Coronavirus Impact Covid-19.
Although we are no longer in lockdown there are still uncertainties. So for the present we are continuing to hold our meetings online.
I hope you are all keeping safe and well and will be able to join us online.
Contact Gareth ( or to firstname.lastname@example.org ) if you don't think you are on our meeting list of participants for online meetings if you are interested in joining in; since he is sending out the links prior to each meeting. Just follow the link and follow on-screen instructions.
There is nothing to download or install. We still meet on the third Wednesday of the month at 7:30 p.m. via Jitsi.org Video conferencing. If using a Mac IOS the Safari Browser works correctly for screen sharing your own screen, but this doesn't work for Firefox.
At the next meeting we will look at a number of Operating System updates, with what is new in Ubuntu 22.04 , Windows 11 and MacOS 12 (Monterey) and time allowing the beta of MacOS Ventura.
Mainly presented by Gareth with inputs from Peter.
Peter began by giving an overview of the system.
Overview of the Creality Ender -3 V2 is the model which both Gareth and Peter own. These are very reasonably priced (under £200). The printer comes flat packed in a large box.
The main parts being the base plate assembly and the support framework for the print extruder head which consists of a horizontal bar which drives in the X-Axis direction and two side rails which support the horizontal bar and provide the Z- Axis vertically. The Y-Axis is provided by the base plate itself, which translates forwards and backwards. There are online videos
and diagrams in the handbook showing how everything fits together. One of the critical features is the adjustment for levelling, which is carried out with four spring loaded adjustment screws under the baseplate one at each corner. Levelling is not literally "levelling", but ensuring that the extrusion head moves so that it is at exactly the same distance from the base plate. The adjustments are carried out with the motor servos disconnected by the software program so that the X and Y motions are free to be moved manually. Normally in optical bench equipment there would only be 3 adjustment screws and here the handbook suggestion is to go around all four corners several times to make the baseplate level and it is correct, however Peter thinks it is easier to adjust by using the screws along diagonals e.g.. AC and BD. The height is set using a piece of A4 paper which is about 0.1 mm thick by drawing it between the extruder head and the base plate with a slight tension whilst making the screw adjustment. There are assumptions on the flatness of the glass baseplate and so it is possible to add a height detector with modified firmware. Peter has one of these to install but has not had an opportunity to do this yet. (CR Touch Autolevelling kit.)
The extrusion filament is supplied on a drum which is supported at the top of the structure so that the filament can feed into the drive mechanism. Initially it is best to start with PLA (Poly Lactic Acid) although ABS and several other plastics can be used. For PLA the extrusion head is heated to about 200 C and the glass base plate is heated to 60 C. There is also a fan or cooling purposes. Some people find adding a thin layer of glue to the base plate helps adhesion of the filament. The filaments are available in various colours and textures and since the PLA is hygroscopic they need to be kept dry which can be done by storing in vacuum bags with desiccant with humidity indicators or by drying out in a small oven at low temperature below 50 C. Peter had a fault on his printer initially where the drive wheel on the feed slipped and it only got traction as the grub screw gripped it which caused no end of problems!
Designs and slicing.
There is a library of designs on thingiverse.com which can be used or one can design ones own objects using FreeCAD or FreeSCAD. Peter has looked at FreeCAD and commented that this is a large piece of software which has been developed over the years and is used for all sorts of design tasks not just 3D printing. The application he was interested in was the Part Design section which is a computerised drawing package. In controlling this the physical control i.e. 2 or 3 buttons mouse, scratchpad and the operating system determines the choice of control for zooming, moving, selecting etc., on some systems known as "gestures"
known here as "Navigation" . It is best to learn one way and stick to it.
The design saved as an STL file then need slicing. Any object design is sliced horizontally and converted to what is known as gcode. This is a text file consisting of settings for X,Y and Z axes, Timecode and extrusion speed. One such program is Ultimaker Cura. The slicer produces a file for the specific printer in use. There are many settings in the program to enable extra support for complicated structures and to change the infilling. An object does not have to be solid but can have an internal scaffolding or infilling to give support and to save on material and time of production. When you have the sliced file it is saved onto an SD card which is inserted into the printer. The slicer software will give an indication of the time required to print an object and how much material will be used. Some complicated designs may take more than 24 hrs to run so it is important to know this in advance. Peter was planning to make an insert to his reel holder to make it more central on the support. designing it in FreeCAD. This will be a good project to learn FreeCAD.
Gareth showed his printer in action producing a stick man design which only took about 2 hr 8 minutes and used 12gm. of filament 3.89 m long.
Gareth had made good use of Thingiverse.com to find designs for track additions to his son's Brio wooden railway including a turntable. He is planning to build a railway tunnel which looked quite adventurous and would take just under two days to print. He has also made some cable brackets for racks for work and is very proud of a Wankel Engine cutaway as a working model which he had printed. His own Wankel engined car is still going well although is not fuel economic. 230 hp and 1.8 litres.
Fig. 1 Gareth's cable brackets.
Fig. 2 The Wankel engine.
Gareth needed to manually adjust his base quite often especially if producing a large area object.
OctoPrint allows printers, like ours with no networking to be connected via say a Raspberry Pi to present a web interface. This is useful in order to remotely check on the printer operation. The files can be modified and run remotely and added thermal upgrades are part of it. Also with an added camera one can get a birds eye view of the machine.
Some of the parts needed for Octoprint are in fact 3D printable too. www.howchoo.com/octoprint. Octoprint is free open source software to remotely control your printer with Raspberry Pi 4. There is a whole wealth of information on this online showing every detail of how to set it up, specific for the Creality Ender 3 V2.
www.creality.com for 3D printers
www.thingivrerse.com library of existing objects to use.
www.ultimaker.com for Ultimaker Cura slicer software
www.howchoo.com/octoprint for Octoprint.
There are lots of online videos showing you how to do everything.
We have now had a Committee meeting and updated our future programme. However we can be flexible and rearrange topics if the need arises, so if anyone would like to present a talk or suggest a topic to be covered please let us know. We are hoping the Covid restrictions will now allow us to have Social Evenings. If anyone has a favourite restaurant suitable for our Social Evening please let us know. We like to hold these in the area between Ipswich and Colchester so that friends from Essex can join us.
Also once the restrictions allow in-person meetings it has been suggested that we alternate our meetings between online and in-person meetings, although online meetings have been quite convenient for several of us to avoid going out and also saving travelling time. Since now the cost of fuel has rocketed it may also be more prudent to stay online only. Gareth suggests this may need a decision at the AGM.
|ICENI Future programme 2022/2023|
|July 27th||Ubuntu 22.04 LTS release and flavours like Mint
Windows 11 update and MacOS 12.
|August 17th||Summer Social Event - Venue TBA.
Suggestions welcome Area between Ipswich/Colchester.
|September 21st||DigiKam and AI software. Auto face detection.||All|
|October 19th||Networks and NAS updates.||All|
|November 16th||Stills and Video Evening||All|
|December 21st||Gadgets and Party Evening||All|
|January 18th||Winter Social Evening - Venue TBA or
this may be a Jitsi meeting.
|February 15th||Audio Processing.||All|
|March 15th||Raspberry Pi and Arduino, USB-C - single board computers
and RISC OS.
|April 19th||Computer Surgery / Firewalls and Computer Security.||All|
|May 17th||AGM + Extras||All|
MEETINGS WILL NOW BE HELD ONLINE BUT STILL ON THE THIRD WEDNESDAY UNTIL FURTHER NOTICE. FURTHER DETAILS TO FOLLOW.
Our meetings are held at the Bourne Vale Social Club, Halifax Road,
Ipswich IP2 8RE ,
for a map and other details please see the website. http://icenicomputerclub.org.uk
Membership fee currently £15, visitors free.
"ICENI does not have any Insurance cover for computers or other equipment so please be advised that you bring machines to the club at your own risk."
However many household insurance policies will include cover away from home often with no increase in premium. (Ed.)