Inventables was out of NEMA 23 140oz stepper motors so I went to another source and after placing my order they came back and said they were sold out also. Apparently the 140 oz is going like hotcakes now. I really hope that means Zach and the team are selling a lot of X-Carves! So, now to my issue- the 156 oz motor is supposed to replace my z-drive (possibly). First of all my z-axis continues to get very hot without any movement. It actually seems to cool off during a carve. So my thought was to order both the gshielf and the stepper motor. I have them both now and am going to start with the stepper motor replacement. So the issue…the new stepper motor has way too many wires for me to simply copy what the 140 oz set up was. ANY help would be great- thank you. V/R J.R.
I think you to follow these directions
http://digital.ni.com/public.nsf/allkb/C4A024DA9F197E6286257BC8005DC236
So to touch on a few things in your post… The stepper gets hot sitting still since it is using all the power to hold stedy in one position. Stepper often use more power to sit still in one spot then they do while carving which is why you see it getting hot while sitting and being cooler while carving. There are a few things you can do to fix that. But sticking with the stock shield limits your options on that front. Things like a TinyG will reduce the heating or a controller that allows you to use DSP drivers from Leadshine will fix that issue right away.
How many wires does your motor have? 6 or 8? You can still wire them up just fine, but you have some choices to make in how you do it. It is easiest if you have a simple multi meter to test the coils with. This should help you out a bit. It shows how to hook them up with 4, 6 or 8 wires. Even though it is for a leadshine DSP drive, it is still the A+, A-, B+, B- connectors on both drivers.
How long is your motor? Fitting tot he Z Axis might not work if it is too long as it is a narrow space as I am sure you have seen.
Thank you again for the feedback. If I read the details right- I can use this motor in bipolar parallel for the 8 wires reduced to 4.
156 oz In. Hybrid Motor
1.8° /200 Steps Per Rev.
3.4 Amps Current Per Phase ( Bipolar Parallel)
8-wire Bi-polar or unipolar, NEMA 23 Frame - See more at: http://www.automationtechnologiesinc.com/products-page/stepper-motors/nema-23-bipolar-stepper-motor-156-oz-in-¼”-dual-shaft-with-a-flat#sthash.O7ouIZii.dpuf
KL23H251-24-8B.pdf (160.0 KB)
I just picked up 3 of these to replace the buggy stock motor I had. http://www.automationtechnologiesinc.com/products-page/stepper-motors/nema23-185ozin-3a-stepper-motor-¼”-dual-shaft-kl23h256-21-8b-duplicate 4 wire and compact with an increase in holding power. So far I like that very much. They play well with the Planet CNC mk3 and Leadshine DSP drivers. not heating at all while standing still (which is due to the DSP drivers.)
With the “stock” Arduino/gShield, you can change the “step idle delay” to something other than 255 to keep the motors from being powered all the time. In grbl 0.9, $1=25 (step idle delay, msec) will remove power after 25 ms, for instance.
powering down your motors is not good if you are doing milling where you need to hold zero while doing a tool change. I have had little success “homing” the mill after a tool change if the zero is ever lost. My motors stay powered until my whole job is finished. With a DSP driver it is not an issue for me. Most of my jobs are milled in aluminum and need a number of tool changes. So for me powering down the motors at all is just not an option.
Jeremy,
I think you are reading things right, at least that is the way that I would do things. The standard color codes given in the inventables instructions won’t match the colors of your wires. Effectively you are going to want to get the motor wires for one phase (i.e. blue and green) to pins 1 and 2 on the g-shield, and the other phase to pins 3 and 4. For the Y axis, you need to criss cross wires from one of the phases between motors.
If you find that the machine is running backwards, simply switch two wires from one phase, either at the motor, or at the g shield.
I had to work out my 6 wire motors with no schematic so you should have an easier time with things having the information in front of you.
–Rick
3.4 Amps Current Per Phase ( Bipolar Parallel)
If you are using the gShield you cannot run these motors at full torque. The gShield stepper drivers are rated at 2.5 amps per phase, but that’s in the lab. Without active cooling you can’t run them at 2.5 amps.
It will not hurt these motors to run them with less current, you just will not get the rated torque out of them.
Check the spec sheet of your motor, odds are it is well within normal operating temperature.
Generally it is not the motor getting too hot that you have to worry about but the drive chip.
(FYI I did a test and was not able to make my chip overheat at max current as long as the cooling fan was on)
To put it in perspective my 3d printer steppers run at around 45c that is 110 F!
So hot to the touch is ok. Too hot to touch, then you might have an issue.