Another modified Wemacro stand

Geopressure · Post by **Geopressure** » Sat Apr 13, 2019 8:10 pm

After reviewing some of the remarkable rigs people have constructed, I decided that I needed to improve my setup.

I had a machine shop precisely drill four holes in the base of my vertical WeMacro stand. This allowed my focus block/frame (from an old Olympus CHBS microscope) to be bolted on. The back of the frame is positioned flush against the vertical WeMacro column. I also had them drill a horizontal hole through the column and into the microscope frame. This allowed them to be snugly bolted together. This created a stiffer stand with a shorter free standing column. Finally my stand and stage are rigidly attached.

I used a hacksaw and grinder to reshape the slide clip, and added a sliding plexiglass plate to the stage. Now the X-Y mechanism works well to position the subject. See photos below:

ray_parkhurst · Post by **ray_parkhurst** » Sat Apr 13, 2019 8:16 pm

Excellent way to make the stand more rigid.

Chris S. · Post by **Chris S.** » Sat Apr 13, 2019 10:30 pm

Geopressure,

Elegant--in a minimum "number of moves," you not only made your rig more rigid, but provided yourself a nice subject stand with three axes of translation. And if I understand correctly, the ability to backlight your subject. Nicely done!

I'll bet this will make your stand a lot easier and more rewarding to use.

--Chris S.

Lou Jost · Post by **Lou Jost** » Sun Apr 14, 2019 4:18 am

Well done. As a next step, with the addition of a Micro-Mate attached to that block, you could increase the precision of your z-axis by an order of magnitude, so you could reach higher magnifications.

Oops, there is no hyphen. "MicroMate" by WeMacro, as linked by YAWNS below.

ChrisR · Post by **ChrisR** » Sun Apr 14, 2019 5:09 am

What's a micro-mate, Lou?
A search finds all sorts of irrelevant things..

mawyatt · Post by **mawyatt** » Sun Apr 14, 2019 5:15 am

Clever adaptation of the stand!!! Nice and clean too!!!

Best,

Yawns · Post by **Yawns** » Sun Apr 14, 2019 5:20 am

ChrisR wrote:What's a micro-mate, Lou?
A search finds all sorts of irrelevant things..

https://www.wemacro.com/?product=micromate-bracket-only

Geopressure · Post by **Geopressure** » Sun Apr 14, 2019 7:15 am

Thanks for all the positive comments guys

It makes for a nice compact unit.

Lou, I didn't realize the micro-mate allowed such small steps..very intriguing. I need to find out how many microns per revolution my fine focus has.

Brad

ray_parkhurst · Post by **ray_parkhurst** » Sun Apr 14, 2019 7:21 am

Geopressure wrote:Thanks for all the positive comments guys It makes for a nice compact unit.

Lou, I didn't realize the micro-mate allowed such small steps..very intriguing. I need to find out how many microns per revolution my fine focus has.

Brad

Even if the fine focus is as large as 200um, with a 400-step motor you get 0.5um full steps, or 125nm quarter steps. If you're looking for fine step sizes, using the focus block is for sure an excellent way to go. But note that it will be very slow to move. Coarse focus should still work properly though, right Lou?

Pau · Post by **Pau** » Sun Apr 14, 2019 2:27 pm

Geopressure wrote:Lou, I didn't realize the micro-mate allowed such small steps..very intriguing. I need to find out how many microns per revolution my fine focus has

Just read the numbers on it: it's 200micron/turn, so each division is 2micron

The micromate motor when directly coupled will allow you to do steps down to 0.1micron with the Wemacro controller in "micron"(slow) mode, more than enough for any optical situation.

Geopressure · Post by **Geopressure** » Sun Apr 14, 2019 4:29 pm

Thanks Pau, but I found an Olympus CHBS manual online and oddly each division is actually 2.5 microns, or 500 microns per revolution. In this case WeMacro gives the minimum step size as 0.23 micron.

rjlittlefield · Post by **rjlittlefield** » Sun Apr 14, 2019 4:46 pm

Geopressure wrote:I found an Olympus CHBS manual online and oddly each division is actually 2.5 microns, or 500 microns per revolution.

Sorry, but you've misinterpreted the dial.

The divisions are 2.5 microns, but there are only 80 divisions around your dial. (Many other Olympus dials have 100 divisions, hence 2 microns as Pau said.)

The numbers are in fact microns. More precisely they're within a few percent of microns because the gearing ratios don't work out quite right.

I don't have exactly the same block that you do, but my CHT measures 25.9 mm of physical movement for each 25 mm (125 turns) of the fine focus knob. More info at http://www.photomacrography.net/forum/v ... hp?t=27549 . I expect a measurement of your CHBS block would give a similar result.

--Rik

Lou Jost · Post by **Lou Jost** » Sun Apr 14, 2019 5:51 pm

Coarse focus should still work properly though, right Lou?

Ray, if the coarse focus knob doesn't turn the fine focus knob, you can use the course focus knob freely. If it does turn the fine focus knob, the stepper motor needs to be powered off before using it. Also, WeMacro recommends only using the "micron" setting when the MicroMate is attached to the controller.

The controller is the same as for the rail.

The MicroMate plus focus block is so smooth and stable that I hardly ever use rails anymore. And it can handle enormous loads.

Geopressure · Post by **Geopressure** » Sun Apr 14, 2019 7:58 pm

OK I see my error now...reading the numbers on the dial instead of counting the actual tic marks! Thanks Rik and Pau.

Pau · Post by **Pau** » Mon Apr 15, 2019 2:30 am

Geopressure wrote:...and oddly each division is actually 2.5 microns...

Yes, really odd: my BHMJ block that also does 200micron/turn has 2 micron divisions, so I assumed that it was the same without counting them at your pictures.
In any case this is irrelevant when motor driven.