Creating the Grim Marrow from Outriders with foam and LEDs!

  • By: NickG
  • Date: November 10, 2021
  • Time to read: 20 min.

Hello guys this is vedlina from comic cosplay and today i’m going to build something truly legendary so square enix asked me to bring one of the legendary weapon from the upcoming game outriders to life and show you how to do it so their weapon designers are i would say quite creative like one of the weapons actually looks

Like a piece of meat and there are plenty of many uh very interesting designs and my choice was actually the grim marrow so the grim marrow is like if you take a wonderful shiny sparkling crystal and put it into the ripped out spine and bones of a demon put it together it’s perfect for a weapon so this is what i’m going to build today i’m going to show you how i

Created the whole thing completely from scratch and yeah this was actually one of my most challenging projects so i promise this will be interesting outriders the game is coming out on april 1st and you can also play the demo ah right now actually and you can even get the grim marrow already in the demo so in case you already got it

Let me know in the comments because then i will be very very jealous since i myself played the demo only a few hours since i was busy crafting my very own real life grammar which i think is pretty cool as well yeah i will actually keep this uh video very simple and beginner-friendly and i basically will just throw everyday stuff together maybe extract the electronics and since i’m pretty sure

That some of you will also have questions on how to do electronics or build weapons out of eva foam i have just the perfect books for you regarding to this topic so i made a book about advanced lights which is about animated leds will show you how to get started and also a book about how to turn simple eva foam into amazing weapons so in case you have any

Questions just check out for more tips and tricks thank you a lot for your support and now let’s start with the video so here is a 3d rendering of the grim marrow this video was actually my main reference for the whole project as you can see it’s very cute very ugly and very amazing based on this model benny

Drew me a blueprint in adobe illustrator you can download it from my website as well by the way he tried to catch all the details but it was obviously quite challenging once done he printed it out for me in a few size variations then i taped all pages roughly together next this version here was 130 centimeter long as you can see benny printed out three

Blueprints in different sizes i could choose from my final choice was 110 centimeter long it just felt natural in my hands and fit to my own body size zelda meanwhile waited for some play time benny also printed a tiny version so i drew in some ideas i had in mind first i wanted to shape the naked core of the blaster for that i wanted to separate the build

Into three individual pieces this would make it much more easier to build up the details but also to prime and paint the prop later for stability i wanted to place a pvc pipe for the whole build so benny drew me a new blueprint but this time it was only the shape of the inner core here you can already see how i would place the pvc pipe and once i cut out the shape how i would separate

All parts then the first crafting step was to prepare the pvc pipe i had two halves which i would connect with a thinner pipe in the middle this one was just glued in with super glue then i drilled some holes glued in some nailed the magnets and this is basically how both pipes were then connected magnet magic next i traced all parts of

The core blueprint onto 10 millimeter high density foam as always you can find links for all used materials and tools in the video description you see i used here several layers since i wanted to build up some thickness i cut all parts with a simple utility knife by the way i really wanted to keep this as easy as possible once done this was basically the puzzle

For my base build the pvc pipe would be placed in the middle and the foam should completely cover it let’s see if this plan would work out oh and i forgot to mention i also wanted to add a trigger mechanic i found this perfect switch button and basically just cut a hole in the middle layer of my core then i freed some space and simply hot glued this thing on

Super professional the wire was then secured with hot glue and this is how my really simple trigger worked hidden inside the foam it would look like a real one i love this super simple solution next it was time to glue all layers together as always i used contact cement for this job afterwards i placed the pvc pipe and

Secured it with a good amount of hot glue then i stacked the next part glued it on as well and attached then the last piece this was my finished base can you already see the grim marrow here well probably not yet right just keep on watching following this i added a thin layer of foam and began roughly carving out the shape

A bit just some quick and dirty work now i wanted to light up the whole crystal area i thought it would be pretty cool and i just enjoy adding leds to everything to control the upcoming leds i ordered a feather m4 a proc maker feather wing a speaker a button and some rgb led strips all from

I already used the setup for my light above a hammer in the past boy the way this build is actually based on the burning fire wizard staff tutorial from aaron sent blaine i’ll put a link in the video description however i adjusted the code a lot and made sure it worked with the new trigger now the led installing fun could begin to be honest with you though it wasn’t actually that much

Fun after a while gluing all the led strips and soldering them together took forever however i want to be always extra power saving so i light up only the area that needed to be lit up this required a lot of extra work though therefore while this looks fast and simple in the video this step took me actually three full days of work in total these are 376 leds if you

Are curious oh and for additional stability i also added a further pvc pipe here by the way so here was the final test almost 400 leds i used here a crawling animation and once i pulled the trigger the speaker played a sound and the lights turned white the code wasn’t done yet though but the first test looked good next i had to prepare the grip part with a

Heated up pvc pipe once hot enough i bent it and cut the end into shape then i placed some markings cut in some holes and covered the pipe with a massive amount of hot glue hot glue is every cosplayer’s best friend afterwards it was time to build the ammo drum this one was made mainly out of 5 millimeter evia foam i traced a rough cylinder pattern onto

The material and cut all parts out then i glued the walls together and carefully attached the smaller circle for the upcoming wire connection i marked and cut out a square at the top later i would pull all wires through there and connect the circuit and the battery inside the ammo drum first however

I had to place the speaker it would actually go in the middle of the drum i thought here it wouldn’t be very noticeable the hot glue gun was perfect to secure it safely and yes the construction was very wobbly at this point therefore i began building in walls to fix this issue to reach the electronics i also cut out

A window in this section then i carefully began connecting everything and oh wait i forgot to add the power button hot glued it in as well now you can also see the walls i placed inside the ammo drum next i could finally close it to attach the build one of my solutions were simply pvc pipes i secured them with hot glue as well

For the little window here i placed additional foam pieces to the inside the door got a tiny grip and well this is how i close the drum very simple but also efficient so and this was the whole base set together as you can see the trigger worked perfectly here is the power button and there is the speaker here i quickly wanted to show you how the setup works i actually totally forgot to record that

I added some magnets but you can see them here the wires were connected to the circuit in the ammo drum which i can detach from the blaster the led strips and trigger are connected with a few connection plugs and the front and the stock of the blaster can be separated as well i already knew that this blaster would be

A monster so working on three individual parts would be just far easier than having this one massive crazy thing in front of me now for the diffusion of the leds i used three millimeter plaster soti i traced the light up area onto the material cut it out alright i secured the wires with duct tape

And then i hot glued the foam onto the blaster all the hot glue here i also placed this middle thing with contact cement and finally the fun part could begin creating the crystals you were probably super curious about this part right well for this job i ordered a bunch of acrylic resin decoration crystals in different colors

On amazon to get a natural gradient i decided to dye a few of them with red iodide pulley i threw the crystals into a tea infuser dunk them for a few seconds into the cooking pot and rinse them with cold water the difference was really cool by using different crystals and different dipping times i got plenty of shades in red pink and purple these were just perfect

So this was my crystal color spectrum then it was time for some burnt fingers hot glue action now you probably wonder did she really just hot glued thousands of crystals piece by piece onto the foam you bet i did and it took me only three days but through the power of video editing you can see all of that in just a few seconds

The crystals also made the gap between the front and the stock pretty much invisible and yeah this added quite some weight to the blaster but i absolutely loved the result here is also a little light test with a new blinking animation and the first layer of crystals so far is so good with the sparkly stuff next it was time for the organic spiky and bony pie my material of choice was eva foam

And foam clay to make the clay sticky i had to add a bit of water to the surface of my blaster then i spread the material all around the light up crystals i was actually super worried that the water or the clay would damage the circuit that’s why i always worked with the lights turned on this way i would instantly see any issues

And could fix them right away water and electronics don’t really like each other you know afterwards i began sculpting on the bony wines all over the crystals i should add here that foam clay is one of my absolute favorite crafting materials and i really enjoy to work with it this part was very chill and i just tried to stay kind of close

To the reference for the spikes i cut some triangles out of 5 millimeter high density foam i glued them together along the edges and got these lovely shapes at the end next i smoothed out the seams with my dremel added some hot glue and attach them onto the grim marrow yes this project required a lot of hot glue i actually have no idea how many sticks i used but they were plenty for some areas

I also used benny’s blueprint for reference i traced those shapes directly onto foam cut them out and used them as a base for further sculpting work as you can also see i placed the blueprint underneath my blaster so i could directly use it as a reference to place the spikes properly then i covered them with water as well

And used foam clay to smooth out the transitions i added some clay here and added some clay there oh and by the way at some point i actually had to open up the stock and add another pvc pipe for additional stability the crystal just added a lot of weight and the step was an easy fix next it was time to add the first bony structure

Here i also used the blueprint as a reference and cut the shape directly out once cut out i grabbed my hot glue gun and spread the sticky stuff onto the foam clay but also onto the crystals then some clay to hide the edges so far is so good i was already really happy with the front but there was still a massive amount of work left so

I had to do every step twice well except for this grip thingy here at least this one was unique as you might guess it actually doesn’t withstand any force so after i covered it with more foam and more clay it stayed only decorative just don’t touch it and then after adding more veins this is how the other side looked like next i began working

On the stock i used the blueprint of the core and traced on the shape of the spine to 5 millimeter eva foam afterwards i glued on the cutout material to the back of the stock for a pretty transition i used foam clay but separated it with a simple playing card well and then i covered the whole back of the grim marrow with more clay

Now the first layer of the ribs this part here was pretty complicated i cut out a bunch of ribs and added a little deepening in the middle these were then filled with contact cement and bended once the glue dried i shaped rip after rip this way and dremel the edges at the end next i attached each one of them with hot glue onto the spine

As you can see each rip looked slightly different i think this made it more organic and natural i also worked with foam clay to sculpt on a smooth transition you can truly imagine that this step took quite a while as well well and then i had to add a second layer of rips again with the blueprint reference this one needed a nice curved shape though

A simple trick is to cover a thinner layer of foam with contact cement place it carefully onto the back and bend it while connecting both parts then i just had to get rid of the excess material dremel a bit and attach the perfectly curved ribs onto the grim marrow following this i only added some extra foam clay for some sculpted on details

For rip layer number three i needed a further template from my blueprint again i traced it onto foam cut it out and this was the final result then i placed some markings and filled the area with contact cement and here you go i used some foam clay to fill out the gaps and add some volume on the top the next step was finally the end of the stock there was actually a hole in the middle

So i had to be a bit creative here after i got rid of a huge piece of foam i built up a wall on top of the remaining material a little bit of foam was placed here and then i closed this rough construction i know i surely could plan this way ahead but often it’s better to keep things simple especially at the beginning of a project

And as you can see it was really not a big deal to fix this issue the result looked also pretty fine i would say so this was how the stock looked so far one more layer of rips was still missing though now quickly back to the ammo drum here a lot of detail work was still waiting for me i used the 3d rendering as my main reference

And just glued on five and three millimeter foam here and there this gave the drum also additional stability for the back i cut out some rings and arranged them around the speaker they also helped a lot to hide the electronics window a little bit better this part was quite simple oh and these ones were supposed to be metal clamps hope they look like metal clamps so this was my

Ammo drum so far next we are coming to rip layer number four this one was really challenging though i had to place this foam part somehow like this okay i got my foam ribs ready and glued on a base onto the drum for them as you remember this part had to stay detachable then i glued on rip by rip and arrange them around the blaster

Again foam clay did a great job on the transition afterwards i cut out five millimeter eva foam base for the organic part i surely could also directly scooped it on the foam clay but having a foam base as a guide just helped me to stay close to the reference so this part got then covered with clay and here is the result this was only one side though oh my i

Was still not done for the middle section i used good old duct tape i drew the shape roughly on traced it onto foam and got done the next puzzle pieces okay the next step was a bit tricky before gluing the middle parts on i placed some baking paper this helped me to keep on using foam clay for the sculpting part but

Prevent it from sticking to the rest of the blaster then once i was done i could easily detach the ammo drum and go to lovely transition here now it was time for the remaining details here i needed a little bit more volume and there a few more thicker veins then i began sanding this made the foam nice and smooth and all the nasty seams bumps and gaps disappear this was the

Results of her but it might be hard to see in the video next i had to roughen up the surface again though to turn my plane foam into a believable and ugly bone structure i had to dremel in a lot of texture and imperfections i used here a simple grinding tip and just try to do some rough and dirty work once done with the stock i repeated the

Same steps on the emmerdrum aside of the little dots i also dremeled in growing marks with a different sanding tip it took me a full day to give the whole blaster this texture you know just in case you’re curious how long such a project takes well this stuff requires a lot of time and patience once done i cleaned up the area

With my vacuum cleaner but i also used an airbrush to blow out the very last foam dust particles and finally i grabbed my heat gun to smooth out the rough foam oh yeah last but not least i totally forgot to add this further pvc pipe to the barrel well and here you can see again how all three parts could be connected

Quite easily just had to hide the wires and done so this is a closer look at the dremeled in surface and the grim marrow build in all of its glory three weeks of work so far but we are nearly done and this was me super happy super proud my green marrow was already pretty and sparkly and ugly and gory at the same time so now finally it was time for the priming and painting for the priming i chose

Flexbond however i mixed it with black acrylic paint after mixing it well i got a dark primer that would seal the foam but also gave me a basic paint job at the same time i’m such a genius then i began applying a thick layer onto the foam as you can see this allowed me also to prime everything around the crystals even without using any kind of masking

Tape i obviously had to be quite careful here though the next two layers were then sprayed on with gummy dip which is like the german version of placid this was just faster and i was able to reach every single corner of my foam build super quick the foam was completely primed with two thick layers of flex bond by hand

Though the painting began with benny airbrushing silver to the ammo drum all organic parts however had to be painted by hand benny and i used liquid x colors which are pretty covering but yeah it was still a lot of work [Music] at least for the stock i was able to use my airbrush for a little bit more texture i still

Grab the acrylics at the end it’s all about the details next it was time for some shading we tried to stay close to the reference and this one actually used a lot of grey but also dirty yellow so we dabbed on grey all over the bony structure and hoped it would look natural at the end then also some yellow spots at this point it looked a little bit

Weird but i trusted the reference and benny’s painting skills while he actually did the majority of the painting work he is also the one holding the camera when we record our seats so it pretty much looks like i painted everything at the end i was also very busy cutting minna’s paw fluff benny then did the final and very texture popping paint layer with a

Creamy white i absolutely love the effect and he did such a great job here once done i grabbed a matte spray varnish and applied two thick protective layers onto the paint job the stock and the armor drum very easy for the front part however benny sprayed the varnish into the spray can cup got some liquid varnish

And then applied it with a brush all around the crystals next i got rid of all the masking tape and coverings and free the crystals it was also time to glue on the foam trigger to the switch and last but not least i also added some additional crystals to build up the structure even further this way the result just looked even more interesting

And the diffusion was greatly improved and then after four weeks of hard work i could finally connect the plugs one last time hide them in the ammo drum and complete the whole build to see the grim marrow in all its glory here it was finished [Music] as you can see i adjusted the animation one last time

And absolutely loved the result now it looks so shame and glittery but super scary and disgusting it’s by far my favorite weapon design from outriders and i really really hope that maybe the concept artist will notice my birth i still could not find out who made the design but i hope you are proud so this is my lovely baby i hope you really

Enjoyed the making of video of my grim marrow i think it turned out really pretty i’m very proud and yes it’s not perfect because it was just you know like it’s not a perfect 3d print and like but i still think i got pretty close to the 3d model and i’m very happy with all the crystals and the bones and yeah i think as i said at the beginning it’s like

Perfect combination for something awesome and to make this whole project even better i also will make a fitting outfit so i will actually pick the outfit from the character in the key art of our traders i think it looks pretty cool i mean like it’s plain it’s simple so all the focus is like

On this beauty here and then i will do also a photo shoot i think it would be really cool i cannot wait to share more of this project with you in the next video and yeah until then if you have any questions leave me a comment down below and yeah as always uh you can find all the tools and materials i used uh in the video description right in the

Video description and yeah as always like and subscribe hit the notification bell support us maybe also in patreon and see you very soon with a super epic outfit from artridas oh and since i know fifty percent of all the questions will be actually how heavy the grim marrow is well it is a quarter of a corgi to be precise so

Thanks for watching bye bye

Play Outriders:
Outriders​ will release April 1, 2021 on PlayStation 5, Xbox Series X|S, PlayStation 4, Xbox One, PC (Steam, Epic & NVIDIA GeForce NOW) and Stadia.
Outriders is a 1-3 player co-op RPG shooter set in an original, dark and desperate sci-fi universe. As mankind bleeds out in the trenches of Enoch, you’ll create your own Outrider and embark on a journey across the hostile planet.

Square Enix asked me to bring a cool weapon from their upcoming game Outriders to life! I chose the Grim Marrow, which is a mix of pretty crystals and deathly bones! Totally love this combination! As always, I kept everything very beginner friendly and literally threw this thing together out of hot glue, foam and plastic gem stones! Hope you will like the result!

Learn how to make costumes:
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– Svetlana

Download the Blueprint here:
For all electronics, just check out the Adafruit tutorial:

Products used:
EVA Foam:
LED Foam:
Foam Clay:
Box Cutter:
Contact Glue:
Dremel Snake:
Hot Air Gun:
PVC Pipes:
Hot Glue Gun:

Dust Mask:
Safety Goggles:

Airbrush Set US/CA:
Airbrush Set EU:
Water Filter:
Cleaning Station:
Vallejo Model Air Paint:
Vallejo Game Air Paint:
Airbrush Cleaner:
Acrylic Paint:

LED strips:
Soldering Iron:
Helping Hand:
Find the rest here:

Video: Sony alpha 6500:
“Cheap” Lens:
Sony a7RII:
GMaster 24-70mm f2.8:
Camera screen:
Sound: Rode Smartlav+:
Rode Wireless Go:
Rode NT-USB:
Smartlav+ to transmitter adapter:
Lights: Studio Lights:

*All Amazon links are affiliate links that we get paid for if you buy a product. You can support us by using these links. Thank you!*

My favorite cosplay material shops (links not sponsored):
A list of worldwide cosplay shops:​​

0:00 – Intro
2:27 – Base Shape
6:24 – Glowing Crystals
13:29 – Bone Spikes
16:45 – Spine, Ribs & Drums
22:22 – Textures
24:01 – Painting
27:42 – Finished
28:29 – Outro


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