The Cabinet Part 3

Plans have changed again. Having swam through a lot of 3D printing vids and blogs I realised that I really wanted to be able to print flexible and soft materials for things like tyres,seals etc.

Actually I got right into the detail and ended up with three basic specifications for Filament type (FDM) 3D Printing machines:

First, GP/ Decorative – materials are not particularly strong or durable but the models are high quality finish. Of course, this machine could also be used for general purpose printing

Next, Strong - this one needs a high temp chamber and temperature control, materials such as PE that can be used in high strength applications – but this needs a lot of specialised equipment to do properly. Prints must be gradually cooled after printing to keep their shape and there are a lot of technical challenges.This could get very expensive.

Third, Flexible – printing soft and flexible materials requires a direct drive printing head (the filament drive is attached to the hot end) and this is not common since it makes the printer head heavier and thus the machinery must do more work to move it around and the process of printing can be slowed down by this. This is why I suggest a specific machine just for this type of material. 

Actually, I really like the idea of a dual head machine for flexible materials since then you could use PVA or something similar for support material – but that is whole new machine again.

I am not going to start building a “Strong” machine: that is well beyond my current needs and abilities due to not having the tools or workshop – but I can certainly get the other two, which led me to buy a second machine with direct drive extruder – the Sidewinder X1. This machine has about the same build volume as the CR10S and good metal construction but it is a lot cheaper.

It also does not have auto bed levelling - but I will see about that - it may be possible to add it later.

Middle space showing 10mm holes for the mid panel nuts.

To get the middle panels on it was necessary to drill holes big enough to get the nuts through and then into the slots in the extrusion bars. The alternative was to try and attach all three side panels together then slot them in as one part (not an easy job) and do up the bolts – but then if you want to take a panel off later all three must come off. It would also require very accurate hole drilling and my hand work is good, but maybe not that good.

Since the design has already changed from my original and the cut panels cost so much I hope to avoid buying more – so the door for the lower chamber had to be made from two parts, joined with a strip. I also fitted the solid feet at the corners this weekend and moved the wheels inside of them using bars to support them – this is because the cabinet needs to very solid. This need drove me to order more parts and I discovered that 45 and 135 degree brackets are available so these will be used to add three diagonal braces to the bottom when they arrive. There is only one bolt hole so maybe I will drill extra bolt holes – but regardless, this will add stiffness. 

Base showing wheels and feet, which can be raised with a spanner.

When taking these photos I put the lower door on where it is intended to mount and discovered that it won't fit flat: the metal right-angle brackets collide with the nuts on the inside of the door. This can be fixed with countersunk bolts but it means using a 45 degree chamfer drill on the plexiglass. Cutting it was bad enough – my first cut was cracked in five places. Using the right tools makes all the difference - well, that and being patient. I will need to do a test drilling or two.

Cabinet redesign with diagonal braces

View from the other side showing air duct system

 The lower chamber will now house the second printer so there is also an air duct for this area too. 

I also have a window exhaust duct designed exactly to fit my window and go around the blinds - but of course it needs to be 3D printed !

Window exhaust duct

The aluminium extrusion building system used here was all bought from eBay – all of the bits from different suppliers, and I am impressed by it: there are a wide range of sizes of the extrusions, the nuts and bolts, brackets and various other parts too. I found a store that precut the bars to my preferred lengths and a supplier for the panels that did the same, and good thing it was too: I don't have the equipment to do these cuts myself – well, not as neatly as the suppliers. Because the parts are all fixed in the slots, you can adjust their positions as required which is great for flexible projects like this – and all of the frame parts can be reused later if desired. Nearly all of the 3D Printers I have seen are made of this extrusion although they do drill and tap holes in it for solid fixings as well. I have even seen factory techs in China building automation equipment from this same system. 

There still as lot to do to get it finished - but progress is happening even if I only have about one day a week to work on it. There is also the enforced delay of waiting for ordered parts to arrive - but then there is an advantage to working this way: I have a lot of time to think about everything - as you can see, the design has already changed in major ways. I have also simplified the design since it is then more flexible.

Finally a special tip of my hat to . . . . . Microsoft. The latest update of Windows 10 includes a screen clip tool that works right – just press Win-Shift-S and you can snapshot your screen just like on a Mac. Ooop. Didn't mean to say that – well, since Apple has left us creative folks out by pricing the new Mac Pro so astronomically that only the elite can afford one (when it eventually arrives) we must make do - except that actually it's not at all bad. See my previous posts for more about going from Mac OSX to Windows 10 if you are interested.  It's actually better in significant ways.

The Cabinet Part 2

Design Ideas

I have been working on cabinet modifications in spare time – easy to do onscreen, a lot more work in real.

To print well in stronger materials you need to be able to get the build area warm but you also need to keep the electronics cool - and there is also a need to be able to vent the build area to outside or a filter, so this means ideally you need four areas:

1. build area with a vent valve
2. circuitry area with cooling airflow
3. intake area
4. exhaust area with extractor fan
   
   So here is the idea modelled: 
   
   
   
   

There is also a change I made here where I put the filament roll directly under the build area – it just seemed natural to do it that way. This means the bottom of the cabinet is empty for now but then the whole thing may be too shaky for normal operation  -  3D printing is dependant on having a very stable surface to operate well – any shake in the table or bench the printer rests on will result in vibrations of the print head and this produces “ghosting” - rippled print surfaces.

I will only find out how good the printing is when it is actually running.

I have identified the air intakes and exhausts on the CR10S Pro case and thus located inflow cooling ducts at these two points. This means a lot of small pieces glued together and I am still unsure how well they would seal onto the CR10S case – ( how airtight do they need to be? ) and also the various parts need to be accessible and I am not certain how practical this would all be. 

I put the second intake where the power cord goes into the case so that covers one matter but there is still the question of just how to remove or replace the surrounding parts around the printer when things need to be looked at – for example, at the moment there is no way to access the USB port on the printer when it is in the cabinet and the power switch will have to be left on and turned on/off at either the power board or a wall socket. I might add a door just where the power board is located which would also have a cutout for the power cord. The power board will also provide for adding lights and any other powered extras I might add later. 

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At some point it becomes tempting to pull the whole printer apart and get rid of the metal case and fix the frame inside the cabinet, thus all electronics can be in their own area with isolated cooling. The trouble with this kind of thing is that I can easily progress to tossing the whole thing out and building a completely new whizz-bang machine with better, more expensive parts and I am in danger of starting a big project I may never finish . . . . 

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Stage 1, or what will definitely be done for starting the machine and getting it running, is completing the upper enclosed cabinet with door and fume extractor. This means cutting a hole in the floor of the chamber and that lead me to buy some new bars of 2020 to support the printer more directly: there is some question about how well the panel sheets will take weight when they get warm and I don't want to cut a hole in the back wall only to need to patch it up later. 

Stage 2 – Getting the printer fully upgrade with all of the extras I have already bought

Stage 3 - adding the Octopi remote controller, lights and camera

Stage 4 - improving the cabinet, including relocating the spool holder and addingthe air ductwork.

Seen in my local supermarket #2: What exactly is "creme"?