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Sunday 28 April 2019

Big sign

We needed to put a sign outside to advertise Shelley's garden open days. Sunday 19 May and Sunday 16 June 2019.

She's letting people in to view the garden in order to raise money for charity. See the entry in the National Open Garden Scheme.

As part of the supplied stationery, we have some paper posters however, these are not going to survive the weather for very long. I put up a temporary solution in a plastic sleeve but to look nicer and to last a bit longer, we need something a little different.

Something 3D printed.

The 3D printer I have is an Ultimaker 2+. Its build area is 220mm x 220mm. That is not large enough for the sign I had in mind. I have, therefore, designed it in multiple parts.

I may have got carried away.

In addition to the 3D printed elements, I've made the supporting structure.

Now we just need people to come on the days.


Monday 22 April 2019

Budget fitness tracker

For over a year I have had a Fitbit. Shelley bought us each one to make sure we stay healthy in to our old age. The Fitbit would no longer sync with my phone.

As a replacement, I have recently bought a low budget, £32, fitness tracker from Amazon and it works better than I was expecting.

Last year, when the Android operating system was updated, my Fitbit stopped synchronising to my phone. This was annoying but, after having reported it, I expected the well known brand to fix their app fairly quickly.

Here are just a few examples of the failure:

6 months or so later, they still answer the queries with "It's not on our compatibility list".
Most people do not check a compatibility lists before buying a device that works with Android and most people expect the well known brands to be on the case to fix faults.

I am very disappointed with Fitbit.

The new one I have bought is branded more-Fit but there were a dozen identical models with different brand names. I picked more-Fit over others because they were on Amazon with answers to customers questions.

The model I have bought is excellent. It was easy to set-up. I just downloaded the VeryFitPro app on my phone, after finding the device it prompted to bind the fitness tracker, I then entered a minimum of personal details, job done.

The fitness tracker I now have does not count as many steps as my Fitbit used to but there is no way to know, which is correct. The software display is not quite as clear but everything I need is there. The fact I can get anything on my phone is the important bit and better still it reliably syncs.

I don't know why but I am, yet again, surprised by how poor some big brands are at looking after their customers and how good some of the very low price, usually Chinese, products are.


Sunday 21 April 2019

Garden screening

In preparation for Shelley opening her garden, for the National Open Garden Scheme, I have built a screen round the 'back stage' areas.

The area the screens cover are those parts of the garden where we store things.That's piles of timber, haylage and bedding for the horses, ladders and spare wheels and even where Shelley does her potting up.

I've used fence panels with removable pin hinges to join them together in whatever arrangement we need.


Saturday 20 April 2019

Cuprinol v Ronseal fence colour

I've used two different makes of black treatment for some garden fence panels.

  • Cuprinol Ducksback
  • Ronseal One Coat Fence Life

I'm primarily using them to change the colour of the panels. The added weather protection is just a bonus.

I have no reason to doubt the protective nature of both products. I have used similar products from both brands in the past and they have lasted well.

Both are water based products. I much prefer that over oil based products.

Ronseal Fence Life

This has a thin, near water like, consistency.
It is fairly easy to apply with a brush and gets in to the crevices.
The colour is described as a black oak colour. I can understand why. On the pressure treated fence panels it is not completely black, more a, watery, very dark brown.

A nice colour but not entirely black.

Cuprinol Ducksback

This has a thick gloopy consistency.
If it is not watered down, it needs a bit of effort with a brush to work in to the rough sawn timber.
The colour is black. No question about it. The result is almost like paint.

I prefer the colour of the Cuprinol and it covers a wider range of materials including, to some degree, galvanised steel.

Watering Down

I'm sure the manufacturers of both products would be horrified that I water down their products.
On sawn timber I find that the thinner consistency is much easier to apply when using a brush.

Mixed to the following approximate proportions the colour change was barely noticeable on sawn timber:
Ronseal: 60% Fence Life to 40% water.
Cuprinol: 40% Ducksback to 60% water.
Remember that I am only interested in the colour. Watering down is likely to have an adverse effect on their protective abilities.

The Ronseal pot is a larger diameter, so it is much easier to fit the brush in to, it is also easier to open and close.
I have kept the Ronseal pot to fill with Cuprinol :-)


Friday 19 April 2019

Mini filament review

For the last couple of days I have been printing some signs.
They are mainly flat with raised lettering.

Due to various failures I have been trying different types of filament among other things to fix the issues.

The results have led to some conclusions and preferences.

Filament choices in order of preference: PLA Plus
This is the best at the job so far. It stays flat on the glass with no warping even on the largest size flat prints.
It's not perfect though. The end of the spool is wound so tightly that the Ultimaker 2+ extruder struggles to get the last half dozen layers of coils off of the spool. That's a lot of wasted filament!
My guess is that the tight loops press against the inside of the Bowden tube so I can't even use it loose from the spool.
Heated to 225C with the bed at 45C.
The results have a nice tidy surface finish with sharp edges.
Takes spray paint well.
Update: is no longer available. They suggest trying I have used them before but have not got any in stock to try out. I'll update this article when I have tested some.
I'll probably try their Premium PLA:

ColorFabb PLA/PHA
This was a lot better than standard PLA. It stayed flat on most prints with only a slight tendency to curl.
I get best result running it hotter than the suggested.
For me I heat to 215C with the bed at 60C.
The surfaces are nice and tidy. The raised details have a very slight bulge at the corners. If I was not comparing to other prints I would not have noticed.
When spray painting it is obvious the surface is porous along the print lines. PLA
This would not stay flat. Even before it had done the third layer the edges of the brim were curling up and by the time the print had finished, the main body had lifted by a couple of millimetres at several corners.
I've used this successfully on other prints. It just does not like the thin flat prints.
Printed at 210C with the bed at 60C

Inconsistent Information
Several of the manufacturers provide guides or printed temperature ranges on their boxes. This information often changes. One manufacturer has three different heated bed temperature suggestions for the same filament, one on their web site, a different figure on a card supplied in the box and yet another range on the side of the box!

I no longer take the instructions as fixed rules. I use the suggestions as a guide to get me in the right direction. Trial and error is the only sure way.


Glass Thickness

As far as fixing the various issues, I think the glass is the main problem.

One of the problems is that the prints would warp. This always started in the rear right corner. For many prints that was the only issue but invariably the print would lift so high it would impede the print head and ruin the print.

I can only assume there is a slight inconsistency in the glass thickness. If I avoid printing on the rear right quadrant of the print bed, I get much more reliable results.
The affected area extends about 50mm from the right hand edge to about half way forwards from the back edge.

I managed to avoid this by rotating the largest prints and they have all worked since.

I plan to experiment with bed levelling to see if by deliberately setting a greater distance at the front left corner I can get better reliability at the rear right.


Worn Nozzle

Before I was able to get anything working I had to replace the nozzle.
The filament would flow for a while then get straggly. Small blobs every few millimetres with thin thread like strands between!

I don't know if the hot end nozzle was contaminated or worn but after I replaced it the flow was even again.


Printed with Thicker Layers

In the past I have found that thicker layers are troublesome. Now that I have done some more trials, I am able to successfully and reliably print with the following settings:
Nozzle: 0.4mm
Layer height: 0.24mm
Edge, top and bottom thickness: 1.2mm
Print speed: 60mm/s
Travel speed: 120mm/s
Adhesion: 7mm brim
Bed: Glass with hairspray (once in a while)

Rules of Thumb
I found on an Ultimaker forum, a rough guide to layer thickness and print speeds.
This approximately lines up with my experience, so I will use it from now on, rather than my usual guess work.

Maximum layer thickness: 3/4 of the nozzle diameter
e.g. 0.4mm nozzle can print a layer up to 0.3mm thick.

Maximum speed
The maximum print speed is determined by how fast the filament extruder can feed.
Stock Ultimaker 2 extruder, maximum throughput of 2.85mm filament: 7mm3/s

Calculation: Nozzle diameter x layer height x speed = throughput area
e.g. 0.4mm x 0.3mm x 40mm/s = 4.8mm3/s
Maximum speed calculation = Maximum throughput / (nozzle diameter x layer height)
Therefore the maximum speed is likely to be:
7mm3 / (0.4mm x 0.3mm) = 58mm/s

I have an Ultimaker 2+. According to the Ultimaker web site, the Ultimaker 2+, can print up to 16mm3/s with a 0.4mm diameter nozzle. It has a maximum travel speed of 300mm/s.
In theory, therefore, I could double the above speeds. In practice I have not been able to a achieve speeds much faster than the above calculations.
I tried, just as a double check. 0.4mm nozzle, 0.24mm layer and 90mm/s at 210C with PLA = 8.6mm3/s. It came out lumpy and did not stick to the bed properly.
The kit was clearly capable of pushing it at that speed but it would need a lot more tinkering to get close to something usable.

Nozzle Temperature
The hot end temperature is far more trial and error. That is partly because the thermostats in the printers are not that accurate.
Most manufacturers recommend starting at the low end of their suggested range of temperatures and work up.
According to most vendors, 2.85mm diameter filament tends to need to be about 5C hotter than 1.75mm filament for the same speed, so for a standard Ultimaker, which uses 2.85mm filament, start at 5C above the manufacturers suggested lowest temperature.
Increase the temperature for faster throughput. Alternately, it would be simpler to increase the speed for lower layer heights so the throughput is always roughly the same area per second, therefore the temperature could remain the same for all prints.


Sunday 14 April 2019

Bifold gate

In preparation for Shelley opening her garden for the National Open Garden Scheme, we have been doing a lot of tidying.

To create a temporary back stage area, I have made a bifold gate out of some doors I had in storage in the shed.

At the moment the gates are latched back against the rear of the stables. When we have arranged some fence panels to hide the pallets of haylage, the gates will come in to action.


Monday 8 April 2019

Computerised filing

For a long time I've found the file systems on computers disappointing. Increasingly I find I want to store things in multiple places.


The concept of folders is not efficient for the computer nor is it helpful in finding files that relate to multiple subjects.

"My-File, #Top-Level, #Sub-Level, #Also-Something"

I think, in this day and age, all files could use a tagging system.
Computers are powerful enough to carry out these searches in real time. The tags would need to be indexed and stored in a database.

Many online systems already use tags instead of folder.

Very simple to implement. When the file is saved the person would get the opportunity to add tags to the file. These would be saved with the file and indexed in a database.
Existing tags should be easily browsable at the point of saving, exactly like the existing folder structure.

"Other-File, #Top-Level, #Something-Else"

When browsing files, the existing folder structure gets translated, automatically, to a search. Rather than a folder and sub-folders, it would be a list of tags with the logical AND applied to them. In addition a manual search box could be used so the logical OR would take precedence.

"#Top-Level\#Sub-Level" = files tagged #Top-Level AND #Sub-Level
"#Top-Level,#Sub-Level" = files tagged #Top-Level OR #Sub-Level

The important bit is that a browsable hierarchy exists. You don't have to remember any of the tags used nor the file name. As you select tags any tags that are also on files with that tag are displayed for easy selection along with a list of all the files tagged with the selection.

File Manager
Browse: #Sub-Level, #Also-Something, #Something-Else
Matching files: My-File, Other-File

File Manager
Browse: #Also-Something
Matching files: My-File

File Manager
Matching files: Other-File

I'm sure there must be some disadvantages but I'm struggling to think what they would be.
The system can easily integrate in to the current way of working with the additional benefits being available in parallel.

If only I had time to write a file system.


Sunday 7 April 2019


I've made a couple of box style shelves.

One for the kitchen, to put the wifi and Sonos on.

The other is in the study, to house the speakers used with the Xbox.


Friday 5 April 2019

Fender enhancements

We've carried out a couple of jobs, over the last week, on Fender.

I've added the letters back to the front, with a slight but significant change.

Dean made a very nice set of hoop sticks for the back including a leaf motif.


Tuesday 2 April 2019

2020 T-slot GX16 enclosure

I have a small CNC engraving machine which I am going to use as part of the proof of concept for my project to convert a Shapecut oxy gas cutter to CNC.

I am deliberately using a more powerful CNC control box than is necessary for such a small engraving machine. As a way to keep the larger cables tidy I have made a small enclosure to mount on to the 2020 T-slot aluminium extrusions. The enclosure fits three GX16 aviation style connectors, which are used for the X, Y and Z axes, and a GX20-4 connector, used for the spindle of the CNC machine.
Initially I made a box that fitted only the three GX16 connectors which I then expanded to fit the GX20.

The 4 pin GX16 sockets are sized for use with NEMA23 stepper motors and are suitable for up to 5 Amps. They are far larger than needed for the tiny engraving machine that I am currently connecting them to.

I've selected a GX20-4 pin connector for the spindle, not because it needs 4 pins but because the individual pins are only rated at 10 Amp each. I can double up the pins to allow for the 20 Amps that might be necessary on a larger router spindle.

The enclosure can be bolted to a aluminium extrusion using either M4 or M5 drop in T-slot nuts. Typically the M4 size fits the 2020 profile extrusion.

The bolts hold the lid closed as well as holding the box to the rail. There is a small tongue and groove detail along the top edge to ensure that side of the lid stays in place.

I 3D printed them, on their backs, without any supports.


Shapecut Series:
Part 1 - Magic Eye to CNC
Part 2 - CNC proof of concept design
Part 3 - CNC controller enclosure


STEP, Fusion 360 and STL files (Zip)
Licence attribution - small business exception