Want to print (close to life size) T-Rex Skull

[Evolutionnext]

Hi everyone,

I got myself a Da Vinci 3d Printer with a 20cmx20cmx20cm build size. I went through my projects over the last few weeks and I see a time where the printer wont be running 24/7 any more. This made me think of starting a larger long term project.

Basically, I was thinking of printing a life size T-Rex Skull and maybe the front part of the skeletton to put up there on my 2 story living room ceiling.

I guess if it was done right, finished to be a smooth surface that is then sprayed to look like white porcelain, it could look quite nice.

Obviously this will take months, but if the printer isnt used.. then why not?

Now I am still quite new to the 2d printing world, and I would appreciate a fet tips form the pro's.

Here are my questions:

1) I have never edited a downloaded STL file. Is this possible in Google sketchup? Any ideas or hints how to cut the model into 18cmx18cmx18cm blocks?

2) How would you design the cuts? just flat surfaces to be glued together or teetch and holes to fit into each other or any other tips?

3) How much material should i cut away when making the cuts between 2 blocks? 2mm? 1mm?

4) the surface must look smooth. Any tips? My idea was to print with ABS and then Acetone-fume it. Or maybe paint with a brush with "ABS-DISSOLVED-IN-ACETONE" Paint. And the spray paint it to be glossy.

5) I only have experience with ABS, though my printer can do PLA. Would PLA have any advantages over ABS I should look into?

6) Any hints how to reduce warping on such large pieces? I fixed it quite well with ABS/Acetone coating the heated print bed to assure adhesion. Any other hints you could recommend?


Thanks a lot!

[djprinter]

I did some quick math, and if you're going life size (about 5 feet long) that's going to be around 150 prints. Print in PLA to avoid warping.

The model will need alot of prepping. Zbrush would be the ideal tool to break it up IMO, but it has a large learning curve.

[LambdaFF]

If you rely on mating surfaces for adjustment of 150 parts... good luck. Try and put some pins here and there, that will help you eliminate deviation and give a solid reference.

[Sebastian Finke]

1) I have never edited a downloaded STL file. Is this possible in Google sketchup? Any ideas or hints how to cut the model into 18cmx18cmx18cm blocks?

Editing stl file is not easy (sometimes impossible). Most professional software can import stl's, although that's a pricey option. Apparently Meshlab can cut stl's too, Ispeak under correction though.

2) How would you design the cuts? just flat surfaces to be glued together or teetch and holes to fit into each other or any other tips?

Depends. Flat surface are fine if you're careful. Using pins is good too.

3) How much material should i cut away when making the cuts between 2 blocks? 2mm? 1mm?

Not sure what you mean here...

4) the surface must look smooth. Any tips? My idea was to print with ABS and then Acetone-fume it. Or maybe paint with a brush with "ABS-DISSOLVED-IN-ACETONE" Paint. And the spray paint it to be glossy.

Don't use acetone fumes unless you to fume to entire glued together skull. You will inadvertently ruin your mating surfaces. After glueing all the parts together you should sand the skull until its smooth. Start with a 150 grit then finish with a 300 grit. After that spraypaint it to what ever finish you want.

5) I only have experience with ABS, though my printer can do PLA. Would PLA have any advantages over ABS I should look into?

You will less issues printing larger parts in PLA than in ABS, no doubt. I personally don't like sanding PLA, its way harder the ABS and doesn't give me a nice finish. YMMV.

6) Any hints how to reduce warping on such large pieces? I fixed it quite well with ABS/Acetone coating the heated print bed to assure adhesion. Any other hints you could recommend?

If you want to print in ABS then you must completely enclose your printer. All holes and openings must be closed! I can't stress this enough. Preheat your chamber for 15-20 min (by leaving the printer enclosed with the bed at print temp) for starting your print.

Good luck. Post pics of your progress!

[Sebastian Finke]

Oh yeah... I believe XYZ filament is considerably more expensive than 'regular' filament. You may want to bear that in mind...

[curious aardvark]

have a word with bassna - he's already printed one large enough to use as a hat on a machine with a smaller build volume.
So he'll be able to tell you how he sliced the file up - or you might just be able to use his slices if he'll let you :-)

At least I think it was bassna :-)

Yep here you go: http://www.thingiverse.com/make:126268

also thread here: http://3dprintboard.com/showthread.p...ant-T-Rex-Mask

[Evolutionnext]

I did some quick math, and if you're going life size (about 5 feet long) that's going to be around 150 prints. Print in PLA to avoid warping.

The model will need alot of prepping. Zbrush would be the ideal tool to break it up IMO, but it has a large learning curve.

Thx a lot for the hint.. I have since found out PLA might be a better choice.

[Evolutionnext]

Depends. Flat surface are fine if you're careful. Using pins is good too.

Don't use acetone fumes unless you to fume to entire glued together skull. You will inadvertently ruin your mating surfaces. After glueing all the parts together you should sand the skull until its smooth. Start with a 150 grit then finish with a 300 grit. After that spraypaint it to what ever finish you want.

You will less issues printing larger parts in PLA than in ABS, no doubt. I personally don't like sanding PLA, its way harder the ABS and doesn't give me a nice finish. YMMV.

Great hints.. thx a lot. Will go with ABS then. Already got myself the first 10 kg of filament. I will then use flat surfaces as a test to see how it works out on a trial. otherwise I would use teeth. Any hints on how much material I need tot ake away from a tooth to fit a hole?

10mm hole wont fit a 10mm tooth...

[Evolutionnext]

Oh yeah... I believe XYZ filament is considerably more expensive than 'regular' filament. You may want to bear that in mind...

Thx for the hint.. got myself a resetter and cheaper filament...

[Evolutionnext]

have a word with bassna - he's already printed one large enough to use as a hat on a machine with a smaller build volume.
So he'll be able to tell you how he sliced the file up - or you might just be able to use his slices if he'll let you :-)

At least I think it was bassna :-)

Yep here you go: http://www.thingiverse.com/make:126268

also thread here: http://3dprintboard.com/showthread.p...ant-T-Rex-Mask

Great info.. thx a lot! Seems like he has some vaporing and fusing together problems. Ill see what I can find out from him. thx a lot