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QuoteThinkyhead
QuotesvantegOne thing I haven't fixed yet is the missing reset for last_position when/if e_position is reset. I think there is one somewhere in the code...
I've done a global search for (last|e)_position to see where this might be, but I couldn't find anyplace where this should go. Maybe you can point out the line in pid_with_kc/Marlin/temperature.cpp — or maybe everything is as
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svanteg
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Firmware - experimental, borrowed, and future
QuoteThinkyhead
Please check out for my implementation of PID_ADD_EXTRUSION_RATE based on the example code above. It probably needs some revision, so please give your feedback on the PR, and I will try to make it as solid as possible!
Thanks! I haven't invested the time to learn how to do the github thing so I appreciate the helping hand. Also I am honored to see some of my "code" perhaps makin
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svanteg
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Firmware - experimental, borrowed, and future
...and the bellow template (BellowTest2). It's designed to fit on one row of standing A4 paper. I used paper for folding and shape rigidity and oven plastic to make it air tight. Use your best long rulers and be meticulous with alignment. I taped all up on a flat table where I was ok with scoring the surface when cutting paper and plastic sheets.
BellowTest contains a single A4 template for prac
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svanteg
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Mendel90
Here is the right x-axis clip. The moving sealing strip comes in above the inner rod and goes down to attach "under" the rollers so the uptake point is at the lowest. The tensioning string winds round the outer wheel in the same direction exiting on top. The inner rod should be fixed so the hole needs to grab onto that. The outer roller rod much run freely so use a 0.1 - 0.2 mm larger drill plus
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svanteg
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Mendel90
Here is the hotend clip. As it needs to cope with high temperature I've milled it from oak which seems to hold up ok at 245 degrees but with some darkening. the four posts (of which three are visible) are clearance around the fastening screws for milling. As I have a probe rod coming though there is a separate hole for that.
Here is the clip and seal together. Note that as kapton tape and oven
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svanteg
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Mendel90
@kitemare: Thanks, I went through quite a few ideas before I settled on this approach. I was concerned about heat loss with only the bed as heatsource and wanted to keep the heated volume to a minumum.
Here are the pieces for the seal. I tried a few other variants without the vertical rails but this was the only one I could get flat and rigid enough for a descent seal.
The rail_connectors sit
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svanteg
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Mendel90
Here is my implementation of an inside the envelope heated chamber for the Mendel90. I am sharing it to inspire others and to get ideas to simplify and improve on it.
Basically it is a bellow with a top labyrinth seal for the standard jhead hotend and it fits inbetween the XZ plate hole and the bed. It clips on to the X axis and follows that up and down during a print. It uses only the bed as he
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svanteg
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Mendel90
Variant of slider for 4mm rod.
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svanteg
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Mendel90
Unfortunately no. I think this happens when the jerk limit is reached for tight segmented curves at high speed. In a way the firmware is doing its best. One solution would be to reduce the commanded speed in gcode.
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svanteg
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Firmware - mainstream and related support
QuoteDaveX
For 500mm/s, a 20W heater wouldn't be able to keep up, since you'd have a heating load of about 21W in the extrusion. A 40W heater would need to vary its CO about 50% full scale to handle the difference between 0mm/s and 500mm/s extrusion speeds. ...
I guess the community will move to higher power heaters as we become more able to use the higher speeds. My J-head uses about 40% to ke
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svanteg
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Firmware - experimental, borrowed, and future
Interesting, informative and I think we agree on most aspects.
QuoteDaveX
In Marlin there's an AUTOTEMP feature in the planner that increases the temperature SP proportionally to the highest E speed in the move buffer.
I have not tried this yet so I might have misunderstood. However my understanding of it is not to regulate a desired set temperature but rather change the temperature based on fl
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svanteg
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Firmware - experimental, borrowed, and future
To see why lag is needed try a free air extrusion that takes at least 20 seconds to run. In Marlin you will want to turn on PID debugging to see the temperature updates at full speed. You will see that the temp does not change immediately - for the reason you guessed - the cooling needs to reach the temistor before it can be seen, essentially the detection delay. So you need to time the heat puls
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svanteg
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Firmware - experimental, borrowed, and future
Here is an initial crude and incomplete hack to add feed forward and lag to enable nulling out extruder temp variation from extruding plastic. The method is to calculate the amount of "new" plastic fed into the extruder per PID tick and adding the corresponding heat via feed forward with adjustable lag. I've found that about 110 * e_steps / steps_per_mm applied with a 2 second lag works well with
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svanteg
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Firmware - experimental, borrowed, and future
Just following up the possibility of sharing the Z endstop signal with the probe... Unless I am missing something an OR gate would work?
Z endstop Z probe out Z endstop state Z probe state Comment
closed closed closed connected; not triggered connected; retracted either all ok or short circuited
closed open open connected; not triggered not known if connected; deployed
open close
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svanteg
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Mendel90
@neildarlow: the way Marlin does a g29 it resets the Z-offset using the probe data - the at-the-top homed Z is discarded. As long as top-Z-referenced "-1" is physically below the plate and you start the probe above the plate you're good. The GitHub snapshot from your repository did not work out of the box though - I don't remember if the fix was mechanical or via code fix but it only tried to pro
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svanteg
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Mendel90
For me the main driver was the fact of experimenting with new things and being human - i.e. I cannot always predict that e.g. the machine is about to plow the extruder into the plate or the top z clamps with enough force to push things out of calibration. An added real benefit is that I can now freely switch between the kit glass pane and the IKEA Sörli mirrors I have - which was a pain before si
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svanteg
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Mendel90
I found that in getting the support as thin as possible it also got almost no stick onto the hotbed. Here is an update to the Raft module that allows to set the flowrate for the first layer of support.
This is based on Skeinforge 50 plus published by Lenbok.
diff:
diff -ru RefCode/Skeinforge50plus-master/skeinforge_application/skeinforge_plugins/craft_plugins/raft.py Skeinforge50plus-master/sk
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svanteg
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Skeinforge
See video here: . Also added starting gcode and some tweaks to Marlin.
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svanteg
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Mendel90
Here are the STL:s...
block_nut_holder - is a slimmed down alternative to the standard wing nut. Needed since the wing nut interferes with the probe rod.
fan_duct_ - is an adjusted fan duct with the main hole relocated to not touch the hotend plus an extension of the hole to allow the probe through.
lever - is used to reduce the weight needed to trigger the micro switch.
pcb_standoff - simple
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svanteg
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Mendel90
Here is my implementation of Marlin auto levelling for the Mendel90. It consists of a new Wades block and an adjusted fan duct plus some minor circuitry for probe and servo. See video here and here . See STL:s below.
The probe is interfaced using the same solution as for the endstops. In wiring it I noticed that that standard wiring of the x-endstop and the extruder temp has ground and signal r
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svanteg
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Mendel90
I am running a fork of the latest Marlin firmware on my Mendel90. I am generally very pleased with Marlin and the smoothness of motion which translates into high quality prints. One issue though is bothering me - when small circles or tight curves are printed I can hear (and feel) a distinct "stutter" or vibration from the motors. My guess is that the tight curve is a sequence of small segments t
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svanteg
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Firmware - mainstream and related support
If you're ok with printing a new one - should heat-fitting the bolt warp the gear you have - then just go for it. If it works it works. If it doesn't you print a new one. Depending on how much you heat it, you might want to be careful not to warp the bolt - that you cannot print a spare for...
Personally I wanted to learn how to get a precise print so I ended up printing about four large gears b
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svanteg
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Mendel90
When I made my large gear I had some issues with the M8 head cavity. One was to get the corners sharp enough so the bolt head did not catch on them. The other was to get the perfect snug fit across the flats so the bolt head was firmly held.
(If your bolt aligns with the standard nophead issued extruder block - spacer - large gear, it should (if seated correctly) align with the above herringbone
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svanteg
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Mendel90
I tweaked these to make the gears I am currently using. The small gear has very little clearance between the gear and the motor so you might want to file off ~0.5mm unless you know how to fix the scad. The set is 39:11 - same as the standard mendel90 set.
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svanteg
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Mendel90