Another Robocop Build

joberg

Master Member
You're right about the paint; it will reveal (or hide) some of the problem areas. Keep up the great work, you're getting there(y)(y):cool::cool:
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
A lot of progress today on the suit.

I started with sanding the back piece and attached some of the greeblies and tested the bolt size

back sanded.jpeg


I then painted the back with filler primer to see what else is needed.
back filler primed.jpeg


So far so good.
I treated some of the printed parts with UV-resin and went outside in the sun to do some serious sanding. I changed to another resin in hopes that it would be easier to sand. It wasn't. It was in fact a LOT tougher, so it will be perfect for reinforcing some parts, but when it domes to smoothing for sanding, I won't be using this one again.

Here's a few pictures of the elbow insert. One sanded, one soon-to-be sanded. (It's been sanded since)
elbow insert 1.jpeg

elbow insert 2.jpeg


These will be painted glossy black and fills out most of the inside elbow and looks fantastic. I really like this version of the armor.

Something I haven't done is collect all parts and snap a pic, so: here goes: The current state of my build:
Robo full suit.jpeg

frog perspective.jpeg


upper half.jpeg

Thighs.jpeg


A few more things that needs cleaning up here and there, but so far it looks decent.
helmet side.jpeg


The neck piece is of my own design.
helmet back.jpeg


And here is finally the back piece after the filler primer has dried. It shows a few small spots that I need to fill, as expected. Last job today was to wet sand the back because I had 15 minutes to spare and make a small resin piece to go in the square on the back.
back filler primer.jpeg

A few more days like today and I am soon at the paint stage!
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Time for another update.

Updates are not as frequent right now as we're in high summer in Sweden, and the weather is gorgeous. Normally I usually say "Oh i LOVE Swedish summer. It's my favourite day of the year!", but this time around, we've had decent temperatures and sun for quite a long time now, so I'm enjoying it while it lasts.

Anyway, this update is mostly about elbow hinges, as I promised on Chris's Robocop thread ;)
I've made one bracket in the past to test the ideas, and since it was working, I made two new ones just for this entry:

I am using just normal aluminium bars. Sawing these off at a good distance:
IMG_2260.jpg


Then I need to bend them slightly, to make the bracket be on the same outside profile as the biceps.

I did this with a vice, hammer and screw driver.

IMG_2261.jpg


Then drilled holes in them, and the brackets are mostly done.

IMG_2262.jpg


I've hot glued them in place for now, as I love the fact that even on a raw 3d print, hot glue can be peeled away instantly with just a drop or two of isopropanol. This makes hot glue a very solid temporary solution. When I'm approaching final assembly (I still have some body work on the biceps to do), I will fix these with two part epoxy.

I will most likely drill a few holes in the metal bars portruding inside the biceps to give more for the glue to grab on to, but for this hot glue test fit, I just sanded the bracket with some coarse sanding paper.

In order to make these fit and be parallell, I made a small distance plate ouf of a scrap piece of styrene.

IMG_2271.jpg

This is to ensure that the brackets are level with each other.

IMG_2272.jpg


IMG_2273.jpg

The elbow joint has gome through some changes from Darthasen's files. I have made the pit where the hinge is slightly deeper, and I've also enlarged the hole to 8mm diameter. The total thickness of the material here is 4.5 mm.

IMG_2264.jpg
One could go with chicago screws and not do these modifications, but I figured that a small 5mm shaft could easily dig through a 3d printed surface, and I wanted something more sturdy that would last.

The 8mm holes are perfect for small m4 distances. These are 5mm in length and are press fit inside. These are made out of delrin and very sturdy.
IMG_2265.jpg


To give a clear idea ow what's going on, here's the planned assembly:

socket nut bolt, 14mm (I only had 16mm at home), a large washer on the outside. Then through the delrin distance that sits in the arm, another washer on the inside, the metal bracket, a third wasker and finally a lock nut, that is closed until the joint locks and just released a tiny bit after that to make it rotate smoothly, but also sit tight.

IMG_2266.jpg


The foot print on the outside is small:

IMG_2267.jpg


This will be covered by a custom made plate later on. The screw will need to be sanded down just a hair in order for this to fit perfectly in the end.
IMG_2274.jpg


This hangs and swings freely, but is still sturdy.

It is a bit too intrusive if I want to use the elbow inserts (Which I might make out of flexible materials as the biceps can't close with them properly anyway), but should I want to use them, I will need to go down to an 10mm m4 button head bolt only use the washer on the outside. This makes everything just fit.

IMG_2269.jpg


With everything in place, the only thing that remains is to test the arm..

IMG_2281.jpg

Without the hard 3d printed insert, I can bend my elbow at 90 degrees without issues.

With the insert, however, movement is a lot more restricted. I have cut away part of it already, but I think I need to carve out more or less everything visible and build that in flexible materials on the undersuit, as per the original suit.
IMG_2283.jpg

IMG_2284.jpg


Finally, a small pic showing how it will look with a quickly printed cap on top of the bolt. Please excuse the print quality on this one. I was pressed for time and had to reduce top layers and increase speed to have time enough to print one to include in this post.

IMG_2286.jpg


As a final note, I have picked up doing the glove. The plan is to make it out of flexible resin, and to keep costs down, I have drawn the fingers from scratch to make the walls thinner, and thus make them more flexible.

In the end, these will be 3d printed in flexible resin, if that works well, if not, TPU, and then hot glued onto a pair of rubber coated gardening gloves, and the entire glove will be coated with several layers of plasti-dip.

Here's a quick image of the finger I've spent the past two nights designing in CAD:

screenshot1.png
screenshot2.png


I apologize for ending this post with giving you the... ... ;)
 
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joberg

Master Member
Great update...loved what you did with the bolt and the attachment parts. Since it's the summer over there, you'll have plenty of light to continue building into the "night" :p (y) (y) I remember my trip to Höllviken...dark "blue" skies until 1AM:eek:o_O
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Great update...loved what you did with the bolt and the attachment parts. Since it's the summer over there, you'll have plenty of light to continue building into the "night" :p (y) (y) I remember my trip to Höllviken...dark "blue" skies until 1AM:eek:o_O
Yeah.. well.. in theory.
"Unfortunately" there is my fiancée who also has vacation, like me and has this strange idea that we should be "spending time together".

I guess that is the new hidden fourth directive that overrides the rest =p

With any luck I'll be doing some test print of a finger in flexible resin tomorrow for the glove, to prepare for the arrival of the new printer that should be able to print most of the glove in one go ;)

About light.. yeah.. well.. you should see winter. The sun comes up after 9 am and sets around 3 pm... so even in Stockholm we have very dark winters when it is at its worst.

Northernmost Sweden has a few weeks during summer where the sun never sets and during winter when the sun never rises...
 

ID10T

Sr Member
I just wanted to comment that this is a fantastic build.

And also, for your elbows, you can get button head screws with an included flange if you need it to look uniform and also keep a low profile. It ends up slightly lower than a button head with a washer.

Also, nylock nuts can be had in low height as well, similar to a jam nut. That would reduce the interior protrusion by a mm or so, if you need the space inside.

I think locking cap nuts also exist, which would avoid any sharp edges (although I’m sure you dress and polish the end of the fasteners)

That costume really looks fantastic. I was brought right back to the movie!
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
I just wanted to comment that this is a fantastic build.

And also, for your elbows, you can get button head screws with an included flange if you need it to look uniform and also keep a low profile. It ends up slightly lower than a button head with a washer.

Also, nylock nuts can be had in low height as well, similar to a jam nut. That would reduce the interior protrusion by a mm or so, if you need the space inside.

I think locking cap nuts also exist, which would avoid any sharp edges (although I’m sure you dress and polish the end of the fasteners)

That costume really looks fantastic. I was brought right back to the movie!
Thank you for your kind words. This is a build that I rather it takes a little longer time to get it "just right".

I will definitely check out the flanged button heads and other suggestions. Greatly appreciated =) . I've already started, in fact.

I started by looking at chicago screws, but that didn't really do the trick, unfortunately.

I just got a bigger resin printer today, so my modified version of the gloves should be ready for printing in a little while..
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Quick update:

I had to completely redo the finger. Turns out the tickness at the base was way, way too much.

Here's a render of the new version:


newfinger.png

newfinger2.png


These fit well around my ingers with my donor gloves on. I've test printed and earlier version of these, but they were only 1mm thin, and I had to redraw them from scratch (!) in order to expand them outward another mm to give them some more meat.

I'll be doing a test print later today on the new resin printer with flexible resin, see how that turns out! =)
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Time for another glove update.

The gauntlets seems to become the most daunting task in this entire build.
Sure, I could take the easy way around and simply print the fingers and gauntlet in PLA or even normal, sturdy resin, but I wanted to have the gloves to actually work. Like me actually being able to grab things.

So, I've done a few experiments that I wanted to share with you.

I guess this post is more an adventure into experimenting than anything else. A venture into finding things that doesn't work...

Before I even got my first resin printer, I started with my old Do3D files and printed the palms, to find a good size. I got the left hand done and sized decently in flexible filament through FDM printing. Around this time, I did a lot of experimenting with the fingers, didn't like how they were, and that started the journey of redesigning them from scratch. That journey took a nnumber of turns before reaching the results you see in my previous post. More in this in a bit.

In the process of this, I even tried building the fingers in EVA foam. The results were notbad, but I was looking for my holy grail here:

After printing the finger pieces one by one in TPU, or flexible filaments, I didn't get good enough results, so I ended up making a "solid" finger where I cut it open so it was actually held together at the hinges. This proved to be a pretty decent solution, but I was not too happy with the layer lines, and as you all know, flexible filaments does not sand well. At all.

So, fast forward to the world of resin printing printing. I got myself a test bottle of eSun's flexible filaments and wanted to keep trying my finger experiments with this, since I figured that printing in flexible filaments and gluleing these on top of my donor glove, would be the perfect way.

So, after testing the new design, and testing the new finger files, I ended up making a very good version of the fingers for resin printing. I've scaled them to a good approximation for my fingers, and set out to print them. This worked fine.

Flexresinfinger.jpg

I then cleaned up the fingers by removing the thin sacrifical piece on the insides of the fingers (so I didn't need to use supports)...

Flexfingers.jpg


Flexfinger cleaned.jpg


This was cut carefully with a scalpel, as the flexible filament does not cut easily.

Some quick test on my rubber gloved hand showed that it fits well, but has some issues:

Flexfinger testfit 1.jpg


Flexfinger testfit 2.jpg

Bending the finger immediately made the flexible resin crack. There was not enough play in this, and it was not rubbery enough to allow this.

So, another batch was made, slightly thicker, and tested with the old TPU palm:

Flexfinger Glove 1.jpg


I tried glueing down the flexible fingers with contact cement, hot glue or even e-6000. Seems nothing is sticking to this rather fat surfaced resin.

Next up: I used more flexible filaments in a syringe and used it as a glue to get the fingers to stick on the glove. That gave some results, and allowed me to test paint with some plasti-dip. A good flexible paint job on top of the flexible filaments..

Flexfinger Plastidip.jpg


However, it turns out the paint does not stick well either, as once it was dry, I could do this:

Plastidip flexresin.jpg


Just rubbing my fingers across removed the plasti-cip without any issues.

Now, I left some sitting for 48 hours, and the paint does stick a lot better after this, but there is still the issue of glueing the pieces in place, plus that they do not bend as intended.

The early attempts on a test glove showed that the only way I could make this happen, was if I coated the entire glove in flexible resin first, put in my curing chamber and then went to town glueing with the syringe and UV light, but this left the glove with uncured resin where ... well .. where the sun didn't shine...

Shame on you for thinking what you just did. I meant on the INSIDE of the glove, of course, closest to the skin. As all who does work with resin knows, this is not ideal.

So, from the looks of it, I will go back to an earlier idea, to print the full finger in TPU and print in fine layers and then rely on plasti-dip to remove the layer lines, if I want a flexible glove.

After all, it looks ok. Not perfect, but getting there. Jst see this comparison with an unglued flexible resin finger.

Resin_TPU 1.jpg


Resin_TPU 2.jpg


This is printed in thicker layers for testing and not coated in anything. I think it will work.

So, My next step is to print another batch in TPU, size them right and go from there. I do have a batch of fingers done in solid resin at the same time just in case. It may be enough by coating them in plasti-dip to allow things like grabbing stuff after all.

So I will leave you with paraphrasing Edison: I have not failed to make the Robocop gauntlet, I have merely found several ways of NOT building a Robocop gauntlet... and I have a pile of rejects to prove it!

rejects.jpg
 
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joberg

Master Member
Ah yes, trials and errors...the only way to learn;) I'm wondering if you could just affix the top parts/end of the fingers to the rubber glove and have the bottom of the print covered with thin layer of rubber.
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Coating with plasti-dip might be enough to get the grip needed, as it is a rubbery colour. Definitely something I am looking in to.

It is also the issue of the solid finger pieces "talking" when moving the fingers that I'm also looking at.

I am printing a set of TPU fingers right now, should be done in a day or so (Printing TPU is SLOOOOOOW) as a final test before I give up on that path, but my one-finger test looks promising.

I can bend the finger fine, it sticks together, it takes paint and can be glued, so, I'm back printing the 2020 version of my thicker version of the fingers again. If this does not work to my satisfaction, I will go with solid finger pieces. I am printing that on the resin printer as well, so I am covered. =)

Sometimes, not having a deadline looming in over you is a blessing in disguise. The gloves could be done and "useable" with much less effort, I just wanted to make them user friendly as well, or at least try to.

In any case, the ongoing finger print will be the last one I'll do before continuing on other parts to get a break from this. I know I am close to finding a good solution =)

Thanks for your input and suggestions. Greatly appreciated! =)
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
So, I've got fresh fingers printing in TPU at the moment.

It turns out you can actually sand TPU and get it quite smooth, so that might be back on the table. I've got a finger drying after coating it with Plasti-dip yesterday in the workshop.

TPU also glues fantastically with contact cement. So this is back on the table.. However..

I did also print a set of hard pieces for the finger, same model as shared above, only that the entire finger is joined together in the print.

I've used a scalpel blade attached to a wood burning tool and essentially used a hot scalpel to cut through the resin. It cuts well but slowly, and the results are very well.

Contact cement seems to be the glue of choice here as well as hot glue does not stick well to the resin. It might stick enough if I go over with sandpaper on the inside to rough up the surface.

I made a small quick video on the fingers coated with plasti-dip...


TL;DR: I have a viable solution, just need to get the finger scaling right and print a proper piece for the base of the hand =)
 

joberg

Master Member
Victory indeed (y) :cool: Question: have you tried different type of gloves? Some dish gloves are very good material and hug you fingers better.
You surely want to eliminate any extra folds of material when bending you fingers and having those folds impede your movements especially in-between the resin joints.
 

askernas

Well-Known Member
RPF PREMIUM MEMBER
Victory indeed (y) :cool: Question: have you tried different type of gloves? Some dish gloves are very good material and hug you fingers better.
You surely want to eliminate any extra folds of material when bending you fingers and having those folds impede your movements especially in-between the resin joints.
These are actually hugging the fingers really good when they are not all gucked up with glue from 3 tests of glueing everything together, but thanks for the tip.

I like these as they have a fabric backing which lets the hand breathe a bit.

Here's a picture of where I'm at with a brand new set of base gloves. I think they will do the trick just fine. If not, I'll find another variant.

These are made with TPU fingers, by the way. I think I'm going with these. I can fit my hand nicely, it has a fair bit of give and I can use the hand almost normally while wearing it.

I'm still printing the thumb parts, so not quite ready to assemble the full glove until Sunday ;)
IMG_2638.jpg

IMG_2639.jpg

IMG_2640.jpg


A few weeks ago I also got a larger resin printer, and I've redone some of the parts, like these fresh off the print hydraulics. I am very happy with how crisp the details are in them =)

IMG_2641.jpg
 

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