Recent Topics


by Renegade1

Hello everybody, sorry we have not been here for a while, but we are glad that all of you joined our group! I hope that we can share advice, and show everybody all the cool things that be built!

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So I made a minor jam a major problem

by nyyark

This is a learn from my mistakes post:

Jammed the nozzle with PLA, and it got back in the gears. Problem is I noob used the cleaning drill and snapped it off in the nozzle. No amount of piano wiring would fix it. Since I had the hot end apart and I needed to replace the nozzle and maybe more I bought the swiss all metal hot end.

So the not metal part for other folks like me that didn't know this is the PTFE (teflon is a brand name ptfe) tube inside the the heating block and nozzle. I think it acts as a reservoir for the melted plastic. It is what causes the upper temp limit on the hot end.

So I follow the youtubes of disassembly. I hit a major snag, I can't get the heat tube out of the heating block. Most places show its only finger tight. Well not mine. What I had to do was heat the element (dangling in the air at this point with nothing but in and the metal tube) back up to 250 C and use vice grips on both parts to get the tube to unscrew. I'm not sure if some PTFE got stuck in the threads, or if it was just to tight cold, but after much trial and error that worked. In doing this I managed to jack up the tape on the heating block. It looks like this will impact my print quality, but not pose a danger. I'll make a follow up post when I find out how bad it is.


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My manual PID tuning method

by nyyark

Hello everyone. I ended up needing to replace my entire hot end (less the fans) and found the autotune PID method inadequate. Being a tech by trade I decided to do it the old fashioned way. There are plenty of PID tuning methods. Mine is not likely the fastest nor fanciest, but it works on a our printers heated nozzle. The method of my madness is simply to try and get a value that doesn't overshoot too badly, stabilizes quickly, and holds stability from against minor changes.

In the printer's menu I have a configuration tab. In there is an extruder tab. In there is a control setting. I changed that to PID.

I zeroed all the values to clear the 100's place as it is only adjustable from the menu on the I setting.

Like most methods I started with the P. I picked a large value and entered it, and saved the eeprom.

Next I picked a temp 5 degrees hotter than I expected to print. Just a preference on my part. Whatever number you pick, stick too it. From the extruder menu (not the configuration->extruder, just the top level one) I set the extruder to the temp.

I watched as it heated up. It heated, overshot the value, then cooled and undershot the value, then heated and overshot again, then began to cool. etc.

My goal at this point was to get the heater to overshoot only once. I like half splitting until I get close, so I cut the P value in half and tried again. Note that for this method 25-30 degrees of cooling is all thats needed to check a new value. So I just turned off the extruder, changed the value, then turned it back on.

I kept decreasing the value if it overshot twice, and increasing it if it did not. Repeat this until you get as close to the breaking point as your patience allows.

Next up I work on the D. This time I was looking to minimize the overshoot. Be aware that there is a sweet spot, to high the overshoot increases, to low and it increases. Follow the same change and check method for the P.

This part is optional, but it can be done several times. I did it once.

You can now decrease the P value a bit and actually further minimize the overshoot. Same rule above applies, too much and it starts increasing. Once you optimize a new P value to minimize overshoot you go back and optimize the D value again.

Once you've done as many iterations of P-D optimizations as you are willing to, allow the temperature to stabilize. It shouldn't take but a few oscillations to get fairly stable (note it never truly stops ringing, it just rings a very small amount).

It should be some value below your desired temperature. This is where the I comes in. I was surprised to find I only needed a VERY small I to get to where I wanted.

To set the I you do not turn off the nozzle, instead you just adjust the I value and watch the temperature. Once the I is not at zero it will start oscillating again. There is a sweet spot here as well. What you want is the I value with the smallest oscillation. Due to the nature of this tuning profile, you can probably just step the I up in increments of 0.01 until you hit it. I did at 0.02.

To verify your tuning, throw the fan on at 100%, it should re-adjust to the previous temperature very quickly with little overshoot. Another verification is to ramp to several temperature levels. You should see a consistent overshoot value and stabilization time.

The reason I picked this tuning is that while the initial overshoot is occurring the printer is likely to be homing, and by the time it goes to print it has stabilized.

TLDR step by step version:

1 Enable PID control and zero everything in Configuration->Extruder
2 Adjust the P value until the extruder only overshoots the set temp once and comes close but does not pass the set temp on the second oscillation.
3 Adjust D value to minimize the overshoot, with the awareness that the overshoots gets worse the further you get from the sweetspot value
4 Optional Re-adjust P to minimize overshoot with sweet spot awareness, then re-adjust D. Repeat as desired.
5 Allow temp to stabilize, increase/decrease I until the extruder's oscillation tightly hugs the set point. Very small value needed.

Happy Tuning! Doing it this way took me a few hours, so be warned.

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Default Maker Select v2 slicer settings?

by 3DimensionalThings

I have what I hope is a simple issue. As you know the v2 comes with a micro SD that has 4 printable files on it. I can print those files without a problem. And they all come out very good. The issue arises when I take an stl that I've either created or downloaded from here and put it through Cura. Once I start to print it the print quality is always bad. The PLA comes out thin and brittle. Layers are missed or poorly printed. Pretty much every print fails. What I'd like to know is what the default print settings are on the factory files so I can duplicate those in Cura. Or should I try a different slicer?

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Cura that comes loaded on the SD Card, Cura V2 or Cura v3?

by thejoester

So I have been just using the Cura that came on the SD card that was included with my Maker Select V2.1. Not sure on the version as it is not labeled anywhere but it seems older. It comes setup for the i3 configuration and has the i3 logo. It is working ok for me but I am wondering if there is any reason to update to the Ultimaker Cura 2 or 3 versions?

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