Wednesday, 23 August 2017

Discover That Logo

Shelley suggested I should include a logo on my 3D print designs.



I have, at long last, got round to designing something.


I wanted it to work on the blog and be able to emboss it in to 3D designs.



To that end, I designed it using Fusion 360 so it could fairly easily be added to any model.

Makita dust cover

I have a few Makita 18v tools that all share the same type battery. I store the tools I use less frequently without any batteries installed however I don't like the electrical terminals getting dusty and grubby so I wrap a cloth round then.


To make it a bit tidier and easier to store, I decided to 3D print a clip on dust cover to replace the cloth. It was also a good way to learn more about Fusion 360 as a 3D design tool.



It took a couple of test prints and adjustments to get it to fit properly.


It was very easy to make accurate changes to lengths, angles and radii in Fusion 360 to exactly fit the shape of the battery mount.


It can be printed without any support structures, just a brim.




After I had a version that fitted the angle grinder I still had to make more minor changes because the Makita tools have subtle variations, between models, to the way the battery is held snugly in place.



I now have a battery mount dust cover that fits all of my Makita 18v tools.

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Downloads:
Makita 18v Dust Cover STL file
Licence attribution - small business exception

My designs on YouMagine.com

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Sunday, 20 August 2017

Gate post repair

One of the 7" square posts, that hold up our large black gates, had broken at ground level.

When Shelley and I started digging it out we discovered that the rot had gone deep in to the ground. That made it very difficult to remove.


As we struggled to get the remains of the timber out of the concrete hole we decided we needed to come up with an alternate plan.

Two bits of angle iron down the inside of the hole and outside of the post would do the trick... but I didn't have any angle iron.

I phoned our neighbour, Lee. Luckily for us, he had a small pile of salvaged posts and two of those were ideal. Thank you Lee.

I ground points on the posts and drilled out some extra holes.
A quick side note, cobalt drills were far superior for drilling holes in angle iron. The normal HSS drills would blunt before getting all the way through but the cobalt versions carried on through and did all the holes.



I chiselled out the corners of the post to fit the angle iron and with some effort we twisted and bashed the heavy post in to position. The angle iron is forced in to the remains of the old post by over a foot and the base of the new post is about a foot underground. That gives about 2 foot of support under ground and the timber tightly held in the concrete hole.


The result, at the moment, is very stable with no movement in the post at all. I think I'd use that method again for putting posts in.

Height sensor replacement

For a few days the rear air suspension has been troublesome. It would slowly drop down on its haunches instead of rising up when starting the car.


A few restarts and tinkering with the calibration using a Nanocom would sort it out but it was a bit inconvenient.

I was hoping it would last until the weekend but by Thursday it was obvious that was not to be, so I took the day off on Friday to fix it.



I was reasonable confident that it just needed new height sensors. I'd had a couple in stock for years from a previous problem that only needed calibration to fix.






I took the opportunity to replace the broken connector housing on one side and to seal the unused cable holes in the connectors, just to be sure.



I think the main cause of the problem was not so much a faulty sensor but a corroded aluminium bush that was fused solid on to a steel bolt on the drivers side.



It was supposed to freely rotate as the suspension arm moved but that was not happening. I had to grind it and bash it with a chisel to get the bush off!



A few cups of tea later and its all back together.



Just needed to be calibrated using the Nanocom. I set the height at 47cm from the apex of the wheel arch to the centre of the wheel.

After a test drive and a couple of journeys, including a trip to have an 'all day breakfast', it is still riding as expected.

Saturday, 12 August 2017

Umbrella brackets

When we had some sun earlier this year I bought a sun shade umbrella for our patio.


The big concrete stand was getting in the way a bit so I've made some brackets attached to the very heavy table.





I managed to bend a spring clip nut back on itself to fit it tightly to the inside of the bracket.


I 3D printed the knob for the M5 bolt.




To protect the pole from the end of the bolt I heated up a strip of plastic and folded it over the bracket with the bolt passing through the outside flap.


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Warping and adhesion issues

Ever since upgrading the 3D printer to the Ultimaker 2+ I've had issues with prints warping and detaching from the build plate.


Today I finally twigged what was different between before and after the upgrade. The 2+ kit came with a calibration card for bed levelling.


I've measured the thickness of the card against the thickness of the paper I used to use. The paper is 0.03mm thinner at 0.12mm thick. Not only that but the new coated card has also picked up a thin layer of plastic in places from the nozzle so the thickness is no longer consistent, at one point is was 0.20mm thick compared to the average 0.15mm. The paper, despite having been in use for two years, does not have anything attached to its surface.


I've gone back to my thinner paper calibration and the first print is still attached to the bed.

I do not use any adhesive on my glass. I keep it clean with an imitation chamois leather and very occasionally degrease it with isopropyl alcohol.


I also made a change to the design of the model to add expansion gaps so that the shrinking plastic cannot pull the full width of the model.



Fusion 360 beginner tips

If I leave this page until I am an expert I will have forgotten what I found difficult when I just started.
Hence this page. As much a reminder for myself as a guide for others.

There are lots of video tutorials on the Fusion 360 site but harder to find are some handy reference pages covering most topics:
http://help.autodesk.com/view/fusion360/ENU/?guid=GUID-18445C60-F9AD-4217-8066-CA48FA11E514


Navigation

I find the use of the middle mouse button for Pan and Tilt unreliable. This is not specific to Fusion 360 I have the same problem in Blender. I prefer to use the keyboard in Blender but Fusion 360 has some very handy buttons at the bottom of the screen which means you can even work with a touch pad.


Click on the Pan and Tilt or the move icons and use the mouse with the normal button. Press the Escape key to exit that mode.


In addition the top right corner has a cube and you can select the faces or corners or other bits to get a quick rotation to the view you want and it is always clear which way you are looking even if your model happens to be completely symmetrical.

I find that cube the most useful.

Finding your work

This took me a minute or two.


To get back to your saved work you need to open up the left side panel using the icon in the very top left corner as highlighted in the above image.

Making changes

This was fairly clearly documented but worth repeating. When you open up your sketch it will be in a view mode.


To make changes you will need to select the script in the list and select edit.


When you have finished editing and want to see the result in 3D, use the Stop Sketch button.

Selecting Edges and Faces


  • Select one edge or face
    left click on the edge or the face.
  • Select a narrow face
    Zoom in until moving the mouse over the face changes the colour of the whole face. Then click.
  • Select multiple edges or faces
    Hold down CTRL and left click on each element.
  • Select an edge loop
    Double click any edge in the loop.
  • Group faces
    Right click on the browser, choose, Create selection Set.
    Select multiple faces.
    Use the icon on the newly created selection set to assign the faces to that set.
    Use the other icon when you want to select those faces.
Construction

You can add features that are not part of the model but used as the basis for calculating other parts of the model.


Like construction lines in hand drawn work.
This allow you to mark centres and position things parallel to faces.

Models, bodies and Patches

Models are made of bodies and patches. Those can be calculated from sketches, created from basic shapes, imported or manually modelled.
The main difference between a body and a patch is that a body must always be solid but a patch can just be a disconnected collection of faces.

Bodies - Solid manifold objects.
Patches - Do not have to be solid.

Only solid bodies can be used for cuts and joints.
Patches will automatically convert to a body if they are stitched together, using the stitch command or the holes between their faces are covered using other patches and planes.


  • Create menu - adds a new body.
  • Modify menu - makes changes to an existing body.

Components

A component is any pre-existing model that you include in your design.
Models within your design can be converted to components.
Existing designs can be dragged from the file browser in to your design.
A component has it's own time line and can be edited separately from the rest of the design.

The components I have created retain their own orientation which gets a bit confusing when trying to move or rotate them. There is a method to capture their position [which I am not sure how to do yet.]

To edit a component. Activate it in the object browser.


To go back to the main design. Activate the top level item in the object browser.

3D Printing and STL files

There is an option on the save menu called 3D print and you can use a workflow designed by Autodesk that I have not investigated. From there you can deselect the Output to 3D print and it will save as an STL.

That's how I first started to get my models to save as STL but I now prefer the other option I came across.


Once you have joined all your bodies in to one body you can export to STL from the Browser list.

Right click on the body you want to export and select 'Save As STL'
A very similar dialogue box to the 3D print dialogue appears but defaulting to save as an STL.

Axes Z up or Y up

My 3D printer works with the Z axis up and down, X sideways and Y back to front.
Ideally, that's how I create my models.

You can change the axes direction in your preferences within Fusion 360.

Keyboard Shortcuts

There are several guides to what keyboard commands are available within Fusion 360 so I won't reproduce the whole table, just refer to one of the following guides:
http://www.cadforum.cz/cadforum_en/keyboard-shortcuts-in-autodesk-fusion-360-tip10167
https://www.autodesk.com/shortcuts/fusion-360

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Special Care

  • Centre your model about the origin.

Many functions work about the origin or a manually added construction element.
I could not find a way to automatically centre a model on the origin. You can move it manually but each group of faces needs to be selected and moved.

Tip: When you start always create your main section central to the origin.
For symmetrical models that you intend to mirror or rotate, starting with one corner on the origin may be appropriate.

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Things I Could NOT Find

In such a professional looking product there were some features that I expected but that I could not find at all. In many cases I even found feature requests from as far back as 2013 and yet today in 2017 I could still not find the feature!

If anyone knows how to do these please post a comment to let me know how.

* Repeating Groups of Faces on other Faces [no idea how]
All I wanted to do was have the same feature on each side of a rectangular box.
I can copy the feature as a group of faces and I can copy sketch elements but I could not find a way to use a parameter to repeat a feature on each face.

If I copy the faces I cannot find a way to line up one face to exactly touch another face. I had to rely on the grid snap. I might be able to mirror the features. I think I will need to create an exactly central construction line.

* Wrap a shape round another shape [Feature request]

According to this forum post this is a requested feature but not implemented, as at Feb 2017.
There are features being added to the sheet metal section as previewed in another post.


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I will add to this post as I find other features worth noting.