Author Topic: Lost PLA bronze casting of John Lennon  (Read 1879 times)

Offline RotarySMP

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Lost PLA bronze casting of John Lennon
« on: May 10, 2020, 07:24:00 AM »
Hi Madmodders,

I took a week off my mini-lathe project to cast a statue for my Beatles fan wife...

My Lost PLA technique is pretty rough. I need to watch more of Jeff the veg oil guys videos, and sort out the details, but it was well received, even with defects.

I made a video of the whole thing here:

Best regards, Meilleures salutations, Mit freundlichen Grüßen, Cu salutari
Mark
https://www.youtube.com/c/RotarySMP

Offline Joules

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Re: Lost PLA bronze casting of John Lennon
« Reply #1 on: May 10, 2020, 08:19:23 AM »
These must be the Yuk, Oh No prints....

10 out of 10 for the volcano model.

Mark, when you need to join PLA parts for casting, consider welding them using a very fine tipped temperature controlled iron.  I use the same tool I used to use for waxing when we did lost wax castin, do it like Tig welding using some filament as filler rod, you can then work the PLA back to blend in.  Likewise never use a pigmented PLA always use natural, no residue left behind and you can easily see your welds using a bright light behind the model.
« Last Edit: May 10, 2020, 10:27:20 AM by Joules »
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Offline RotarySMP

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Re: Lost PLA bronze casting of John Lennon
« Reply #2 on: May 10, 2020, 08:57:57 AM »
Thanks a lot for the advice. I didn't even think about welding it.  :doh:

That oil burner is a bit of a temperamental beast. The home made needle valve is not perfectly concentric, so it goes low-high-low-chernobyl! A little too much, and it is like one of those tractor drag racers.

Have you ever tried spraying the part with clear coat to smooth it? I saw it in this video,

 and was wondering of you know if there is anything special to look for, or just cheap rattle can?

I'll buy some more clear filament.

We went to the Yoko Ono exhibition in Krems a couple of years ago. Her art doesn't work for me. at all.
Mark
Best regards, Meilleures salutations, Mit freundlichen Grüßen, Cu salutari
Mark
https://www.youtube.com/c/RotarySMP

Offline Joules

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Re: Lost PLA bronze casting of John Lennon
« Reply #3 on: May 10, 2020, 10:37:37 AM »
Can't help with advice on coating prints for casting.  I have used sanding sealer for some commercial pieces and then wet sanded them.  For casting I would be tempted to just wet sand the PLA, time consuming but you get out what you put in.  I did change to a 0.3mm nozzle a few years ago and get much better quality prints, less work needed to get a good surface finish.  You do pay a penalty in print time, wish I still had contacts for casting these are interesting times.
Honour your mentors, and pay it forward.

Offline RotarySMP

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Re: Lost PLA bronze casting of John Lennon
« Reply #4 on: May 10, 2020, 01:50:44 PM »
Good point. I am still on a 0.4 nozzle, and printed with 0.2 layer height.
Best regards, Meilleures salutations, Mit freundlichen Grüßen, Cu salutari
Mark
https://www.youtube.com/c/RotarySMP

Offline efrench

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Re: Lost PLA bronze casting of John Lennon
« Reply #5 on: May 10, 2020, 03:09:27 PM »
I have a .3 nozzle and use a .07mm layer height for most things.

Offline RotarySMP

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Re: Lost PLA bronze casting of John Lennon
« Reply #6 on: May 11, 2020, 02:54:15 AM »
The prints must take forever dont they?
Best regards, Meilleures salutations, Mit freundlichen Grüßen, Cu salutari
Mark
https://www.youtube.com/c/RotarySMP

Offline Joules

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Re: Lost PLA bronze casting of John Lennon
« Reply #7 on: May 11, 2020, 06:18:30 AM »
I print at 0.1mm, so they take about twice as long as 0.2mm   Time generally isn’t an issue as I leave the machine running whilst doing other work.  My machines are pretty well dialled in and very rarely have failed prints (use support for prints)  For a long print I will get up early, set the job running, and hopefully be finished before going to bed.  If a large print, I will do it in sections over a few days and weld the parts together.

You can print smart by having voids inside a large print and only mesh between thin inner and thicker outer shell, making a stiff print that doesn’t use as much material or time.
Honour your mentors, and pay it forward.

Offline RotarySMP

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Re: Lost PLA bronze casting of John Lennon
« Reply #8 on: May 12, 2020, 01:46:40 PM »
Smart use of voids is a good idea. Thanks.
Best regards, Meilleures salutations, Mit freundlichen Grüßen, Cu salutari
Mark
https://www.youtube.com/c/RotarySMP