Initial thoughts and impressions

[jwr]

I’ve just discovered Shapr3D, and after the first “wow, somebody finally nailed it!”, I thought I’d share my initial thoughts. Please do not take these as judgments, but rather as my impressions and statements about my particular usage patterns.

First, the positives:

First, I think it’s fantastic that the app is being developed specifically for the iPad. The latest iPad Pro is an unbelievable computer: the CPU and GPU power close to a MacBook Pro, but in a package that is 6mm thin and can be held. It lacks good applications, and this is where Shapr3D shines. I also think the decision to require a pencil is a very good one, as it doesn’t compromise and dumb down the UI.

I’m very glad that Shapr3D is being offered as a subscription, I believe that is the only way to sustainably develop an app.

I was pleasantly surprised by the number of features present (draft angles! project!).

Now for the negatives, or rather things that are missing:

The big one: without feature history and editable features I am unable to make practical use of the program. The pre-planned demos look fantastic and impressive, but my workflow doesn’t look like that: I try things, and then come back to change them when I find out that something doesn’t work well. When doing product design, I need to be able to change things after getting comments on the initial design, and this should not require recreating a large part of the design from scratch.

This is, unfortunately, a complete deal-breaker for me. I can see how the product is being marketed as a “concept” or “drafting” tool, with the idea of more mature tools taking over later, but I can’t justify spending time making 3D designs which I know will need to be re-created later on. And for concepts, well, I just use Concepts (the 2D sketching app).

I suspect that editable feature history is on the roadmap and that Shapr3D will get there some day, but until it does, it isn’t for me.

The second big thing is fully parametric modeling, e.g. a table of parameters which can be used in formulas everywhere. In some applications this is crucial: an example is designs built from laser-cut plywood, where you really want to have a “thickness” parameter in a single place that you can change at any time. I’ve also worked on enclosures for electronics which needed to be quickly adapted to changing requirements or changed to accomodate several variants of electronics inside. For injection-molded designs, one or two draft angles as parameters really help when choosing prototyping manufacturers.

I think both of those are within the reach of Shapr3D and I hope the authors are moving in that direction.

The other shortcomings were relatively minor and I’m sure they will be addressed with time. Things like extrude to face, or extrude in both directions would be quite useful. But these are less significant and would not influence my decision to subscribe.

[Background: I have experience with Solidworks, Fusion 360 and OnShape].

[Istvan]

Hi and welcome to the forum!

We hear you! One thing that would be really great to understand, is that what are the typical modifications that you would generally like to do with design history that you can’t do (or hard to do) with direct modeling. Can you give a few examples? Maybe with screenshots? It would be really helpful to better understand your needs.

[jwr]

I’m sorry, I don’t have screenshots, but I think I can describe use cases that I remember from the past.

First, nothing is “impossible” with direct modeling, some things are just too tedious and the entire solution stops making sense if there are other options which are automated.

For laser-cut designs in plywood, the plywood thickness will vary and you want to enter it at the last moment, after you’ve seen and measured the actual plywood stock. Having that as a parameter is a life-saver. Get it wrong, and none of the joints will fit together without lots of additional manual work with a file. Think of a T-shape: the top of the T must have holes for the stem extrusions to fit into it, and their size will depend on plywood thickness.

For prototype designs in machined aluminum (electronics enclosures in my case), the case design evolves together with electronics design. The assumption is that many dimensions will change, and very little is known in advance. With parametric modeling, this isn’t much of a problem, but without it one needs to be careful, because unless you keep the enclosure a simple box, you will have a bad time when it comes to modifications. I guess a basic example is a chamfer/fillet that gets cut in the middle with a subtracted body — with direct modeling, it becomes two chamfers now. If I get a request to change that chamfer, I need to do it in two places.

It gets really bad with designs that target injection molding, but on the way there get 3D-printed (SLS) and might go through low-volume injection molding. You not only get something that changes often (I’ve had to update dimensions, PCB shapes and major connector openings several times), but you have changes that are required by the manufacturing process of the week.

As an example, draft angles: these will depend on the final texture. ProtoLabs recommends 1-2 degrees as a minimum, but requires 3 for their rougher textures and 5 for the coarsest ones. Choosing the external texture is not an engineering decision that gets made early in the process, it might (and will) change. Also, when preparing for actual injection molding, you’d want to reduce the draft.

Even with parametric tools modifications aren’t always easy and things can break (first commandment: always do your fillets last!), but they are possible and significantly reduce the amount of work.

Also, many things can be interdependent, especially with injection molding: internal fillet radius will depend on wall thickness, for example.

None of this is impossible to do with direct modeling. But it requires lots of work and often re-doing large parts of your design. This might be acceptable sometimes, but I think the niche that Shapr3D is addressing is not people who do full-time modeling work, but rather people who need to do 3D design as one of their tasks. I fall in that category: when doing early product prototyping and development, I might work on electronics design, mechanical design and firmware. I don’t need specialized tools like what Solidworks provides (such as injection flow simulations), because I know I will eventually hand off my work to people who will deal with this. But I do need agility, ease of use and a way to quickly get things done.

I came up with one example of a past design for which I can provide a visual example. It’s an enclosure for a stereo camera. For this design, the width of the entire camera changed many times and had to be kept flexible until the last moment, as the software team was trying to find out how far the cameras need to be spaced in order to achieve key metrics. Notice the curved cutouts on the front face — these would cause trouble. In Solidworks (or Fusion 360 or OnShape) this requires opening the base sketch and changing a single dimension.

I think there is a niche for Shapr3D. It can’t compete with Solidworks on features, and it should not try to compete with Fusion 360 on CAM integration. But it can definitely compete in the “agile and easy to use CAD for hobby and professional prototyping and product development work” category, with the additional differentiator of running on iPads. You’ve done excellent work on easy sketching, if you could do similar work for constraints (constraint display and debugging is a weak point of all CADs) and parametric modeling, it would be a very useful tool.

[Istvan]

Thanks a lot, very helpful!