Author Topic: Printing thin flat parts (or how not too...)  (Read 191 times)

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wcfn100

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Printing thin flat parts (or how not too...)
« on: December 03, 2018, 01:41:09 AM »
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So I've spent the last few days experimenting with how to print box car door and car sides and here's what I've learned.

First of all, the ideal way to print these is standing straight up.  It eliminates the build lines and you can fit a ton onto the platform.  When Mark4Design printed some doors for me years ago, I notice they were just in a row without anything but bottom supports, so I tried this.



It worked okay with most of the thicker doors, but the thinnest one for my CMO Express box car, I had many failures.  I think it's so thin it collapses on itself as it works up and down in the resin bath.  Maybe I could tweak the print setting to fix this.  :?

So the second attempt put the doors at an angle.



This worked but leaves build lines and had some warp when it cured.

Third run put everything right on the plate without supports.  Why not.   :lol:



This added thickness to the parts at the FEP film.

Forth try I went with supports.



This was a total failure and a lesson into why some parts have to print at an angle.  Basically it prints the circle bases and then the supports, but once it gets to the flat part of the doors, it becomes a stronger bond to the platform than the supports are to the door and it rips off.  Had to clean the FEP after this one.

My last attempt is getting some extra curing as I type.  Will report later.



Jason

« Last Edit: December 03, 2018, 01:56:45 AM by wcfn100 »

C855B

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Re: Printing thin flat parts (or how not too...)
« Reply #1 on: December 03, 2018, 01:43:30 AM »
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Yes, but how did the gas pumps come out? ;)
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wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #2 on: December 03, 2018, 01:45:46 AM »
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Yes, but how did the gas pumps come out? ;)

I'm checking that too.  The first prints worked except didn't print the hose.  I adjusted that on the model and went with heavier supports and it looks like it printed this time.  I'll post something if it all worked.

Jason

wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #3 on: December 03, 2018, 01:52:09 AM »
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Oh, and I wanted to add...

This file prints in about 4 hours.



And this file prints in about 30 minutes.



Jason

Chris333

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Re: Printing thin flat parts (or how not too...)
« Reply #4 on: December 03, 2018, 01:57:21 AM »
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They all turned out like screen captures   :P

How bad are the lines when printed at an angle?


wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #5 on: December 03, 2018, 02:04:36 AM »
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They all turned out like screen captures   :P

How bad are the lines when printed at an angle?

It's a little more visible in person but not bad.  The paint was brush painted.  You can see it's built up in a few places.



Jason

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Re: Printing thin flat parts (or how not too...)
« Reply #6 on: December 03, 2018, 02:08:41 AM »
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Silver paint?  To use light reflections for indicating the problem areas?  I would have thought that a standard gray primer could be better for showing problem areas.
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wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #7 on: December 03, 2018, 02:11:31 AM »
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Silver paint?  To use light reflections for indicating the problem areas?  I would have thought that a standard gray primer could be better for showing problem areas.

I've been experimenting with what brush paints best with the resin but would also show detail.  Silver covered pretty good but has too much body. Next models will try the Vallejo grey primer.

Jason

Chris333

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Re: Printing thin flat parts (or how not too...)
« Reply #8 on: December 03, 2018, 02:47:02 AM »
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In the pic with the gas pumps, did those door print? I was going to recommend supports up the back, but I see you have them.

wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #9 on: December 03, 2018, 02:57:00 AM »
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In the pic with the gas pumps, did those door print? I was going to recommend supports up the back, but I see you have them.

Yeah they printed but I'm having some uncured resin issues I think.  This happened to me before and the only common thing I can think of is dirty (green tint) IPA used to clean them.  I have one door back in the curing stand to see if I can lose the shine.

Jason

wcfn100

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Re: Printing thin flat parts (or how not too...)
« Reply #10 on: December 03, 2018, 03:17:26 AM »
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Here's the pump and an why I tried starting with silver paint.



I'll get some better pics tomorrow and hopefully the door will be done.

Jason

Chris333

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Re: Printing thin flat parts (or how not too...)
« Reply #11 on: December 03, 2018, 04:15:08 AM »
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No sexy girls to pose?

peteski

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Re: Printing thin flat parts (or how not too...)
« Reply #12 on: December 03, 2018, 05:02:04 AM »
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No sexy girls to pose?

And is that a 1:160 or 1:144 scale model?

I also must be dense as I can't figure out what does a model car and a figure next to a dark-colored gas pump have to do with using silver paint. Is the gas pump too dark to see the details or printing errors? 
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