Filament - Showdown

The one thing I like about PET- G is that you can print with out much of a raft. 

Petg - setting

I am printing in on the raise3d n1 printer and use just a skirt line around the print on to buildtak

The settings have been Extruder temp 255 and bed Temperature 70

PLA + with a raft 

I recently got some PLA+ from eSun printing that at Extruder temp 205 and bed Temperature 60

The image The same part is printed with PLA and PETg both look good but the PLA+ looks smoother and has less problems with warping. 

Filament - PET-G vs PLA+ eSun 

Here is a list of aspects typically associated with PLA+:

• Surface texture: Standard PLA has a rough surface both on the surface of the layers and on the outer part of the layers.
• Overhang: PLA+ has better overhang properties that leave less stringing on the final print.
• Print temperature: PLA+ typically has a higher print temperature than PLA.
• Reflection: PLA+ has a glossy reflection that helps to showcase it better.
• Strength: Based on a number of videos on YouTube, PLA+ seems harder to break. Users exposed it to various tests, including smashing, weight holding, and bending. When over-stretched, PLA+ bends while regular PLA snaps

Counting instances that aren't in a set of values

Using Google sheets

People are give an option to reply other in a form. I want to be able to count The number of these. So I am using Countifs

Countifs allow us to count something if it meets multiple criteria

The first field is where to look ie where is the range.
In this case it on the tab responses in the range B2:B
note you need the exclamation mark to reference the tab
responses!B2:B

Determining if a value is not equal
"<>" in quotation marks is the same as not equals

Checking against a cell use an ampersand
&A2 will check against the value in A2

Here is the whole thing below each condition is separated by a comma.


=COUNTIFS(responses!B2:B,"<>"&A2, responses!B2:B, "> ", responses!B2:B,"<>"&A3,responses!B2:B,"<>"&A5,responses!B2:B,"<>"&A6,responses!B2:B,"<>"&A7,responses!B2:B,"<>"&A8,responses!B2:B,"<>"&A9,responses!B2:B,"<>"&A10,responses!B2:B,"<>"&A11,responses!B2:B,"<>"&A12,responses!B2:B,"<>"&A14,responses!B2:B,"<>"&A4)))

Checking for a generic welcome post in a twitterfeed - python

Well I have been thinking this was necessary for a while because when a year starts or a new class begins their individual blogs these start clogging the twitterfeeds with generic welcome posts. The feeds start looking like this.

Now I am no Python Guru so here is what I found out in creating the solution

I made a variable to hold what would be the last characters of the url 

welcome = 'welcome.html'   note you can replace this with what ever you have at the end of the blog title eg tenei-taonga.html

I put the last 12 characters [-12:] into a variable(welcomecheck) to check against 

welcomecheck = d.entries[0].link[-12:]

We were already checking if the post had already been promoted the highlighted text below adds a check to see if the post is a welcome one. It took me a while to work out the if statement needs to finish with a colon: the == sign is used to check that the strings match.

if post in url_string or welcomecheck == welcome:

        print('No new entries or welcomepost')

The rest of the code remains the same.

https://github.com/davein2it/twitterfeed 

Check out a sample of the learners blogging at these twitter feeds.

Coffee Handle fun.

I have had a bit of fun with the 3D printer since trying out PETG filament as a replacement to ABS for some of the parts I have been making about the place.

I have a had a go at replacing the melted handle of an old yet beloved stovetop espresso with a 3 printed one and have learnt a few things that I thought I would jot down here and explain abit.

Learnings

1. Even though the 3d printing process takes place at a high temp eg PETG @ 230 degrees the plastic will glass (start to melt much earlier) @ 90
2. To prototype a fitting like a handle a good approach is to make a model of what is being fitted to and turn that into a hole or an object that will remove material from the finished item. ie make the easy small bit first
3. You don't have to print every material yourself - I have used a service called 3dhubs to print in polycarbonate. The part will cost $9 delivered and means I can do the modeling and prototype ensuring that the print will fit.

High Temp Parts

The coffee pot handle fit perfectly is strong and feel solid  to pick up the pot though when the coffee has just brewed it is soft and bendy -- oops. My temporary solution is to put a bit of cold water just on the handle which soon firms it up again. I have looked at different types of filament and my conclusion at this stage is that Polycarbonate is the most suited to parts that need to face up to hot conditions.

Make the easy bit first

before I made the handle i made a model of the piece that fitted the handle first. Luckily I had the handle there to test with. In that way I could be sure that I had the right model of the part of the pot that the handle joins to. 
Next I

Getting all your Drives Linux - Memory games

One of the things that happened to me through using the Raspberry Pi and Linux is that over time I have learnt a few things to type into the shell to get around. 

this is my blog to self of all I can remember in 5 mins

cd  -  change directory

df -h   - list files and sizes

sudo nano /etc/fstab    - describe what drives get mounted at boot

cp +rwx /location directory  /destination directory

chmod - change permissions

chown - change owner

cd ./directory  a directory with in the present directory

ls - list directory

apt-get install package 

crontab -e  -edit the cron tab

ctrl c - escape current process

python /programme path  - run a programme

reboot - reboot the pi

rasp-config

TIMES up 

Note to self must do better

Solving no network for my pi

On a reboot I was able to ssh into the device but not the internet.

What was effected was both the gateway and DNS server settings

Tested gateway issue through trying to ping google

ping 74.125.29.138 Google

Gateway resolution 

The solution was to add a default gateway which was missing from the routing table

sudo route add default gw 192.168.1.1

With the internet established I was still unable to intstall packages or

apt-get update

This was caused by being unable to resolve the address

mirrordirector.raspbian.org/raspbian

DNS Resolution

Edited the file /etc/resolv.conf

to add the google name servers

done by

sudo nano /etc/resolv.conf

added the following two lines

nameserver 8.8.8.8
nameserver 8.8.4.4


Then we we good to go

test