Been a little while since I’ve posted. Nearly complete with my IDEX design, just trying to figure out how I want to level the build plate. I’m using magnetic build plate with a removable steel sheet. Trying to decide between using the nozzles to close a circuit with the bed or to use an inductive sensor for each head. The former will give better precision and will likely result in not needing to tweak the Z offset for the 2nd head, but if I go for the inductive sensors I can try to get the entire sheet dipped in PEI which would be extremely wear resistant and give 2 sides to print on. So what do you guys think?
Induction will give you the best flexibility in the choice of build surface.
Bonus points - use the coil of the heater as your inductor for inductive sending.
@Jason_McMullan The coil of the bed heater? I’m using a steel sheet on top of an aluminum plate, both will trip the sensor before the heater.
@Adam_Steinmark
The coil of the hotend heater. Would probably require a customer hotend, with the heater coil on a brass core.
@Jason_McMullan Eh I’ve got a couple other things I’m working on before I start prototyping hotends. Using an E3D Aero’s for this build.
Inductive is a long term eaiser choice. No making sure your hot end is clean all the time. Out of interest what/ where are you vetting your bed from? Presumably neodium magnets? Would that trip the inductive sensor?
@Jonathon_Thrumble Haven’t chosen a manufacturer yet, waiting on quotes from a few sources. It’s a 1/4 in MIC 6 Aluminum plate which I’m requesting to be milled flat on both sides and blind holes for high temp neodymium magnets (standard NdFeb magnets have a max temp of 80 C). These shouldn’t have an adverse effect on leveling, BuildTak and GeckoTek3D use a similar system.
As for cleaning the nozzle, I was just going to have a small, 3D printed container with a wipe pad on each side of the frame for each nozzle to wipe and prime into. Similar to what’s on the dual head XYZprinting machines or Voxel8. I could even have it retract before probing.
Like I said I’m nearly complete with the design so look out for a post from me soon with some snapshots of the CAD.
Did you go with probing only 1 head and use z offset for the 2nd head? Or do you probe both heads?
@Step_Cia Gonna try to probe both heads. You’re a bit further along than me though so let me know how it works for you.
Wht I thought you are ahead of me lol… Yes I plan on probing both heads so I don’t have to fuss about z offset at all even if I swap nozzle. We’ll see.
@Step_Cia Don’t you have it built?
Yes I can print with 1 tower at the moment. The second tower is not quite there yet. Need to do wiring.
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Yeah I’ve only bought an Aero head to test fitment and screw length. Still waiting on payment from my summer internship. I would’ve been done a month or two ago but I had to scrap my other design using all metal components because it was getting a bit too pricey. New version has a smaller frame and is significantly cheaper. Took a while to get quotes on some of the parts too, I’m using genuine Hiwin linear guideways for the X and Y axis.
Even with nozzle cleaning, I personally never got bed touching to work reliably.
In the UM3 we use a zero-calibration method with a captive sensor, same method should work for inductive sensor as well. You do need an analog value.
The trick that we use is we move towards the bed, notice the change in sensor value, and then move the nozzle into the bed noticing the sensor value no longer changes at the same rate. The tipping point is where the nozzle hit the bed.
This gives you the option to sense the bed, per nozzle, and also calibrate the Z difference between the nozzles. Without user intervention.
Looks good for the bed and not bad prices
why not have the edges not dipped in PEI and use them for close circuit leveling?
@Daid_Braam Impressive, I always wondered how the 3 did its auto leveling. I was actually going to use BLTouch sensors for leveling but then I saw Tom’s video and decided that inductive sensors are much more accurate. He also mentions capacitive sensors are extremely sensitive to humidity and particulate in the air. That being said, I never really had much trouble with the UM3 I used over the summer but it was in humidity controlled room. Source: https://www.youtube.com/watch?time_continue=356&v=il9bNWn66BY
@Jonathon_Thrumble I’d still need it machined for the magnet holes and I’m not sure they mill both sides flat. It’s gonna be cheapest to have one place do everything, plus I’m in the US and shipping a giant aluminum plate is going to be pricey.
@Hakan_Evirgen That might be possible, I’m using a 350x350 mm bed but with a 300x300 print area so I don’t have issues with cold corners which can be a big issue on a bed that size. I have no idea how the coating process works though and if it would be possible to to only coat the print area.
@Daid_Braam That’s clever.
YAY!