Centroid CNC4

More
22 Jun 2011 11:26 #10760 by BigJohnT
Replied by BigJohnT on topic Re:Centroid CNC4
Would the existing steppers need greater capacity of say a Gecko 203V drive at 80v 7a? Or am I missing some huge chunk of the puzzle?

John

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 14:09 - 22 Jun 2011 14:17 #10766 by forhire
Replied by forhire on topic Re:Centroid CNC4
BigJohnT wrote:

Would the existing steppers need greater capacity of say a Gecko 203V drive at 80v 7a? Or am I missing some huge chunk of the puzzle?


Good question and I'm not sure. The manual page for the Centroid MAE 1350 (M.A.E. HY200-4270-710 A8) simply lists the holding amps as 7.1 unipolar and 10 amps bipolar. The drives appear to be in a bipolar configuration. I'm not entirely sure what I really need. I believe the Gecko would drive the stepper and I really doubt it would need 10 amps in my application as I believe these steppers to be over sized. It's possible my manual has the power supply specs someplace. Does Gecko have anything larger than 7 amps?

Here is a link to the spec sheet, the stepper is listed on page 22:
www.sodimatel.fr/image_base/Img_1637.pdf
Last edit: 22 Jun 2011 14:17 by forhire.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 16:23 - 22 Jun 2011 16:37 #10776 by forhire
Replied by forhire on topic Re:Centroid CNC4
The Centroid manual states the control is rated for 50V 8 amps / phase.

From the manual:
"Drive Type: Open loop or closed loop 50 VDC bi-polar micro-stepping
chopper-drives, 8 amps/phase max, 8 micro steps per full step. (1600
microsteps per revolution at a 1.8 degree stepping motor)"

So if the G203V will do 80V 7A... that's 560 watts vs the 400 watts delivered by the Centroid. The Gecko is 40% more powerful. I think the G203V drivers would work dandy.

Am I looking at this correctly?

Bonus is I'd pick up 400 more micro steps also :)

UPDATE: Wouldn't the G213V be better than the G203V because it support micro stepping?
Last edit: 22 Jun 2011 16:37 by forhire.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 16:53 #10778 by andypugh
Replied by andypugh on topic Re:Centroid CNC4
forhire wrote:

"Drive Type: Open loop or closed loop 50 VDC bi-polar micro-stepping

So if the G203V will do 80V 7A... that's 560 watts vs the 400 watts delivered by the Centroid. The Gecko is 40% more powerful. I think the G203V drivers would work dandy.

Am I looking at this correctly?


Not really as steppers don't really work that way. However, going from 50V to 80V will give you a lot more speed. (or, more accurately, the same torque at higher speed)

Wouldn't the G213V be better than the G203V because it support micro stepping?

I am not a huge fan of high microsteps. 4x is about as high as I see any point going.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 17:25 - 22 Jun 2011 17:28 #10780 by forhire
Replied by forhire on topic Re:Centroid CNC4
andypugh wrote:

Not really as steppers don't really work that way. However, going from 50V to 80V will give you a lot more speed. (or, more accurately, the same torque at higher speed)


I'm really trying to find out if the driver is sized appropriately for these steppers. Additional speed would be great :)

Wouldn't the G213V be better than the G203V because it supports micro stepping?
I am not a huge fan of high microsteps. 4x is about as high as I see any point going.


I'll have to dig through the manual and the settings and see if I the current control is using micro stepping. I suspect it is using the 8 micro steps as specified. I'd be inclined to duplicate that unless there is a really compelling reason not to. My understanding is that micro stepping is smoother than full steps at the expense of speed and torque.
Last edit: 22 Jun 2011 17:28 by forhire.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 17:50 #10782 by andypugh
Replied by andypugh on topic Re:Centroid CNC4
forhire wrote:

I'll have to dig through the manual and the settings and see if I the current control is using micro stepping. I suspect it is using the 8 micro steps as specified. I'd be inclined to duplicate that unless there is a really compelling reason not to. My understanding is that micro stepping is smoother than full steps at the expense of speed and torque.


Yes. You also lose some positional repeatability. (you get more positions, but they are less well defined).
The thing to do is to experiment, changing microsteps is easy.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 19:19 #10785 by BigJohnT
Replied by BigJohnT on topic Re:Centroid CNC4
As for microstepping the G203v is the best of both worlds. It starts out sending 10 microsteps to the stepper motor and morphs to single step. There is a pot to control when the morphing happens so you get a smooth stepper at all possible speeds. The step input is at 10 microsteps all the time.

There is a page on the wiki that has stepper formulas to help figuring voltage and such.

John

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 20:33 #10788 by tpwjayson
Replied by tpwjayson on topic Re:Centroid CNC4
Forhire, I have a computer to use for the terminal, it runs windows now but was considering switching to linux because it seems there is more peer support for linux. My CNC4 works just fine as far as I can tell but I have yet had time to really try it out, I just got the machine about 2 weeks ago. I have the manual and cencomm software but would like to use a more modern program to control it. I would really like a program that graphically shows changes to the gcode as I program.

As far as how my motor is mounted, my setup is completely different than yours because I have a bridgeport that has a BOSS knee on it. So the motors are mounted in the same configuration as the original ones. I have however seen machines set up the way you would like to change yours to. Seems a little weird that the motor is mounted in the back like that.

Please Log in or Create an account to join the conversation.

More
22 Jun 2011 20:35 #10789 by tpwjayson
Replied by tpwjayson on topic Re:Centroid CNC4
So what hardware exactly should I look at to upgrade? I searched a bit but dont really know what I am looking at.

Please Log in or Create an account to join the conversation.

More
23 Jun 2011 00:51 - 23 Jun 2011 00:51 #10793 by forhire
Replied by forhire on topic Re:Centroid CNC4
tpwjayson wrote:

Forhire, I have a computer to use for the terminal, it runs windows now but was considering switching to linux because it seems there is more peer support for linux. My CNC4 works just fine as far as I can tell but I have yet had time to really try it out, I just got the machine about 2 weeks ago. I have the manual and cencomm software but would like to use a more modern program to control it. I would really like a program that graphically shows changes to the gcode as I program.


I have never used the cencomm software. On Windows you can use HyperTerminal which is bundled with many versions of the OS. Generally it is found under Accessories, Communications. I know ProComm supports all the features to drip feed the control. Normally the g-code is generated by your CAM software or you write it by hand. The cnc4 control is a great control to learn basic g-code, especially if you have the manual.

You should look at NCPlot ( www.ncplot.com/ ), it is inexpensive, is a handy editor and has a graphical viewer. It also supports DNC so you can send files to the controller. I don't know if it works with the cnc4 as I haven't tried it. I frequently use this to verify code before sending it to the control.

As far as how my motor is mounted, my setup is completely different than yours because I have a bridgeport that has a BOSS knee on it. So the motors are mounted in the same configuration as the original ones.


The BOSS was designed for CNC from the beginning. I assume you have something like a Boss 3? Your using the factory steppers?

I have however seen machines set up the way you would like to change yours to. Seems a little weird that the motor is mounted in the back like that.


Yeah, I have whacked the encoder a time or two. I tore it apart today, drilled a few holes, flipped it around. I gained 6 inches of travel and I will never hit the stepper/encoder again. I should have done this years ago :laugh:
Attachments:
Last edit: 23 Jun 2011 00:51 by forhire.

Please Log in or Create an account to join the conversation.

Time to create page: 0.203 seconds
Powered by Kunena Forum