Hi WesM,
It sounds like you may have already reached to Teknic and spoken to someone, but if you haven’t, we’re happy to help. Please feel free to contact us through
https://teknic.com/contact/, or call us directly at +1-585-784-7454.
Hi Joeavaerage:
Teknic follows these forums (and many others) to respond to users and provide support, we’re sincerely not trying to hound anyone. Teknic’s two reasons for responding to any forum posts are to answer questions and correct factual errors or misleading information.
I’m sorry if you feel that Teknic is hounding you in any way. That is definitely not our intent. A few of my colleagues have tried to explain Teknic's goals in responding to forums on some of your previous posts, but I'll restate them here for others as well. Teknic follows these forums to respond to technical questions and to correct any factual errors or misleading information about our products and service (and many times other topics related to general motion control).
If you state your opinions about Teknic or our products without any incorrect or misleading/incomplete information, regardless of how negative your opinion is, we will rarely post a response. And, if you post a misstatement of fact that puts a Teknic product in a better light than it deserves to be based on the facts, we'll correct that too (you can see many examples of this on YouTube or various forums). Our goal is to help others understand motion control technology and apply it in a way that makes them successful. If this forum’s members (and the general market) are well-educated, they will choose the best products for their needs.
With that in mind, I have the following comments and corrections:
Teknic offers NEMA 23 brakes for $219, and a NEMA 34 brakes for $296 (single-piece pricing).
Teknic’s NEMA 23 and NEMA 34 ClearPath motors contain a 12,800 count optical encoder, and the NEMA 56/143/D100 models have a 64,000 count per rev optical encoder.
A few of my colleagues have made mention elsewhere on what makes for a high-quality encoder, but it bears repeating here:
It would be fair (although incomplete) to say that the Delta encoder has more resolution based on its specs, but it isn’t accurate to say that the Teknic encoder is subpar. As you stated, “a 10,000 count encoder will be perfect for CNC in every way.” Moreover, resolution is only one figure of merit for an encoder, and the number of counts per revolution does not convey any information about the other important metrics that characterize a high-quality encoder.
In order to get extremely high resolution out of a magnetic encoder (or even a high-quality optical encoder, for that matter) you have to do an extreme amount of interpolation. An encoder on a motor at the price point you mention will typically have noise, drift and other variability that makes the accuracy about 15 times (!) worse than the resolution. And if that isn’t enough, the filtering required to pull that fine a signal from the noise means that the servo gets its information delayed (and if it’s a serial encoder, the communication delays make it even worse). This all has a significant negative impact on servo performance.
Finally, even with a hypothetical “perfect” encoder, the mechanical imperfections in the motor and bearings will turn that extreme resolution into random noise, so even if you’re not bothered by the poor accuracy, the noise means your servo loop gets feedback that impairs its smoothness and dynamic performance.
We know all this because our engineers evaluated these encoders for ClearPath (and again recently for some yet unreleased products). It’s tempting to use these encoders because they’re so cheap, and because some people do mistakenly assume that more resolution must always be better. But we’ll be sticking with a high-quality, more expensive optical encoder and reasonable interpolation until there’s a magnetic encoder that can give us better performance.
Thanks,
Bridgette O. – Teknic Servo Systems Engineer