wemacro or stackshot, rail only

Adalbert · Post by **Adalbert** » Mon Dec 10, 2018 2:58 pm

Hello everybody,
Does anybody know if wemacro is better than stackshot?
I’m interested only in the mechanical accuracy.
I don’t want to use the original controller.
BR, ADi

mawyatt · Post by **mawyatt** » Mon Dec 10, 2018 4:55 pm

I have both and don't see much of a difference between them, but haven't done an exhaustive test. If you use "Off Axis Loading" the effects of backlash and rail wobble can be significantly reduced.

The main difference between the Stackshot and Wemacro is the superb Stackshot controller, especially when operated from Zerene.

If you are looking for high precision focus rails the surplus THK KR types are really good also.

Best,

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 3:03 am

Hello Mike,

If you are looking for high precision focus rails

Yes, I’m looking for such one with the smallest step and the finest, precise screw.
And I’m absolutely not interested in the controller (I have already the best one :-)

BTW, I have found two interesting offers:
- Stackshot rail without controller : 390 Euro
- Wemacro: $250 + customs duties + vat

BR, ADi

Macrero · Post by **Macrero** » Tue Dec 11, 2018 4:13 am

The best option (as Mike suggested) would be to get an industrial rail such as THK KR or Hiwin KK. Those, IMO, are more reliable and precise than any specialized macro-rail on the market. And they can be found at the second hand market for a very reasonable price.

I currently use a Hiwin KK4001. I was looking for a THK KR2001, but I came across new/unused Hiwin and pulled the trigger. I was previously using a motorized Newport linear stage + fine thread (100 TPI) screw. It worked well, but the difference with the Hiwin was day and night, in terms of wobbling, backlash and precision. I don't use to work at very high magnifications, but I tested it at up to 60X and I didn't see any wobbling, backlash or anything that could impact final result.

Best,

- Macrero

ray_parkhurst · Post by **ray_parkhurst** » Tue Dec 11, 2018 11:57 am

Adalbert wrote:Hello Mike,
If you are looking for high precision focus rails
Yes, I’m looking for such one with the smallest step and the finest, precise screw.
And I’m absolutely not interested in the controller (I have already the best one :-)

BTW, I have found two interesting offers:
- Stackshot rail without controller : 390 Euro
- Wemacro: $250 + customs duties + vat

BR, ADi

My main stacking system uses a THK KR2001A for vertical stacks. I actually use a 200-step motor with it since I don't need full steps smaller than 5um, but if you need finer steps you could get 2.5um full steps using a 400-step motor, with reliable 625nm quarter steps. I originally had this system configured to move the subject, with camera fixed, but recently changed it to move the camera when I added the XY system for stack and stitch. If you can tolerate moving the subject (ie if you are just doing stacking, no stitching) then a KR1501A might be a good choice as well.

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 12:55 pm

Hello guys,
Thank you for the hints!
Unfortunately I haven’t found any THK KR2001 up to now

What do you think about these two offers?
https://www.ebay.de/itm/HIWIN-Linear-Ac ... :rk:3:pf:0

https://www.ebay.com/itm/THK-KR20A-Line ... rk:15:pf:0

Thank you in advance!
BR, ADi

Saul · Post by **Saul** » Tue Dec 11, 2018 1:42 pm

Are you looking for horizontal only ? If vertical - why do not use a microscope base ?

ray_parkhurst · Post by **ray_parkhurst** » Tue Dec 11, 2018 1:56 pm

Adalbert wrote:Hello guys,
Thank you for the hints!
Unfortunately I haven’t found any THK KR2001 up to now

What do you think about these two offers?
https://www.ebay.de/itm/HIWIN-Linear-Ac ... :rk:3:pf:0

https://www.ebay.com/itm/THK-KR20A-Line ... rk:15:pf:0

Thank you in advance!
BR, ADi

Hi ADi...that KR20A you linked to is indeed a KR2001A, just not correctly listed by seller. In addition to the rail, you'll need a shaft coupler, a motor adapter, and a motor. I would recommend buying a system that already has these things. The coupler is fairly easy, but getting the right one may take a couple tries. The motor mount is not easy to find. The motor is easy.

So this one looks much better:

https://www.ebay.com/itm/THK-KR20-Linea ... rk:16:pf:0

You would need to swap the motor only.

This one same situation and a little more:

https://www.ebay.com/itm/THK-KR20-LINEA ... rk:10:pf:0

This one may be even better, has coupler and mount, no motor, but you would need to verify it is 1mm pitch:

https://www.ebay.com/itm/1pc-THK-KR-20- ... rk:11:pf:0

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 2:56 pm

Hello Ray,
Many thanks for the answer and for the links!
I would like to attach the NEMA 17 to the rail.
So, I will have to find the appropriate motor adapter (for the NEMA 17 alone and one with the gear box).
BTW, which one of the THK KR* does have the finest accuracy?
BR, ADi

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 3:00 pm

Hello Saul,
Actually vertically and horizontally :-)
BTW, I have a Biolam, which can be disassembled.
BR, ADi

ray_parkhurst · Post by **ray_parkhurst** » Tue Dec 11, 2018 3:19 pm

Adalbert wrote:Hello Ray,
Many thanks for the answer and for the links!
I would like to attach the NEMA 17 to the rail.
So, I will have to find the appropriate motor adapter (for the NEMA 17 alone and one with the gear box).
BTW, which one of the THK KR* does have the finest accuracy?
BR, ADi

Not much difference between models, or pitches for that matter, but they do have different grades within models. Precision is better than High Accuracy is better than Standard, but Standard is still excellent. most of what you'll find on eBay is Standard.

You can read all about the KR series here:

https://tech.thk.com/upload/catalog_cla ... _kr_en.pdf

Edited to add: just saw ref to "gear box"...what is this?

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 3:34 pm

Hello Ray,
I use in my current rail the NEMA 17 with the gear box 100:1
http://www.photomacrography.net/forum/v ... highlight=
BR, ADi

Adalbert · Post by **Adalbert** » Tue Dec 11, 2018 4:35 pm

Hello Macrero,
Do you have something like that?
https://www.ebay.de/itm/HIWIN-Linear-Ac ... :rk:3:pf:0
If yes, what kind of motor do you use?
BR, ADi

ray_parkhurst · Post by **ray_parkhurst** » Tue Dec 11, 2018 7:58 pm

Adalbert wrote:Hello Ray,
I use in my current rail the NEMA 17 with the gear box 100:1
http://www.photomacrography.net/forum/v ... highlight=
BR, ADi

I'm curious why do you need such a small step size? Even with NA 0.5 you only need ~2um steps.

Lou Jost · Post by **Lou Jost** » Tue Dec 11, 2018 8:17 pm

If small steps and high mechanical stability are important to you, you should consider WeMacro's MacroMate stepper motor that drives a rotating ring that connects to a microscope fine focus knob. Depending on the microscope, this can cut your minimum step size down by a factor of ten! Nikon focusing blocks are rock-solid and don't wobble at all (as far as I can tell at 20x or lower). I now prefer this approach over my WeMacro rail and my Stackshot rail.

https://www.wemacro.com/?product=micromate