Kraahkan 2

[tahu505]

I initially had no plans to document this build due to how rushed it will be and the overall nature of the build, but some stuff came up that I felt was interesting enough to document and could be helpful to others. I will also be trying a new post processing technique for 3d printing on thus build.

Some more background. A bit over a year ago, I created a life sized kanohi kraahkan from Bionicle as a commission for Essenger, an electronic music artist. Flash forward to a few days ago. Essenger was returning from the first half of his current tour when his tour van caught on fire. He and his friend were able to get out of the van, then the van exploded. Everything was lost from music equipment to personal items, including the mask. This 2nd mask is a gift, rather than a commission, to help Essenger recover what he can. My goal is to try to get this mask done and shipped out to him before he leaves for the 2nd half of his tour. Worst case, he still gets the mask back at some point.

Now for what I wanted to document. About 53.5 hours into 3d printing this mask, I noticed one of the supports kept getting hit and knocked around. When taking a closer look, I could see the nozzle was randomly extruding mid air where there were no supports. The extra extruded material was sticking to the nozzle, then hitting and whipping off on the supports, causing lumps and potentially support failure.

I pulled up the gcode and found there is a support structure that starts mid air on this print.

This print takes about 760g and due to the time crunch of this project, restarting with new code is not an option. With no way to change the code mid print and prevent material from extruding, I had to find a way for the extra material to not get in the way. I decided to try making a surface for the extra support to start building itself on. If the support actually builds up, then the extra material would not be knocked into the other supports. I used masking tape to build a bridge across the other supports, which would be removed when the print is done, so there is no damage to the actual part. I chose masking tape specifically because it is commonly used for adhesions on 3d pri ting beds. I had to stack some layers of tape to get it level with the current layer.

About an hour later and the support continued to build itself and its been smooth printing from here.

 

[S225]

I'm glad everyone was okay with the van going up like that. It's also really nice of you to replace the first print after all that happened.

I've caught my printer doing something similar once and even though I found out after it started printing mid air, it somehow managed to actually print the supports there off the excess filament that was getting left behind on earlier layers. CURA is a wonderful program but I still feel the need to check the layer preview after this and seeing how it tends to randomly move full layers to the print bed for some reason.

 

[tahu505]

I'm glad everyone was okay with the van going up like that. It's also really nice of you to replace the first print after all that happened.

I've caught my printer doing something similar once and even though I found out after it started printing mid air, it somehow managed to actually print the supports there off the excess filament that was getting left behind on earlier layers. CURA is a wonderful program but I still feel the need to check the layer preview after this and seeing how it tends to randomly move full layers to the print bed for some reason.

Looking back, I think I've had supports start midair before, none of them were affecting the surrounding supports though like on this one. Last night I had to add a 2nd layer of tape to stop it from wobbling and I woke up this morning to find a few layers after the 2nd tap, it bridged over and connected to the other supports. It seems to all be stabilized now.

 

[tahu505]

This is the least happy I've been with a print. Turns out it's smaller than it should be and there are walls missing on the 2nd mouth section. I talked it over with Essenger and he still wants it. The plan is to clean this up as much as I can, get it out in time to be used in the 2nd half of the tour, we'll later make another one, then this one will be given away to someone who helped donate to Essenger to help recover items from the fire.

Moving forward, the plan is to use foam to create a flat surface under the mouth piece with the missing walls. It won't be as accurate to the Lego piece, but it will be a cleaner look for the stage. Before I get to that, I'll be sanding the rougher areas and using UV resin to get rid of the layer lines. The UV resin is still on it's way. Unluckily yet luckily, the first 2 shows for the 2nd half of the tour were canceled, which gives a little more time to finish this.

I also tried out these new paints I found. A metallic black and a frosted pearl clear coat.

Scrap piece used for testing the colors.

 

[tahu505]

A lot happened today. This has really turned into a Frankenstein, experimental build. I started off today with hand sawing off this mouth section. I kept it as in tact as possible for later.

Then I did some electric and hand sanding to clean up the mask a bit.

Next I tried out the UV resin with UV light. After hitting it with the UV light I also let the mask sit out in the sun a bit to fully cure.

Because the resin is transparent, it's hard to see what's been filled in and what imperfections are left, so I painted it white.

While waiting for the paint to fully dry, I used that piece I cut out and saved from earlier to make a foam template. This foam piece can be inserted in to make a clean fill for the hole.

Now that I know the foam fits, I needed to seal it. I didn't have access to a heat gun but I had a 3d print running with the bed at 70°C, so I pressed the foam against the 3d printer bed and that sealed it enough. I then did some plastidip.

While the plastidip was drying and the white paint was done drying, I applied bondo spot putty to the imperfections on the mask. The left side seemed to have more, I think I rushed that side a bit, but it's fine because it will all be sanded and blended together.

 

[zelusamare]

This is the least happy I've been with a print. Turns out it's smaller than it should be and there are walls missing on the 2nd mouth section. I talked it over with Essenger and he still wants it. The plan is to clean this up as much as I can, get it out in time to be used in the 2nd half of the tour, we'll later make another one, then this one will be given away to someone who helped donate to Essenger to help recover items from the fire.

Moving forward, the plan is to use foam to create a flat surface under the mouth piece with the missing walls. It won't be as accurate to the Lego piece, but it will be a cleaner look for the stage. Before I get to that, I'll be sanding the rougher areas and using UV resin to get rid of the layer lines. The UV resin is still on it's way. Unluckily yet luckily, the first 2 shows for the 2nd half of the tour were canceled, which gives a little more time to finish this.
View attachment 337103View attachment 337104

I also tried out these new paints I found. A metallic black and a frosted pearl clear coat.
View attachment 337105

Scrap piece used for testing the colors.
View attachment 337106

You’re a good lad, Matt x

 

[tahu505]

Got the wet sanding done today. I'm not too sure how I feel about the UV resin method yet. I'll go over that again once this is fully finished.

Next I glued in the foam cutout I made using high temp hot glue, then I reinforced it with shoegoo.

 

[tahu505]

Painted and clear coated the mask today! It's all packed and shipped out, on its way to Essenger in time to finish up the 2nd half of his tour!

This mask I believe will eventually be donated by Essenger as part of a giveaway for the people who helped donate to him so he could recover his equipment lost from the fire.

For the next mask I make for him/any other of my future projects, I absolutely love the metallic black paint. The frosted pearl clear coat was great for keeping the metallic look, without being too glossy. The only downside to the clear coat was the nozzle broke and I had to swap it. The only nozzle I had fit enough to get the paint to spray through in a controlled flow to finish the mask, but also sprayed clear coat all over my hands. I'll try it again in the future and hopefully that doesn't happen again. For the UV resin, it's definitely good for finishing a fast project. The mask was overall smooth. I could still see the layer lines if I looked close but honestly not the worst. Where I did really like it, was one section of the mask broke and I used the UV resin to adhere it back together. You can not see or feel where the break was. For future projects, I see myself using the UV resin again to hide where parts join together but still using the samding/filler primer method as my main form of smoothing the print. Maybe resin then filler primer? It definitely has potential.