best controller for THK KR2

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dhmiller
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best controller for THK KR2

Post by dhmiller »

I recently purchased a used THK KR rail. I already own a complete Stackshot system (though it mysteriously failed a few days after I bought the THK -- jealousy??), but I would like to purchase a second controller so I can have two complete systems. I also have my sights on a 50x Mitutoyo (one of the reasons I bought the THK), so I am curious what the best option would be for controlling the THK with the Mitutoyo. Is there a controller that would be a better option than a second Stackshot? Something with greater precision, down to 1 um reliably, perhaps? Thanks for any suggestions.

Adalbert
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Re: best controller for THK KR2

Post by Adalbert »


dhmiller
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Re: best controller for THK KR2

Post by dhmiller »

Thanks, Adalbert. Well beyond my skill level ;-)

mawyatt
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Re: best controller for THK KR2

Post by mawyatt »

Check out the many threads on the Trinamic Controllers, they are superb with the THK KR20. The TMC5130, TMC5160 and TMC5072 all work well with the THK KR20.

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

ray_parkhurst
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Re: best controller for THK KR2

Post by ray_parkhurst »

I use KR15, KR20, and KR26 with various stepper motors, mostly from Lin Engineering. I control the steppers with the mjkzz controller. It is quite easy to use, and inexpensive. Prior to using the mjkzz I used Helicon Remote via a USB-RS interface to a Trinamic controller IC. This system worked well but I had many problems trying to replicate it (mostly in bad Trinamic drivers) so I gave up and went with the mjkzz solution, which has worked flawlessly for several years now.

edited to add: which KR rail did you buy?

mawyatt
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Re: best controller for THK KR2

Post by mawyatt »

Ray,

Think the Trinamic device you have/had is an old device and not the same as what we've recently (past few years) developed based upon the modern TMC5130, 5160 and 5072 BOB devices. The hardware motor driver and micro controller are integrated on the same chip, as is the interface. This is a complete single chip solution without additional chips involved. The micro controller, regulators, charge pumps, H bridge bi-directional motor driver, current sensing, thermal sensing, motor waveform generation, position/velocity control, micro stepping and multi-interface are all integrated on a single chip (the 5072 is a dual and 5160 uses external FETs for higher voltage and current motors ~3A at 36V). We developed the interface around the SCI bus for the Raspberry Pi with a custom "HAT" PCB that sits on top and plugs directly into the RPi I/O connector (single, dual, triple and quad axis), others have also developed Arduino interfaces.

When you invoke the Trinamic Motor Velocity Profiling features on the TMC5130, 5160 or 5072 which are tuned to the rail and motor to optimize performance, the other controllers like the MJKZZ can't perform anywhere near the level of the modern Trinamic devices. The Trinamic based controller is quiet (almost silent), silky smooth inducing no detectable vibration, precise, very quick, efficient (little motor heating), and much more. I know because I've tested the MJKZZ and others, even measuring the actual motor sine and cosine current waveforms to "see" what's going on with a custom developed motor current sensing probe.

When these controllers coupled with the superb THK rails KR15, 20 and 26 with quality 400 step motors you have, think this is the SOTA for stepper based focus rails.


BTW, we don't use the RS or USB interface, it's direct SCI based to RPi and involves no Trinamic drivers, works superbly too!! Works with KR15, 20, 26, HIWIN KK50 (KR26 clone), Stackshot, Wemacro and MJKZZ rails, with various stepper motors NEMA 11, 14 ,17, including the deep, thin and pancake types, 200 and 400 step types, we've tested them all.

Heres some video example of these controllers.

https://drive.google.com/file/d/1P-95Ic ... sp=sharing

https://drive.google.com/file/d/1Ld40wU ... sp=sharing



This video is at 800X and shows the precision and smoothness.

https://drive.google.com/file/d/19wE-B- ... sp=sharing

Best,
Last edited by mawyatt on Wed Jul 29, 2020 10:00 am, edited 2 times in total.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

ray_parkhurst
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Re: best controller for THK KR2

Post by ray_parkhurst »

mawyatt wrote:
Wed Jul 29, 2020 8:01 am
When these controllers coupled with the superb THK rails KR15, 20 and 26 with quality 400 step motors you have, think this is the SOTA for stepper based focus rails.
Probably true, but I got the sense that the OP was looking for a more plug and play solution like I was when I bought the mjkzz controller. That said, I'm curious if you've pulled the hardware together and made a simple interface that might compete with the commercial solutions. What is the state of your controller now? Last I inquired I think I needed to buy a Raspberry Pi, and somehow make a VPN connection to get it to work.

mawyatt
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Location: Clearwater

Re: best controller for THK KR2

Post by mawyatt »

ray_parkhurst wrote:
Wed Jul 29, 2020 8:25 am
mawyatt wrote:
Wed Jul 29, 2020 8:01 am
When these controllers coupled with the superb THK rails KR15, 20 and 26 with quality 400 step motors you have, think this is the SOTA for stepper based focus rails.
Probably true, but I got the sense that the OP was looking for a more plug and play solution like I was when I bought the mjkzz controller. That said, I'm curious if you've pulled the hardware together and made a simple interface that might compete with the commercial solutions. What is the state of your controller now? Last I inquired I think I needed to buy a Raspberry Pi, and somehow make a VPN connection to get it to work.
Yes this is not exactly Plug-N-Play , but a number of folks are using these, many outside this site.
They simply plug into the RPi I/O connector and run from the RPi interface Python shell. The code is written in Python so it's very easy to manipulate (I'm not a programmer, so it had to be easy :>).

You can operate directly with the RPi or wireless via VNC.

It's not as easy to setup and use as the MJKZZ, Wemacro or Stackshot, but I believe the performance is well beyond anything these controllers can achieve. However once setup and operating it's as easy as entering a start, end and step size and starting a session, even saving parameters to a file. Then you can proceed to completely automated Stack And Stitch sessions with a multi-axis controller all on the single RPi "HAT" custom PCB. Here with a triple or quad axis controller you can control just about any combination of motors and rails as you wish, from combos of Stackshot, Wemacro, MJKZZ, THK KR15, 20, 26 and so on.

So lots of options with theses Trinamic devices.

Edit: The link to the above videos was messed up, fixed now. Be sure and view the 800X. Also, my gallery isn't showing up, so you'll have to do a search to see the finished custom PCBs. here's couple I just resized to fit. If I can recover my gallery I'll post some more images of the finished PCBs, they are above commercial average for PCB quality having double side with thru vias and stenciled.

Best,
Trinamic Quad Axis Dual TMC5072
Trinamic Quad Axis Dual TMC5072
Trinamic Triple Axis TMC5072 & TMC5130
Trinamic Triple Axis TMC5072 & TMC5130
Trinamic Single Axis High Current and Voltage TMC5160
Trinamic Single Axis High Current and Voltage TMC5160
Various Trinamic Controllers
Various Trinamic Controllers
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

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