SYIL X4 CNC Mill: Teknic Clearpath SDSK Centroid Acorn Project: Overview and Unboxing

[@danielminskey]

thank you so much for doing this video...I am getting ready to build my box for my mill...i am going to go withthe DMM servo motors..mainly becuase of budget...great video

[@Autonomation365]

I’m excited to see the build! I have seen a lot of people who have had interference issues in their clearpath machines with error 73, input timing error, when using ACORN. Good luck!

[@martyscncgarage5275]

Thanks. Indeed, I hope all goes well.

[@Z-add]

So clearpath claim that their motors are not susceptible to intereference isn't true?

[@martyscncgarage5275]

@@Z-add Where did you clean that from. Indeed, they have been engineered so they are not susceptible to EMI.

[@TeknicInc]

Hi Clay, I’m an engineer at Teknic and came across your comment about step input timing errors and noise interference. The ClearPath motor inputs are optically isolated and current limited. This design provides exceptional noise immunity even in the most difficult EMI environments like plasma CNC machines and applications that use a VFD. The optical isolation hardware of the ClearPath motors provide enough noise immunity that shielded and twisted pair cables between the CNC motion controller and the ClearPath motor are not required. You might wonder, “if the noise immunity of the ClearPath motors is so good, then why is there a possibility of getting step input timing errors and why are the termination resistors required?” Great question! The minimum length of time for a step to be “on” is 715ns. In addition, the minimum length of time for the “off” period between steps is also 715ns. The ClearPath “step input timing error” occurs when the “on” time of a step is shorter than 715ns, and/or the “off” time between steps is shorter than 715ns. Typically this error is elicited when one or more of the following conditions occur: - The controller has open collector outputs and the resistors specified in the ClearPath manual are not installed correctly, or not at all. Here is a link to the fractional hp ClearPath manual:(www.teknic.com/files/downloads/clearpath_user_manual.pdf) An open collector output “drives” the signal to a true logic state but then the return signal “floats” back to its false logic state. This floating nature of the open collector signal means that the signal might not be “off” for at least 715ns required between steps before the next step is sent. This behavior is often exacerbated by capacitance in the control system, whether due to long cable runs or the electrical design. The Centroid Acorn uses 24VDC open collector outputs, so installing 10k ohm resistors across both the step and direction outputs for each axis of motion is appropriate. This resistor promptly drives the signal to an “off” state between steps. In contrast, a driven TTL signal (this is a different hardware architecture than open collector signals) is less prone to this behavior because the circuitry “drives” the signal to ”on” and then “drives” the signal back to ”off”. This type of signal is referred to as a “driven signal”. - The controller output voltage is lower than the minimum 4VDC required for the ClearPath motor and is unable to reliably turn on the optical isolated inputs. For example, some controllers only output a 3.3VDC signal. - The controller's maximum step pulse output frequency is higher than 700kHz, or the step pulse time is less than 715 nS. These settings are typically configurable in the controller. (www.teknic.com/files/downloads/clearpath_user_manual.pdf#page=152&zoom=100,0,0) - Shared return paths for outputs. The V+ and GND wires for each controller output should travel the entire distance from the controller to the motor and then back to the controller. Some systems have limited I/O connections so the output signals go individually out to the motor, but then they share a common return path back to the controller. For example, three output signal wires could go out to the motor but then the return wires are tied together and only one return wire comes all the way back to the controller. This can cause problems related to noise immunity. As a side note, we’ve recently reviewed the Acorn schematics with Centroid and they will be updating their schematics to include this 10k termination resistor. This should address the issue that you mentioned. I hope this helps you and other users. If you have any other questions regarding the ClearPath motors, please feel free to use Teknic’s "Contact Us' form (www.teknic.com/contact) or give us a call at 585-784-7454. Best regards, Tom T. - Teknic Servo Systems Engineer

[@offuttjr]

Thanks Marty for all that you share and explain

[@jamesmaccubbin7434]

This is great - thank you Marty!

[@ortegasculpture]

do you do Paid conversions in the phoenix area?

[@martyscncgarage5275]

Reach out to me at my KZbin channel name ATgmailDotcom. With details of the build and photos.

[@FreedomFactory3D]

How did you mount your Z-axis servo motor on top? I've been considering doing this as well. Did you have to modify the ball screw?

[@martyscncgarage5275]

@@FreedomFactory3D It's been awhile. I have a photo album you can look at. I know I didn't make mounts. I may have replaced the couplers. photos.app.goo.gl/dBqDGCTgPwpsip29A

[@TheThomasdahl]

Marty.. This is brilliant. Do you habe wiring diagrams and parts list?

[@hamiltonpianos]

Excellent stuff Sir! I'm currently deciding between Acorn and the Masso G3. The all-in-one aspect of the Masso is very appealing, but the heritage of the Acorn can't be ignored. What sort of PC will you have driving your X4? Are you going to drive all four ClearPaths from one power supply? If you need more power, can you plug an extra supply into the power hub? (It looks like it has two inputs and four outputs.) Very much looking forward to more episodes in this series! :)

[@martyscncgarage5275]

Using Lenovo Tiny M92P. Virtually any Intel CPU running at 2.9ghz or faster meets the minimum requirements. www.centroidcnc.com/cnc_pc_performance_requirements.html Centroid CNC has been specializing in CNC Machine motion control for over 30 years. Hardware and software from the same Company, USA based and built, and constantly improving the hardware and software based on customer feedback. www.centroidcnc.com/centroid_diy/acorn_cnc_controller.html. If you have any questions ask the users on the Centroid user forums. See the projects they have done: centroidcncforum.com/ Certainly lots of control options to choose from! Hope you find the series useful in helping you make your decision.

[@SyilCNC]

Very impressive

[@Z-add]

Their was a question from masso controller engineer about the closed loop clearpath sd on one of their videos. Based on the complicated answer from teknic engineer i got the impression that these are not true closed loop servos. The masso engineer was disappointed. I don't remember which teknic clearpath video had this exchange.

[@martyscncgarage5275]

It has an encoder, it has a drive. The motor can not function without the drive the drive can not keep the motor in position without the encoder. The Clearpath SD motor is a closed loop assembly as I demonstrated in the dry erase board. The job of the drive is to ensure that motor is kept in position and it does that by monitoring the encoder.

[@Z-add]

@@martyscncgarage5275 can you explain this comment from teknic engineer. what i understand is that the controller doesn't get encoder information from clearpath. Hi Masso CNC Controllers, At this time, it's not possible to stream an output signal from ClearPath's encoder. Teknic made the active decision to design ClearPath this way for both cost and robustness reasons. Depending on the application objectives, ClearPath can often accomplish the user's goals through a different method. For applications where streaming encoder data is necessary, mounting a third party external encoder may be a suitable option. Best regards, Bridgette G

[@martyscncgarage5275]

@@Z-add There is NO encoder feedback from Clearpath SDSK to any controller. Period. I don't know anything about MASSO. You send step and direction signals to SDSK and the drive/encoder keep the motor in position. I have no idea what you are trying to accomplish, but you will NOT get encoder feedback from SDSK to close any controller loop.

[@umargul5644]

Well done