[Guide] Frankencasing guide (Work In Progress)

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Sephiros
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[Guide] Frankencasing guide (Work In Progress)

Post by Sephiros » Wed Mar 01, 2017 3:38 am

I have put together a few steps on how to approach Frankencasing.
This guide is by no means the only way to go about this, it is based on my experience and how I usually do it.

What’s is frankencasing

Well, basically it’s the action of cutting and sticking together 2 or more pieces to add parts to a case.

What do I need

To be able to to Frankencase you will need a few supplies:
Protective gears
- Protective googles
- Disposal gloves
- Mask

For ABS cement
- Glass jar with lid
- ABS plastic
- Acetone
- Ice cream sticks or small brushes
- a way to cut the ABS, usually use a cable cutter

Cutting and holding parts
- Rotary tool with a variety or accessories if possible.
It’s handy to have a few options, For example I use mine to cut, sand, grind, drill
- Masking tape

For the finish
- Filler, I’m using Plastic Bondo (australian brand) which is an Bondo (American brand) equivalent
- Sanding paper, I usually get a pack of 80, 150 and 240 grit and I get a few sheets of 400, 600 and 800 grit from an Hardware store
- Spray paint primer
- Spray paint with desire colour

Safety
As always make sure that you wear the proper protective equipment, when cutting using protective googles, when sanding a dust mask and gloves when handling chemicals.


Making ABS cement

I have played with different product in previous build like epoxy but with shocks or motion the joint can crack.
ABS cement on the other hand melt the different pieces, especially when working with ABS parts, which create one solid piece instead of two pieces glue together.

The process of making it is pretty straight forward, fine some ABS, cut it into small piece, place the pieces in a glass jar with a lid, submerge the pieces with Acetone, close the glass jar and wait a few day. After a few day comeback to it and check the texture, you want a runny texture because it is easier to apply it that way. To adjust the texture just add a bit more acetone if it not runny enough or leave it for a few more days if it is too runny.


How to find ABS
A lot of plastic case and enclosure use ABS, you can usually identify an ABS case/enclosure with the following symbol which is placed in the inside of the case
Image

But it is not always that easy, sometime you have ABS cases which doesn’t have that symbol.

In that case just cut a small piece, place it in a glass jar with some acetone an check the result after a few hours or over night.
If it become runny then it is, if it doesn’t melt or become lumpy then you know it’s not.

Alternatively you can find ABS sheets or ABS rods in most hardware stores

Tips
Something to be aware of is to avoid applying it on large area by itself because when drying it does contract and you could end up with a twisted case.
For example I used it once on a abs protective WII U case to cover the screen cut out and after drying the case was starting to bend.
A better approach would be to cut in a ABS sheet a piece which would fit within the gap and apply ABS cement between the two pieces to create a solid pieces.


Let the frankencasing begin

Step 1 Cutting
Once the ABS cement is ready then the fun can start. You will need to prep your piece by measuring and tracing on it.
Make sure that you have enough space to fit the part in your case then with a marker draw some marking on the piece that you want to fit into the case
Image

Once you got that piece cut out you can then use it to trace the cut marks on the case
Image

Put the them together to make sure they fit well, if not just adjust accordingly
Image

Tip
When cutting with your rotary tool try to cut just before the mark and not on the mark because you need to take into consideration the wheel thickness. Better have a bit of a buffer instead of having cut to much ;)

Step 2 Gluing
Using some masking tape, I tape the outside so that i can apply the first layer of ABS cement on the inside of the case.
Image

Using your ice cream stick or brush apply the cement between the 2 pieces
Image

Let it dry over night. The day after you can remove the tape and check the result
Image

I then apply a thinner layer on the other side to fill up any bit holes and gap, again let it dry over night
Image

Step 3 sanding
Once dry you can use your sanding paper between 80 and 150 grit to sand down the layer on the outside of the case.
Image

Ok we are getting there, the result is pretty good but because of the nature of ABS cement you are bound to have some air bubble which create some holes. That's normal, what you will need to do is with a sharp tool remove that fine layer.
Image


I know it’s tempting not to do it but if you leave then you could end up with those holes opening after you finish painting which could be a nasty surprise.
Image

Step 4 filler
You will need a few thing for this step, a set of disposal glove, ice cream stick or a brush that you don’t want to use anymore and a cardboard or plastic plate to mix your filler
Image


Plasti-bond is made of 2 parts a resin and as hardener you will need to mix both to have the filler ready. On top of of my head I don’t remember the recommended ratio but I usually try to go with 1/10 ratio, 10 being the resin and 1 being the hardener.
Image

After mixing them you will need to work fast as it dry within 10min, using your ice-cream stick apply it to the desire area and trying to make as flat and homogeneous layer as possible. let it dry completely, usually 5 to 7 hours is enough for a thin layer.
Image


Step 5 sanding
With a 150 or 200 grit sanding paper sand down the layer until you have a smooth surface. If you see any holes you can try to sand more or if the holes is too deep then apply some more filler on that area and sand it down.
Image

once you are happy with the surface you can move on to using a 240grit sanding paper to make the surface smoother so that any big scratches a removed, then doing the same thing you would move on to a 400 grit and finally a 600 grit.

upcoming steps…

Step 6 primer
Step 7 sanding, again….
Step 8 painting, finally!!!


The next steps will be completed within the next few weeks as I progress with my project.
Hopefully you found this guide helpful and I'm happy to answer questions if you have any.
Last edited by Sephiros on Thu Mar 02, 2017 10:59 pm, edited 3 times in total.

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abrugsch
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Re: Frankencasing guide (Work In Progress)

Post by abrugsch » Wed Mar 01, 2017 3:47 am

Thank you very much for this!

for what it's worth, for a source of ABS, my hackspace has a 3D printing "Can of fail" where all the offcuts and bad prints go. since we use either ABS or PLA, there's always some ABS in there that can be used (was originally used as a source to make "slurry" for bed adhesion but now we use PEI for the print bed so it isn't needed but I digress) anyway, if you know someone or somewhere that 3D prints with ABS, then that's a great source.


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Sephiros
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Re: Frankencasing guide (Work In Progress)

Post by Sephiros » Wed Mar 01, 2017 7:16 pm

No worries @abrugsch, hopefully that will help a few people.
Also good idea, didn't think about 3d printing places.

ismailhamzah
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Re: [Guide] Frankencasing guide (Work In Progress)

Post by ismailhamzah » Sat May 20, 2017 4:27 pm

No more?

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Re: [Guide] Frankencasing guide (Work In Progress)

Post by abrugsch » Mon May 22, 2017 6:36 am

ismailhamzah wrote:
Sat May 20, 2017 4:27 pm
No more?
It would be nice to see the finished project, but priming, sanding and painting isn't now specific to frankencasing...
however it looks like @sephiros has left the building more or less (or at least his project has stalled)

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