--Betty
DIY specimen holder
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Unfortunately I don't like crowds and my Ikea tolerance level only gives me about 10mins residence time before I start twitching and have to head for the exits ! If anyone finds something suitable I'll brave it and get one. Or send a friend !Planapo wrote:This calls for a stroll through IKEA with a magnet in hand.
--Betty
I did toy with the idea of learning how to hydroform but that seems a bit extreme and might not go down well with the family, neighbours and local law enforcement. But it would be fun !
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
Well you need a mould, a big bucket of water, steel sheet and explosives. Ikea might be saferelf wrote:The only problem with hydroforming is you first have to turn a steel sphereAndrewC wrote: I did toy with the idea of learning how to hydroform but that seems a bit extreme and might not go down well with the family, neighbours and local law enforcement. But it would be fun !
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
These Ikea Blanda bowls are magnetic, I've just tested with my 12cm version which I use for producing shaving lather.AndrewC wrote: Well you need a mould, a big bucket of water, steel sheet and explosives. Ikea might be safer
That looks optimistic
I assume there's a flat circle at the (normal) bottom of the bowl, which you would need to avoid.
A a 3-point tool cut from card should show if the remainder is spherical or not. If all three points stay in contact as you move and twist it around, then it's a sphere.
The blue circle suggests it's close for a usable sector, though that wouldn't be the easiest thing to cut.
I assume there's a flat circle at the (normal) bottom of the bowl, which you would need to avoid.
A a 3-point tool cut from card should show if the remainder is spherical or not. If all three points stay in contact as you move and twist it around, then it's a sphere.
The blue circle suggests it's close for a usable sector, though that wouldn't be the easiest thing to cut.
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Planapo
- Posts: 1583
- Joined: Tue Nov 07, 2006 2:33 am
- Location: Germany, in the United States of Europe
I just checked, indeed my mini BLANDA bowls are magnetic too. Their diameter measures just 5 cm.
--Betty
--Betty
Atticus Finch: "You never really understand a person until you consider things from his point of view
- until you climb into his skin and walk around in it."
Lee, N. H. 1960. To Kill a Mockingbird. J. B. Lippincott, New York.
- until you climb into his skin and walk around in it."
Lee, N. H. 1960. To Kill a Mockingbird. J. B. Lippincott, New York.
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Edward Ruden
- Posts: 42
- Joined: Mon Feb 21, 2011 10:24 am
- Location: Albuquerque, NM
- Contact:
Spray can bottom stage design
I've found an excellent and convenient source for a ferromagnetic spherical shell for the goniometric stage application. Many pressurized aerosol spray cans have a spherical concave shell on the bottom to help contain the pressure. Some have more complex shapes, but spherical seems to be the most common. To remove the shell, I used a One Touch(TM) side-cutting electric can opener. The shell came off fairly cleanly, with only a little sanding needed on one spot to remove a sharp edge. Here's what I made with it:
From top-down, we have:
1. A foam pad covered with Prostar self-adhesive flocking felt. I chose this since I work mostly with pinned insect specimens. I plan to replace it with a flat plate with a thin cork covering to minimize thermal expansion effects during halogen lamp illumination.
2. The bottom of a 2 inch diameter spray can to which the pad is glued.
3. A 15 mm diameter, 20 mm long round cylindrical rare earth magnet topped with a 15 mm diameter disk of flocking felt. The cushy felt provides enough contact area and friction to prevent the shell from slipping when supported sideways, but still allows the shell to be repositioned by hand smoothly and easily.
4. A 4 inch diameter, 0.08 inch thick round steel plate.
5. An aluminum adapter epoxied to the steel plate with a central 1/4-20 threaded hole for tripod mounting.
6. An ultra-light duty tripod ball head, which attaches the stage to my linear translator for stacked imaging. The stage faces the camera during normal use. The ball head has it swiveled upward for this photo.
My next step is to flock the steel plate. I will slide a 4 inch diameter clear plastic tube over the steel disk cut from a peanut butter jar and covered with light diffusing fabric for the lateral component of diffuse illumination. The spherical shell is small enough to avoid contact with the diffuser throughout its entire range.
From top-down, we have:
1. A foam pad covered with Prostar self-adhesive flocking felt. I chose this since I work mostly with pinned insect specimens. I plan to replace it with a flat plate with a thin cork covering to minimize thermal expansion effects during halogen lamp illumination.
2. The bottom of a 2 inch diameter spray can to which the pad is glued.
3. A 15 mm diameter, 20 mm long round cylindrical rare earth magnet topped with a 15 mm diameter disk of flocking felt. The cushy felt provides enough contact area and friction to prevent the shell from slipping when supported sideways, but still allows the shell to be repositioned by hand smoothly and easily.
4. A 4 inch diameter, 0.08 inch thick round steel plate.
5. An aluminum adapter epoxied to the steel plate with a central 1/4-20 threaded hole for tripod mounting.
6. An ultra-light duty tripod ball head, which attaches the stage to my linear translator for stacked imaging. The stage faces the camera during normal use. The ball head has it swiveled upward for this photo.
My next step is to flock the steel plate. I will slide a 4 inch diameter clear plastic tube over the steel disk cut from a peanut butter jar and covered with light diffusing fabric for the lateral component of diffuse illumination. The spherical shell is small enough to avoid contact with the diffuser throughout its entire range.
Last edited by Edward Ruden on Sat Mar 08, 2014 2:21 pm, edited 6 times in total.
Don't have any pictures to hand for what I'm putting together but in words:
- easy enough to cut a disk out of the Ikea bowl with a Dremel cutting disk, but I am always astonished there hasn't been a class action suite shutting Dremel down for self inflicted injuries. Be careful how you hold things and wear eye protection !
- only problem is that the Ikea bowls are pressed and somewhat strained so when you cut out a disk it relaxes and loses shape a little. Not a massive issue as this is only to approximate a goniometric stage
- to keep structural rigidity I filled the cut out cap with epoxy
- specimen mount will consist of a section of thin tube (hypodermic needle as it happens) mounted orthogonally semi-permanently to the cap. Insect pins then slide in and out of the hypo tube - put a slight kink in the insect pin and / or fill the needle with plasticine and it holds it perfectly.
- bowl sits on magnet which sits on an xyz stage
I'll post some photos later.
- easy enough to cut a disk out of the Ikea bowl with a Dremel cutting disk, but I am always astonished there hasn't been a class action suite shutting Dremel down for self inflicted injuries. Be careful how you hold things and wear eye protection !
- only problem is that the Ikea bowls are pressed and somewhat strained so when you cut out a disk it relaxes and loses shape a little. Not a massive issue as this is only to approximate a goniometric stage
- to keep structural rigidity I filled the cut out cap with epoxy
- specimen mount will consist of a section of thin tube (hypodermic needle as it happens) mounted orthogonally semi-permanently to the cap. Insect pins then slide in and out of the hypo tube - put a slight kink in the insect pin and / or fill the needle with plasticine and it holds it perfectly.
- bowl sits on magnet which sits on an xyz stage
I'll post some photos later.
rgds, Andrew
"Is that an accurate dictionary ? Charlie Eppes
"Is that an accurate dictionary ? Charlie Eppes
In a discussion about equipment here:
http://www.photomacrography.net/forum/v ... hp?t=22868
Tony Irwin (dipterist/entomologist) commented "When I'm examining a fly I usually keep adjusting the pin in a bit of foam until the angle is OK, but I can see from the photos on this forum that it's important to get the viewing angle spot-on!"
I echo his comments.
I have been following this current discussion and am thinking despite all the innovative ideas there has been no improvement in functionality on the original description by Lothman.
It doesn't matter how "many bells & whistles" one incorporates in the design nothing has been gained in the ability to position a specimen accurately and precisely.
So, what did I do? I essentially copied Lothman's excellent original idea and stuck the alligator clip onto a small goniometer to give me accurate positioning.
It seems somewhat of an anomaly when many people incorporate electronic devices to move a linear stage when it can be done less expensively, yet simpler and equally accurate, by twiddling knobs by hand and yet insist on positioning specimens manually.
NU-13-03-08
http://www.photomacrography.net/forum/v ... hp?t=22868
Tony Irwin (dipterist/entomologist) commented "When I'm examining a fly I usually keep adjusting the pin in a bit of foam until the angle is OK, but I can see from the photos on this forum that it's important to get the viewing angle spot-on!"
I echo his comments.
I have been following this current discussion and am thinking despite all the innovative ideas there has been no improvement in functionality on the original description by Lothman.
It doesn't matter how "many bells & whistles" one incorporates in the design nothing has been gained in the ability to position a specimen accurately and precisely.
So, what did I do? I essentially copied Lothman's excellent original idea and stuck the alligator clip onto a small goniometer to give me accurate positioning.
It seems somewhat of an anomaly when many people incorporate electronic devices to move a linear stage when it can be done less expensively, yet simpler and equally accurate, by twiddling knobs by hand and yet insist on positioning specimens manually.
NU-13-03-08
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
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Edward Ruden
- Posts: 42
- Joined: Mon Feb 21, 2011 10:24 am
- Location: Albuquerque, NM
- Contact:
Goniometer function
I think you're missing the point of going from a ball bearing pivot to a spherical shell, based on your photo. I see it was not actually mentioned in this thread, so that's understandable. A critical design feature of a goniometer is that it allows rotation of the specimen while avoiding simultaneous translation, which would throw the subject out of the field of view of the imaging system. You can move it back if the stage includes an x-y translator, but that takes time. Given the time it takes me to take a good stacked image set, I'll take any productivity improvement I can get. In order to avoid translation, the field of view must be placed at the center of curvature of the goniometer slides. In my design, that's about 4 cm above the pinning surface. In the design you show, it's about 1/3 the way up from the base of the alligator clip. Your specimen will be much too high, therefore.NikonUser wrote:... there has been no improvement in functionality on the original description by Lothman.
Automatic linear translation and camera triggering for stacked image stepping specifically is also a productivity measure. High resolution images like this can require hundreds of images taken 15 seconds apart (to avoid overheating my flash array). While it's clicking away, I'm off doing other stuff.NikonUser wrote:It seems somewhat of an anomaly when many people incorporate electronic devices to move a linear stage when it can be done less expensively, yet simpler and equally accurate, by twiddling knobs by hand and yet insist on positioning specimens manually.
Last edited by Edward Ruden on Sat Mar 08, 2014 2:25 pm, edited 5 times in total.
Compare to industry made specimen stages
Folks,
Acquired these over the years from ebay. I use these for my stereomicroscope, Axiomat, and Nikon Multiphot. While I have fabricated a few DIY specimen stages I keep coming back to the industry made ones shown below. All of my studio photomacrography and photomicrography efforts are done with vertical rigs. I mostly use my horizontal rig in the field.
All of my studio stacking efforts, so far, only need the stepping movements with camera body/lens/objective/rail/stepper motor/controller/stand not my specimen stage.
The difference I have found between my DIY specimen stages and those sold by various companies are:
1. Just the right amount of resistance to manually adjust the slant of the industry made specimen stages.
2. Everything stays relatively aligned with its own components.
3. Tolerances remain unchanged for my purposes.
4. Ability to return to a specific specimen position quickly. If I
remember to take the needed readings!!
5. Enough mass in the XYZ/goniometer/rotating specimen stage that I
can make very fine adjustments without unintentionally moving the
stage and specimen.
If my fabricating skills ever become good enough to overcome the defects I keep building into my DIY specimen stages I'll put these stages back on ebay.
The first set are of my Olympus "bowl" stage.
The second set of photos are my Zeiss "ball & socket" stage, (If anyone has a set of Zeiss stage clips they would like to sell please PM):
The third set of photos are my favorite almost DIY fabrication consisting of a Velmex rotating stage, 2 gonimeters, and a micrometer adjustable XYZ stage. All centered. It weighs enough to not move when trying out different specimen positions and light adjustments. Presently machining some prototype specimen holders/mounts that can be screwed into the center of my Z stage. On top.
Hokan
Acquired these over the years from ebay. I use these for my stereomicroscope, Axiomat, and Nikon Multiphot. While I have fabricated a few DIY specimen stages I keep coming back to the industry made ones shown below. All of my studio photomacrography and photomicrography efforts are done with vertical rigs. I mostly use my horizontal rig in the field.
All of my studio stacking efforts, so far, only need the stepping movements with camera body/lens/objective/rail/stepper motor/controller/stand not my specimen stage.
The difference I have found between my DIY specimen stages and those sold by various companies are:
1. Just the right amount of resistance to manually adjust the slant of the industry made specimen stages.
2. Everything stays relatively aligned with its own components.
3. Tolerances remain unchanged for my purposes.
4. Ability to return to a specific specimen position quickly. If I
remember to take the needed readings!!
5. Enough mass in the XYZ/goniometer/rotating specimen stage that I
can make very fine adjustments without unintentionally moving the
stage and specimen.
If my fabricating skills ever become good enough to overcome the defects I keep building into my DIY specimen stages I'll put these stages back on ebay.
The first set are of my Olympus "bowl" stage.
The second set of photos are my Zeiss "ball & socket" stage, (If anyone has a set of Zeiss stage clips they would like to sell please PM):
The third set of photos are my favorite almost DIY fabrication consisting of a Velmex rotating stage, 2 gonimeters, and a micrometer adjustable XYZ stage. All centered. It weighs enough to not move when trying out different specimen positions and light adjustments. Presently machining some prototype specimen holders/mounts that can be screwed into the center of my Z stage. On top.
Hokan
SOM, (Son Of Multiphot), a DIY macro/micro rig.w/120, 65, 35, 19mm Macro-Nikkors, Nikon AZ100 1X and 4X objectives. Nikon Plan Fluor W objectives, 10X, 20X, 40X.
With Zeiss infinity objectives, LD, Epi, APO, Plan types.
With Zeiss infinity objectives, LD, Epi, APO, Plan types.