Close



Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1

    Idea of controlling chamber temperature by adding temperature-controlled exhaust vent

    Over the last five or so years, ABS warping has always come back to me for certain models.

    Having perfect bed adhesion fixes the problem most of the time. However, it is just solving the symptoms. The internal stresses are still in the part. Increasing the bed temperature causes drooping and will still not solve the internal stresses in the model, which can get very large, depending on the shape. In the end, there are still temperature gradients present.

    That is why some parts print fine for me, but become bent after removing them from the build plate.

    Apart from looking at software which can simulate warping before printing, which I am also looking into, I just got an idea which I am curious to hear your opinions about.

    This is the idea:

    1. You thermally insulate the printer as well as possible.
    2. You add a vent at the top of the printer which allows hot air to flow out.
    3. You add one or more temperature sensors mounted close to the bed (so they are at the same height of the bed regardless of the layer which is being printed) but thermally decoupled from it (spaced around 10-20 cm. from the surface).
    3. A arduino a similar device is connected to the mentioned temperature sensors and to a small servo motor (i.e. a micro RC servo) driving a valve inside the vent, allowing it to partially close and open.
    5. The arduino is programmed to fully close the vent if the measured chamber temperature is below 50 deg. C. Once it exceeds this temperature, the vent is gradually opened until the temperature is maintained stable at 50 deg. C.
    6. Before printing, you heat the chamber by turning on the heatbed and extruder heater to normal printing temperatures. Once the chamber is at 50 deg. C, you start the print.
    7. No more warping?

    Could this work?

  2. #2
    Student
    Join Date
    Aug 2019
    Location
    online at www.thegentlewolf.com
    Posts
    10
    Follow Petercat On Twitter Add Petercat on Facebook Add Petercat on Google+
    Would there be any benefit to mounting the sensors to the extruder so that they would move with it and get readings across the print surface? Maybe mount them an inch or so away from the nozzle?
    I doubt if cooling is the problem as much as uneven cooling is, though. At least that's what causes stress in castings, especially in materials that don't conduct heat very well.
    As I recall, cooling large glass telescope mirrors is a process that must be carefully controlled over a period of years to prevent stress distortion.

  3. #3
    Technologist
    Join Date
    May 2018
    Posts
    177
    I have a home made enclosure with a small heater and an InkBird thermostat. With the thermostat set at 100F the small heater and heated bed keep the enclosure at 100F without external venting. I put the sensor near my rambo board.. probably hotter up on the build platform.
    Attached Images Attached Images

  4. #4
    Student
    Join Date
    Aug 2019
    Location
    online at www.thegentlewolf.com
    Posts
    10
    Follow Petercat On Twitter Add Petercat on Facebook Add Petercat on Google+
    You could take care of that with a small recirculating fan somewhere in the case. I have an oil-filled heater in my bedroom, when I stand up my head is hot and my feet are cold. Adding a fan solved that problem!

  5. #5
    Engineer Roberts_Clif's Avatar
    Join Date
    Jun 2017
    Location
    Washington State, USA
    Posts
    596
    Add Roberts_Clif on Thingiverse
    Quote Originally Posted by airscapes View Post
    I have a home made enclosure with a small heater and an InkBird thermostat. With the thermostat set at 100F the small heater and heated bed keep the enclosure at 100F without external venting. I put the sensor near my rambo board.. probably hotter up on the build platform.
    I Too have a home Made enclosure, with a outdoor thermometer behind each 3D Printer and the temperature stays pretty close to 100F .
    I do not have to do anything, however I have a bathroom vent with a light dimmer switch to vent smells outside.

    Have not had any problems with venting the smelly air outside.
    Here is a sample of an ABS Print.

    XY_C_Burly.jpg

  6. #6
    Super Moderator curious aardvark's Avatar
    Join Date
    Jul 2014
    Posts
    6,878
    I can see going to this trouble for polycarbonate or nylon - but why do you still bother with abs ?

  7. #7
    Technologist
    Join Date
    May 2018
    Posts
    177
    For my purposes I find ABS to be much more rigid than any of the Nylon I have used (6xx, 910, EPA) or PETG. Also the ABS MakerGear sells prints very nicely and is easy to print especially with the enclosure. I have also not been able to stop the nasty warp of larger Nylon parts like I have with ABS. It was actually not much work adding at $15 thermostat and a $30 heater. Enclosure was built to keep the cats out of the mix :-)

  8. #8
    Student
    Join Date
    Aug 2019
    Location
    Long Island
    Posts
    7
    Maybe you could have the vent double as a fume filter. I don't know about you, but the fumes always get to me.

  9. #9
    Technologist
    Join Date
    May 2018
    Posts
    177
    My printer is in an extra bedroom.. with my home built enclosure, there is no need to vent anything. it does not smell, and it stays at 100F with heat and heated bed.. youi all make this much more complicated than it needs to be

  10. #10
    Engineer Roberts_Clif's Avatar
    Join Date
    Jun 2017
    Location
    Washington State, USA
    Posts
    596
    Add Roberts_Clif on Thingiverse
    Every filament I have printed with has its indiviual smells.

    Do not know why you can not smell it but they all smell.

    https://ultimaker.com/download/13079/SDS%20ABS.pdf

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •