to use 20mm steel rods instead.

concon · Post by **concon** » Thu Mar 22, 2018 9:07 am

The use of arcas and extrusions is a great method for creating a rig- it's one I use myself and one that I've seen throughout the forums. With my experience, I found that raising my rig from the table created more stability issues (unless you have something very heavy which can dampen vibrations). I travel with my rig so I try to account for size and weight. 8020.net has one of the largest selections of extrusion bars and carry most sizes in black (mine are all black). I always look back at normal design principles- what's one of the most stable structures out there- pyramids.

perdu34 · Post by **perdu34** » Thu Mar 22, 2018 9:40 am

Hi Concon,

Thanks for the link to 8020.net, I've not seen them before. It does look like there are a lot more options in the US than here in the UK. As far as I've seen so far there are some Ebay shops, amazon and Ooznest.

Extrusions are something I've seen about for a little while now but not given a second thought to until recently.

I must admit, I've built microscopes before, but that's always been a process of sitting down with a Nikon or Zeiss sales rep and picking parts off a list. This process is way more complex than that. I don't have a clue about how these parts, all from different ecosystems, are meant to fit together.

I will take a look at how to increase stability for the rig. I am thinking some kind of brace between the legs at the moment, but then again I don't really know what I'm doing

ray_parkhurst · Post by **ray_parkhurst** » Thu Mar 22, 2018 11:27 am

I've found it does not matter so much if the whole rig moves around, as long as the camera is held rigid versus the subject.

concon · Post by **concon** » Thu Mar 22, 2018 11:30 am

I definitely hear that! I acquired so many pieces, all with different mounts. It's funny how you begin to ask friends for their skills to help you with your own. My gf's dad has a moderately sized shop so he was able to tap and die areas for me to mount too. I then went to other friends for their 3D printers for various other pieces. I really appreciate how diy it can become and how different people go about it! That's a bummer regarding your resources over there- if you're in the UK you pretty much have to source there- getting my bars shipped within the US was a fair amount so I wouldn't even want to think about the international shipping prices!

It looks like you're on the right track and I'm excited to see how it all comes together

perdu34 · Post by **perdu34** » Sat Mar 24, 2018 5:13 am

After a couple of tries at the print lab I now have a diffuser and shade I'm happy with. They are nice and big, allowing me lots of room to move the insect around.

The 58mm adapter ring is going to be glued to the front and the shade is held in place with the metal pins.

I've painted the shade with Stuart Semple's Black 2.0 - apparently the worlds most matt black paint. It is VERY matt but in my hands it's a dark grey not a black.

Black 2.0 inside

Spray painted outside

The test prints for the adapter plates have also been printed. These didn't come out too well as there was a little dirt in the printer that messed up in a few places. The upper wall for the top of the plate was also a bit thin. I've made the changes to the drawing now and will re-print on Monday.

perdu34 · Post by **perdu34** » Wed Mar 28, 2018 9:41 am

The new rig is almost finished, just a few bits that need fixing including making everything straight with additional corner braces.

This is the first stack using my new diffuser and shade system. I used my "test bug" which has been dropped, broken and squashed more than a few times so excuse the subject.

I am not massively impressed with the way the lighting (two flash heads at 3 and 9 O'clock) covers the subject. The left leg is pretty dark for being so close to the lights. This is something I'll have to investigate and play with. I may just need to place the lights in a more suitable position.

What I am super happy about is the great separation between with subject and the background. The above image is straight out of Helicon with only the faintest halo and but crystal clear separation.

I think with a little bit of work on the lighting and some post processing I can really make the subjects pop.