Subject Positioner

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Subject Positioner

Post by mawyatt »

Here's a few images of a Subject Positioner based upon a WeMacro Precision X-Y Adjustment Platform and an eBay Rotational Stage add on.

http://www.wemacro.com/?product=fine-x- ... t-platform

Edit, new link.

https://www.ebay.com/itm/NEW-Rotational ... 2080741488


The Rotational Stage attaches to the XY Platform with 4 M3 short bolts. Gluing a short M6 bolt to a short 1/4-20 Allen head bolt allows the usual 1/4-20 attachments. The M6 bolt is longer than I would like, but that was the shortest bolt Ace Hardware had in stock. The M6 nut allows the M6 to tighten down before it bottoms out in the rotational stage.

This produces a reasonable cost XYR stage for small subject holding (like my chips).

Best,
Image

Image
Image
Image

Admin edit RJL: shorten new link by removing tracking hash
Last edited by mawyatt on Sat Jan 27, 2018 8:09 pm, edited 2 times in total.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

GaryB
Posts: 521
Joined: Fri Jul 29, 2016 12:18 pm

Post by GaryB »

Nice!
Does it have much in the way of slack or backlash? Also, how many turns per mm? It seems surprisingly cheap for a precision adjuster. I have the exact use for one of these :D

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

It has micrometers with 10 micron fine increments, one full turn is 500 microns. Honestly don't know about backlash or slack, can't feel any but never measured it.

It's good enough for my chip imaging use. The micrometers are very smooth, and it "feels" & looks like a very expensive piece of precision instrumentation.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

ray_parkhurst
Posts: 3416
Joined: Sat Nov 20, 2010 10:40 am
Location: Santa Clara, CA, USA
Contact:

Post by ray_parkhurst »

This type of stage has the moving part spring-loaded, with the micrometer tip pushing against the stage, so there is no backlash. There may be some wobble, depending on the quality of the bearing. Most are caged-ball types so they are fairly smooth with minimal wobble. I don't know about the qualityof the stages sourced by WeMacro but the best Chinese ones I've found are made by SELN. Of course if you find ones made by Sigma Koki or Suruga Seiki or similar Japanese manufacturers they are also likely very good.

I use this type as well as screw-driven ones from same manufacturers. Some screw-driven ones are spring-loaded like the WeMacro, but others are not, and these generally have a little backlash.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

The WeMacro XY section is from SELN.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

ray_parkhurst
Posts: 3416
Joined: Sat Nov 20, 2010 10:40 am
Location: Santa Clara, CA, USA
Contact:

Post by ray_parkhurst »

I'm also very fond of the SELN Z-Stage. The "lever" type Z-stages are brilliant for fine focusing and stacking at lower mags. Like the XY they have 10um steps on the micrometer, but it's not too difficult to do half-increment movements with them, so stacking up to 10x is possible. The stack increments are compressed/expanded a bit at the end of movement, but in the middle they are quite linear and consistent.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

It's an SELN LGY-R 40mm for the WeMacro XY stage, the rotary stage from eBay doesn't have any markings though.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

Great looking setup Mike, should be very useful.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

I'm shooting a test image of a resistor using this now. It's my vertical setup, so it's positioning the resistor under then lens which is a Lomo 3.7. Very handy to get the resistor located to fit within the frame instead of the usual fiddling.

I've got a XYZ positioner I made out of an old Cascade wafer probe stage that I use on the horizontal setup. I might add a rotational stage like this to the Cascade probe stage if I can figure out a clean way to do such, but that's a project for a latter time.

Best
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

Macro_Cosmos
Posts: 1511
Joined: Mon Jan 15, 2018 9:23 pm
Contact:

Post by Macro_Cosmos »

Looking nice! Mine is fairly similar.

ImageSpecimen Holder with Coarse and Fine Adjustment by Macro Cosmos (DH), on Flickr

ImageSpecimen Holder with Coarse and Fine Adjustment by Macro Cosmos (DH), on Flickr

ImageSpecimen Holder with Coarse and Fine Adjustment by Macro Cosmos (DH), on Flickr

It allows fine three-axis adjustments. No rotations though, but I can include a rotary stage if I need to. Rotation can be coarsely done by the small ball head. I can also attach goniometers if necessary.

The thorlabs dovetail allows coarse adjustments, but it's not necessary. I currently don't have a way to attach the specimen holder to the stages. Will get some adapter plates made.

Those "MMT" stages I got from China seems to be counterfeit, they have a lot of play and various issues with assembly. Even the printed logo looks gruesome. I better just stick to sniping Newport stages on Ebay.

Macro_Cosmos
Posts: 1511
Joined: Mon Jan 15, 2018 9:23 pm
Contact:

Post by Macro_Cosmos »

Image
This is what the printed logo looks like. Urgh, just screams counterfeit at me. It wasn't exactly cheap either. :roll:

JasonC
Posts: 14
Joined: Fri Feb 14, 2014 10:57 am
Location: Swadlincote, Derbyshire

Post by JasonC »

I have a very similar position device, they work quite well. I'm doing a few upgrades to mine though including a universal stage which I'm in the process of designing.

Image
Image
Image
Image

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

Jason,

That's a really nice fixture you are designing and making with the 3D printer. I would love to have that top plate with a 1/4-20 thread sticking up so you could mount a subject holder or small ball head on top.

Do you make the background support fixture with the red disc?

Best,

Mike
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

Nice setup.

JasonC
Posts: 14
Joined: Fri Feb 14, 2014 10:57 am
Location: Swadlincote, Derbyshire

Post by JasonC »

mawyatt wrote:Jason,

That's a really nice fixture you are designing and making with the 3D printer. I would love to have that top plate with a 1/4-20 thread sticking up so you could mount a subject holder or small ball head on top.

Do you make the background support fixture with the red disc?

Best,

Mike
Do you have a 3d Printer? I could make the file available.

That top plate actually has magnets embedded so I can attach other accessories to it and they just stick to it firmly, such as that pin adaptor. I am in the process of making some flexi-arms which will be 3d printable.

Yes I made the background holder which holds those multi-colour disks using magnets. Adjusting the angle of the disks determines how much light is reflected and you can also create vignette type backgrounds with it too.

The positioning table and all the other items on my rig have magnetic bases too which slide easily but with some resistance on teh Black cloth for easy positioning of everything, including my lights which are not shown. The rig is also portable so that Black board can flip over into a case, shut the lid and off you go!

Post Reply Previous topicNext topic