Axiom Controller VS Mach 4

[Dan Richeson]

Hello All

Its been almost a year from when I had ordered my first CNC and had a terrible experience with it. So I'm on the hunt again to get one ordered. Just wondering if any one has used a Axiom controller vs a computer with Mach 4? I think I have my choices down to an Avid or Axiom machine. Just was wondering if one finds it more difficult loading the different tool paths on the controller style CNC. Thanks

[Jim Becker]

Personally, of the two, I believe I'd prefer the Mach4 as it's not tied to a pendant, but that's a subjective thing. Mach4 is "more like" the WinCNC controller my machine uses in that respect. I'm also a fan of AVID being a North American manufacturer as well as the fact that their machines are extensible over time if your needs "get bigger". Again, that's subjective, too.

[Gary Campbell]

One other option, AVID with Centroid controller. The closed loop NEMA 34 system for AVID was our best seller for 2020-21

[Ed Fang]

My understanding is that the only way to have a closed loop was to use the centroid oak - which I would love to use but the components get pricy in a hurry. I think it’s $500 just for say delta servo drive cables for 3 axis. The acorn can do a hybrid closed circuit with clear path or dmm drives ?? Obviously deferring to Gary on this one as he knows these a /lot/ more than anything I would on this.

[Dan Richeson]

Hello Gary

I'm totally lost on what you were talking about. Is that another company that makes a cnc controller ?

[Ed Fang]

Hello Gary

I'm totally lost on what you were talking about. Is that another company that makes a cnc controller ?

centroid is another platform that a lot of commercial/industrial companies utilize for CNC control. they left the step/direction game (where most hobbyists are) and went with direct servo control many years ago. they have recently come back to it with their acorn CNC control board which many have adopted. The Acorn is supposedly a really nice control board and seemingly outperforms many other platforms (linuxcnc, ethernet stepper, etc etc). but to get a fully closed loop system, I think you need to step up to their OAK board.

[Jim Becker]

Hello Gary

I'm totally lost on what you were talking about. Is that another company that makes a cnc controller ?

There are lots of CNC controller systems on the market. Centroid, that Gary mentions, is a company that produces CNC control systems that are a step (or several steps) above the lower end and open source controllers that are typical on "value priced" systems. Mach4 is nice; Centroid Acorn is nicer. In the case of an AVID machine, you buy the AVID machine sans the steppers/controller and then work with a resource like Gary's company to add the more robust controller and motors in lieu of buying AVID's standard or enhanced controller packages.

Ed, if there is any one who is an acknowledged industry expert in the US on Centroid, it's Gary.

[Ed Fang]

Ed, if there is any one who is an acknowledged industry expert in the US on Centroid, it's Gary.

Oh I know. . . lol.. . which is why Im not questioning but asking for clarification on his part about the closed loop centroid. pretty sure he knows more about the innards of centroid and for that matter cnc than I even know their name. . .

[Gary Campbell]

Dan:
"I'm totally lost on what you were talking about. Is that another company that makes a cnc controller ?"

Centroid is a US based company that makes industrial controllers. (since the mid 80's) For a few years they have also been producing a step and direction controller, called "Acorn" for the DIY and stepper based router world. My company, GCnC Control, is an approved Acorn system builder. We build replacement controllers for users that want to upgrade from ShopBot, Mach, RichAuto, Hust, etc. And as stated, one of our best selling items over the last 2 years is the "Acorn closed loop for AVID" for those that do not want to run on Mach 4 and want the advantages of a closed loop stepper system. We also build systems for guys building a new machine and dont want to suffer the woes of DIY experimentation while sourcing and wiring components.

Ed:
You are correct. Centroid's Oak, Allin1DC, and Hickory products are true closed loop, i.e., with encoder feedback to the controller. Acorn is step & direction, and by definition S&D systems cannot be true closed loop, as it has encoder feedback to the drive. The drive has a set threshold that tracks received step pulses against actual encoder pulses and will issue an error if the motor shaft is not within "some number" of tolerance. If over that number for a set amount of time, the drive issues an alarm which the controller receives and halts motion, allowing the operator to correct the error and resume cutting.

Because the DIY / sub $50k router world is ultra-competitive, they have a tendency when marketing to usurp terminology from "up markets". Common usage of closed loop in the stepper world would be "closed loop stepper" or "closed loop" or "hybrid servo" to name a few that I've seen. This is just a terminology game, same as the guy at the back of the parade is now an "equestrian environmental monitor" instead of a "pooper scooper". Stepper guys want to sound like servo guys.

We build "closed loop step and direction" 4 and 6 axis systems using 1) Steppers, 2)Teknic ClearPath servos and 3) LeadShine AC servos with Centroid's Acorn 4 and AcornSIX controllers. None of these systems have feedback to the controller, just to the drive.

1) is a great and inexpensive way to eliminate the woes of the dreaded "lost steps" from operators that have been plagued by them.
2) and 3) add the advantage of power, smoothness and duty cycle of DC (2) and AC (3) servos without incurring the costs associated with true closed loop industrial controllers.

And of course, they all add the benefits of running on a Centroid controller, which is top of the line industrial quality.

Hope this helps

[Ed Fang]

Hey Gary. Thanks for the clarification. And yes - I get the fact that everyone wants to claim something more swanky than it really is. And thank you for the detailed response.

Question - is their any real benefit to having encoder feedback back to say the oak controller over just the driver with an acorn setup for any sub 50k system. Like say any moderate sized avid cnc system ? Is it totally overkill to say go to an oak system with delta/yaskawa servos and drives on such a system ? Because a teknic clear path servos already gain you smoothness and speed and presumably accuracy over the stepper motors even though it’s still using step/direction vs direct to servo drive commands.

[Jim Becker]

Ed, I think that part of the answer to your question is whether or not the work you need to do can benefit from the investment, probably more from a precision standpoint, I would think.

[Ed Fang]

Ed, I think that part of the answer to your question is whether or not the work you need to do can benefit from the investment, probably more from a precision standpoint, I would think.

very true. I guess Im coming from it from a tinkering point of view. I've worked with steppers before. I guess I just want a reason to build a servo - like a true servo based system. . But maybe the question can be better asked - is/would there be any benefit to even going down that true servo based type of system from a extruded aluminum frame point of view for the size machines we are talking about in wood/aluminum.

perhaps maybe its only beneficial for larger machines or working in steel type of thing which something like the avid isnt well suited for. Or perhaps its really beneficial in a haas type of vmc machine..

It certainly wouldnt be anywhere required for anything that I work on. The question is a) is there /any/ benefit from the machines we are talking about (or even for a camaster) - and what benefit is there from a hybrid servo with encoder feedback within the unit vs a true encoder feedback to an oak machine.

[Jim Becker]

From the standpoint of "tinkering", I think I'd like to have the more advanced setup including servos for sure if I were doing more than incidental non-ferrous metal work or a lot of really fine 3D machining. Servos were not an option when I was buying my Stinger II but me being me, I probably would have opted for that had it been an option. LOL

[Gary Campbell]

Hey Gary. Thanks for the clarification. And yes - I get the fact that everyone wants to claim something more swanky than it really is. And thank you for the detailed response.

Question - is their any real benefit to having encoder feedback back to say the oak controller over just the driver with an acorn setup for any sub 50k system. Like say any moderate sized avid cnc system ? Is it totally overkill to say go to an oak system with delta/yaskawa servos and drives on such a system ? Because a teknic clear path servos already gain you smoothness and speed and presumably accuracy over the stepper motors even though it’s still using step/direction vs direct to servo drive commands.

Not really, unless you just want to tinker with parts that cost 4 times as much. And then there is the issue of structural flex. If we are talking about an extrusion machine here, they are not machined for linear rail placement, they will flex more than machined steel in both the length of the member and (especially) at the connections. From an accuracy standpoint, you will be limited by what the frame can deliver. Lets be honest, the extrusion kits are less money than fully assembled "branded" machines, that why they are popular.

That said, most non-commercial users will not have the need for tight tolerances and high thruput and they are served well by the lighter extrusion products. But they still "are what they are". Built to fit a price class. And they do it well.

Ol fat guy wisdom: Nothing is gained by putting a BMW motor in a Pinto.

[Ed Fang]

Ol fat guy wisdom: Nothing is gained by putting a BMW motor in a Pinto.

Ol but Gary - we do that all the time!!! Look at the old vintage cars that have big block engines retrofitted. And you can’t say the chassis, suspension, tires can handle it but we do it anyway. And look at the Subaru wRX and those civics. Some of those civics will give a Ferrari a run for their money. Lol. But I digress.

Understandable. So the limit of diminishing returns is essentially going hybrid servo mode. Which the acorn would make more than enough sense. Anything beyond would be to just “play” and be an exercise in coolness. Lol

[Gary Campbell]

Ol Understandable. So the limit of diminishing returns is essentially going hybrid servo mode. Which the acorn would make more than enough sense. Anything beyond would be to just “play” and be an exercise in coolness. Lol

Agreed. If you wish to put motors capable of 1/10,000th resolution on a frame capable of holding .003-.005" tolerance to cut a material (wood) that is +/- .010" (at best) to .030" (normal) after cutting, then by all means post videos!

[Dan Richeson]

So one would just buy the frame from avid and go with a Acorn system and that is motors and the software to control them? Sorry I'm very new to this.

[Jim Becker]

So one would just buy the frame from avid and go with a Acorn system and that is motors and the software to control them? Sorry I'm very new to this.

Yes, actually...the machine, base, spindle, etc. from AVID and the motion and control from a Centroid provider like Gary's organization. You'll want to check with the latter for the specifics of what you need from each side so you don't buy things you don't need or in duplicate.

[richard newman]

As a musical instrument maker, I'm much more concerned with accuracy and precision than with beefy cuts and thru-put. And reliability, as sometimes I'm cutting on a part that already has many hours into it and expensive if not irreplaceable materials. Losing a step could be disastrous in such a situation. I've gotten by with a little old Techno Davinci machine ,by just never challenging the steppers, and so far so good, but I'd really welcome some sort of "closed loop" solution. I suspect the ClearPath servos running on Acorn would be an excellent choice, and if I ever upgrade to a larger machine that would be a prime candidate.

[Jim Becker]

You also have the option of a more custom, "right sized" machine for your production work, Richard. Gary did a number of those for folks since I've been acquainted with him. Beefy, accurate, yet small and to the point. It's not the size of the machine that matters as much as the work performance expected.

[richard newman]

Yes Jim, one of those 24" x 36" machines that Gary made could have been ideal for me. Unfortunately I wasn't in a position to make that sort of investment. The cnc is a very small part of my operation, just use it for inlay work and slotting fingerboards. But I never want to cut or inlay pearl by hand again, so it's indispensable!

[Jim Becker]

Yes, wonderful for inlay and fret slots for sure...I'm VERY thankful for that capability even in my amature guitar building!

[Gary Campbell]

So one would just buy the frame from avid and go with a Acorn system and that is motors and the software to control them? Sorry I'm very new to this.

There are 2 answers to this question.
One: Being very new (your words) you can benefit from both the complete package, i.e., all parts provided with few questions to answer and from the one stop shopping that AVID can provide. The OEMs have new user built into the price
Two: If you have been using a machine for some time and know which areas you would like to improve with your build then a 3rd party specialty provider like myself can offer custom options that the OEMs do not.

For example: about 40% of our AVID customers want Centroid control. Another 40% want closed loop. The last 20% are a mixed bag of both and ClearPath servos and/or a special purpose feature. Most of these are 2nd or 3rd machine purchasers with specific requirements.

The OEMs are setup to offer certain options at a given price point. Along with "stock equivalent" replacement controllers, we can offer custom options beyond what the OEMs can provide.

[vince mastrosimone]

I did not intend to get involved with this topic, but......

Gary, My understanding of a controller is that it interprets the CAM instructions for the CNC machine. What are the features and advantages of the various controllers your rep?

[Gary Campbell]

Vince...
Good question, but the complete answer would be longer than I care to type. Todays industrial controllers have virtually all the features, but the real magic is in how the processing takes place. PC controllers from yesteryear used the PC to generate pulses to drive stepper drives. Worked pretty good in the DOS days, but with each version of Windows becoming slower and more polluted, proper timing and thruput became more difficult.

Centroid has developed an 8 axis controller that mounts in the control box, on the IO board, that handles the vast majority of CNC tasks and saves the Windows PC for user interface. This allows CNC commands to operate in near real time and at much greater speeds than a PC can provide. For example, most PC generated pulses are in the 30k/sec (SB), 60k/sec (Mach) 75-85k/sec(linux & others) (all sub 100k/sec pulse rate) and Centroid's can produce 400k/sec, even close to a million with proper drives and cabling.

They (Centroid) have made this controller available to the DIY and small CNC market (2017) in 4 and 6 axis products and have been adding support for user requested features ever since. I've been building control systems with them since early 2018. It is likely that the features that impress me the most wouldn't even be on an end-user's wish list, but 2000 line look ahead makes a machine run very smooth. Smoother and more accurate than most guys running PC control are used to and they notice it right away.

[vince mastrosimone]

Wow, Gary, I do not realize the high level of operation for an industrial machine. Not much in common with my $500 Ortur. Thanks for the response Gary.

[Dan Richeson]

Thank you very much for the replies. I will be getting ready here soon to get a machine on order.