THE SHOLLEY PROJECT

 

I have a Clax shopping trolley - Original cost $285.00 AU

Made almost completely of injection moulded plastic parts.

Original model weaknesses

1. Front wheels are too small. Even a small ditch stops the cart.
   

2. Bendy. Some would call it a feature but the plastic frame bends on uneven ground. I want something a bit stronger. I am concerned that this will eventually result in it breaking.

3. Folding. The current model has a lot of complexity and parts because it folds flat while I don't need that. Yes, it is nice but unnecessary for now. Who knows what will happen in future though.

   4. Stairs and steps - gettign it up stairs when full is less than ideal.
   

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This one has kept me thinking for a while since I use it every weekend for our home shopping.

I started by designing it in Blender.

The Mk.1 has a simple 4 wheel design and folding frame.

 

The folding frame was a major complication but if I want to sell the design or the finished unit to anyone it is pretty much essential. I may not be living in a place where I can leave it up all of the time in future too so it is a desirable feature.

There was a lot of design work to get to this point and I planned to make it from aluminium extrusions and plates with some 3D printed parts for style or rounding corners. The folding system really needs to be made in the physical to test everything but I am not going to do that at this point.

Here is the folded look:

 

This was all okay but I realised that taking it up stairs or steps is a major need so I designed a new version with stairclimber wheels, the Mk.2

I believe this design of 3 wheel arrangement is patented and you cannot sell anything using it legally without giving a certain big defence contractor money which is a bit of a pest for a tiny one horse operator like me, so I thought up a cheaper slightly different version using two rear wheels per side to cut down on weight and cost. The down side is that it loses most of the benefit of having the three wheel arrangement since the pivot point is level with the wheel axles thus there is no reduction of effort. It doesn't matter if you are only making one for your own use, you don't pay for the patent then.

 

The main issue with building this thing is that I only have a little tin shed and no time to muck around building a milling machine etc. etc. to do the project properly. This is a big pain for me as I like to make things and not having a workshop is annoying but I can't do anything about it right now. I can't move due to family issues.

So there it is for now. Maybe in a few years when I am forced to retire I can get onto it. If you want plans and so on or have comments, just let me know. 

In case you were wondering . . . .

 Just for you, dear reader, this video tells you all about what is going on today. 

Just in case you didn't see it yet . . .

The Tool Case Project Part 1

Tool Organising, or The Adam Savage Obsession – TOOL CASES 

Okay I admit it. I watched Adam and realised that my workshop was hopeless – I don't actually have a workshop in fact. I need a space that can be organised as a workshop but more than that, it needs places for all of the tools I use and they must be organised so I can find them. I have suffered though moving house and as a result everything shop was packed in cardboard boxes and shoved in a tin shed until now. Then I decided to start making things again. I ended up buying tools I already had again because I didn't even know what I had, and even if I remembered it, I couldn't find it: a nightmare.

I won't get this problem again if I make my tool boxes well and so this is that project.

This is not a new idea for me either: I have been saving some cases from old video equipment I found years ago for exactly this purpose – they are mainly plywood and even if I only use the metal corner bits and hinges it will have been worth it.

I looked at buying tool cases but there is nothing that meets my needs – either they are impractical, too expensive or both. Lots of blowmould plastic: Nope. I will be getting some organisers for parts like nuts & bolts but none of the tool cases I have seen make sense to me.

I don't really want any big freestanding tools like a sawbench since I don't expect to do that much sawing – and I would rather find or make some sort of compact, folding alternative instead – I know I will have to move house again sometime and if any item is too big it will just be a burden, and don't even think about the cost. Those things are expensive.

DESIGN

I first set out some categories for my tools so that I could decide how many cases and what for:

I came up with six : (1) marking, (2) drill/tap, (3)saw/file, (4)join/clamp, (5)electrical and (6)paint.

As I learned from Adam, the best cases can either be sat at the back of the workbench for easy access or they become the workbench itself – this I intend to do for the electrical case. 

I also want to avoid making layered cases where you need to open layers to get at the tools behind: that means you can't see what you have got. Everything should be visible at a glance.

The cases must also be hand movable which limits the weight, so I might need to split the power tools up. 

It is also a good idea if heavier items should be lower down in the case for stability.

I expect to make them mostly out of plywood so I will need a saw with straight guides for that: not sure exactly how that will be done yet. I may need to buy a new tool for this !

There is one more issue to mention: expansion. I expect to be getting more tools as time passes or replacing tools that fail, so there must be some room for expansion and ways to modify or replace the tool clamps as needs arise, so the cases should be like this: there should be a solid main case body and then tool clamps screwed or otherwise removably attached to that.

As always I begin the design phase by measuring and modelling in Blender to get an idea of how things will be packed in and so forth.

Here are the two basic design ideas as described:

Basic case

Case/bench combination

 Yep, that means I now have a whole heap of projects to keep me busy every spare moment  - and this one could stall the others for weeks  - but it has  very good reasons why. I don't ever want to dig through piles of rusty tools for a chuck key again. It's kind of a metaproject: all others will benefit from it.  

Special thanks to Adam Savage for reminding me of my maker roots. Maybe other people have their ethnicity or something to identify themselves with, but me? I'm an engineer, a maker.

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"?