The Gizmo

I recently posted an article on my blog about my Wise Engineering Works Gizmos .. and also I suggest they could be called a “Greeble”. This is a piece of machinery that hangs on a wall with multiple pipe connections, interesting shapes and bolts. I just wanted something that would add to industrial ‘grit’ without having to know what the darn thing is supposed to represent. That is .. “whatever you wish”.

It worked very well .. mostly. Visually I was happy with the project .. not so much on the cost. 3D printing with a company such as Shapeways can be relatively expensive. The Gizmo is a good example when someone looks at the cost and asks … “Is this for ONE item?” .. and I answer .. “Yeah .. farming out your 3D printing can be expensive” .. no kidding Sherlock.

So ….

A look inside

Let’s take a look at a Gizmo. Here I have sliced one down the center. The orange color is the edges of the slice colored while the blue highlights reinforcing internal ribs that I added (the ‘why’ of V3 in part) as the original flexed (thin walls) and this was an attempt to strengthen the model with making the walls thicker and therefore more expensive (ok. More expensive than they are already. There is nothing in the design that is supposed to represent anything other than to be ‘interesting’.

The tapered portion between the top and bottom ‘bells’ is where a goodly portion of the volume of the piece and therefore represents a goodly part of the price. It is a bit more complicated than just the volume of the plastic but we can ignore that for now (or forever).


After the question “Is that price for ONE Gizmo?” (I could almost sense the shock in the question), I was wondering how that cost could be reduced. My first thought was .. what if we replaced the tapered body portion with a cheaper (possibly much so) tube and then glue on the top and bottom bell shapes and all the other ‘bits’. The downside is that the body would be straight rather than tapered .. but that is just aesthetics after all. The upside is that other than selecting the appropriate diameter it can be any length that makes you happy .. and is esthetically pleasing to you.


When I created the Gizmo V1 I had it too large. Not that something like it could not have existed in the size I made but simply too darn large to have printed at Shapeways .. aka EXPENSIVE. I resized the thing until I was happy enough with the size if not the cost even if it had been reduced in size

I applied some measurements to the sliced Gizmo. You can by the way take the mm measurements with a “grain of salt” .. those numbers are simply Sketchup being ‘OCD’. In reality printing this at Shapeways means your minium detail is .1mm .. so there is that!

With that said what we have is a truncated cone with the small diameter 0.65 in and the larger diameter 0.9 in. I am going to ‘assume’ that I want to keep something close to that 0.9 in dia for my tube so let’s look at what is readily available online. I am looking at Plastruct tubing since the assumption is that we can create our bits and pieces to fit this ‘standard’ sized tubing. (on an aside if we were to replicate the Gizmo in HO … HO being 55% of O … then the diameters would be 0.358 in and 0.495 in)


The following round tubing I found in the Plastruct online catalog

  • Butyrate: TB-28 7/8″ 22.2mm OD – 3/4″ 19.1mm ID – 1/16″ 1.6mm wall
  • Butyrate: TB-32 1″ 25.4mm OD – 7/8″ 22.2mm ID – 1/16″ 1.6mm wall
  • Styrene: TBFS-12 largest dia OD is 3/8″ 9.5mm
  • ABS: TB-48 1-1/2″ 38.1mm OD – 1-21/64″ 33.7mm ID – 3/32″ 2.4mm wall
  • Dark Gray ABS: TBAL-24 3/4″ 19.1mm OD – 5/8″ 15.9mm ID – 1/16″ 1.6mm wall
  • Clear Acrylic: AT-24 3/4″ 19.1mm OD – 5/8″ 15.9mm ID – 1/16″ 1.6mm wall
  • Clear Acrylic: AT-32 1″ 25.4mm OD – 7/8″ 22.2mm ID – 1/16″ 1.6mm wall

Weld-On 3 will bond acrylics, butyrate, styrene .. so that is probably not a problem with what we select. Honestly, if I want to keep my tubing dia close to the largest dia of the Gizmo then that would be the Butyrate TB-28 with a 22.2mm OD and a 19.1mm ID. That then seems like a reasonable ‘starting point’ for a Gizmo with a cylindrical body.


Using the TB-28 tubing I am modifying the bits and pieces to fit.

And .. here are the results. This shows the cost to me .. no markup etc. $5.92 saving right off the bat.The Plastruct TB-28 7/8″ OD tubing is $6.30 so it would seem to negate the savings ..but that is a 15″ tube. I could probably easily turn/bore some PVC pipe to work too ..Anyhoo .. thought the costs compared to the data below each might be of interest.. I can point out that I put everything on a sprue on the new version so the parts count dropped from 3 to 1 so there’s that too.
Gizmo T2 V1-B on Shapeways

2 thoughts on “Gizmo – Type 2 V1B”

  1. My public library here in Mesa, AZ now has a small 3DP. I can build an STL file at home and take it in to build for a nominal charge. Their bed is only about 12″ wide but that is great for modeling.

    1. One of the things that come into play when printing on a printer you didn’t design for is the minimum wall thickness. This is probably not that big a deal with a SLA or DLP printer but I found out it makes a big difference right off the bat with my Prusa FDM printer in that it has a .4mm nozzle and running a model through a slicer it simply ignores anything smaller than .4mm .. meaning the walls need to be thicker. That’s fine .. except if you do that and have it printed say at Shapeways the cost goes up .. always something!! 🙂

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