Alice In Wonderland White Rabbit

[RKapuaala]

Ethan,,,, are you doing a hollow print of the Rabbit? I just noticed that your pistol is solid. I'm not sure if it speeds up printing, but it should save you on material costs.

 

[Ethan]

Just a quick update. The last two test prints have gone marginally well so we are going to run a test print on the Rabbit this evening. I am going to scale the whole piece down to fit into the printing window as one, uncut figure; so a wild guess is the Rabbit will be around 75mm. We will be printing at 25microns. I expect the print to take somewhere around 10 hours so expect some pictures Wednesday but I will try to keep you guys posted. Even if this first print is a fail I'll get some pics out there for ya'll to look at!

 

[Ethan]

RK: At the scale we will be printing at I don't think the saved resin will be enough to warrant the time it takes to create a shell in Zbrush so no, not this time. If we are able to get quality out of the larger printing spaces then I will be forced to start using the shell.

 

[RKapuaala]

BTW,,, I spoke with a friend of mine who has been printing for a while and he says it does improve the time but marginall since the support material has to be printed too.
As far as savings. If I print a 3 tall piece the cavity is cost effective at shapeways,,, anything smaller it is impossible. It takes me about3 minutes using 2 different tools to make a cavity now. I thought zbrush does that automatically?
I have to use meshlab to do a uniform resampling of the original mesh. Save that and then modify it in meshmixer by removing the resulting outershell and making some extrusions on the inner shell.
Then export it.
Then open my model and append the inner shell to it. Do boolean union and then remove the excess geometry. Reimport the inner shell, stitched it to the model and then weld the seams then export again.
How is the inner shell done in Zbrush?

 

[Ethan]

RK: I will reply to the shell question tomorrow in depth

Just a quick FYI; rabbit test print failed and we have to redo the nonstick silicon layer again. We also have decided to wait for some product information updates that are late in coming that may have an effect on the problems we are having. I will explain it all in the morning...

 

[Ethan]

RK: In Zbrush there are a couple ways to make a shell. First I have to have the model in what is called Dynamesh form. This is a resolution based form of sculpting and at this point I will have a non-detailed blob in the shape of the rabbit. I can then insert a cylinder into the mesh and a couple of settings will create a shell. Not so hard. However I have the mesh cut into 5 pieces, each needing a shell of the same thickness and they all need to fit back together. So you're looking at some actual sculpting time again to fix any anomaly's. Then I have to get the blob back to a high quality model. I have to have made a copy of my high poly mesh before I converted to Dynamesh and I can use this to project my old mesh onto my new one. I do this three times and I now have 3 subdivision layers of high quality. However there is always edge damage so I have to re-sculpt all the edges. Also any changes I made to the mesh in Dynamesh form must be masked off to prevent the computer from trying to put them back in their original places and exploding the polygons. This method is what I would do if I tried to do the Rabbit now. WRONG WAY! The best way is to know what your doing before you start the project! Since the rabbit was my first attempt at Zbrush at all I had no clue what I was doing and learned from mistakes. This has caused a post production nightmare! The right way is to make the shell as soon as you import your mesh from Modo, 3DsMax, create base mesh in Zbrush, etc. and then cut the model for printing, then after all the prep is finished, put all the details in. Now you don't have to worry about dealing with keeping all the details at the end because you did it all at the beginning. Also, large topology is very important for cutting the model for printing/casting as it gives you wonderful straight cut lines to follow! Also I will be working on putting up that thread on printing, this week. I think I can give some great insight into whether this is a realistic business venture.

Alright, so last night we attempted twice to print the rabbit and both times didn't make it past the base before the layers stopped sticking and floated off in the vat or attached themselves to the silicon surface of the vat. This ruined the surface and set us back another weekend of cure time on replacing the surface. Here is my hypothesis:

The print is supposed to attach itself to the arm that is submerged in the resin. This arm then rises one layer at a time as the projector adds layers. Well for some reason the plate of the arm is pretty much the same size as half the vat which is causing some kind of suction under the surface; creating air bubbles that encroach upon the printing area. Eventually these air bubbles reach the edge of the printing area and I think it forces an edge of the current layer that is being exposed, to stick to the bottom of the vat and the print itself. Think of an air bubble sandwiched between your print and one layer of plastic. That layer probably gets lost in the vat but this problem will repeat until finally the layers stick hard enough to the vat to pull the print off the arm and cure to the vat. FAIL.

To fix this problem I believe we need to make a special support material setup that has enough density to hold large objects but also is small enough that the bubbles can't get to it. Then if we make this material tall enough to raise the arm out of the resin before the actual print begins, the bubbles will never touch the real print. We are also considering some modifications to the plate on the end of the arm as well. All I know for sure is the bubbles are the culprit and we don't have enough information from the engineer on the exposure time of each layer.

So now we wait for an update to the printing software as well as a detailed guide to calibrating the process. The guy should have had this stuff to us a month ago so who knows how long it will take but in the mean time I will finish cutting and sizing the Rabbit for final prototyping, post that up. I have a website to finish and Alice to start so there will be no lack of business from here and of course school! and day job.... Damn too many things!

 

[RKapuaala]

Sorry to hear about the failure and resurfacing. Now I know why the formlabs demonstration showed the model being supported by 100s of tiny rods about an inch from the model.
I did not realize what a pain zbrushes shell creation was.
You should get a free copy of meshlab.
You just use the filter Uniform Mesh resampling and it creates the dynamesh inner and outter shell for you in a separate layer. You export the dynameshes to another file. No need to resculpt or anything. Your original meshes is not altered and with a couple boolean operations you can connect the cavity to the original and weld them together.

 

[Ethan]

Thanks RK, I will def look into that. I think if I start the creation process correctly then Zbrush should be quick and easy. I think I can use 3dsMax to also make a shell that is importable. I will cross that bridge when I am ready to print at 8 inches or higher!

Still waiting on replies from the engineer. I may have pics of some cut pieces before class today. We shall see.

 

[RKapuaala]

Good luck David. Hoping to see images really soon.

 

[RKapuaala]

Sorry to keep bothering you with questions David, but you are the only one I know that has any direct experience with a 3D printer.
I was sitting in my lotus chair today watching the news and sipping some water. I trucked passed outside,,, I could barely hear it because my walls are so insulated, but water in my glass started vibrating ever so gently, and then I realized the truck was passing and causing the water to vibrate.
Since the material is liquid and the lazers heat the liquid in 50 micron layers,,, how did they minimize interference from small vibrations like that?
Also, how level does your printer have to be or does level have any effect on the print?
Finally what kind of stand do they recommend the printer be placed on, or again is that just not an issue?
Thanks in advance and I hope all is going well with your printing.

 

[Ethan]

Sorry for the late reply RK, and where did you get the name David? It's Ethan lol. I don't think small vibrations play any part in the printing process but if you had massive vibrations you could cause a problem or two. As far as the levelness goes, the levelness of the printer has no bearing on the print unless the projector is not attached to the printer. As it is right now, all of the pieces are level with each other and the liquid itself does not have to be level to print with. For the most part I would say small vibrations and levelness have no issue with the printing.

As for the weekend. We weren't here for most of it but we re-did the silicon coating on Thursday using a quick cure method of baking it at 185 degrees for 2 hours. The silicon cured and left air bubbles all over the printing surface! So we let it go for the weekend and did the silicon again last night, taking care to let the air bubbles come to the top before baking. Now we have a perfect surface again and will be trying a print tonight at 50 microns. This is the only micron quality that we know for sure our math is right for exposure and rest time to get a good print. I'll be playing softball so my brother will choose to either try the rabbit or do a print of the pistol in the vertical position, trying to get a perfect print on both sides. Adjustments will be made on both to make sure the beginning support material clears the resin before the actual print starts. This should be interesting!

 

[RKapuaala]

Good luck Ethan... I was just having a senior moment when I called you David

 

[Ethan]

Our test print was a success! The following images show the White Rabbit, printed as one piece at 50 microns with no clean-up. Right now I am about to start the cleaning process, sharpening a few edges and sanding away any small evidence of layering. Then I will prime and post up a new set of images that should show off the detail better. I'm very happy with this print! The height is just around 80mm so it is a good subject to look at if any of you wanted me to produce at a 75mm or 90mm scale and my actual piece will be almost twice as big so you can just imagine the level of quality I will be able to achieve at that scale! Enjoy

 

[Ethan]

Quick update. Cleaned up the print a bit and primed it. I've got a good amount of paint on him right now but I will wait to show those pictures until he is finished.

 

[Ethan]

Quick paint-up. Probably around 3 hours. At this point the proof is pretty much finished. What do you all think of it at half the scale the finished product will be?

 

[RKapuaala]

Sweet print! Did you need supporto n the ears and the chin?

 

[Ethan]

Thanks!
I added 2 small tubes to support the ears and one support from the upper half of the cane into the coat to help support the weight of printing the hand before it attached to the body. Both were easy to remove and clean up.

 

[RKapuaala]

Thanks for the info Ethan. It sounds like you have a lot of control over where and how much support material you use,,, that is definatly a good thing.

 

[Ethan]

Just wanted to show ya'll a picture of hopefully the last test print of the rabbit before we print the official prototype. Here is a bust of the Rabbit with support material added so you guys can see what manually has to be done before it goes to the slicing program.

Also I have decided to produce this kit in house so I am in the process of purchasing the pressure pot, vacuum chamber, and molding and casting supplies. I would like to be shipping by November 15. Lofty goal I know! the price will be 60.00 plus shipping.

 

[Ethan]

I'm sorry it has been so long in updating all of you on my progress. It has been a long almost-two-weeks! So the test print of the bust turned out very smoothed out because the light from layer-curing was traveling too far into the part of the print above the working layer. So that was a fail. So we waited until we received our additional pigment in the mail. During that time I build the vacuum chamber and pressure pot for production; also purchased resin, poly material (to be announced later) and molding silicon.

The pigment denser. The test print showed promise so we re-worked the entire rabbit in post and added keys to every piece so the kit would fit together perfectly. Then we started with the legs. At layer 884 the print skipped a layer and dropped the rest of the legs into the vat, one layer at a time. This happened 3 times over 15 hours of printing. We finally narrowed down the problem to a bug in the computer itself over the last couple of days and just over the last hour we got the print to go through each and every layer. We have started the legs again lol! If this works we will continue all week; I will play hooky from college and the prototype will begin production this weekend.

During this time the packaging materials have come in and we are finishing up the labeling designs to go get those printed. I am still getting the last couple kinks worked out on the website so no announcement there yet but once I have all the information you guys need to be able to purchase these kits I will make a formal announcement. Over the next few days I'll get some pictures up here so you can follow the process and check out the packaging.

Here's hoping!