Butterfly

I had a friend apply her much-more-artistic skills in decorating one of the models, and this is what she came up with.

Goes to show what someone with talent can do!

Jeanené is an artist and does facepainting for markets among her other creative outlets. She can be contacted via email at nanni.com.au@gmail.com or on 045 206 1416.

Photos by Kara Rasmanis

Butterfly plans from MakeCNC.com

MakeCNC Lifetime

I’m quite the fan of MakeCNC‘s plans, as you will probably have gathered!  They are useable for more than just CNC machines – the plans can be used with scrollsaws, plasma machines, laser machines, even an exacto knife and cardboard.

The total library is huge, and it keeps on growing as new plans come out regularly.  Buying the individual plans can add up very quickly, so buying the plans in a pack is much more cost-effective.

The most cost-effective pack is the lifetime membership pack, where not only do you get every single plan they have produced, you get every single plan they produce into the future.

A pack like that doesn’t come cheap though, given the total number of plans available.  With over $US10000 worth of plans now available, the price is about to rise (tomorrow) to $US2000.  So if you are really keen, today is the very last day that you can purchase lifetime membership for $US1500.

To give you an example, in the month that I was away, I got back to 107 new plans sitting in my inbox, and there are another 60 odd plans to come that I know about.  That is on top of the over 1500 plans I already have!

So if this is something you have been thinking about, but haven’t made a decision, or if this is something you haven’t heard of, but are tempted, this is the last chance to get them for $US500 less than they will be tomorrow.

The 45190

It sounds like another Whovian thing (or more precisely, Torchwood) (aka “The 456“), but instead, it is a lot simpler than that.

The 45190 is a router bit.  For my current activities on the CNC, it is THE router bit.

It is not overly complicated – a straight 1/16″ (1.59mm) 2 flute solid carbide cutter embedded in a 1/4″ shank.

Amana Tool 45190 Carbide Tipped Straight Plunge High Production 1/16 D x 3/16 CH x 1/4 Inch SHK Router Bit
from: Tools Today

But it is what I have been able to do with it that sets it apart.  Or rather, that it gets done what many other router bits have failed to do.

As many would know, I am cutting out a lot of patterns on the CNC, particularly from 3mm thick MDF. To get the level of detail I need, I am using a router bit that is around half that thickness so it can get right into the various corners.  But it also needs to do some miles, and that is also where this router bit has been scoring some exceptional goals.

I have tried other router bits, with some (but decreased) success – spiral upcut bits work, but have a tendency to pull the resulting piece that has been cut out, right out of the sheet.  It can then be thrown or bumped to a point where the router bit plunges through it while cutting another.  I’ve even found small pieces that have been cut out subsequently stuck on the router bit, trying their best to emulate a helicopter!

Downcut spirals work better, but they still have a problem that the dust they are carrying downwards gets deposited under the sheet, causing it to lift, and in the worse scenarios, to completely detach from the vacuum table.  Granted my vacuum table might not be as strong as a commercial one, or may not be able to carry away any sawdust produced so this doesn’t happen.

I’ve also tried larger bits (specifically 1/8″), but they do not give the same degree of detail, and the joints are not as tight.

So that leaves the 45190.  Yes, I have broken a fair few (and am again down to my very last one, that makes me nervous!) but that has always been the result of something other than cutting normally.

So far, the router bits I have broken have been:

Forgot to slow the feedrate back to 100% from a previous operation, and the router bit tried to cut 3-4 times faster than I have worked out to be a good speed for my machine for that bit and that material.

I’ve hit the clamp on at least one occasion, and a screw on a couple of others.

I’ve had a piece come loose and wedge itself against the spinning bit, and it has broken when the CNC moved in that direction.

Sadly, I have occasionally forgotten which is Y and which is Z (or have simply clicked the wrong button), and instead of lifting the bit, have tried to drive it through the material.

And more than once I’ve had the CNC get its + and – directions confused, and it has driven down hard, rather than up.

In spite of all this, when the router bit is treated correctly, it does the energiser bunny thing – it keeps going and going and going.

Check out the teeth on the dinosaur (Spinosaurus) and you will see what I mean about retention of detail.  Remember that MDF is 3mm thick to give you an idea of scale.

The straight cutter is also not the worse solution either.  The dust that is produced gets packed into the cut, which helps hold the piece being cut from moving.  The top and bottom surfaces stay pretty smooth, and only a very light sand is required.

The detail is retained, which is important, and the yield from each sheet is maximised.

So when I am doing these CNC MDF jobs, and I keep mentioning this one router bit, there is good reason. The 45190.  Its a Whovian thing!

 

 

Busy work

Haven’t posted anything for a while – longer than I realised it seems!  Not that I haven’t been working in the shed, but sometimes I just need to get my head down and power through to make some progress.

The latest work that I have been doing is for the next issue of The Shed magazine – those deadline come around so quickly!

For a bit of a sneak peek, I am working on a water wheel – will end up being a garden feature, but I am trying to make it with some thought behind the design, and not just a basic layout.  You may well ask, just how many ways can you actually make a water wheel, and the more I think about it, and the more research I do on the topic, the more surprised I become about the breadth of the topic.

I found a particularly interesting reference, quite the authority on the topic.  It is The Engineer’s and Mechanic’s Encyclopædia: Comprehending Practical Illustrations of the Machinery and Processes Employed in Every Description of Manufacuture of the British Empire, Volumes 1-2

by Luke Herbert, and the title is quite the mouthful!  Interesting to find a book that has such a strong understanding of the science of water wheels.  Of course, that it was written in 1836 might have something to do with it!  I found some of the relevant text online so was able to glean what I could from that, and I have the book on order from Amazon – looking forward to seeing what other gems it contains!

I’ve been playing around with fin design, with this as an early model

This was with a fin angle of 22.5^o.  I’ve since refined the angle to 30^o, and the result is a lot better, with the inner circle now having a much greater diameter.

I am designing it as an overshot water wheel, so the turning moment of the water is important – the further away from the point of rotation that the water is maintained, the greater turning force it exerts due to gravity.  In any respect, it is quite a fun evolution!

I’ve also been making a number of models on the CNC while all this has been going on, in preparation for an upcoming school fête fundraiser.

So as I said, I might have been a bit quiet on here, but that doesn’t mean that it has been so in the shed! Bags and bags of sawdust coming out (especially now I have the new collector, and the cyclone separator makes removing the full bags a breeze).

Voyager

I don’t think there is any craft or vehicle that captured my imagination more as a child than the Voyager spacecraft.  Launched in 1977, the two identical probes were sent on a journey that to date has taken them 1.97×10¹⁰ km away from Earth, past the gas giants of the solar system and then way beyond.

There is a lot of information about them on Wikipedia these days, so if interested you can read up more there.

What I was excited about recently, is that the Voyager probe is one of the models on the Makecnc.com website.  So I made it.

Over 200 individual parts, cut from 3mm MDF, using the 45190 1/16″ router bit from Toolstoday.com (which is still going strong).  Cut on the TorqueCNC.

It took me 2 nights to assemble the model, and a lot of hot glue (which I have been finding to be an excellent way to assemble these models).

I had my friend Kara Rasmanis take a couple of photos of the model, suspended in front of a green screen, and she has then inserted in some royalty-free backgrounds, for a truly stunning result showcasing the model from the front, and back.

Even made from 3mm MDF, it is 900mm across.

For a model, cut from MDF, that is awesome!  Currently sits in my office – when I can part with it, it will be off to my daughter’s school science classroom.

A Momentary Lapse of Concentration

On the turning away
On the CNC router
And the words we say which others won’t understand
“I don’t believe what I’ve just done
Another bit is now suffering
I’ve mixed up the axis again
And now it is gone”

That moment, 2 seconds after clicking a button, and hearing the tip of the bit hit the wall of the shed.  When you have moved the tool in the Y axis, and not the Z.

And another 1/16″ bit bites the dust (literally, and figuratively).

For Numismatists, Notaphilists & Coin Collectors

Here is my latest project, ready for the next edition of The Shed magazine.

It is a coin storage cabinet, with spaces for 1200 individual coins, stored in acrylic trays.  It has a curved top (using kerfing) and tambour door.  By replacing a 6mm thick tray with two sheets of 3mm clear acrylic, bank notes could also be stored and displayed.

Each tray has a tab with a descriptor of the tray engraved in it, such as “Australia 50c Commemorative”, and each coin slot is sized to the specific coin that it is to house.

When the edition of The Shed comes out (soon), the article goes into detail how it was made, using both CNC and non-CNC techniques.

Corian

Been looking at a few different materials as part of this exercise on routing (CNC) a range of alternate materials and surfaces.  Had a closer look at Corian today, and while I was generally aware of the term, and the look/feel of kitchen benches made of the stuff, I didn’t actually know much more about it.  While this is unlikely to be news to everyone, a bit more information about what this product is may be quite interesting.  Not sure how I missed knowing more about it until now, but there you have it – can’t know everything!

Turns out it is around 50-50 polymethyl methacrylate with aluminum trihydroxide filler.  To put that in more common terms, it is around 50% acrylic polymer, and 50% alumina trihydrate, which is a product derived from bauxite.  Bauxite, as you may well know, is the raw material that is processed into aluminium.

Makes a lot more sense to me now why some people have been using it to make pens on the lathe!  Probably makes a bloody good pen if the truth be known, look, feel, finish and weight.

While it can be thermoformed into various shapes, it can also be machined relatively easily as well.  So I will be rather interested to see how it goes on the CNC, both in shaping, even 3D work, and engraving.  A number of router bits in my CNC collection are rated to handle solid surface materials, including the 3D cutters.  Think it will look rather interesting, and opens the door to combining it as another material in a mixed material project.  Especially given its machinability.

Multiple Materials

I’ve been trying out some different materials on the CNC, using some of the other router bits in the Toolstoday.com Master Collection.

Using the 51411 “Spiral ‘O’ Flute” upcutting plastic cutting solid carbide bit, I tried a bit of polycarbonate.  This is 3mm thick, which ideally suits the plans I currently have.  I started with some clear, to try it out as much as anything.  I slowed the feed rate down (given I am currently restricted to 12000RPM), then slowed it down further.  I found it ran pretty smoothly at 10mm/sec.  I plunged at the same speed, but for future reference, ramping the bit down should be a better approach.  With a 1.5mm depth of cut, things worked pretty well.

My next endeavour will be to approach the same model again, but choose different materials for the different components.  So far I have about 4 different polycarbonate colours (one being fluoro), some aluminium and brass in the design.  Hopefully it will all work together and not look too mismatched.

Clear red poly for the flames, aluminium for the nostril smoke, and for the centreline of the body (up to and including the tail), brass for the small plates on the underbelly (like Smaug and his gold-encrusted hide), and a combination of solid green poly and fluoro green poly (for the scales, and head).

Celtic Knot

I’ve been working on becoming more familiar with Vectric Aspire, which is used to both create objects (including three dimensional ones), and turn existing designs into the code required for the CNC machine.

In this case, I wanted to work out how to make a celtic knot design.

To start, I have defined a sheet of material 600x900x16mm.

Next, under “Gadgets” there is an option for a “Celtic Weave Creator”

This creates a vector that can then be used to generate the 3D pattern.

I have also placed a border around the outside.

Next, under the Modeling tag (the 3D section), click on the extrusion tool.

By using the existing selection, and a small curve vector (not shown), the 3D object is created.

It shows starting points, paths and how the paths are dealt with when they overlap.

By first choosing the 3D Roughing Toolpath and a larger bit to waste away as much material as possible,

then the 3D Finishing Toolpath with a ZrN tapered ball carving bit for a final pass.

FWIW, I am slowly entering the CNC router bits I have into the Tool Database.  No point having tools in there that I don’t have.  I’ve been including the router bit number (all being Amana Tool CNC router bits) so I can reference back to the Toolstoday.com website to confirm spindle and feed rates, especially for different materials.

Finally, with the path calculated, the simulator is run to see what the program predicts the outcome will be.

Looks pretty good!  I wasn’t going for anything particularly artistic, or complicated here – just learning the basics. All very interesting stuff.