Help Understanding Smoothing

All things related to the Centroid Acorn CNC Controller

Moderator: cnckeith

corbin
Posts: 51
Joined: Fri Nov 08, 2024 2:57 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 3484E42757Cd-1018248693
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Help Understanding Smoothing

Post by corbin »

suntravel wrote: Wed Dec 11, 2024 4:23 pm 0 buck first try is to set up 4000 steps/rev

Better bet is a good quality 5:1 gearbox and servos with differential line drivers instead of steppers,

or servos without gearbox set to >8000 steps and differential line drivers to make use of the high step rates Acorn can put out.
I'd definitely like servos, but I can't justify the cost -- maybe some day!

I'll play around with 4000 steps/rev and see how it helps. I think my vector lengths are still larger than the current resolution (0.0004).

Maybe I should change that setting in Vectric to be .001; probably no reason I should be using 0.0004.

I definitely have a few things to try, so I appreciate the help! Currently it is all running pretty smooth at 15-20 IPM for face grain.

Corbin


ShawnM
Posts: 2651
Joined: Fri May 24, 2019 8:34 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 7804734C6498-0401191832
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Clearwater, FL

Re: Help Understanding Smoothing

Post by ShawnM »

You are nearly 1:1 and that'll never cut good as a router. As Uwe stated, you need to add some gearboxes to your setup. Or if you have a gear/belt reduction now change it. You also have your steps per rev for the X and Y axis exactly the same and there's no way they are EXACTLY the same but that's a discussion for another time. If you want your router to cut smoothly add some gear reduction.

https://centroidcncforum.com/viewtopic. ... pot#p75374


corbin
Posts: 51
Joined: Fri Nov 08, 2024 2:57 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 3484E42757Cd-1018248693
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Help Understanding Smoothing

Post by corbin »

ShawnM wrote: Wed Dec 11, 2024 6:46 pm You are nearly 1:1 and that'll never cut good as a router. As Uwe stated, you need to add some gearboxes to your setup. Or if you have a gear/belt reduction now change it. You also have your steps per rev for the X and Y axis exactly the same and there's no way they are EXACTLY the same but that's a discussion for another time. If you want your router to cut smoothly add some gear reduction.

https://centroidcncforum.com/viewtopic. ... pot#p75374
I mentioned earlier, but this is a stock Avid CNC machine; it uses a gear/belt design. I could probably reduce the ratio, but think I'd need to do the opposite, which isn't possible, as space is limited. For reference, here's the exact gearing (photos and specs):

https://www.avidcnc.com/pro-rack-and-pi ... -1388.html

Maybe a smaller pinion gear would do it...

They do have thousands of these machines out in the world -- maybe the all have a fundamental flaw!

I've measured my steps on the X/Y; seems fairly accurate. I can cut a square dead on to size within my 6" caliper's measuring ability.

Corbin


avp
Posts: 153
Joined: Fri Aug 13, 2021 12:25 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: E062346A1C67-0716214939
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: New York

Re: Help Understanding Smoothing

Post by avp »

I know those drives plates well, I had them on my machine until I went with helical rack and pinion and gearboxes with servos. I ran those nema 34 steppers for over 10 years. Switched to Centroid about 2017 and sill ran the steppers until 2022. I did have good performance with them with smoothing on for many years. The servos with gearboxes are a different animal though.


corbin
Posts: 51
Joined: Fri Nov 08, 2024 2:57 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 3484E42757Cd-1018248693
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Help Understanding Smoothing

Post by corbin »

avp wrote: Wed Dec 11, 2024 8:44 pm I know those drives plates well, I had them on my machine until I went with helical rack and pinion and gearboxes with servos. I ran those nema 34 steppers for over 10 years. Switched to Centroid about 2017 and sill ran the steppers until 2022. I did have good performance with them with smoothing on for many years. The servos with gearboxes are a different animal though.
Awesome! What gearboxes/servos are you going with? Maybe I should consider this option.

Thanks,
Corbin


cnckeith
Posts: 8235
Joined: Wed Mar 03, 2010 4:23 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
CNC Control System Serial Number: none
DC3IOB: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Help Understanding Smoothing

Post by cnckeith »

corbin wrote: Wed Dec 11, 2024 8:03 pm
ShawnM wrote: Wed Dec 11, 2024 6:46 pm You are nearly 1:1 and that'll never cut good as a router. As Uwe stated, you need to add some gearboxes to your setup. Or if you have a gear/belt reduction now change it. You also have your steps per rev for the X and Y axis exactly the same and there's no way they are EXACTLY the same but that's a discussion for another time. If you want your router to cut smoothly add some gear reduction.

https://centroidcncforum.com/viewtopic. ... pot#p75374
I mentioned earlier, but this is a stock Avid CNC machine; it uses a gear/belt design. I could probably reduce the ratio, but think I'd need to do the opposite, which isn't possible, as space is limited. For reference, here's the exact gearing (photos and specs):

https://www.avidcnc.com/pro-rack-and-pi ... -1388.html

Maybe a smaller pinion gear would do it...

They do have thousands of these machines out in the world -- maybe the all have a fundamental flaw!

I've measured my steps on the X/Y; seems fairly accurate. I can cut a square dead on to size within my 6" caliper's measuring ability.

Corbin
not a flaw, they picked a ratio that works for a wide variety of diy cnc router applications.
you can always build a machine to optimize it for a particular application of course.
see my write up on this subject here.
see https://centroidcncforum.com/viewtopic.php?f=63&t=8649
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html


cnckeith
Posts: 8235
Joined: Wed Mar 03, 2010 4:23 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
CNC Control System Serial Number: none
DC3IOB: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Help Understanding Smoothing

Post by cnckeith »

do you have a photo album of the machine?
what make model axis motor drives are being used?
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html


corbin
Posts: 51
Joined: Fri Nov 08, 2024 2:57 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 3484E42757Cd-1018248693
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Help Understanding Smoothing

Post by corbin »

cnckeith wrote: Thu Dec 12, 2024 2:29 pm do you have a photo album of the machine?
what make model axis motor drives are being used?
Sorry for the slow reply, I was on vacation a bit!

They use OEMOTOR 85YGH100B-04 Nema 34 motors all around, specifications: https://www.avidcnc.com/cdata/cad/specs ... _sheet.pdf

For photos, it looks just like any other Avid CNC 4x4 with Nema 34 motors, albeit I have an ATC HITECO spindle and my own table, which can be seen on their website:
https://www.avidcnc.com/pro4896-4-x-8-c ... -1337.html

But the important bit is their rack and pinion drive set, seen here with the ratios they use:

https://www.avidcnc.com/pro-rack-and-pi ... -1388.html

I think, at this point, I am not going to mess with changing the gearing at all, but it is something I'll consider in the future.

Thank you!

Corbin


Post Reply