@mattling9 said in Need Help with Stepper Motor Data (Completely Off Topic):

Can a NEMA 17 with a 10:1 Gearbox REALLY output more torque than a NEMA 23 with a 3:1 Gearbox if the output speed of the gearbox is fixed at 60RPM???

High speed motors have much greater power density than low speed motors, so your results aren't particularly surprising. When building model airplanes we often have to decide between a heavy direct-drive motor and a lighter geared motor.

For model airplanes the heavy direct drive motor typically wins after considering the weight, cost, efficiency, and complexity of a gearbox. But in your situation both motors would require a gearbox so its not surprising that the Nema17 wins. Just make sure the 10:1 gearbox survive the planned load.

If your goal is simply to prevent static buildup then I would use copper tape to connect the stepper frame to the printer frame. Even an ultra-high impedance connection can bleed a static charge just fine, so you don't need to do anything heavy duty.

To be honest if you crank down the screws hard enough (or use a biting washer on one of the holes for each mate) you will be grounded. The connection doesn't need to be great - they put 1meg resistors in anti-static wristbands. http://www.circuitnet.com/experts/87211.html

If you want a low impedance ground connection then you can slip a ring terminal under one of the mounting screws and run it to either the frame or the grounding bus depending on how concerned about ground loops you are. Note that grounding your steppers like this will make you look absolutely insane to most people.

Think I have see a gcode for arcs. When it's used?

G-Code for arcs are mostly a historical artifact from the days when G-Code programs might be handwritten and controllers only had a few kB of memory.

Modern CAMs will have an option to use circular movements where possible, but the truth is that modern toolpaths just cannot be expressed with arcs. Even if you are cutting prismatic shapes a constant engagement toolpath will be a mix of helixes, spirals, and trochoids, not arcs:

On a modern controller there really isn't any advantage to arcs - memory is plentiful and you have 300+ segment lookahead. When your g-code is going to be 99.99% line segments anyways, why bother using arcs at all?

The Titan has some difficult bearing alignments and sliding fits, and the idler is cantilevered off the stepper shaft. If anything is out of place it will start to skip.

As well, if you apply too much force to the bearings during assembly it will indent the raceways and grind itself to pieces. Its best to locktight that screw and stop tightening as soon as it makes contact with the lid.

The Titan is a very light and compact design when it works, but they got a little too clever.

Larger CNC machines respect acceleration during homing moves, but homing typically involves moving past the home switch (sometimes by a considerable margin) then backing up to the nearest encoder index.

In larger CNC machines switches can never be crushed by over-travel, they activate and allow the axis to pass. Axis travel is typically limited by rubber bumpers. Here's a small linear stage with a representative arrangement:

As the machine gets heavier you need to think of endstops as more of a notification that something is wrong than an actual travel stop. Any fault should de-energize the axis drives, after which inertia will take over and allow the machine to coast (or smash) to a stop as physics dictates.

Homing is expected to overshoot the homing switch (which is not necessarily the limit switch). There is a very detailed overview of how homing and limit switches can be placed and configured starting page 88 here: https://www.parkermotion.com/manuals/Digiplan/ViX-IH_UG_7-03.pdf

That being said, this kind of setup is far more complicated than you want in a hobby 3d printer and rigid z-probes pretty much necessitate an immediate stop.

If your goal is simply to prevent static buildup then I would use copper tape to connect the stepper frame to the printer frame. Even an ultra-high impedance connection can bleed a static charge just fine, so you don't need to do anything heavy duty.

To be honest if you crank down the screws hard enough (or use a biting washer on one of the holes for each mate) you will be grounded. The connection doesn't need to be great - they put 1meg resistors in anti-static wristbands. http://www.circuitnet.com/experts/87211.html

If you want a low impedance ground connection then you can slip a ring terminal under one of the mounting screws and run it to either the frame or the grounding bus depending on how concerned about ground loops you are. Note that grounding your steppers like this will make you look absolutely insane to most people.

Larger CNC machines respect acceleration during homing moves, but homing typically involves moving past the home switch (sometimes by a considerable margin) then backing up to the nearest encoder index.

In larger CNC machines switches can never be crushed by over-travel, they activate and allow the axis to pass. Axis travel is typically limited by rubber bumpers. Here's a small linear stage with a representative arrangement:

As the machine gets heavier you need to think of endstops as more of a notification that something is wrong than an actual travel stop. Any fault should de-energize the axis drives, after which inertia will take over and allow the machine to coast (or smash) to a stop as physics dictates.

Homing is expected to overshoot the homing switch (which is not necessarily the limit switch). There is a very detailed overview of how homing and limit switches can be placed and configured starting page 88 here: https://www.parkermotion.com/manuals/Digiplan/ViX-IH_UG_7-03.pdf

That being said, this kind of setup is far more complicated than you want in a hobby 3d printer and rigid z-probes pretty much necessitate an immediate stop.

You should be looking at acceleration as well as speed. A drawback of screws in a 3d printer is that the screw is attached directly to the motor shaft and therefore needs to be spun up without any mechanical advantage.

Every gram of screw might have the same inertia as 5-10 grams of extruder weight. The exact ratio will vary dramatically but is a function of screw diameter and lead.

I don't use any leveling system at all, I shimmed the bed into alignment by individually adjusting stainless steel spacers with sandpaper, and it has never moved since.

This system is the heaviest (and maybe also the most expensive), but if you find yourself constantly adjusting and probing the bed you have to wonder if other alignments are shifting as well.

@mattling9 said in Need Help with Stepper Motor Data (Completely Off Topic):

Can a NEMA 17 with a 10:1 Gearbox REALLY output more torque than a NEMA 23 with a 3:1 Gearbox if the output speed of the gearbox is fixed at 60RPM???

High speed motors have much greater power density than low speed motors, so your results aren't particularly surprising. When building model airplanes we often have to decide between a heavy direct-drive motor and a lighter geared motor.

For model airplanes the heavy direct drive motor typically wins after considering the weight, cost, efficiency, and complexity of a gearbox. But in your situation both motors would require a gearbox so its not surprising that the Nema17 wins. Just make sure the 10:1 gearbox survive the planned load.

This seems to have almost all of the problems of 5-axis slicing. It works when the entire part is a single feature, but for anything more complicated the nozzle will collide with the part.

For example you cannot have a wavy surface adjoined to a flat one.

Think I have see a gcode for arcs. When it's used?

G-Code for arcs are mostly a historical artifact from the days when G-Code programs might be handwritten and controllers only had a few kB of memory.

Modern CAMs will have an option to use circular movements where possible, but the truth is that modern toolpaths just cannot be expressed with arcs. Even if you are cutting prismatic shapes a constant engagement toolpath will be a mix of helixes, spirals, and trochoids, not arcs:

On a modern controller there really isn't any advantage to arcs - memory is plentiful and you have 300+ segment lookahead. When your g-code is going to be 99.99% line segments anyways, why bother using arcs at all?

The Titan has some difficult bearing alignments and sliding fits, and the idler is cantilevered off the stepper shaft. If anything is out of place it will start to skip.

As well, if you apply too much force to the bearings during assembly it will indent the raceways and grind itself to pieces. Its best to locktight that screw and stop tightening as soon as it makes contact with the lid.

The Titan is a very light and compact design when it works, but they got a little too clever.

Your first post mentioned that your components were printed in Extrudr's GreenTec PRO for heat resistance. Was it necessary to replace them with PC?

There isn't really a debate once you leave hobbyist circles. Every professional guideline is crimp-only, primarily because crimps are faster than soldering and are less skill-dependent.

It is fairly hard to mess up a ratcheted crimp (assuming you are using the correct tools) whereas a beginner soldering crimps is going to be a disaster. If you put too little solder it might not penetrate, but if you put too much or apply too much heat the solder will wick onto the contact surface and/or up the stranded wire. If this happens, it possible that the crimp will fail without warning in the future.

If I don't have the appropriate ratcheting crimp tool I'll go at it with pliars and solder, but I will inspect every joint very carefully before using it. Non-ratcheting crimping tools are garbage in my experience, and I've used some expensive ones.