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Thermistor wires being squished
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Description

It seems like the thermistor wires on the heater are being squished by everything. Once you torque the glass down there isn't any wiggle to the wires and if you look under the bed you can see them being squished. Also once you take the heater off you can see indentations from the wires in the heater. This may be causing the left side to be more squished too still.

Event Timeline

robert created this task.Sep 3 2019, 6:30 AM
robert triaged this task as High priority.
robert created this object with edit policy "LulzBot Hardware Products (Project)".
tutley added a comment.Sep 3 2019, 7:18 AM

@robert this is the same bed setup as taz pro so the issue is present on both machines. There is a lump in the silicon patch where the heater wires go in and this is where the thermistor wires can get smashed. If you route the thermistor wires around the side of the lump you should be able to tighten everything down without it smashing the thermistor wires

robert added a comment.Sep 3 2019, 7:20 AM

@tutley Unfortunately theres too many beds with inconsistent thermistor wire lengths. I tried this already and its not possible on some machines cause wires are too short. But we can try on ones that have longer wires.

robert added a comment.Sep 3 2019, 7:34 AM

@tutley So I tried it just now and its pretty difficult any way because if you route the wires on the idler side of the hump, you run into the wiper mount, and if you route them on the motor side of the hump the run into the cable cover. Plus its just difficult in general to keep those wires on the side of the hump when laying the bed down.

robert added a comment.Sep 3 2019, 7:36 AM

@tutley Its not impossible to route them around the hump on the idler side, just very difficult.

logan added a comment.Sep 3 2019, 9:56 AM

Right now we're looking at raising the bed surface 1.11mm to make room for those wires. This will require changing bed spacers to these: https://www.mcmaster.com/92320a763 and modifying the flexy corners.
This would accomplish similar to what was proposed in T9909 so the plan is to test on Mini 2 also. There is a little of the bed mount fasteners sticking out the bottom of the bed plate so hopefully no new hardware will be needed there.

karrad added a subscriber: karrad.Sep 3 2019, 10:07 AM

@logan Will this require any change to start gcode?

adam added a subscriber: adam.Sep 3 2019, 10:09 AM

Is this going to change bed sagging/bulging? Do we need to modify the printed standoff in the center with these other changes?

logan added a comment.Sep 3 2019, 10:09 AM

@karrad we will find out during testing, wont affect the wipe at all so I cant think of any reason it would off the top of my head

logan added a comment.Sep 3 2019, 10:10 AM

@adam probably will need to add the same amount of thickness to that center standoff

@logan Awesome, I am not sure how we would have identified users in the field easily for inclusion into Cura if that was required.

adam added a comment.Sep 3 2019, 10:14 AM

@logan can you put in a PR for the new bed spacers in whatever quantity we need to test this?

@adam @logan @karrad i believe we will need to adjust the flexy corners as well as the center standoff all by 1.11mm

tutley added a subscriber: Heather.Sep 3 2019, 10:26 AM

@adam i ordered these 11.11mm spacers back when we were developing the modular bed system. i sent 20x pieces with @Heather to give to @logan. I have another 20pcs here for further testing in R&D

logan added a comment.Sep 3 2019, 10:27 AM
This comment was removed by logan.

These adjust the bed corner and standoff by 1.11mm

tutley added a comment.Sep 3 2019, 1:26 PM

i have installed these on my quiver and if install the bed so the thermistor wires come straight out the side, you can shine a light from the backside of the bed to the front and you can see the light under the wires, so the wires are not being compressed at all and have a bit of a gap.
These parts combined with the 7/16 spacers should alleviate any issues here. This should give a more consistent first layer as well.
I am printing another set to install on my mini 2 and this should alleviate T9909

logan added a comment.Sep 3 2019, 2:05 PM

Sounds great! I will get some prints of those corners going over here so we can continue testing

zachah added a comment.Sep 3 2019, 3:03 PM

I measured some of the bed heaters we have in production to get a range of thicknesses for them.

w/thermistor wiresw/o thermistor wires
16.426.33
25.455.05
35.625.15
46.395.88
55.655.22
65.735.17
75.915.20
85.845.36
95.614.92
106.235.89
115.635.37
125.955.67
135.655.26
146.015.58
155.645.36
166.045.40
175.555.29
185.625.40
195.835.20
205.745.15
215.755.38
225.825.40
235.935.14
245.765.30
255.375.14
265.665.35
275.755.50
285.605.39
295.815.64
305.815.64
315.835.37
325.855.40
335.675.31
346.005.40
356.015.62
366.265.50
375.865.48
385.745.39
395.725.26
405.725.26
415.755.30
426.035.80
435.875.50
445.755.56
455.855.32
logan moved this task from Report Issues Here to Change Order on the Redgum board.Sep 5 2019, 8:19 AM
bmh added a subscriber: bmh.Sep 5 2019, 1:02 PM
adam removed a project: Redgum.Fri, Nov 22, 12:19 PM
karrad closed this task as Resolved.Mon, Nov 25, 11:26 AM
karrad claimed this task.