Hi Mark,
I second the THK KR type rails for precision use. The commercial Stackshot and Wemacro rails are very good, probably significantly better than the link you posted, but the THK rails are even better. Virtually no backlash or rail wobble if you get a good rail that hasn't been abused. If you like to tinker you will like these!!
For custom controllers consider the Trinamic devices, lots of data posted on here about these, some of the popular controllers based upon the TI and Toshiba chips have shown motor current waveform issues. I use the Trinamic with the Raspberry Pi, and when setup with the right parameters they are superb. I have single, dual, 3 axis and quad axis Trinamic controllers working with the RPi, the "push" behind all this development is a 3 and 4 axis Precision Fully Automated "Hands Off" Stack & Stitch System capable of massive sessions.
Here's a quick video of the Trinamic and THK KR20 at 800X to demonstrate the performance.
https://drive.google.com/file/d/19wE-B- ... sp=sharing
Good luck with your project.
Best,
DIY Macro Rail - is the thread pitch on this small enough?
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Hi Mark,
If you prefer Arduino please take a look at this thread:
http://www.photomacrography.net/forum/v ... c&start=45
BR, ADi
I totally agree with Mike.Mike wrote: “but the THK rails are even better”
If you prefer Arduino please take a look at this thread:
http://www.photomacrography.net/forum/v ... c&start=45
BR, ADi
This is my first post on the forum.
Your post caught my eye as your rail is almost exactly like the one I used to make my homemade auto macro rail.
Mine is controlled by an Arduino Uno with a TB6560 stepper controller. The interface is a 4x4 membrane keypad and a 4x20 LED display. The coding is not too difficult – I hadn't coded anything since using Visual Basic back in the 1990s. It was learn-as-you-go, but there are plenty of resources on the web.
My system is set up so that I enter the slice thickness I want and the actual depth of the subject. The code moves the camera 80% of the slice thickness to create an overlap between images. Each step has delays before and after the actual shutter actuation to allow the camera to settle and the flashes recharge time. Prior to beginning the stack the camera will back up a bit and then return to start. This is done to "pre-load" the screw and remove any slop before beginning the stack.
I don't think you have to worry about accuracy up to 8 or 10x macros – or even greater. Stepper motor controllers can add micro-stepping up to a factor of up to 8 or 16. With 16 micro-steps, your control goes to 3200 steps per revolution or 8.89 micro-steps per degree. I tested my rail with 125 slices for a 1.0mm stack. I measured the actual stack length at 1.04mm with a digital micrometer.
If you have the time or inclination, there is a very short hand-held video of my rail on the Pentax Forums website at this address: https://www.pentaxforums.com/forums/62- ... z62MfIrzkH
If I can help with any more info, please get in touch.
Don
Your post caught my eye as your rail is almost exactly like the one I used to make my homemade auto macro rail.
Mine is controlled by an Arduino Uno with a TB6560 stepper controller. The interface is a 4x4 membrane keypad and a 4x20 LED display. The coding is not too difficult – I hadn't coded anything since using Visual Basic back in the 1990s. It was learn-as-you-go, but there are plenty of resources on the web.
My system is set up so that I enter the slice thickness I want and the actual depth of the subject. The code moves the camera 80% of the slice thickness to create an overlap between images. Each step has delays before and after the actual shutter actuation to allow the camera to settle and the flashes recharge time. Prior to beginning the stack the camera will back up a bit and then return to start. This is done to "pre-load" the screw and remove any slop before beginning the stack.
I don't think you have to worry about accuracy up to 8 or 10x macros – or even greater. Stepper motor controllers can add micro-stepping up to a factor of up to 8 or 16. With 16 micro-steps, your control goes to 3200 steps per revolution or 8.89 micro-steps per degree. I tested my rail with 125 slices for a 1.0mm stack. I measured the actual stack length at 1.04mm with a digital micrometer.
If you have the time or inclination, there is a very short hand-held video of my rail on the Pentax Forums website at this address: https://www.pentaxforums.com/forums/62- ... z62MfIrzkH
If I can help with any more info, please get in touch.
Don
Don