So, I was thinking about trying to replace teh z stepper my self, or maybe finding someone who could for cheaper, but looking back at my email they said “the Z-axis motor cannot be replaced without recalibrating the printer” so is me trying to do it myself a waste of time? or is recalibrating the printer not a big deal?
Where is the zero reference on the Form 1+? If it’s at the top, I don’t see why you need to recalibrate, unless you need to disassemble it. The stepper motor is most likely an open loop system, so it will not store it’s absolute location either.
It looks like a fairly standard stepper. If you measure the the dimensions and mounting hole distance, you’ll probably be able to find a matching one.
The Home position is at the top. Unless I missed an encoder somewhere, it is an open loop system. If it was a closed loop system, the printer would have known the printer didn’t move and would have thrown an error. I find it hard to believe that the printer needs to be recalibrated when a new stepper is installed, but what do I know.
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Now taking the above with a grain (or two) of salt, I do not know how much of the printer needs to be taken apart to replace the motor. I do not know how the Z screw attaches to the stepper. It shouldn’t matter but while I can make assumptions, I am guessing. My printer is out for repair and I can’t look at the connections.
Is it worth taking an already broken printer apart to try, that is your call. While the motor is most likely around $20.- (again, no printer so I can’t look for a part number on mine) FL shouldn’t charge you more then the already quoted amount for the repair, unless you send it to them in pieces or have cut off the connectors, etc.
For me, I might try replacing the motor. But, I have the connectors and crimpers to make up the proper ends. I have the tools to see if the Z axis is dropping to the same height before and after I attempt the repair. I also know that if I really messed up, I would have to pay.
For most, the best option is to send it in for repair and not worry about messing anything up. That way, the printer gets the proper once over, it is returned repaired. You get back printing without having to find someone able and willing to take your rather expensive investment apart.
Even with knowledge and tools, the best ones to service these printers is FL. As I have stated above, my printer is at repair. There is a reason I sent it to them. They are qualified to perform the repair and the best ones to do it regardless of what is wrong with it.
I’m temporarily unlisting this thread. I’m getting a file download prompt upon opening the thread and I want to make sure someone from our software team takes a look at it.
Update: It looks like a Google Drive link gone rogue was triggering a script which caused a file to automatically download. We don’t expect that the file was malicious, but we’ve removed the link and let us know if you’re seeing an automatic download upon opening this thread.
Frew, I had noticed unexpected files downloaded in my browser. Usually they were STL so I assumed they’d come from the forum but I think I saw at least one download with a non-descript file type, too. None (that I noticed anyway) were anything my Windows system recognized as an executable payload.
As for the Stepper, I suspect DavidR is right. Stepper motors are open-loop rotary positioners. They’re assumed to have stepped if they’ve been told to step. When overloaded so they can’t step, the controller has no way of knowing. Systems that use steppers have to re-calibrate “home” each time they’re used in order to ensure the home position doesn’t drift over time due to accumulated errors from past missed steps. In most cases a stepper-motor drive axis will have at least one “limit switch” to tell the controller that the stepper is in the home position (some have a second sensor at the other end of the axis so you don’t “overdrive” the axis).
For the Form printer, setting home with a limit switch at the top of the screw would make the most sense. Every printer is calibrated at the factory, so the printer knows how many steps from platform full-up to platform in the right “zero” location for the first layer. But it can never know exactly where the bottom of the resin tank is, there are too many mechanical variations from printer to printer and tray to tray and build platform to build platform. That’s why there’s a z-height adjust in the fine tuning.
I would bet someone from FL will ultimately confirm this. But my expectation (and I have stepper motors in a lot of machines besides the FL printer) is that provided you replace the existing motor with one of at least equal torque (but not a lot more) and the same step resolution, all you need to do is swap it and the printer will take care of the rest…