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A fun one for the DIY set: pantographic micromanipulator

Posted: Wed May 13, 2020 2:08 am
by BramHuntingNematodes
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So after looking at the "diatoms a different way" and the water bear hunt posts I was filled with a terrible envy and lust for those micromanipulators that could pick out specimens and arrange diatoms. Although there seem to be some workable and terrifically cheap Prior mms on the `bay even as I speak, I didn't want to have to mess with all those dials and anyway, I don't have enough space on my bench! I just made this table but then somebody decided to solve a jigsaw puzzle on it so space is again at a premium. The Singer Mk1 is intriguiging, but I think it runs between $5,000-$6,000 and I definitely don't have that kind of scratch. So here is a very simple alternative.


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The best solid wood to make mechanisms with is clear beech, but I only had one tiny stick of it left, so I used the runner-up hard maple for the rest. The holes are space 2" and 6" apart (all drilled simultaneously after taping the stuff together tightly) so that the reduction is at 25%. Brass tubes, flared at the ends so they wont slip out, are used at the joints to minimize slop. There was a bit of stiction at first but oils and wax and some breaking in has left the motion quite smooth. The holes were even made with normal twist bits, no fancy forstners. The knob is a ceramic cabinet knob we had spare.

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The sharp-eyed among you will have already noticed that the 5/4 hard maple slab is not the factory Bausch and Lomb stand for this stereo microscope. It was extra cheap without a base, and turns out very useful to modify here. I drilled a hole in it and, using chisels, made a rectangular recess underneath. The ball-and-socket is a bought camera mount, for which I paid an extravagant $14 or so for, almost as much as the microscope itself, but looks and operates very nicely. I attached to a hunk of 1/4" 1018 steel plate for weight and stability.

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The probe is a piece of twisted sheet steel sharpened to a point and pictured here menacing a splinter of wood at 60x. At some point I want to try to make some miniature forceps and also a trigger controlled pipette. It works really very well and was easier to make than I imagined it would be. I would heartily recommend this project to anyone looking to poke some microbes on a budget. If the woodwork is for reason intimidating, professionally made pantographs can be had from art supply stores relatively inexpensively as well.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Wed May 13, 2020 5:51 am
by MichaelG.
Great stuff, Bram

MichaelG.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Wed May 13, 2020 8:23 am
by MicroBob
Hi Bram,
great idea! I have never seen a pantograph based micro manipulator but the principle is quite ideal for this application. And contrary to metal dovetails, spindles and gears it is comparatively easy to build.

Bob

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Wed May 13, 2020 11:29 am
by tgss
Excellent job Bram. Really nicely done.
Tom W.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 1:37 am
by BramHuntingNematodes
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I don't think I put it up here but I had modified this one slightly to accept some homemade forceps. This is iteration three with a simplified mechanism that holds Dumont forceps such as these an opens them with a trigger actuated cam. The design should be easy to reproduce. The cam is a sawn off end of dowel. A few bits of aluminum bar and some screws and nuts.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 2:46 am
by Element 56
Hi Bram,

Nice little homemade micromanipulator! Thanks for sharing!

Kirby

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 4:12 am
by hans
This brings to mind the "Building Prototypes" video series by Dan Gelbart: https://www.youtube.com/user/dgelbart/videos

He talks a lot about how clever mechanism design can greatly reduce the need for precision fabrication.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 5:19 am
by Hobbyst46
Amazing project !

Would be nice to know working experience, of picking and moving stuff with the micromanipulator.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 5:26 am
by BramHuntingNematodes
I will try to update when possible-- I only finished this one today!

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 5:28 am
by BramHuntingNematodes
hans wrote:
Sun Aug 30, 2020 4:12 am
This brings to mind the "Building Prototypes" video series by Dan Gelbart: https://www.youtube.com/user/dgelbart/videos

He talks a lot about how clever mechanism design can greatly reduce the need for precision fabrication.
Thanks Hans, I am looking forward to watching these.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sun Aug 30, 2020 2:27 pm
by DonSchaeffer
Wow! Just wow! what a setup.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Fri Dec 18, 2020 9:30 pm
by ebenbildmicroscopy
THAT looks awesome... must make one. I particularly like the way that spring is built into the system!

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Fri Dec 18, 2020 9:58 pm
by BramHuntingNematodes
It's pretty great one thing though is that the end of the tweezer needs to be closer to the joint than pictures to accurately reproduce the hands motion.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Fri Mar 19, 2021 1:58 pm
by krame
This is pretty wild!

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Fri Mar 19, 2021 6:19 pm
by PeteM
I like the tweezers cam operation - very clever.

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sat Mar 20, 2021 8:31 am
by Chas

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sat Mar 20, 2021 10:07 am
by Chas
(No tweezers though )

Re: A fun one for the DIY set: pantographic micromanipulator

Posted: Sat Mar 20, 2021 2:29 pm
by BramHuntingNematodes
This is great chas! Thanks.