Hi DaveyHi, Not all micro switches are of equal quality. For a z-min probe, it is a plus to have a micro switch which is good quality, has a soft spring, and does NOT have a spring arm. I got some excellent ones from TriDPrinting.com.
You don't want to wire the FSR's directly to your printer controller. Instead use the Trinket Fsr.ino file to program your Trinket, and use TrinketWiring.png as your wiring diagram. Note: I normaly wire 5v from the printer controller to +USB on the Trinket (and not to BAT+). You could wire BAT+ to 12v. On an 32-bit printer controller, usually there is a jumper to select for using 5v (and not 3.3v) for the endstop switches and z-min probe. Also, note that I use a 5v Trinket, and not a 3.3v one.
DaveyHi
about 9 years
The issue I have with the effector microswitch is that there is inherently slop in the mechanism and my distrust of microswitches. My cheap Micromake Chinese delta came with one that was incredibly sloppy. Even after some hacking to get it stable enough to print its replacement (lol) it's probably still the weak link in the system. It is kinda nice having a spring-loaded hot end though, for the inevitable crashes.
I oedered the 0.25" ones but looks like you used the 0.5". This is the first I've heard of a Trinket. I'll have to look into that :-) I was going to try to wire them straight into the digital in.
My FSRs arrived today but I'm still trying to get this $%#@ to print accurately enough to make new parts. By the time that's done, my AZSMZ board will be in and I'll be starting all over! lol
Haydn Huntley
about 9 years
I've seen people design FSR into the effector, however you don't need to worry about keeping them independent of bed weight -- the software on the Trinket automatically adapts to the bed weight. I suspect a problem with locating them in the effector is that the effector goes through a lot of acceleration changes, which might trigger it. Believe it or not, but a well designed micro-switch-based z-min probe can actually work quite well.
DaveyHi
about 9 years
That's good to know. I was thinking of mounting them in the effector as that would solve the heat issue (if there is one) and keep them independent of the bed weight.
Haydn Huntley
about 9 years
FSR's don't like high temperatures, but with the setup I'm using, there is a plastic "button" and several mm of glass insulating the FSR's from the heat.
I haven't tried printing ABS with this setup yet.
It also probably helps that typically I calibrate the printer once, without heating the bed (using RC's Marlin's auto calibration "G30 A Dnnn.nn" command, and the printer stays calibrated until the next time I change some of the parts.
DaveyHi
about 9 years
I thought there were temperature issues using the FSRs on a heated bed as the bed temp exceeded the FSR's rating?
ronnien1
over 9 years
<p>nice way to probe the bed, do you think it is possible to put on a MakerGear that would use 4 sensors?</p>