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Post Production techniques

Posted: Thu Nov 15, 2012 8:11 pm
by Numonic
Can anyone here let me know the best post production techniques for after printing a model.
Meaning I would like the finish to be smooth as close to injection molded plastic as possible?
I am going to be working on figures with many parts and would like them to look great.
A good workflow as well as the names of the tools would be helpful.

Thanks :D

Re: Post Production techniques

Posted: Thu Nov 15, 2012 9:17 pm
by wilsonj
Hi Numonic,

Have your parts arrived yet?

For your application, sand paper, small files and a small hobby knife/scalpel would work best. Ultimately an acetone vapor bath or similar would be best to get that smooth look. But that is something you would have to experiment with yourself. Be warned, they are dangerous!

Stratasys offer a finishing tank for about $40K........

Cheers
Jamie

Re: Post Production techniques

Posted: Thu Nov 15, 2012 9:37 pm
by amd-tec
Here`s bit cheaper version for smoothing parts.

https://solidoodletips.wordpress.com/20 ... g-station/

Thanks to juancr (www.imprenta3d.com) who mentioned this tip!

Re: Post Production techniques

Posted: Fri Nov 16, 2012 1:22 am
by Numonic
I have the parts and to my surprise they came out looking amazing! Jamie you are the man :) thank you so much for your hard work.
I found that it's a little weak when trying to assemble the parts some of the openings would crack and split :x pretty upsetting.
But he printed that with the UP Plus I believe wondering if it will print like that with the up Mini?

Re: Post Production techniques

Posted: Fri Nov 16, 2012 1:45 am
by Numonic
Got the parts super excited :)

Re: Post Production techniques

Posted: Fri Nov 16, 2012 4:15 am
by wilsonj
Glad they arrived.

Yes I had the same trouble. But as I mentioned, they really need to be designed for FDM, which they aren't. No big issue. You can still put parts together, just be gentle. Welding parts together with acetone could help some too.

You should be able to print all the parts with a Mini.

Cheers
Jamie

Re: Post Production techniques

Posted: Fri Nov 16, 2012 4:38 am
by Numonic
Jamie,
Yeah I see some areas when inserting the pegs the outter ring cracks :shock: but I went in and put the peg inside of the bicep and forearm looks like just turning it around like putting in a screw helps. The parts are awesome especially the head I noticed it's a white material but what kind of white is it?
Another question how did you position on the print bed? Was it laying down or was it facing up?

If I can print the figures on the Up Mini that'll be my best bet hearing rumors the level of the bed can be easily fixed via the 1.18V update coming soon.
Also wondering if you can send me a screen shot of how you positioned each of the parts I'll be doing that on my end and studying it when I come around to purchasing the printer. :D :D Also amazed the ball joints work great but I will be covering them up with a box lock outter shell to make it stronger and have the inside be a shape that needs for the other insertion.

Can I smooth the model by putting nail polish remover as well? Also what did you use to glue the gun to the forearm?



Thanks again for the help really appreciate it I'm so excited :)

Re: Post Production techniques

Posted: Fri Nov 16, 2012 8:57 am
by eyUP
There are some model finishing tips in this thread:
http://www.pp3dp.com/forum/viewtopic.php?f=4&t=982

Re: Post Production techniques

Posted: Fri Nov 16, 2012 9:44 am
by wilsonj
Numonic wrote:Jamie,
Yeah I see some areas when inserting the pegs the outter ring cracks :shock: but I went in and put the peg inside of the bicep and forearm looks like just turning it around like putting in a screw helps. The parts are awesome especially the head I noticed it's a white material but what kind of white is it?
Another question how did you position on the print bed? Was it laying down or was it facing up?

If I can print the figures on the Up Mini that'll be my best bet hearing rumors the level of the bed can be easily fixed via the 1.18V update coming soon.
Also wondering if you can send me a screen shot of how you positioned each of the parts I'll be doing that on my end and studying it when I come around to purchasing the printer. :D :D Also amazed the ball joints work great but I will be covering them up with a box lock outter shell to make it stronger and have the inside be a shape that needs for the other insertion.

Can I smooth the model by putting nail polish remover as well? Also what did you use to glue the gun to the forearm?



Thanks again for the help really appreciate it I'm so excited :)
The white is OEM ABS. I ran out, so needed to change over.....

As for positioning on the print bed. A bit of trial and error, but with experience you get to know how some parts should be printed. I try to make sure holes for pegs were printed laying flat, so the peg would go in vertically.

Ha, could you see I glued the gun back on! keen eyes. I used Tetra, which is similar to MEK, but works better as its designed to work with ABS.

You can use nail polish remover, its basically acetone. I think acetone might be better though.

Sorry no screen shots of positioning.

You're welcome!

Cheers
Jamie

Re: Post Production techniques

Posted: Fri Nov 16, 2012 10:50 am
by Lawrence
Hi
this may not give the surface you want, but, I have found that a few light coats of clear acrylic sprayed over the model results in smoother surfaces. When I run my fingernail across an unsprayed surface i can feel the layers, but after the acrylic is applied it is quite a lot smoother.
See details in my Up! Versus Mojo posts: http://www.pp3dp.com/forum/viewtopic.php?f=4&t=2034
I hope this may help.
Regards
Lawrence

Re: Post Production techniques

Posted: Fri Nov 16, 2012 12:30 pm
by roller
You can just just polish the surface with acetone to get a nice finish. I use gloves, a gas mask goggles and a rag soaked in acetone to smooth the surfaces when I need it. You can get a nice smooth surface just like an injection molded model. You can use use a light dip or thin coating of MEK to strengthen the bonds in the ABS but this also makes the plastic stiffer and more brittle so it's a little bit of a double edged sword but stiffness always is.

Re: Post Production techniques

Posted: Fri Nov 16, 2012 12:47 pm
by JuliaDee
Something called "spray putty" has been mentioned a few times; I think it's an auto body thing. High solids content gives you a quick fill of the layer lines, then sand.

Re: Post Production techniques

Posted: Fri Nov 16, 2012 1:13 pm
by roller
Oh yes, spray putty is an excellent suggestion - I see Industrial design students use it a lot to smooth out surfaces. The also use rapid filler for walls etc and applied with a spatula.

Re: Post Production techniques

Posted: Sat Nov 17, 2012 1:50 am
by pp3dp.nl
Yes the putty stuff is what I use when painting models. Actually it is Motip Filler, someone told me that is better than putty because it is easier to sand down. My last project was easier because I tried the acetone dipping, it worked great!

I had to print 30 fairly big models and paint them orange. So I dipped them for 15 seconds in acetone in a bucket, let it dry on baking paper and applied the filler. Then some putty like Motip orange paint and the models look great. Most people say they feel like a wooden figurine and don't know it is FDM printed.

Sorry no pictures because I don't think the client wants them out there :)

Re: Post Production techniques

Posted: Sun Nov 18, 2012 2:59 pm
by marto
I tried this today.

http://solidoodletips.wordpress.com/201 ... -finisher/

I bought a $12 rice cooker and a bottle of acetone. Works pretty well although bit more tweaking needed to get the time and levels of acetone right.

Image
http://i1113.photobucket.com/albums/k51 ... 151535.jpg

Image
http://i1113.photobucket.com/albums/k51 ... 6C4EEE.jpg

Apologies for the Iphone pics.

Steve

Re: Post Production techniques

Posted: Thu Nov 22, 2012 12:18 am
by marto
I have been continuing to experiment with this.

I am getting a significant increase in strength when I do the acetone treatment. I am also doing multiple lighter treatments now which seems to give a better finish.

One thing which I would like to try is putting a fan in the vessel as the sides seem to get a lot more acetone on them than the other surfaces.

Steve

Re: Post Production techniques

Posted: Thu Nov 22, 2012 4:55 am
by JuliaDee
Make sure it's a fan that cannot possibly make a spark... no, electricity anywhere near an enclosed vessel of acetone and/or acetone vapors is probably a Really Bad Idea.
marto wrote:I have been continuing to experiment with this.

I am getting a significant increase in strength when I do the acetone treatment. I am also doing multiple lighter treatments now which seems to give a better finish.

One thing which I would like to try is putting a fan in the vessel as the sides seem to get a lot more acetone on them than the other surfaces.

Steve

Re: Post Production techniques

Posted: Thu Nov 22, 2012 9:21 am
by marto
PC fans are brushless motors DW. I am trying to not to blow myself up as much as possible.

Re: Post Production techniques

Posted: Thu Nov 22, 2012 1:45 pm
by roller
Brushless motors can still spark ... not by design but because PC fans are often cheap 'n nasty - a bit of runout resulting in contact can cause sparking, or a lead breaks loose, or a bit of debris can get into the motor housing (a sticker isn't exactly a bulletproof seal). We don't want to hear about you on the news Marto!