Episode 120 Making the TT Rex

Material: 3mm Acrylic
Router Bit: Amana Tool 51441 – 1/16″ Spiral-o-Flute upcut from Toolstoday.com
CNC Router: Torque CNC 9060
Spindle Speed: 12000RPM
Horizontal Cutting Speed: 5mm/sec
Vertical Cutting Speed: 10mm/sec with ramping

Plans from MakeCNC.com

English Manor Dollshouse

First attempt at a larger build of one of the MakeCNC buildings.

Made from 6mm MDF, it took a bit to assemble- friction really increases dramatically with the larger sizes.  

The result is quite impressive.  Feeling inspired to make some of the others.

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.

Garrawi

Black Friday

Over in the US (and seen on many websites around the place if they are US based), you will find reference to this phenomenon called “Black Friday”, which is the day after Thanksgiving.

While it may not necessarily seem relevant to those in other places around the world, it still presents an opportunity to pick up some online discounts, especially from those companies who sell items that are digitally distributed.

One such company I have been doing quite a bit with (as you may have gathered!) is MakeCNC.com.

They produce plans for woodworking, and although (by their title) this is pitched at the CNC owners out there, the plans can be used on scrollsaws and bandsaws, so if you like the designs, you don’t have to feel left out.

I don’t have the specific prices, but a little bird has mentioned that they will be discounting (for the day) their Lifetime Subscription (which gives access to all their plans, and all they produce in future!), their plasma mega pack (for those lucky enough to have a CNC plasma cutter), and their Super Seven Mega Pack (which has around 150 of their plans).

They will also have some dollhouse packs, a Barbie pack, their MZST packs, an HO scale pack, a holiday pack (just in time for Xmas) and others, including buy one get one free for some items.

You’ll have to look at their website on the day (in US time) to get prices, but if you like some of the models I’ve been making (and others), this would be a pretty good time to pick some up.

Toy Story

I have often been critical of just how little imagination is needed by kids to play with modern toys.  They come with all the bells and whistles – dolls that talk/cry and have all the bodily functions, dinosaurs that walk, and roar all on their own.

But kids don’t, and shouldn’t need such props to be able to have fun, and treasure the toys they have.

A few visual clues are really all they need, and their imagination fills in all the additional details.

My folks took these photos in one of their recent trips, of some kids playing

There is an obvious attachment to that toy car.  But when you look closely at it, you realise that most of the details are being filled in by the child’s imagination, not with photo-realistic modelling of the real thing (let alone sounds, lights, remote control etc etc)

As far as toy cars go, that is awesome.  That is a real toy.

I was over in NZ last week for a bit of a break, catching up with family. I took a few of the CNC models over – a couple for my brother who is a teacher, as I thought his kids would appreciate them.

Unexpectedly, he had the idea that I visit his class, and build the models with them, in person.

The kids were really taken with them, and the experience of putting them together.  We all had a lot of fun.

We made a dolphin and a velocirator in the session, and they are getting painted up at some stage by the class.

If you were wondering about the school uniform – it was a couple of days after the rugby world cup final, and it was “all black dress day”.

There is no fate

At least not till next year, as the school fete has come to an end.  After 8 or so hours, a bit weary, but it was fun.

Quite an interesting learning curve – got a lot right enough, but there is always more than can be refined, if I ever intend to do this again!  I do have one other planned fete coming up in November, but that is about it.

Fun seeing the kids’ reactions.

The display stand with the black cloth covering it, is the Centipede XL which I just got back after lending it at the start of the year.  It is perfect for this sort of thing.  I made a top from 6 panels of MDF which were cable-tied together to create one overall top.  This allows me to take the top off and fold it up for storage/transportation.  I made it from 3mm MDF as that is what I had to hand, but 6mm or 9mm MDF would have been better.  As the MDF only has a few holes drilled right at the extremities for the cable ties, I can still then use the pieces on the CNC machine 🙂  It worked very well – easy to transport, easy to set up, and stable.  (Does that make it a stable table?).  In comparison the vacuum-formed tables are reasonably easy to transport (they weight quite a bit more but have much less surface area) and quicker to set up (if you factor in attaching the top).

That gets me thinking – I could come up with a segmented top for the Centipede, which engages with the holes in the leg caps.  That would remove the need for cable ties and make a really rigid (crossbraced) system.  Make a good way to use it as a workbench as well.  Alternately, I could recess out the area where the top of the leg touches the top, so the whole top piece can still be stored perfectly flat.  I’ll work on that, and let you know what I come up with!

Sales were ok, not unreasonable, not as high as I would have expected.  I did a quick gender comparison – ie assuming some models would appeal to one gender more than the other (and those that would appeal more to both).  It is a really rough tool – for example, I chose a swan to be oriented towards girls, and a cobra to be something that would appeal more to boys, and a turtle to be neutrally biased.  That might infuriate some people, but the reality is that if you got a bunch of primary school students and gave them the choice (with no observers, or chance that classmates etc would ever know the choice made), that certain toys would be selected disproportionally higher for one gender over the other.

The analysis is very loose – I did not record the gender of who was making the purchases, or who they were purchasing for, so already there is a lot of interpretation built into these stats.

Toy Variety

Girls liked a lot less variety than boys in the toys chosen.

Of the total variety of girl-oriented toys, sales were concentrated around 41% of the range available.
Of the neutral toys, 53% of the variety available were purchased.
For boys, 75% of the range had at least one sale made.

Kits vs Preassembled models

This data is not very relevant, as the models were only able to be collected at the end of the day, whereas kits taken straight away.  Additionally, there was only one of each type assembled, and between 0 and 10 kits available.

Girls’ purchases were 71% kits
Neutral purchases were 53% kits
Boys’ purchases were 78% kits

Total Sales

Of all the purchases available:

Total sales of girls-oriented models: 20%
Total sales of neutral-oriented models: 23%
Total sales of boy-oriented models: 56%

As very few types sold out completely, this data was not heavily influenced by particular models becoming unavailable.

Other interesting observations – quite a few people looking (kids and adults) – “Wow, these are really cool”, then after checking the price “Wow, these are really cheap” (the vast majority being around the $5-$7.50 mark).  However even after uttering both those comments, the person looking around would then wander off.  Interesting that something that is regarded as “cool and affordable” still does not necessarily result in a sale.

I would have sold more if there was no restrictions on whether the person could buy and take the pre-assembled model, so having two or three of the most popular kits pre-assembled would be beneficial.

It may also be better if there was less variety of kits available, and so people could select the ones they want for purchase, rather than having to ask for them.  While this makes perfect sense (and is how we shop most of the time), it is a lot harder to do this in a market-like scenario with limited space.  Especially with bulky products that have a degree of fragility to them.  Again, if I was doing this on a regular basis, I would be able to justify the additional investment in the multiple storage containers needed to keep everything sorted.  For a one (or two) off, that is less practical.

All in all though, it was a fun evolution, and I’d do it again.

Occasionally!

Sucking in the sides

Back to the vacuum table for a sec.  I’ve been cutting out a bunch of designs on the CNC, for a school fete in October – while the machine sits idle during the week, there is no reason for it to do the same on weekends.

The vacuum table makes a huge difference – designs can be cut out without tabs, which saves a phenomenal amount of effort.  Just the time saved between removing a sheet and securing down the next is enough to be significant.

I happened to glance over at the vac this evening, and more specifically to the Clearvue cyclone-like separator (I have the older version of the mini, where they had departed from a traditional cyclone design).  The collection bin on the separator had almost completely collapsed from the vacuum that was being generated.  Lucky it hadn’t caused the lid to spring a leak, otherwise I would have lost what was being cut, and probably the cutter as well.

It makes very evident that this is generating a pretty significant vacuum, and therefore there will not be a great deal of airflow.  Problem with that is the vacuum cleaner itself.  I expect it relies on the airflow for cooling, and without it, I’m probably slowly cooking the bearings.

While the bearings can survive some heat soak, they will be mounted in plastic, and that will not be enjoying the temperature at all.  When that fails, releasing the bearings and therefore the shaft of the motor, the failure will be catastrophic.  Something that is still on my mind.

Just as an aside, after testing out the new dust extractor yesterday, cleaning up around the CNC, I kept using it today after each job, and was easily able to keep the whole work area satisfyingly clean.  This is despite having had to temporarily reduce the 8″ opening to a measly 4″ (in hindsight I should have checked what the inlet was on the unit – I need to get a multi-inlet, or drive a whopping great cyclone unit with the thing).

Thought I would be alright – drop down to Bunnies and get some plumbing fittings to carry me over.  Except they don’t have fittings that run to 200mm!  Let alone tubing.

Based on cross section area of the inlet, I can connect 4x 4″ inlets simultaneously, as the cross section area of 4x 4″ is the same as 1x 8″.  Anything less than that is restricting the extractor’s performance.  Either way, I have some thinking to do to maximise the dust draw from around the workshop.  And where the extractor will permanently reside.

Addendum:

Had a thought, and took another look at the Oneida Super Dust Deputy.  Interesting – the version available in Oz is steel, but in the US there is also a couple of statically conductive resin versions.  One that is the equivalent of the steel version is a whole $US170.   Even if the libs go and dump us with paying GST on overseas purchases, $US170 equals $A267 at the current exchange rate.  There is an XL version, with 6″ inlets and outlets.  That is interesting, but as it is not available here, a bit academic.

The steel Super Dust Deputy has one problem for me (other than being $A500), it is only for 350-850 cfm.  I can now generate 2900cfm!  Hmm – wonder what a home-made Thein could handle?

Update 2 – fixed up my maths – the Sherwood has an 8″ inlet, not 6″!

SSYTC082 Australian Animals Series

(A slight delay in the SundayCNC post!)

The Australian Animal series, from MakeCNC.com (scroll down a bit to the Australian Animals)

A really nice set of designs, with some real standout patterns.  By far and away, the Sulphur Crested Cockatoo is the most impressive, at least in my opinion.  However, it was the Echidna that I had to make a second time, because the first was ‘requisitioned’ by one of my work colleagues, as being “too cute”.

I really like the delicate magpie, and the facial (and mouth) detail of the Tasmanian Devil.  But I’m sure everyone will have their own favourites.

I would say these are more advanced patterns, as they take a bit more effort to assemble, but slowly and surely each can be bought together.  I occasionally shaved some pieces down just a little to loosen the fit, as I was gluing them, rather than leaving the models so they could be disassembled at a later stage.

Routed on the Torque CNC 9060, using the 1/16″ straight, 2 flute 45190 cutter from Toolstoday.com, running at around 40mm/sec, and 12000RPM.  Each cut from 3mm MDF, with most being able to fit either 2, sometimes 3 to a 900×600 sheet.  Except for the Cockatoo – that took pretty much an entire sheet on its own.  Of course, there is no reason why you cannot go bigger if you choose – cutting from 6mm, 12mm (or thicker) MDF.  And you don’t actually need a CNC to make use of the patterns.  A laser and/or router are all very well, but you are not limited to computer controlled machinery.  Print out the designs and stick them on stock timber, and you could cut them out with a scrollsaw or bandsaw.

The animals in the series are:

Sulphur Crested Cockatoo
Magpie
Kookaburra
Emu
Echidna
Bilby
Frilled Neck Lizard
Salt Water Crocodile
Dingo
Wallaby
Wombat
Kangaroo with Joey
Tasmanian Devil
Koala Walking
Koala in Tree
Platypus

A fun series, with some real standout designs.

CNC Sunday

I had an idea that perhaps I should consider limiting my posts about working with the CNC to one day a week.  But I doubt that is a resolution I’ll stick to for longer than 5 minutes!

I spent the day carving out a bunch of nested designs from MakeCNC.com, on their Australian Animal series.  I’ve put together one so far (a Bilby), and have cut out the cockatoo, kangaroo, croc, frilled neck lizard, and a bunch of others- about 6 to go of the 16 in total.  I’ll post more about them (including pics) when I have them together in the zoo.

In the meantime, I finished the spitfire for my daughter’s school.  This was also cut out of 12mm MDF (as was the pteradactyl), and has a wing span of about 1.4m

The last is shot with a bottle, to give a bit of a sense of scale.  Solid thing!  I engraved the wings before they were cut out using a v bit.  Rather cool all told (found here)- almost tempted to make another to the same size to hang in the shed (and have it painted up).

Speaking of painting things up, that is what my daughter decided to do today.  So with a bunch of acrylic paints, she first undercoated, then painted a couple of the models I made for her yesterday.  The came up really well!  Really adds an extra dimension to the models.

Fun day, lots of sawdust! (After all, that is what it is all about).