I am still very much a "newbie" to CNC, and it turns out that many of the things I "discover" are "common knowledge" that I failed to read the memo on. DynoMotion's KFLOP may well be an example of just such a "public secret", but I am so excited I feel the need to "share"! This will be an ongoing thread describing my experiences with the KFLOP. My goal will be to define what the KFLOP does (and why one might buy one) and document the process of implementing it in a simple 3 axis, stepper based router with a G540 driver. This first post will focus on the "Why" and "What it is", and in subsequent posts I will document "How To" starting with the hardware connections. I also plan to highlight features/problems/bugs in separate posts as I go along. It is my hope that my experiences with the KFLOP will help other DIYers find solutions to their motion control problems/limitations.

What is the KFLOP:

The KFLOP is part of a very sophisticated motion controller system. It is wildy robust with a DSP (Digital Signal Processor), FPGA and 16MB of on-board memory. Quoting from KMotion's description:

....(the) KMotion Family of High Performance 8-axis Motion Control Boards.....

This board has capabilities above and beyond anything else in its class - starting with a data-hungry 1.2 GFLOP DSP all the way to our customized software that includes C-code, G-code, Motion Libraries, KMotionCNC, and many prepackaged filters.

Here are just a few highlights of the Motion Control Board:
High Performance 1.2 GFLOP DSP
64-bit Double Precision Hardware Math
90us Servo Sample Rate (that's 90us for all 8 axes, inclusive)
USB 2.0 Full Speed Host interface (or run stand alone)
16 MBytes RAM
Digital I/O (44)
At the most basic level the KFLOP is a way to replace your LPT port with a USB connection; a topic that comes up FREQUENTLY in this forum, but it is SOOOO much more than just a USB to LPT interface! When I purchased my "A4" from John (Microcarve) back in March I thought I had read enough to hit the ground running. I ordered a G540, matching 381oz-in steppers, a 12A 48V PS and Mach3. I built a new desktop to run it all from and made the mistake of installing Win7 Ultimate. I beat my head against a wall attempting to get Mach3/Win7 to "play nice" with my little router for over a week before I finally installed WinXP. With WinXP I was able to run a gcode file from start to finish w/o missed steps//motor locking, but 30IPM was the fastest I could achieve w/o problems. I read, posted and talked with the folks @ Mach3, but the problem persisted; it is likely a combination of my MOBO, XP install and Mach3 settings, but no amount of fiddling solved the problem, and I was considering a new PC when I started reading about motion control boards.

There is amazingly little information on motion control boards, but I read everything I could find and finally posted a thread here: http://www.cnczone.com/forums/diy-cn...ol_advice.html . Two different people mentioned the KFLOP in response to my query, and that was enough to narrow my focus. I contacted KMotion with a few questions and was pleasantly surprised by their quick and informative responses, so I ordered a KFLOP. @ $250 + Shipping it seemed like it had a better chance of solving my problems than buying another MOBO or doing another OS install. I am still in the learning phase//conversion process, but once I wired the KFLOP to my G540 and made the steppers spin, WOW what a difference! In the set-up utility you can test the motors at different step rates and I could not believe my eyes and ears! I "tested" my x-axis first @ 24,000 steps per second (200 Steps/Rev * 10 uSteps/Step * 12 Rev/Inch ==> 24,000 Steps/Inch ==> 60IPM//720RPM) and it responded smoothly and quietly (@ 60IPM using my LPT with Mach3 the motors sound like a transmission with a broken gear). Then I sped it up to 48,000 steps per second (120IPM//1440RPM) and was amazed my little machine was capable of moving that fast (did I mention SMOOTHLY?). I kept increasing the step rate expecting to hear the familiar "missed step" or "locked motor" sounds, but my steppers acted like finely tuned race cars. I stopped @ 120,000 steps/sec (300IPM//3600RPM) because I was afraid I couldn't hit the "stop button" fast enough to prevent a "crash" (11inch axis travel @ 300IPM = 2 seconds from stop to stop not counting acceleration/deceleration! and I hadn't figured out yet how to use the console to move fixed distances, more on that later). While I have not even begun to delve into any of the advanced features the board is capable of, I am VERY IMPRESSED with it! @ 120,000 Steps per second in up to 8 Axis Simultaneously, the KFLOP is not even breaking a sweat, it is capable of 2,500,000 steps per second! I cannot imagine the set-up that might be able to utilize 2.5MSteps/Second, but if there is one the KFLOP can handle it!

The board comes with tons of software including KMotionCNC, functionally equivalent to Mach3. KMotionCNC does not have 50 screens and tons of bells and whistles, but it is clean, uncluttered and intuitive to use. It also has a plug-in for Mach3 if you don't want to learn yet another application (I have not tested the Mach3 plug-in yet.) The board is also capable of running in "stand alone mode"; that is, with No PC interface at all (load your "program", ie gcode, onto the board and then take the board to your machine and "plug and play" w/o a PC connected to the board.) A Visual Basic and Visual C++ "Jogger" application is included to demonstrate how to interface with the KFLOP via code for custom front ends. All of their software includes source code for those who want to modify/customize the applications. The trajectory planning is configurable and fairly intuitive. It runs gcode generated for Mach3 with minor header alterations (more on that later).

With a "free" Machine Controller the "real cost" of the KFLOP is only $75 more than Mach3 (Mach3 is $175 per PC if you obey the licensing agreement, the KFLOP is $250 but includes the Machine Controller Application for free so $250 - $175 => $75. I know there is a huge support base for Mach3, and Mach3 is a great Application, but modern Operating Systems and MoBos are making it increasingly difficult to use the LPT port for precision timing. If maintaining a dedicated, legacy PC for machine control is not your cup of tea and you want to be able to plug your modern Laptop (or any other USB enabled PC) into your CNC machine then the KFLOP is a Godsend!

Ok, that's it for the "Why" and "What it is". I will break the post here and begin the "How To" with the hardware connections in my next post.

Fish