Hi all, I built a Bluumax router that came with a c-10 board and some pretty weak steppers. I just expanded the table to 2x4 feet and want to get some more speed and reliability. I run a smoothstepper into the C-10 and then to some small motor drivers.
For more speed and torque with rapids, Should I ditch the C-10? Can I just upgrade the drivers? What is the best option for getting at least 200oz of torque in a Nema 23 profile?
A stepper motor is rated at its holding torque, ie. the torque it provides when it's not rotating. Once it starts rotating the torque remains at or close to the holding torque through a small range of rpm. After that it begins to diminish. If you want 200 oz-in of torque at high speeds then you really need to look at the torque curves for steppers with higher holding torques than 200 oz-in in order to find torque values and rpms that match your requirements. I don't know anything about the C-10 driver. I would recommend that you read the information that is available on the GeckoDrive site regarding steppers. Also check out the G540 driver for a comparison with the C-10. Higher voltages used with chopper drives increase acceleration and speed (up to point). The Gecko site explains this in detail also.Originally Posted by geostomp
Chris
Thanks for the reply! I went and read the gecko page and also did some more hunting aroud for prematched systems that incorporated the c-10. I saw a web site that was selling 425oz steppers driven by 5040 drivers. So this would be an option although a bit expensive for an upgrade.....ie buying new steppers AND drivers.
I also ran across some 150oz steppers rated at 1.5 amp per phase in series. With my drivers rated at 1 amp per phase and 2.5 max, do you think I could run the 1.5 amp steppers as long as I didn't load them up too much??
I understand that if they run free they draw less, and under load or stall they draw lots of amps.
Thanks for the reply! I went and read the gecko page and also did some more hunting aroud for prematched systems that incorporated the c-10. I saw a web site that was selling 425oz steppers driven by 5040 drivers. So this would be an option although a bit expensive for an upgrade.....ie buying new steppers AND drivers.
I also ran across some 150oz steppers rated at 1.5 amp per phase in series. With my drivers rated at 1 amp per phase and 2.5 max, do you think I could run the 1.5 amp steppers as long as I didn't load them up too much??
I understand that if they run free they draw less, and under load or stall they draw lots of amps.
I took a look at the Bluumax site. That seems like a very lightly built machine. You definitely don't need 425 oz-in steppers. Xylotex has a 3-axis kit with 269 oz-in steppers that might be appropriate. I hadn't heard of the 5040 drive until you mentioned it. You also need to consider the pitch of the lead screws on that machine when looking at feed speed. Do you know what the screw pitch is? Using a screw that gives you a lead of 1/4"-1/2" per revolution will help with feed speed while keeping the steppers operating in there low rpm high torque range. I don't think that the C-10 is adversely affecting performance. Having said that I don't use a BOB on my machine. I feed the output of a SmoothStepper directly into Gecko 201 drives. My own philosophy has been to purchase high quality drives and consider them an investment. You have the option then to build a variety of machines around them without ever having to reinvest. In other words a key to trouble free 'cnc'ing is to get the control signals out of the computer and into the motors with the highest reliability and adjustability. If the drive electronics are sub-par then you're always playing 'catch up' and working in a semi-frustrated mode. It's also important to match motors and drives. Anyone selling drives should be able to tell you what the motor characteristics should be to get the best performance from their drives.
Chris
The interface board C10 by CNC4PC is just an interface board to your computer and should be retained. To get more speed you will need to upgrade IMHO do this in stages:- FIRST upgrade the driver. SECOND upgrade the PSU to suit the new driver. THIRD consider new stepper motors but do look at the torque curves against stepping speed. You also need to consider the rigidity and wear on the lead screws when stretching a design.
NOTE that the stepper motor current is not related to the mechanical load on the motors shaft but is a function of the resistance of the motor winding and the current limit set by the driver electronics. The voltage is determined by the electronics capability of the driver and MUST never be exceeded - the current is controlled by pulsing the drive on and off - assuming this is a pulse width modulated driver OR is set by a series current limiting resistor. So upgrading the driver to a GECKO or a Leadshine should be your first step.
Regards - Pat
Last edited by wildwestpat; 04-26-2012 at 06:17 AM. Reason: NOTE added
Your steppers, drives, power supply and leadscrews all need to work together as a matched set for best performance. A motor that works great on one machine may work terrible on another.
You need to provide more information about your machine, and what type of performance you're looking for.
Gerry
Mach3 2010 Screenset
http://home.comcast.net/~cncwoodworker/2010.html
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
I hadn't thought of upgrading the pitch of the screws. I actually just recieved some longer 3/8-12 acme screw stock and installed it on the router.
Though I plan to cut a new gantry for 5" Z travel and ad an additional bearing under the table that runs on a rail to keep the Y axis from coming off its linear rail. Xand Y
are now 21.5"x40" work area.
Also, I plan to cut foam to be used as a plug in mold making. Also, I may cut some corian or tooling board and mill the mold itself with no plug.
In addition, I am currently completing a certificate in Numerical Control at my local community college.
Currently, I can cut at 30ipm at about an inch depth with a 1/4" endmill. The small foam jet shown took about 5 hours to cut with a parallel finish cut at .05 stepover. I would like to take advantage of the size of my table ,with a newly built gantry and rigidity, and cut a project at 100-300ipm. I roll this thing outside and I need to complete projects in a few hours. It would be nice to be able to cut mdf also.
Last edited by geostomp; 04-26-2012 at 10:09 AM.
Shelby township huh? I'm in Ypsilanti. We're neighbors!
I would suggest trying 3/8"-8 two start (gives 1/4" lead per rev.) or 3/8"-8 four start (gives 1/2" lead per rev.) acme rod and use anti-backlash nuts from dumpstercnc.com. I think ger21 has used the xylotex board and might be able to comment on that. Cutting at 30ipm is quite slow for foam and wood. You'll be impressed with what you'll be able to do if you can get your feed speeds up into that 100-300ipm range. At a minimum it seems like you'll need the higher pitch screws and better drives.
Chris
Yes, I have a Xylotex and 250oz motors, and can cut at up to 190ipm. I'd recommend going with the G540 instead. it's not much more money, and can provide double the performance. But you really need screws with 2-4 turns per inch to take advantage of new motors and drives.
Changing the screws would be my first change.
Gerry
Mach3 2010 Screenset
http://home.comcast.net/~cncwoodworker/2010.html
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
I gotta wonder if my 40oz in stepper would even turn with a 1/2" or thread per turn. Looks like at some point I will move in the direction of the 540.
These are the kits I was considering modeling my system after as I already have some of the parts. Gotta wonder if the 540 would be better.
NEMA 23 CNC Router Stepper Motor kit
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