SoliForum - 3D Printing Community — PRACTICAL ways to finish ABS parts

Re: PRACTICAL ways to finish ABS parts

2013-07-15T19:38:05Z

I came across The Touch-Up on Indiegogo the other day, a clean-looking take on the smoothing station.

Edit: Oh yeah, it was here in the forums at http://www.soliforum.com/topic/3099/the-touchup/

Re: PRACTICAL ways to finish ABS parts

2013-07-15T19:19:13Z

I've made an acetone polishing station using an old cofee maker. It's more convenient because it's cheap and you could see directly the results, in order to stop the polishing process when you desire (because you could see thru the glass whats happend).
I notice that the exposure time depends on the quantity of acetone and the size of the object. Usually it takes 15-20 min.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T15:44:31Z

There is more stepping in gradual curves to it take more melting than mostly smooth walls. You can get good results by sanding it with 80 or 120 grit sandpaper first. It will take some material off fast and give you a head start. The melting will fill in the scratches from the rough paper.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T15:24:40Z

So after some further investigation I see that where the acetone has smoothed the print has less to do with the height of the print and more to do with the curvature of it. The steeper/more-vertical a slope is the more it has smoothed and glossy, while the tops of all of the spheres are clearly defined lines made by the 3d printer.

I will do another test on a tall vertical wall to see if I get better results with a more consistent slope.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T14:36:59Z

Or why cant you rotate the part as you do multiple dips?

Re: PRACTICAL ways to finish ABS parts

2013-02-28T03:50:22Z

This is the problem with the room temperature acetone. There isn't much convection or pressure, so the vapor stays in the bottom of the container. Warming it gets it to spread out more. Soaking the towel gets the vapor to originate higher up and drop down, but the quantity of the vapor is still low. You might try setting the print in a smaller pot inside the can and then pouring acetone around it so the print is mostly below the surface of the liquid.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T03:18:50Z

So I finally got my rig set up and my results are mixed.

The bottom of the print smoothed way more than the top did, and there was a lot of sticking to the bottom of the metal can. It took approximately 1 hour to get this result, doing approx 12 minutes in, followed by 3 minutes out four times in a row.

The top is a little bit more glossy than it was coming out of the printer, but the bottom of the print was almost entirely smooth. Does anyone have any ideas how to change this to get a more uniform result?

Re: PRACTICAL ways to finish ABS parts

2013-02-28T00:30:41Z

If you are getting peltiers involved, you might be able to use one to chill the top of the container. This would keep the vapor inside the container without needing to seal it and possibly create dangerous high pressure.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T00:22:23Z

Aron wrote:

For making a steady stream of vapors come OUT of the system, we should create a structured way for the fumes to exit the chamber. Is there a material or apparatus, that preferentially absorbs/removes the acetone in a consistent manor?

Temperature. At 55C (30C above a 25C ambient), acetone has a vapor pressure of 1000mmHg. At 10C (15C below ambient), acetone has a vapor pressure of 100mmHg.

Put a peltier on the bottom of the paint can, with a heatsink on the other side of the peltier. Power the peltier. Reverse polarity to chill the vapors once done smoothing.

Re: PRACTICAL ways to finish ABS parts

2013-02-28T00:10:19Z

You could simply drain the vapors into a chamber that is lower and chilled so they condense when they get there.

Re: PRACTICAL ways to finish ABS parts

2013-02-27T23:44:51Z

I am obsessed about process repeatability, because I am shipping 3D Printed parts to clients.

Based on my engineering background: the paint can with paper towels attached via magnets sounds like the best answer so far.

It could perhaps be improved further, if someone can think of a simple way to move the vapors though the system.

For making a steady stream of vapors go INTO the system, we might attach the towel to a small container of acetone via a small diameter "wick" touching the towel, so that it will always stays the same wetness.

For making a steady stream of vapors come OUT of the system, we should create a structured way for the fumes to exit the chamber. Is there a material or apparatus, that preferentially absorbs/removes the acetone in a consistent manor?

Re: PRACTICAL ways to finish ABS parts

2013-02-26T23:34:22Z

Thanks guys, that is good to hear. Kinda gives me the motivation to go back and rework it. I tend to be more function based in my concepts and aesthetics tends to take a back seat in my thinking. And though my concept was strong enough to carry me through the class, they were not too happy with the bottle's silhouette.

Re: PRACTICAL ways to finish ABS parts

2013-02-26T17:54:00Z

vince7c95 wrote:

Using a brush is still doable, though it is more of a pain

VERY Nice!!!!!

Re: PRACTICAL ways to finish ABS parts

2013-02-26T17:09:45Z

vince7c95 wrote:

Using a brush is still doable, though it is more of a pain

Crap that's nice

Re: PRACTICAL ways to finish ABS parts

2013-02-26T16:55:32Z

That is really nice. Yes you can tell by the finished you had to use filler and lots of prep work. It looks great and your sustainability concept is great.

I was looking to paint small thins like phone cases brackets etc. Just simple aluminum look or primary colors. I was hopping some auto primer with filler, sand, then color top coat maybe a clear coat all rattle cans. (no air brush) would give a good look

(no clay)