The Voron kit build thread

MikeWi said:
Klipper handles limit switches, but it can also do sensorless homing if you're using TMC2309 stepper drivers.
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It seems like terminology is pretty loose on the 3D printing firmware. We have homing switches (or sensorless homing), not really limit switches on most of these printers. I haven't seen real limit switches on a 3D printer.
 
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A limit switch used for homing an axis would be a physical switch like a microswitch or an optical switch. Sensorless homing uses a stall detection ability in the driver to detect when the axis is at the end of its travel.
 
MikeWi said:
A limit switch used for homing an axis would be a physical switch like a microswitch or an optical switch. Sensorless homing uses a stall detection ability in the driver to detect when the axis is at the end of its travel.
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Since the firmware is set up to allow motion beyond the switch (depending on the value of "position endstop"), it would seem that it is not exactly a real "limit" switch, and is used only as a homing switch and ignored at other times. Also, when hit, the switch doesn't shut down motion at a very low level, perhaps even hardware level, as limit switches generally do. 3D printers generally use soft limits rather than hard limit switches. With the absence of cutting forces this is generally adequate and lowers the cost and complexity of the machine.
 
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The PTFE tubing arrived, so just made the first print from the Repbox. There's a bit more friction on the spool from the support "rollers" which don't really roll, so the spool slips on the edges against the PETG. There are other options but in most cases the number of reels the box can hold is reduced. The print came out fine, so for the moment I'll go with it stock. But I'll look and think about better solutions that will still allow six reels and handle at least some of the wider spools.
 
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Perhaps the missing steps above 250ish mm/s is an acceleration issue, rather than a speed issue.
An ion engine with a few ounces of thrust can push a probe to 80,000 km per hour, but it takes a long time. I'm gonna try jogging it around at 300mm/s at lower accel rates. Any thoughts?
 
Have you set up the accelerometer and run input shaping? That should scope it out. Might be some resonances that it needs to avoid. Sometimes there's a cracked part or loose joint that causes problems.
 
AlanB said:
Have you set up the accelerometer and run input shaping? That should scope it out. Might be some resonances that it needs to avoid. Sometimes there's a cracked part or loose joint that causes problems.
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No my kit didn't come with an accelerometer. It's on my short list.

Reducing the accel to 2000mm/s seems to have done the trick.. visually, I can't tell the difference in the reduced accel rate, but no missed steps after 10 minutes of jogging it around.
 
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The accelerometers (for input shaping) are inexpensive. The process collects some impressive data.

Also Nero recommends don't use stealth-chop mode, it is more prone to step loss. Use spread-cycle instead. Mentioning just in case.
 
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