Anyone used online 3D printing services

[SteamyTea]

I don't think there is a 1Wire sensor that goes that high, more usual to use a thermocouple, and then you are into ADC and extra hardware.

 

I don't understand software, but I think that with Python, it is normal to write little scripts that spew out just the information you want either to a file or a display.

Our mate Ed Davies is the Python man, may be worth giving him a shout by email.

 

You get the sensor number by initially interrogating it from the terminal.  Everything in Linux is a file, so it shows up as a file.

/sys/bus/1w/devices

Bit of a faff initially, but easier than writing something to automatically find it.

There is OWFS that I think connects the DS18b20 via the USB port and does a lot of the hard work.  I think TerryE knows about these.

 

The DS18b20 are, when working at the extreme ends of there temp scale i.e over about 70°C a bit flakey, so you need to keep an eye on that and reject false readings.

To give you an idea, I have some stuck in the ground and out of 87750 readings, 40 are false.  Not bad, but that is working within the normal range i.e. 0°C to 30°C.

 

[ProDave]

I would not use a Pi for this, I would use an Arduino.  But that is more because I am familliar with the Arduino.  You will buy an arduino for less than £10 and the programmign software is a free downloadl

 

Here is an example to get you started https://create.arduino.cc/projecthub/TheGadgetBoy/ds18b20-digital-temperature-sensor-and-arduino-9cc806

 

To view the temperatures on a pc screen you can use the serial monitor built into the arduino programing package, but better would be to use PuTTY but in this case as a serial terminal emulator (PuTTY is very versatile)

[Onoff]

21 minutes ago, ProDave said:

I would not use a Pi for this, I would use an Arduino.  But that is more because I am familliar with the Arduino.  You will buy an arduino for less than £10 and the programmign software is a free downloadl

 

Here is an example to get you started https://create.arduino.cc/projecthub/TheGadgetBoy/ds18b20-digital-temperature-sensor-and-arduino-9cc806

 

To view the temperatures on a pc screen you can use the serial monitor built into the arduino programing package, but better would be to use PuTTY but in this case as a serial terminal emulator (PuTTY is very versatile)

 

Thanks. Can you get an Arduino with onboard Wi-fi? Printer might be placed in another room with no ethernet port. 

 

CPC for it?

Edited May 16, 2020 by Onoff

[ProDave]

51 minutes ago, Onoff said:

 

Thanks. Can you get an Arduino with onboard Wi-fi? Printer might be placed in another room with no ethernet port. 

 

CPC for it?

I don't know, I would have to look.

 

The arduino connects to the pc used to program it via USB with a simulated serial port and that is what you normally use to read out data.  I used one for my PV dump controller and if I want to see what it's doing I just open a terminal screen with PuTTY.  I have my old, almost falling to bits ubuntu laptop now pretty much sitting there dedicated to that.

 

EDIT:  Here you are, arduino wifi https://www.arduino.cc/en/Guide/ArduinoUnoWiFi

[Temp]

Someone must have done this before. Google found..

 

https://makezine.com/projects/pimometer-raspberry-pi-remote-temperature-sensor/

 

Uses four thermocouples. Has Github page with the code. But needs an add on PCB you would have to make. Not sure if you can buy that. Says it's based on a Max31855 board which is probably a single thermocouple? 

[PeterW]

3 hours ago, Onoff said:

 

Thanks. Can you get an Arduino with onboard Wi-fi? Printer might be placed in another room with no ethernet port. 

 

CPC for it?

Think you’re over thinking this ...

 

I’ve had to insulate the bottom of the print bed to get it to hold at 110c to do ABS, and it printed fine in a standard room but wasn’t that thick. The fan blowing across the nozzle heat sink creates more of a draught than something in the room. I’m looking to build a base box for mine to stand on, and mount the PSU and the control box in that and put a decent fan on the back to keep it all cool. Then may decide to do something with the outer but tbh PLA+ is proving fine for pretty much everything I’m doing, I may go to PS at some point but not really going to start worrying about anything more exotic. 

[Onoff]

Filling & sanding today hopefully!

 

 

 

 

[Onoff]

Going for 3 coats of rollered, Bedec, satin black barn paint on the printer enclosure. Hugely expensive at about £50/5l. Got for our front gate originally.

 

Drilled for an extract fan (if needed) and the rear power socket:

 

 

Re-assembly tomorrow hopefully!

[Temp]

Gutted...

 

I was just about to pack up 60 visor bands to go in the post Monday when I hear the government have issued new guidance for small scale PPE manufacturers. It essentially makes it almost impossible to 3D print PPE for the NHS in the short term. As a result the project I've been working with has stopped accepting visors and is investigating shipping those already printed abroad. The new guidance also requires small suppliers to have liability insurance. 

 

 

 

[Simplysimon]

21 hours ago, Temp said:

Gutted...

 

I was just about to pack up 60 visor bands to go in the post Monday when I hear the government have issued new guidance for small scale PPE manufacturers. It essentially makes it almost impossible to 3D print PPE for the NHS in the short term. As a result the project I've been working with has stopped accepting visors and is investigating shipping those already printed abroad. The new guidance also requires small suppliers to have liability insurance. 

 

 

 

what about care homes they may not need the same criteria as nhs?

[Onoff]

Little by little it's getting there. Blingy lights awaited. Power socket and extract fan to be fitted though the holes are all there. More trim round the front doors etc. Not too shabby for what was scrap timber and free plastic:

 

 

 

 

 

 

[Temp]

1 hour ago, Simplysimon said:

what about care homes they may not need the same criteria as nhs?

 

Apparently the government advice also applies to care homes. That said I've heard lots of people are supplying to nursing homes and mental health facilities "direct" rather than via companies or organised groups. However this means they are probably getting unsterilised PPE. It's a mess. 

 

 

 

 

 

[Onoff]

Omfg! I tried sitting down to watch an online Python for beginners thing yesterday. Yep I can download it and PyCharm.

 

What did I get from it?

 

There's Python 2 (legacy) and Python 3 is about all I can remember. Must have drifted off thereafter. 

[SteamyTea]

2 hours ago, Onoff said:

There's Python 2 (legacy) and Python 3 is about all I can remember. Must have drifted off thereafter. 

I would not worry about that for what you want to do.

Write the script and run it, the RPi will decide the rest.

 

Have you downloaded PuTTY yet?

https://portableapps.com/apps/internet/putty_portable

and WinSCP

https://portableapps.com/apps/internet/winscp_portable

 

You can use them to log into just about anything on your existing network if you now the IP address, user name and password.

 

Because Linux is a secure system, learn about permissions.  If these are set wrong it can be hard to move things about.  It is easy to change though.

In PuTTY you log in, then use "sudo", at the beginning of what ever you want to do, this gives you root privileges.

Then change the permissions on the files/folders you want to play with.

So something like this.

 

sudo chmod 755 /home/pi/temperatures/temperaturescript.py datafile.csv

 

Then you can easily run the script and read or move the data file.

 

The other thing is if you are using the PC to display the readings in PuTTY, it will keep going until you either shut PuTTY down, or stop the python script with Ctrl+C.

You can make the script run in the background by using a "&" after the script you want to run (may be two &, so &&, I can never remember, someone else will be along to remind me).  Harder to stop the script, I pull the plug on it.

 

I find it easier to write the script on the PC (I use EditPad Lite https://pendriveapps.com/editpad-lite-portable-text-editor/) and then just drag the file to the appropriate folder on the RPI using WinSCP.  Just make sure that the script is not running otherwise any changes will not happen until it is restarted.

 

If there is an error in the script, the line number, and some basic info, will be shown in the PuTTy screen.

 

And remember to either be in the correct folder for what you want to do, or use the full path.  So if you are in /home/pi but your python script is in /home/pi/temperatures either type:

python /home/pi/temperatures/temperaturescript.py

or change folder with cd temperatures

then type

python termperaturescript.py

 

(if you insist on using Python3 then just type python3 temperaturescrip.py)

 

ls shows the contents of a folder.  That is elle ess not eye ess or one ess)

 

First things first though, get an RPi set up so that you can SSH into it, you have to change a file via sudo raspi-config.  This can be done manually on a PC, just create a file and name it ssh in the /boot directory of the PRi file system.  No extension and nothing in it.  Or you can manually edit the /boot/config.txt file by putting in enable_uart=1 at the end of the file.  That config.txt file basically holds the information about what you want to use the RPi for, so it will have lines in it that refer to the 1Wire stuff, any real time clocks and so forth.  Probably easier to initially add a keyboard, mouse and monitor and use the raspi-config though.  Just a drop down menu that you can work your way though, including changing the password, setting up the wi-fi, enabling the 1Wire, the shh and so on.

 

I have no idea how much egg sucking I am telling Granny here)

 

Edited May 19, 2020 by SteamyTea

[Onoff]

18 minutes ago, SteamyTea said:

I have no idea how much egg sucking I am telling Granny here)

 

Whilst I'm very grateful for that...

 

I literrally understood very little of it. You might as well be speaking Cornish!

 

?

[SteamyTea]

1 hour ago, Onoff said:

You might as well be speaking Cornish!

Right on me bird.

 

Get a Pi up and running, the rest is easy to talk though.

Then download those 3 utilities I suggested.

Make a desktop folder and copy the files into them.

Then follow instructions.

[Onoff]

ABS printing is proving as unsuccessful as it has been up until now!

 

 

 

 

I'm wondering if the extract fan position is wrong and too high up, as in taking heat away from the print area?

 

On the test cubes above X is the face you see as you open the door. It's pretty good imo. Y is the real screw up face. It looks like the layers have been affected by "drag" whilst being put down. I'm betting that's the front to back air flow caused by the fan. Z should be "flatter" but it's not. The laying down of material is obviously helped by gravity but there appears to have been some slight "lifting". Again, betting caused by the fan.

 

One chap I've read has a similar 120mm fan to this but lower down in one of the corners, not sure if it's on the back or side of the enclosure..

We're limited with the enclosure sat on a desk as it is at the mo. Can't vent left or right or low down to the rear.

I might quickly knock up a ply "chimney" to go on the back wall of the case. The idea being that "damaging" heat from around the electronics and psu will be drawn in at the base through the "fireplace". Above the bed will stay nice and warm. Excuse the dog rough sketch this morning!

 

Hopefully it'll drag in any smell too.
Mind you, no discernible smell last night whatsoever, fan on & using Steadytech ABS Pro.

[Temp]

I've no idea if its any good but Amazon has put some "Amazon Basic" filament on their store recently at under £18/kg. Never used it myself as never been able to buy any. 

 

 

[Onoff]

Packet of 10 DS18b20 sensors have turned up in the post finally! I'll have the necessary resistors kicking around in spades I'm sure. Once out of quarantine I'll give to my lad to play with on one of the Pi's. He's stopped trying to print in ABS at the mo. Space around the psu was getting in the mid 40s degC. That'll have to be relocated.

[Onoff]

This is the code my lad used for showing the temperatures, simultaneously for 4 DS18b20 sensors. Ripped off from somewhere. All's he's done is add 1 line to the config file on the Pi to get it to work. This even though it should have defaulted to pin 4 anyway:

 

#!/usr/bin/env python

import glob
import time

# DS18B20.py
# 2016-04-25
# 73 01 4b 46 7f ff 0d 10 41 : crc=41 YES
# 73 01 4b 46 7f ff 0d 10 41 t=23187

while True:

   for sensor in glob.glob("/sys/bus/w1/devices/28-00*/w1_slave"):
      id = sensor.split("/")[5]

      try:
         f = open(sensor, "r")
         data = f.read()
         f.close()
         if "YES" in data:
            (discard, sep, reading) = data.partition(' t=')
            t = float(reading) / 1000.0
            print("{} {:.1f}".format(id, t))
         else:
            print("999.9")

      except:
         pass

   time.sleep(3.0)

 

Of course it does this all in a terminal. How then would he make a graphical representation of the enclosure on screen with text boxes for each sensor? I just need to point him in the right direction.

 

Cheers

[Temp]

Google found this YouTube video for a simple project with visual display. Uses a library called TkInter.

 

 

[Temp]

My current 3D printing project is a 1/3rd scale version of this Greek bronze Griffon currently in The Metropolitan Museum of Art. The print has been done and painted in white primer and I'm currently copper plating some test pieces to figure out how to get a decent finish. 

https://www.metmuseum.org/art/collection/search/255367

 

[Onoff]

Makita Li-ion battery to Ferrex (Aldi) tool adapter in one main piece. Head hurts. Test print soon hopefully! Only because, on a whim I bought a bare18V Ferrex hedge trimmer the other day. 

 

The Makita 2 Ferrex on Thingiverse/Yeggi is 4 pieces! Hoping to get it down to 2, possibly 1. 

[Temp]

I don't know about that adaptor but I sometimes split things into several parts to be glued together later because it either allows you to avoid printing supports or produces a better print quality.

 

[Onoff]

30 minutes ago, Temp said:

I don't know about that adaptor but I sometimes split things into several parts to be glued together later because it either allows you to avoid printing supports or produces a better print quality.

 

 

Me too. The 4 piece design I referred to has the two main sections screwed together.

 

I'm mulling printing the moving parts that will in effect be captive, with supports. Then incorporate accessible slots where I can slide a hacksaw blade in to invisibly remove the supports.