wemacro or stackshot, rail only

Adalbert · Post by **Adalbert** » Wed Dec 12, 2018 1:05 pm

Hello Lou,
As far as I can see, on the left side you have Wemacro and on the right side the MicroMate.
May I assume, the accuracy of the MicroMate with the NIKON microscope is better than the accuracy of the Wemacro?
BR, ADi

Lou Jost · Post by **Lou Jost** » Wed Dec 12, 2018 1:33 pm

Yes, as I said above, the accuracy is TEN TIMES better with the MicroMate!! And no backlash.

ray_parkhurst · Post by **ray_parkhurst** » Wed Dec 12, 2018 8:39 pm

With the 100:1 gearbox, you could consider a 2mm pitch rail and still achieve 50nm full steps with 400 step motor. Here is a very good deal on a Precision grade KR2602B. The "B" means it has an idler carriage which can be used to provide much better mounting stability than a single carriage, and reduced torque on the carriages:

https://www.ebay.com/itm/THK-KR2602B-25 ... 2660805178

mjkzz offers mounts, carriage brackets, couplers, etc for the KR26 so you will have no problem getting what you need, though I'm not sure what mount your gearbox will require. That one may need to be custom made.

Macro_Cosmos · Post by **Macro_Cosmos** » Wed Dec 12, 2018 9:41 pm

Lou Jost wrote:Macro_cosmos, resizing is done in an external editor like Photoshop.

I'd like to simply link to the online sources rather than taking and editing to be honest... I'll watch out next time

viktor j nilsson · Post by **viktor j nilsson** » Thu Dec 13, 2018 1:05 am

Macrero wrote:
viktor j nilsson wrote:Macrero, that is very neat. Where does your xyz stage come from?
From ebay. It was not cheap, those precision stages are quite expensive. But it was just what I was looking for. I only made the top plate for the magnetic ball.

Thanks. I don't think I've seen that exact model. It looks much more ergonomic than the stacked micrometer stages I use. Are those coaxial coarse/fine control knobs? Looks like it. That would be awesome.

Macrero · Post by **Macrero** » Thu Dec 13, 2018 4:00 am

Adalbert wrote:Hello Macrero,
Yes, the HIWIN is a really good alternative.
In my rail I use a linear stage from Mitutoyo with the range of 17mm
This stage is small and probable not strong enough to be used vertically.

BTW, your black setup looks very noble :-)
My setup is made of wood:

BR, ADi

Adi,

yes, the Hiwin is a very good option, and 35mm stroke is more than enough given the magnification range you are working at.

Black is my favorite color

I actually got the black cased motor just to be in line with the rest of the setup

The base is black-painted marble, though apart from the aesthetic reasons, that also avoids unwanted reflected lights hitting the subject.

Best,

- Macrero

Macrero · Post by **Macrero** » Thu Dec 13, 2018 4:20 am

viktor j nilsson wrote:Thanks. I don't think I've seen that exact model. It looks much more ergonomic than the stacked micrometer stages I use. Are those coaxial coarse/fine control knobs? Looks like it. That would be awesome.

I also find it more ergonomic and comfortable to use than the micrometer stages, it also offers more travel.

Yes, there are coarse and fine knobs for each axis.

Pau · Post by **Pau** » Thu Dec 13, 2018 5:09 am

Macrero, do you know the original use of your positioning device? To me it seems from a micromanipulator or related equipment.

Macrero · Post by **Macrero** » Thu Dec 13, 2018 6:09 am

...........

Adalbert · Post by **Adalbert** » Thu Dec 13, 2018 6:27 am

Hello Macrero,

Bear in mind though that buying an used rail may be a tad risky. Those are intended (and used) for exhaustive industrial work and and like everything in life, they deteriorate and lose precision and reliability with time and kilometers traveled. But if the rail has not been abused, it will work fine.

So, I have just asked the seller for the condition of the rail.
“This actuator was taken from working inspection machine. (vision machine) and keeps good working condition. (mechanical and cosmetic). Can't feel backlash and play.”

So, I think it should be OK.

BTW, what kind of sliding is better?
- Guide rails as in the THK KR or HIWIN
- Guide pipes as in the StackShot and Wemacro
- Rolling balls as in the Mitutoyo

BR, ADi

Macrero · Post by **Macrero** » Thu Dec 13, 2018 6:39 am

Yes, it should be OK. You would have to get (or make) the Nema 17 motor mounting plate and the camera/bellows plate.

I havent used the StackShot and Wemacro rails, but personally, I would go with either the THK or the Hiwin.

Best,

- Macrero

ray_parkhurst · Post by **ray_parkhurst** » Thu Dec 13, 2018 7:13 am

Macrero wrote:Yes, it should be OK. You would have to get (or make) the Nema 17 motor mounting plate and the camera/bellows plate.

I havent used the StackShot and Wemacro rails, but personally, I would go with either the THK or the Hiwin.

Best,

- Macrero

Misumi rails are also very good.

Crossed roller or V-track ball bearing rails are generally better than the rod type.

Adalbert · Post by **Adalbert** » Thu Dec 13, 2018 12:34 pm

Hello everybody,
I have just found two interesting offers:

used:
https://www.ebay.de/itm/THK-KR20-Linear ... SwYlRZFa-C

new:
https://www.ebay.de/itm/New-THK-KR20-Li ... Swux5YQVcY

Question:
How can I mount the NEMA 17 to this rail?
Can I remove this this V-belt mounting so that I will be able to use a simple couple shaft?

BR, ADi

ray_parkhurst · Post by **ray_parkhurst** » Thu Dec 13, 2018 12:53 pm

Adalbert wrote:Hello everybody,
I have just found two interesting offers:

used:
https://www.ebay.de/itm/THK-KR20-Linear ... SwYlRZFa-C

new:
https://www.ebay.de/itm/New-THK-KR20-Li ... Swux5YQVcY

Question:
How can I mount the NEMA 17 to this rail?
Can I remove this this V-belt mounting so that I will be able to use a simple couple shaft?

BR, ADi

If you want to hard-mount the motor to the rail, you would need to come up with the "cage" that interfaces between the rail and the motor mount. This cage has a space milled out to hold the shaft coupler. I've never seen the cage available separately, so probably you'd need to cannibalize a damaged KR20 to get it. You'd also need the mount for the 100:1 gearbox or motor.

You can soft-mount the motor via a belt. You'd need to get a pulley to mount on your 100:1 gearbox or motor which matches the pitch of the one on the used KR20, or if you get the new KR20, buy a pair (one for 4mm shaft for the KR20, and one with correct shaft diameter for your gearbox). Then you would need to buy the right length belt, and mount the KR20 and motor at appropriate distance from each other.

Advantage of the soft-mount is you could do further reduction based on pulley diameters by putting a larger pulley on the KR20 versus the gearbox.

Macro_Cosmos · Post by **Macro_Cosmos** » Fri Dec 14, 2018 7:01 am

I feel the need to clarify my original post.

The newer Wemacro stacker features a multipurpose platform with various mounting options, as shown:

It accepts most commonly available acra swiss clamps with multiple mounting holes. It seems that the clamp can be mounted in both directions, which is great. My Hejnar platform allows that.

I recommend low profile hex screws, such as this one from Amazon:
https://www.amazon.com/YXQ-4-20x3-Butto ... B07DG6D6FW

Or better, these Thorlabs ones:
https://www.thorlabs.com/thorproduct.cf ... r=SH25LP38

These feature a flat thin head rather than conventional hex screws, which are quite beefy, and has a potential to protrude and interfere with arca-siwss dovetail rails. The rails that have a hollowed out section wouldn't be affected however, which is actually most of them. Example of affected ones will be my 70-200 f/2.8E FL Nikon lens' arca-swiss replacement foot from ReallyRightStuff, or the Laowa 25mm f/2.8 Ultra-Macro's optional lens collar. These feature a flat rear surface which can be problematic.

One advantage of the expensive Stackshot platform is a lowered centre of gravity. Whether that translates into any advantageous real world performance, I'm not sure and frankly not really in the mood of spending $$$ to find out.

For those who do not have the newer rail, an adapter can be purchased for $9. Really cheap and reasonable in my opinion.
Link: https://www.wemacro.com/?product=upgrad ... ease-clamp