Do we even need / want heated bed on gigabot? With newer materials and surfaces like PEI now plentiful, it’s possible to print most things without a heated bed.
With such a large bed, it seems like it may be like bringing a gun to a knife fight.
Saturday, Ryan gave me an intro to the Gigabot, which required unloading all of the 3D-prints from the Z plate (pretty expensive shelf?) and pulling off all the blue tape…
We checked the straightness and orthogonality of the frame and bed plate. Other than a ding or two in the bridge runway rails the frame is pretty square and true.
Bed Plate Flatness.
We checked the bed plate for flatness with a big straight edge and paper as a feeler gauge. The plate was flat within the width of paper in the x, y and diagonals. Given the plate was at room temperature, we could not see the cup shape distortion. Perhaps it distorts when heated. This was not tested as the heat pad and thermistor were disconnected.
Next Step - Need to get the heat on to evaluate distortion at temperature. Anyone know the pin-outs for the heat and thermistor?
Ryan and I wonder if the heater heats the entire plate or just a portion of the plate, which could cause distortion. Might need an IR thermometer to check the heat pattern once the heater is on.
Z-Plane
One of the Z axis screws wasn’t seated in the thrust bearing. Once seated, the bed plate was more level. Manually turning the Z-screws got the bed much closer to level (orthogonal to the X, Y plane.)
Next Step - More tweaking to precisely align the bed plate. I’ll bring framing squares, beam levels and a laser level from home.
I’m going to read through the Gigabot wiki and the Re3d website. Yes, RTFM. Ryan will continue my 3D printer education.
Observations:
a) The Gigabot needs more care and feeding than mass market 3D printers. (Mechanical, electrical and software.)
b) Complexity can be overcome with process, including maintenance and operation check lists. (Witness airline safety records)
We need some team input from Hive members to fix Gigabot; Get the heater and thermistor wired in for a test of heat distortion.
Check orthogonality and dimensional stability throughout the complete print cavity.
Until we can duplicate the bed plate distortion, adding a new bed plate layer seems to be unnecessary.
Best Regards,
Dave Velzy
Awesome!
I bought some semi-nice machinist rulers and small machinists squares. They should be in the toolbox by the lathe.
Brad
Heated bed is offline because of an incompatibility between firmware and thermocouples. Marlin won’t support 2 thermocouples, thus the heated bed has not been used in a long time. Bill took it offline.
Answer: use thermistors. They’re very accurate at the needed temp range and all firmware supports them. They’re also cheap. In theory, thermocouple is more accurate, but in practice it’s not worth it and no longer supported.
Thermocouple / thermistors:
I was going to do this before I became too weak: mount 4 cheap thermistors in four corners of bed. If you wire in parallel pairs then wire the pairs in series the combined array will be same as one thermistor, 100k, which is what the input on electronics wants to see. Or just mount one thermistor for now.
Best way to mount thermistors:
Maybe warping is not primary issue. Could be leadscrews or something else. Regardless, you guys are doing the trouble shooting needed all along. Thanks.
Hopefully I can help in person in 3-4 weeks.
Lorin
From: Dave Velzy
Sent: Sunday, December 10, 2017 8:26 AM
To: Hive13 Hackerspace
Reply To: cincihackerspace@googlegroups.com
Subject: [CHP] Re: Status of the gigabot
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- |
Saturday, Ryan gave me an intro to the Gigabot, which required unloading all of the 3D-prints from the Z plate (pretty expensive shelf?) and pulling off all the blue tape…
We checked the straightness and orthogonality of the frame and bed plate. Other than a ding or two in the bridge runway rails the frame is pretty square and true.
Bed Plate Flatness.
We checked the bed plate for flatness with a big straight edge and paper as a feeler gauge. The plate was flat within the width of paper in the x, y and diagonals. Given the plate was at room temperature, we could not see the cup shape distortion. Perhaps it distorts when heated. This was not tested as the heat pad and thermistor were disconnected.
Next Step - Need to get the heat on to evaluate distortion at temperature. Anyone know the pin-outs for the heat and thermistor?
Ryan and I wonder if the heater heats the entire plate or just a portion of the plate, which could cause distortion. Might need an IR thermometer to check the heat pattern once the heater is on.
Z-Plane
One of the Z axis screws wasn’t seated in the thrust bearing. Once seated, the bed plate was more level. Manually turning the Z-screws got the bed much closer to level (orthogonal to the X, Y plane.)
Next Step - More tweaking to precisely align the bed plate. I’ll bring framing squares, beam levels and a laser level from home.
I’m going to read through the Gigabot wiki and the Re3d website. Yes, RTFM. Ryan will continue my 3D printer education.
Observations:
a) The Gigabot needs more care and feeding than mass market 3D printers. (Mechanical, electrical and software.)
b) Complexity can be overcome with process, including maintenance and operation check lists. (Witness airline safety records)
We need some team input from Hive members to fix Gigabot; Get the heater and thermistor wired in for a test of heat distortion.
Check orthogonality and dimensional stability throughout the complete print cavity.
Until we can duplicate the bed plate distortion, adding a new bed plate layer seems to be unnecessary.
Best Regards,
Dave Velzy