3D Printing Custom Design Requests or Requests to change the Scale of a Model – Not as easy or appetizing as people think

On a semi-regular basis I get two kinds of emails from people through my Shapeways 3D printing store:

  1. Hi, can you 3D draw item XYZ for me and not charge me an hourly rate for your design time.  I think you’ll sell lots of them and make money?
  2. Can you re-size item ABC that you’ve already drawn in HO Scale to N or S or O or whatever scale?

The first question is easy.  No, I can’t spend tens or hundreds of hours researching and designing something for you that I’m not interested in for no money.  The 3D modelling package I know and use is an older one that I learned in University and we bought at my office eons ago because I knew it.  It’s a bit (nee a lot) dated, but it works for me.  But, the fact that it is on my work computer means that I maybe get 30-40 minutes at lunch, and any time I want to hang around after work modelling (and contrary to popular belief, I do have a life and spending hours at work after work isn’t my idea of fun, even if it does lead to more models!).  I don’t have a sense of how long a project is going to take me to do when I start.  Some projects I thought would be easy have taken ages, and others I thought would be hard, have been advanced quickly.  And I don’t track how long I spend working on a model, as in some ways, I don’t want to know.  As my model making and Shapeways Store are a part of my HOBBY, I don’t want to put a dollar figure on my time, the hobby is expensive enough as is!!  Equally simply, in honest terms, large 3D printed items are not for the faint of heart.  The GO Single level coach is around $200US in cost before I apply any markup to make some money on it.  That’s just the cost from Shapeways.  That means, depending on how much markup I add to make some money, if I mark it up 30%, that’s a $260.00US model kit that doesn’t have wheels, decals, or detail parts.  I may not be a model railroad manufacturer, but I don’t need to be to know there isn’t a market for that when a complete resin coach kit from BGR group is around $160.00CDN and they are a niche market for people who actually want to build kits!

An accurate reflection of the transaction most people expect when they ask you to do custom 3D modelling for their Model Railroad projects, apologies for the swear word (Courtesy of Matthew Innman at theoatmeal.com)

So, on to Question 2.  First up, I need to explain how I create a 3D model.  I draw whatever I am modelling at full size inside the computer program (i.e. an 89′ long passenger car is 89′ long in the computer program.  Over the 5 years I have been designing for printing at Shapeways, I have learned their material tolerances.  For example, in Frosted Ultra Detail, the material I print most of my models in, I know that the minimum width for a wall to successfully print is 0.6mm, or 0.02 inches.  This works out to 1.75 inches in the 1:1 scale real world.  This, is the minimum width that a wall of a building or car needs to be to print.  As you pay by volume of material, you want to minimize any additional thickness to parts to avoid paying for material that isn’t needed. This means, that I know exactly what i am doing in HO Scale, as that’s what i model in.  Once I am done the model, I split it into parts as appropriate (i.e. car underbody, interior, body shell), and re-scale it down to HO scale, and then upload to Shapeways.

FormZScreenshot of FormZ 6.5 and the 3D model of Don Station (before parting out for printing)

So you ask, why is it so hard to then change it to N scale or S scale or something else?  Well, its twofold.  Going smaller to N-Scale, the fine details may no longer be thick enough to print. Going bigger to S or O Scales, the walls may be too thick, and details that are passable in HO become blocky lumps that look terrible.  This is particularly a problem for buildings, as the window mullions are so fine in HO they barely print, which means they won’t print in N. In S or O Scale, if the part will even fit in the print envelope of the machine, the parts can look clunky and oversized, as they probably are over true scale in HO to meet the minimum printable dimensions.

Another problem, especially for locomotive bodies or coaches I’ve done, in shrinking them to N Scale, I know nothing about it.  I don’t have N scale equipment or couplers to understand correct heights, how things are mounted, what will and won’t negotiate a curve or switch and on and on.  When I was convinced to re-scale my CNR D-1 to N Scale, I had to go buy an N Scale mechanism for it to make sure the body would fit over it and to see where the mounting points were as opposed to the HO Scale version. I also discovered that I had to turn the roof into part of the body in N scale to make it strong enough.

When I up-sized D-1 to S Scale, that then posed the problem that the body was too big for the printer, on top of needing to thin the walls to try to bring the huge cost down to something reasonable for my friend who wanted it.  At least in S-Scale, there is no expectation of a commercial mechanism fitting it, so I only had to design with mounting blocks to allow the body to be attached to a custom-made brass frame.  For the carbody to fit in the printer, it had to be split in two.  It took me a long time to figure out where and how to split it, and make sure I had found every possible place where parts needed to be cut, and adjusted so they didn’t bind up when the two parts of the print were assembled.  It worked, but similar to the requests above, if I’d been billing time, it wouldn’t have been cost-effective.

D-1 in Many Scales.  S and HO together on Trevor Marshall’s kitchen table, and N scale on my workbench.  The S Scale required the body to be split apart, while the N-scale required the roof to become a part of the body to be strong enough.  Not just a quick click to re-size when changing scales.

Similarly, I received  a request a few months ago to re-size an HO Scale Fairmont Speeder to S scale.  A request I would normally ignore, though in this case, I didn’t.  The problem with making things bigger, is that it exposes any faults in the modelling. The smaller the model, the more a fudge here or a size issue there goes unnoticed.  I honestly think the only reason I even considered the request was that I have a friend who models in S Scale that I could at least give it to when done.  I also have a lot of respect for S Scale modellers.  They can’t generally go buy anything off the shelf and run it.  They have to work at it to find models, and build things.  I am totally behind that, and like the notion of helping them with a few hours of my time on the speeder resize to make another model available for them.  S Scale is called a “Builders Scale’, you don’t get into it because you want to buy stuff and run trains, you get into it because you are a modeller who likes building things.

The S Scale and HO Scale speeder together, and the S Scale speeder showing it modified to be two parts instead of the single piece of the HO Scale one to ease painting the larger and slightly more detailed version.

For the S Scale speeder, with the details being more visible, it gave me more opportunity to improve the model, and to fix things like the seats which hadn’t printed right in several HO attempts.  I also modified it to have some extra details, to allow wood strips to be inserted for the hand lift bars for turning it.  Making these changes probably took me 4 or 5 hours of fiddling about to make sense of where more detail was needed, trying to do things like make the axles roll (didn’t succeed). I’ve sold one to the person who requested it, which is nice as at least he was true to his word that if I did the work, he’d buy it.  This is where these resizing requests become a problem.  On top of the time sink which is not insignificant to adjust a model, and go through all the checks, I have no reason most of the time to order one myself to make sure it prints and looks right. I also don’t have the budget to be doing that, as it would be even more of a sink than doing the modelling for free is.  Suffice to say, I’m not much of a business man, as I probably made about $1/hour for the modification time on the single sale to date!!

While it may not seem like a lot of time, any time I spend working on adjusting a model for someone else, is taking away from the limited amount of time I have to work on designing things for my own projects, or going home and actually working on the models.  There are times I wish I could walk away from my day job and make enough money designing model railroad parts and models for a living, but I know from friends that turning your hobby into a job takes away the fun of the Hobby.  I am happy to offer for sale what I do come up with on Shapeways to help build a community and help others, but that’s done with the understanding that I don’t have the time to do extensive customer support or custom projects. I will continue to generally politely decline requests for projects and re-sizing for the most part, though as you can see, I’m also inconsistent and at least sometimes, something will pique my interest enough to get me to take it on.

Advertisements