Woody's Workshop – Page 13 – Keeping the Grey Matter active

April 23, 2023April 23, 2023

Joining PLA filament

A simple but easy way

I found a simple solution to joining PLA on a YouTube video that seems to work and does not need any after cleaning. It appealed to my lazy approach to find simple solutions to problems.

Buy some 1/16″ bore / 1/8″ outside diameter (1.6mm x 3.2mm) silicon tubing from Amazon. This is sold in 10 feet lengths. Note it must be silicon so it does not melt with heat.

Cut off a 1″ / 25mm length of the tubing. Cut the ends of the filament square. Insert the ends of the filament into the tube so they butt into each other. It helps to stretch the tubing so when it is released it puts pressure on the two filament ends.

Use a soldering iron or similar hot device, heat the tube in the area of the join for a minute or so. Once it has melted, roll the warm joint gently between your fingers and then leave to cool. Once cool slide the tubing off the filament or if mid reel then slit it and remove it.

You will have a joint that is hardly visible and which does not need any further processing such as rubbing down.

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April 17, 2023April 17, 2023

Illuminated Optical Centre Punch

A variation of a recently published design

There was a feature in a recent engineering forum by Nell’s Mechanical Man Cave regarding a 3D printed Optical Centre Punch. The design had an angled magnified side window allowing the viewing of the punch point. This conveniently allowed viewing of the point without having to swap out the viewer lens.

The author was offering a free download of the STL files for the punch body and also two versions of a base print. I made contact and received the print files and duly printed out the body and base models.

To get a better understanding I suggest you view the YouTube post on the following link :

My immediate impression of the design was positive with the only drawback being the limited light available inside the punch body when trying to align the punch point.

I started a dialogue with Neil and suggested to him that the addition of LED lighting inside the punch body might solve this problem. Neil was positive and supportive of the suggestion and the result is detailed below.

I re-modelled the punch in Fusion 360 and after some experimentation decided to mount two white light LEDs inside the dome of the body with the associated battery and switch mounted in the top surface of the body under a removeable cap. Here are a couple of visual views out of Fusion.

You can download my full write up and updated STL files from the following ZIP file link.

optical-centre-punch-STL-and-PDF Download

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April 3, 2023April 3, 2023

Ubiquitous Dishwasher Tablets and their uses

Worth a mention but not engineering (sorry….).

We are still in France so engineering activity is minimal other than time on Fusion 360 which sadly included creating a layout plan for a small tiling job we had to do. (Must recommend this to Autodesk ….).

Some years ago we installed a Jacuzzi spa. This contains two large filter cartridges. These need regular cleaning. You can buy the branded proprietary cleaning agent either as a powder or a spray on fluid. Both work well but are expensive. The powder is used as an overnight soak. The problem with cleaning spa filters is if the cleaner is the wrong compound you cannot get rid of the soap content and the spa becomes a huge bubble bath when you turn the pumps on. There is a similar problem if you rinse your swimming costume afterwards in the shower. The soap residue in the material leads to spa froth when you next use the spa. You can of course go ‘au nature’ but that’s another story.

After some research we found a source of bio dishwasher tablets. Four of these dissolved in a large container will clean the spa filters overnight. The tablets do not appear to damage the filter material fibres and rinse well to not leave a contaminating soapy content. Needless to say they are much cheaper than the proprietary cleaning chemicals.

This got me thinking. How many other such filters are there in the house which could also benefit from a clean and reuse rather than dump and replace ? A vacuum cleaner is another which depending on the model could contain three or four filters. Cooker extracts are a possible target although many now have a stainless steel filter which can be cleaned in the dishwasher. HEPA filters in 3D printer enclosures ? (not tried this)

Finally, same theme, it’s Saturday night and you have had maybe a nice steak or fish cooked in your griddle pan. It’s late and you want to crash out and clean up in the morning. You know how horrible that pan is going to be to clean tomorrow but bed calls. Just part crumble a dishwasher tablet into the pan and add some hot water. Tomorrow morning you will be able to just wipe it clean.

These tips brought to you by Woody’s Workshop, a Yorkshire born engineer always looking for a lazy, low cost way to solve a problem. (Smiley face)

Don’t worry I’m just going stir crazy and need to get back home and into the workshop.

BTW – Did you see that Clough42 got the YT 100k subscribers award. Well deserved. Congratulations James.

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March 23, 2023March 23, 2023

One Hundred Subscribers

I didn’t see that coming and fibre in France

When I installed Gravitec it was more out of curiosity than anything else. Did people read any of my waffle or was it just a freaky high bounce rate ?

While this number is just a drop in the ocean on YouTube sites it’s nice to know that people still read things and for some weird reason must enjoy my Yorkshire sense of humour and my engineering inquisitiveness.

If you are one of the Hundred – thank you !

Other things …. we are currently in France (hence the lack of posts). We had an offer we couldn’t refuse from our service provider SFR to swap out our ADSL copper based connection for a fibre-to-house replacement. The ADSL dribbled along at around 9Mbps which was more than enough for Fusion 360 to connect and for Netflix to keep us entertained in the evenings.

The house sits around 60m from the roadside telecom pit and is connected via an underground duct. I fully expected the duct to be blocked but the engineers successfully used the ADSL copper to pull the fibre through.

Not quite so simple in the house.

The external duct rises in the utility room and then branches via internal buried ducts to various telephone points around the house. The copper was solidly stuck in the one duct we needed so a Plan B was needed. After 3 hours of drilling holes in walls, floors and pipework trunking we finally got the fibre upstairs into the office.

The fibre is clocking a fairly symmetrical 800Mbps according to Okla which is staggering. Fusion is a bit quicker to load and general web activity seems a bit quicker but not 10 times quicker. Downloads are pretty quick though. If we had a house full of teenagers we would probably appreciate the increased bandwidth but we are long past that scenario – well that is until the grandchildren get online…….

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March 11, 2023March 11, 2023

3D Thin Wall Printing Experiences

Probably An Inconclusive Ramble

Some while ago I was asked to 3D print the component parts of a 1200mm wingspan glider. The design STL files are available as a paid download from the SoarKraft website.

The first problem this created was that my Sindoh 3DWOX had insufficient Z height for the 200mm high print sections. This was a thinly disguised excuse to upgrade my 3D printer to a Qidi ifast. This has proved to be a good decision and I am very impressed by the Qidi and the quality of the print results that it generally produces.

I now need to qualify that statement because I have struggled (and also learned a lot) trying to print thin wall prints for the glider parts.

The Qidi comes with a slicer that is a skinned version of Cura. I struggled to get good thin wall results. The main problem being transparency effects in the printed surfaces immediately following internal bulkheads within the wing design. I mentally envisaged this as the extruder being unable to start pumping filament fast enough following the bulkhead transition. You can see this along the inner curved line on the image below. There are very fine threads of PLA bridging the gaps.

I am also a subscriber to Simplify3D. Their website has a help article on Thin Wall printing and a recommendation that the Thin Wall Behaviour can be improved under the Advanced/Thin Wall Behaviour by selecting Allow Single Wall Extrusions for both internal and external walls. Playing with these options led to good prints that met the SoarKraft recommended weight. I need to do more investigation on the other options in the two Thin Wall drop down boxes but here is an image of two examples.

I asked Qidi if there was a similar fix in their slicer. They sent me a revised config file that did fix the problem but led to a significant increase in weight on the finished print.

The problem has also been beneficial in making me realise how important the slicer simulation was as a tool (as can be seen above). It allows you to see what is likely to happen with each change to the configuration print settings. Obvious but not always investigated.

The other discovery was that neither slicer (Qidi or S3D) are able to import STEP files which does seem a bit strange. STEP files are more accurate than STL files and STEPs are easier to modify in CAD programmes.

Sorry this is not a radical post but does show that 3D printing is not just ‘click and go’. The other comment is that there are so many options to change in a slicer config that I don’t think I will every get to grips with their individual impact on the print.

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