As I embark on initially calibrating my printer I imagine that the gearing associated with the stepper motors is going to cause some problems both with determining whether the stepper motors can supply enough torque and how to modify the standard PrintrBoard firmware to accommodate all this gearing. Why so much gearing? Well the only reason is that this is the gearing that comes directly from the large format scanner that I used to create the X and Y -axis for this printer. The X-axis has uses the same stepper motor that came with the old scanner, the Y-axis stepper motor I upgraded to a new NEMA 17 66oz-in stepper motor.
This setup will have a lot of backlash and will be very hard to print anything . The gearing is because the scanners usually have motors with low resolution ,so to get sufficiant resolution they are geared.
It was something I was worried about especially with the gears being plastic. There is significant play in them. This combined with the significant lever arm on the z-axis makes this a difficult application. You have motivated me to make a command decision. I either have to modify my design to eliminate the gearing completely or scavenge all the parts purchased for this and incorporate them into a established printer configuration. The second one is probably the most reasonable as the only losses in that case are some wood, hardware, $60 for the original non-working scanner and of course pride. Excellent comment thanks again.
Just get nema 17 motors and be done with it. These motors are not worth the effort
I support @ekaggrat_singh_kalsi , this kind of gear is an accident waiting to happen. Keep the build as simple as possible.
If the backlash is consistent and equal on X and Y could increasing Jerk setting compensate? Just an idea. Is there wobble on the Z rail in the X direction?
@Daniel_Kruger Jerk is not for compensating for backlash, it is how fast the axis can change speed without the need of acceleration.
Wow, I guess I came to the right place for suggestions! You have forced me to reevaluate my project, mainly due to the gearing issue inherited from the large format printer upon which this was based. You are correct in that all the stepper motors except for the one on the x-axis are new NEMA 17 motors. The one of the x-axis is a much smaller from the original scanner that I left due simply to the physical constraints of the build. I have always been worried this would not have enough torque. As I see it now I have two options. First, I can reconfigure the x and y- axis to eliminate the gearing completely and connect the stepper motor shafts directly to the drive belts. This can be done, but it would take some extensive physical modifications especially for the x-axis. If I did this I would have to most definitely change out the x-axis stepper motor to a new NEMA 17 one. Even with this I still have the “wobble” issue on the z-axis. The other option would be to abandon this configuration and incorporate the new stepper motors, PrintrBoard, hot bead, extruder, hot end, and power supply into a more traditional design. The second option is what I am leaning towards at this time. I can always use the resulting 2x4s and mounting hardware on some other less technical project like fixing my fence in the backyard!
You may be able to use a couple of those rods and bearings if you designed your own smartrap corexy. I could do the prints for you. I think you have some carma points to cash in.