Robotic/Automail Arm

Hey guys,

 

I'm looking for some ideas. I'm considering using one of the new Granado Vindoll boys to embody a character from the new Voltron: Legendary Defender series on Netflix. The character, Shiro, has a cybernetic/robotic right arm. So, I'm trying to think of different methods of trying to accomplish that. I know there are a handful of resin automail-type arms out there, but one of the concerns with that would be attachment.

 

I also thought about trying to do some additive mods and/or painting of his actual arm to give it the right look. I've also thought about starting with one of Granado's articulated resin hands, painting it, and going from there, but again, the problem is attachment.

 

Has anyone done anything similar before? Am I barking up the wrong tree to even consider doing this with a vinyl doll?

 

Thanks!

I've been thinking about making a robotic leg for my girl when I eventually get her. In theory it seems pretty simple, just get a dremel, or some sort of carving tool, to carve lines then use some epoxy to add things on. But again that's just in theory... I haven't actually tried it out at all, it might be harder than I think.

 

With Shiro's arm you wouldn't need to add things on, mostly just carve lines. You could use epoxy to maybe smooth the arm out if you don't want such a muscle-y defined arm, but depending on the vinyl thickness you might just be able to sand it smooth.

 

I think the main challenge here would be the hands, if you want them articulated, and the wrist and elbow joints.

 

With the hands, I have no idea how to even start modding them to fit Vindoll's wrists. Hopefully someone else here knows? If not, you might just have to settle for the standard Vindoll hands that come with him.

 

And then with the joints, they would need to be painted or dyed black to look the most accurate:

 

 

Well, maybe not the entire elbow joint, just the inside part of it...

 

But the problem with painting joints is that the paint chips really easily. And I've heard that, at least with Dollfie Dreams, the inner frame is hard to dye if you need a specific color. Then again, it is black so maybe just drop it in a vat of dye and leave it for a few hours?

 

But again, that's just all in theory. I have no actual experience doing any of this so if someone else contradicts me, you should probably listen to them instead.

 

And if this whole modding idea doesn't work out, you could always just sew a sleeve that looks like Shiro's arm and put it on the doll... in fact, that'd probably be the easiest way to do it, if you're okay with a robotic arm being made of cloth.

That's a good point with only needing to carve the lines. May have to start doing some research on painting vinyl. As far as the articulated hand, I'd be fine with the regular one, I was just thinking it had a more 'robotic' look to it as a place to start, but attaching it would be a bear.

 

Normally I wouldn't even go there, but I wonder how Sharpie would hold up just to color the joints? Also something to research.

 

I actually had thought about sewing or creating some kind of cover for his arm, I just don't know that I'd be satisfied with the end result. Hm.

 

Thank you for all the input, you gave me a lot to think about!

This might not be too helpful, but I cannot stop thinking about some SmartDoll photos. (It is so hard to track down, since Danny post so many!)

Maybe ask Danny what he did to make the glove fit..? Or where he got it from, and so on.

 

And the SmartDoll frame hand

 

Like I said, it might not help much. But maybe it could be an easier mod option..? (not that I know anything about Granados doll)

Thank you for all the input, you gave me a lot to think about!

 

Glad I could be of help!

So, to update this, obviously no real progress until the doll arrives, but I've been thinking through my strategy. I think I am going to work with the existing arm and simply modify it. One of the techniques I've found is one used to scribe panel lines on Gundam models:

 

 

VolksUSA had the Tamiya scribing tool in their hobby shop section, so I tossed it into an existing order. I found the Dymo tape on Amazon, it's about $5 for a roll.

 

Now, obviously vinyl is going to be softer than the plastic used for gunpla, but I'm hoping with experimentation I can determine the right amount of pressure to use. The other concern will be whether the lines will be wide enough for my purposes, but I think that's something I can work with. Once I have my lines, then I'll seal and paint.

Hopefully it all goes well. Please keep us updated, I would love to see your progress once you get your doll!

Update- Still waiting for Granado, but working on my game-plan once my boy arrives.

 

First step will be etching the lines, and is possibly what I'm most nervous about, because it will be difficult to get them even and straight. People doing Gundam panel etching use Dymo tape to guide their lines. I bought some, but in testing using a DD thigh I bought specifically for practice, the tape doesn't stick as well as I'd like.

 

Afterward, I have tentatively decided to start with a dye bath using Rit Dyemore in Graphite. I'm going to dye the arm and the skeleton pieces underneath it. Then I'm seriously considering using Rub 'n Buff in Pewter for color. The suggestion was made be someone on DoA, and initially I was skeptical, but I'm concerned about regular paint cracking. In doing research I've seen several examples of where people have used Rub n' Buff on vinyl furniture with good results, so I think it may ultimately give me the flexibility I need. It will probably stain, but given that I'm already dyeing the arm, I'm not concerned.

 

Beyond that, I'm debating whether I need to put a layer of MSC over it. Maybe, maybe not? Thoughts, anyone?

So! Finally got my doll in July. In the meantime I'd gathered all my tools and was ready to proceed. However, I did procrastinate a bit. Most of all, I was nervous about etching the lines, with good reason.

 

The vinyl has a tendency to 'catch' on the blade, making it slip. I used the tool I bought from Volks, but in retrospect I'm wondering if I would have been better off with something sharper. An X-acto, etc. Warming the vinyl to make it softer might also have helped. The lines wound up not being as straight as I'd like, and it was a struggle to get the marks wide and bold enough without going too deep. (The green is a water soluble fabric marker, which worked great, btw)

 

 

 

I was able to clean it up a little, but the lines are definitely the weakest part of the mod.

 

Moving on, I dyed the vinyl 'skin' parts and the underlying frame with Rit Dyemore in Graphite using the stovetop method. This worked really well. The vinyl only required 1-2 minutes to turn a nice, even black. The harder plastic frame pieces took 12-15 minutes to take color.

 

 

I gave everything some time to cool, dry and cure. I also took some gel superglue and ran a line of it inside the hand on a spot where I almost went through the vinyl, just to reinforce it.

 

Then I used Rub n' Buff in Pewter for the silver. I really like the Rub n' Buff, it was very easy to apply. I was also able to use a small brush dipped in Winsor Newton brush cleaner to clean up around the edges to keep it neat.

 

 

However, I did find it tacky and with a tendency to rub off on my fingers. So I experimented with putting a layer of MSC over it. Initially it gave the silver a kind of stainless steel quality that I liked, but I also found that it caused the black to start showing through for some reason? Not sure why. However, it did give me a toothy surface for a second layer of Rub n' Buff, which went on less tacky. Also, after reading some feedback online, I thoroughly 'buffed' all of the silver areas which helped a lot.

 

Here are the final pics of the arm on the (headless, he's out for a faceup) body:

 

 

 

Ah, that's a really good Shiro arm! It's a little disappointing that the tool caught on the vinyl, but at least everyone now knows for future reference.

 

I can't wait to see your doll when he gets back from his face up, though! Please post plenty of pictures!

He looks pretty good. I'd love to see how he looks on the whole. As for the vinyl catching, maybe a scriber will work better and give cleaner lines? Might be less 'dangerous' than an Exacto (I'm scared of those things after having nicked a nerve when I managed to stab my hand with one - good thing it healed).

Thanks Katnaper!

 

A Scriber is actually what I used. I bought one from Volks USA specifically to use on this project.