Centroid CNC Plasma Manual error? <old manual, download latest here>

[bertieboy]

Centroid CNC Plasma Manual error? Looking Back I now know why I was confused. Also a question. This sweet spot area of a motors performance, its gearing to put its usable rpm, much like a car, in the speeds of our requirements etc...readable in that chart.
Now they word it ....."more is better" the wrong way around but they clearly say 1 to 2 inches of travel per 1 turn of motor shaft. My machine does that straight on the rack, just under 2 inches per 1 shaft spin. So I dont need gearboxes. I was under the impression 1 inch per 1 shaft motor revolution? max.....but my machine was accurate before i upgraded to acorn. And my other question is Ive upgraded from the nema 23 57HS76 260 oz in....to the nema 23 424 oz in. So having a bigger motor should handle the low down speeds easier with no stalling etc. The old motors never stalled and were accurate, I just wanted closed loop and get rid of grbl and got acorn.heres some pics. The gear is really small so thats why my gearing is ok.

[Joey]

This was an error in the manual that went under the radar.

The highlighted blue sentence is the correct one.

The highlight red sentence should read.

1-2.5 revolutions of the motor per 1 inch of travel

2 inches of travel per 1 rev of the motor is an overall turns ratio of .5 turns/inch

This is not ideal. But tolerable

The Higher the number of turns per inch of travel the better. To an extent of course.

Better resolution means more accuracy and smoother motion.

The goal is to enable the control to command the smallest amount of motion as possible. Having a greater distance of movement per 1 revolution forces the control to make the same gcode move in bigger and bigger jumps instead of being able to break up the move more finely. In the extremes this will result in harsh motion and noticable banging.

But hey it is a CNC Plasma table and most are Okay with the motion they have. Most just don't realize how much nicer there table could be with better resolution.

[bertieboy]

cheers Joey. I thought so! This is why I got confused at the start months back. But totally get it. Resolution is smaller\ hence more accuracy. As stated the gears I have are tiny 11 tooth on the motors, workable as the old motors did, so i will go with that for now as I need it up and running plus gearboxes look heavy as my motors stick out further plus a gearbox might be too heavy a load. Z axis motor is straight up verticle, so weight is ok loading straight down.See how it goes. Thanks for your help again. Im going to start a build log now as ive got nearly all parts, just waiting on new double shielded motor and signal wiring to get delivered. lots of cleaning of linear slides etc. and to finish turning up my round mount too. i will look up build threads on here and where to start it. cheers again

[cnckeith]

Hi! the latest manual can always be downloaded from the website!
your manual is rev40 1-25-23, the latest one is rev50 dated 3-5-24
here is the link.
https://www.centroidcnc.com/centroid_di ... manual.pdf

if you have used this link before always refresh your browser to get the latest PDF.

[cnckeith]

thanks for posting photos, consider putting all your photos in one spot with a google photo album. here is how.



Create a online photo album of your project put a ton of photos of everything you are doing in the album so all photo are in one place. Then you can paste the link to the photo album in any thread and anyone trying to help you will see the whole project at once which will give us a much better idea of what you are working with and therefore give you good advice. each picture is worth 1000 words. This allows all your machine and control photos to be in ONE location and provides a "history" of your machine/project, then you can easily post one link here in the forum and we can see all the photos or just the one you want to show us