3d printing from rhino

Hey all,

I do a good deal of product design for the toy industry. Currently I do 5 sided technical drawings that we send to a sculptor in china for our looks like samples that then get turned into our final product. There is always a good deal of back and fourth with the sculptor based on the interpretations of the 5 sided technical drawings. We finalize and then work on the final tools based off of the sculpts. That is my current process. I’m trying to find a better process and I am very capable in Rhino 4.0 and I’m wondering if instead of having a sculptor use my drawings or renderings, if it would be more cost effective/effective to have a 3d print made of renderings in Rhino. I’m not even sure if it is possible to make 3d prints from Rhino, so I would really apreciate any input anybody has on the subject.
Note: I do renderings that are functional (i keep in mind production) but don’t necisarily function from a engineering standpoint.

Bpo

Yes you can 3D print from Rhino. It is just a bit harder as you need to ensure your surfaces stich cleanly into a solid object (IE gaps between surfaces that might be minimal and not noticable in drawings or renderings may cause the object to fail if it is 3D printed).

Also check out sensable.com - their software is good if you do a lot of sculptural stuff in the toy realm and this can be converted over to Solid gemetry as well as for rapid prototyping.

Not sure what you mean by renderings, but as long as you create a watertight model (ie joining all surfaces and no geometry hidden inside that body) you can print 3D. Talk to your vendor about what format they prefer to receive.

I’m in the US. Does anybody have any vendors that would be able to help me out?

You can check out http://www.shapeways.com or http://i.materialise.com/ which allows you to upload a model and order the prototype. I think i.materialise actually have a plug-in just recently for Rhino, although it does nothing but upload your model to their site, there is a discount if I am not wrong. I am not sure though if they are based in US though.

You might want to ‘hollow out’ your 3d model so that you can save on material and money cos they can be quite expensive if the prototype gets big.

My best tip is to remember to set you tolerance to .001, and to continually check you geometry with the “join” command as you are building.

Save as an .stl file and any online rapid-prototype company can give you an instant quote. There are hundreds out there and it wouldn’t surpise me if there is one within a mile of anyone.

Use your F3 key to get object properties. Hit the Details button to see if you have a Closed, Valid Polysurface. As others noted, you can’t make a 3d print if it is open or invalid. You can use Analyze to find any open edges.

Also, Rhino doesn’t do some types of “hollow”. For example, you can’t do a Boolean Difference of a sphere inside a larger sphere to make a “hollow” ball. Don’t know why, it just doesn’t recognize the “inside” surface. Also, some 3d prints need a support material and making it hollow wouldn’t save much money.

One thing you could do in a case like that is create a very small pin hole to connect the outside to the inside. We do this frequently on shelled SLA’s so that the support material can drain out.

Thanks all,

I apreciate the help. This gives me a good direction to go in and I will look into this further for sure.

Okay, let me expand on what other have said as I deal with this on a daily basis. Can you 3d print from Rhino, yes. However there is often cleanup work on the service bureau side. The issue with Rhino, Maya, and 3D max is that they are not solid modeling CAD softwares, but surface modeling softwares. There are typically parts intersecting parts so the 3d printers do not know what is the inside and what is on the outside. The solution to this for many companies is to use boolean/unite those parts into a watertight part with only 1 shell. You also need to make sure your surfaces are stitched and the parts are watertight. To my knowledge, Shapeways is just a website and outsources all printing. I’m not sure if they have application engineers who can handle the CAD clean up involved. Eitherway, the best way to find out if your part is printable is to import it into the 3d printer software and look at it 1 cross section at a time. Some softwares like Zprint (for ZCorp 3d printers) will let you get away with a less than perfect model. IE: If you have surfaces next to eachother, the binder will bleed into the next surface and you will end up with 1 part. SLA softwares run a bit different and could take up to 18 hours just to load, so it’s better to make sure you have it right the 1st time before sending it to the machine.

The goal is making everything solids with some sort of volume (water tight). You can do this in Rhino as well as polygon modelers like 3ds max, Modo or Maya.

If you try to print a surface from any parametric modeler (Solidworks, pro/E, etc) you will have the same issues mentioned.

“analyze > edge tools > show edges” will be your best friend.
You can also set up Rhino (tools > options) to display naked edges as a different color

Rhino’s biggest disadvantage with RP is that it isn’t great at doing wall thicknesses via approaches like shell or thicken. As long as you know the limitations you can do quite a bit.

One of Rhino’s biggest advantages how easy it is to fix stuff and how well it works with different file types. I actually find my self using Rhino mostly as a translator as it does a great job going from NURBs to Polys (which you have to do for any RP process, usually as a STL file).

Hey gang I currently have a client working in Max but having a hard time exporting a smooth surface. It seems to come out faceted. I am more familiar with SW than Max type softwares. Any ideas how to get it done? Maybe through rhino or a few other softwares in between? Not sure if there is a trick or it is something obvious staring us in the face…

-newbie

p.s. I know we can sand a Z Corp part, but both the client and I would like to learn how to do it right…if it is possible.

It really depends on the geometry in 3dsMax. Maybe you could post a screen shot of the problem areas, that would help diagnose the problem. Keep in mind that 3dsMax is a sub-D/polygon modeler…its completely different that building something with NURBs.

I would, but we are under an NDA. It is similar to the surface of a boat hull. My boss seems to think there may be correlation with display settings. Not sure if that makes sense, I’ll keep digging and post what I find.

Creating items from 3ds max can be a huge pain.

I am going to assume they are using polygonal box modeling in 3ds Max and using a mesh smooth modifier to get things to smooth out.

If this is the case, have them remove the final mesh smooth modifier and export the model in a format compatible with rhino.

There is a plugin for Rhino called T-Splines that helps with this transition. It works with box modeling and nurbs together.
http://www.tsplines.com/

You should be able to bring it into Rhino and create a nurbs based model off of their 3ds Max Model. You do this by converting it into a T-splines Object.

Here is going to be a quick run down of the method.

This is the 3ds Max Object. Box modeled with a Turbosmooth Modifier applied. This is most likely what they are using.


This is what the model looks like without the Turbosmooth Modifier.

You want them to export this object as an .OBJ file type without the turbosmooth modifier applied.

You import the .OBJ File into Rhino. It will look like this.


Once you covert it to a T-Splines model it will still look the same.

After the model is converted to a T-Splines model hit the T-Splines Smooth Toggle and it will show in its smoothed form.


Once you have the model converted and smoothed you can use the Convert to Rhino NURBS or polysurface button and you will have a nurbs model of your hull design.

I hope this helps. It’s a pretty straight forward method when having the T-Splines plugin.

Why even bring it into Rhino if you don’t need to do further modeling?
Convert your turbosmoothed Mesh to a Editible Poly and then Export it as a STL.

I have yet to work with a Z-Corp Machine so I really don’t know if a nurbs model is needed. Do you know if they work better with NURBS or Sub-D modeling? I have run into issues with using a sub-d model with 5-axis cnc machining in that too much info is created. I’m not sure if sub-d modeling creates too much info for 3d Printing.

every RP machine i’ve ever used (Objets, FDMs, SLAs) use STL formats which will require any nurbs model to be converted prior to building.