District 9 Fuel Cell modelling, here I go!

[scornflake]

So I have covid. Yay. About a year ago now I made a replica of the D9 AR.
Someone asked about the fuel cell, so I thought I'd begin modelling it, since I've not much else to do while I mope around the house!

Q: How big do you think that fuel cell is? I've been staring at pics. I havn't seen it in movie yet (I assume it's in a shot, somewhere).
I thought I could get semi-accurate dimensions by using the "inside" of the hand grip as a guide. Figuring if a prawn can hold it, and guessing their hand size is 1.2x ours ... if my inner grip is ~90mm and theirs ~108mm, then the barrel is about 1/2m long. That's a tad longer than from my fingers -> end of elbow. Hmm. That's *seems* too long but I've not seen it in context yet.

I'm parameterising the model as I go, so I can just change a number and hey presto make it bigger/smaller (or change the length ratio to hand grip size as well)

(yeh I know the pic is pretty boring right now, but I felt I had to post *something*!)

thoughts?

 

[scornflake]

Time for some measurements. This gets me closer. The front canisder draft is different in the drawings to the sketches tho. Oh well; get something done and then tweak...

 

[scornflake]

Time for a break. This is the start of the rear handles. The cylinder that you see sticking out the back will slide inside. I'm *just* starting to work on the lower handle frame. It'll be covered by 2 part clip ons to give it more "width" (you see a similar thing going on in the mock ups)

 

[scornflake]

Hmm. Something isn't adding up. The handle is WAAAY to thick. I don't think the drawings match the artwork. Not suprising I guess.

I'm prob going to deviate from the "drawings" and make it more like the concept art. I *much* prefer the handle to not be so bulky.
I tripple checked my measurements, and also played around with rail widths (which have to be guessed). Nothing really works. If you have the sphere/ball sticking out from the top rail, with some kind of handle covering; you either have to have a MUCH wider lower rail (and the lower rail looks REALLY thin in the concept art) or ... or .... actually, I dunno. There is no or

Anyway; that's things for now.
Spent most of the day watching movies and sleeping.

 

[scornflake]

btw: does anyone know if this canister shows up in the movie? I cannot remember. If you know where, or if it does, can you reply here?

 

[scornflake]

OK. I think I was on the wrong track. Hadn't quite triggered that the ones I was modelling were concept and not used in film. I think. Maybe. Covid. Who knows. Either way; I got *very* annoyed with the @*#@!*#@! handle and thought: "I know, why don't I model the other one instead?"

 

[scornflake]

OK. This might work. Dunno what to do with the glass yet. Right now I'm modelling it as a printable part.
It *might* be possible to polish a clear PETG to something approaching glass? maybe? never tried it. It'd take ... aaaaaaaaages.

You *could* stick actual glass in there I guess. If you could find the right dimensions (said dimensions are pretty fluid right now too).

The concept artwork says 150cm in length. But I reckon staring at Wikis puicking it and holding it in hand its closer to 200 total. That's what I've modelled on. Need to do a spiral vase test print and hold it to see if I'm close.

Next job!

 

[scornflake]

Thoughts so far:

For normal 3D FDM printer: designed to be printed easily enough. Nothing hard in the model. I've put in 0.03mm separation between all parts. Some will be tight-ish, but should fit with minimal cleanup.

The part with the iris would need to be printed with a very small nozzle. The gaps are .2mm at the moment. I suspect if you printed in 0.4, the slicer wouldn't even render out the gap.

 

[scornflake]

Added more of the detail today. Very slight insets into the body. Some "glass" panels, insets for those panels, and detials on the end caps (again, as a small inset around the circumference of the end cap itself)

 

[scornflake]

Hah. so I had a go at printing some "glass" using clear petg.
I tried 0.1mm layer heights, did a small bit of it, then sanded with 200/320/600/1000/1200. Then cutting compound, then polishing compound (same stuff I use with a DA polisher on my car)

Suffice to say: "no worky" (tm).

I think partly because the material itself isn't actually "clear". It's a bit milky. Also because you can still see print lines even though the surface is smooth. I might yet try printing with a 0.8mm nozzle with 0.6mm layer heights. Hmm. Very. Very slowly. Perhaps with some more 'flow' in the slicer I might be able to "push" some of the filament out towards the walls a bit more. Either way. VERY time consuming.

I'm just a novice builder. How else would you approach these glass panels? (40mm OD diameter).

I do have planar sketches of the window inserts. So if there *were* a way to print/laser cut something; and then bend it around a 40mm object, that might be an option. Just dunno suitable materials.

 

[scornflake]

Initially I had a 50mm outside diameter. It just looked.... a bit thick.
Here's a spiral print (with much of the outer deteail removed for simplicity of print) for size.

to me this is looking pretty good!
I'm comparing against both the in-film shots of Wikus finding the item in the shack, and when he recovers it from the MNU facility. I'd post here but dunno about copyright etc. It'll all available on net. e.g: "District 9 - Wikus and Chrostophor break into MNUU [Clip 9 of 13]". See 2:37-39 of that clip.

 

[scornflake]

annnnd, I had another go. This time using a flat surface.

came out better than I thought. Very prone to scratching tho.

 

[scornflake]

If anyone is interested, I've put up the model on Etsy

https://www.etsy.com/nz/listing/1260592248/district-9-fuel-cell-stls?ref=listings_manager_grid

 

[Rogviler]

Hmm, yeah the windows are a tough one. PETG is basically what disposable water bottles come in, so I can imagine your difficulties. Heat forming something is where my mind went. You would probably have to use clear styrene or acrylic. Both have their pros and cons. But either would slump around a piece of pipe or something without much effort once heated to the proper temperature. I have seen some impressive pieces cast in clear resin, but to me that would be more trouble than it's worth.

 

[scornflake]

Hmm. Ponder ponder.

I've ordered some correctly sized acrylic bottles. I'll try cutting the windows out of those; and see what happens. Might work. Might not. It'll still be "not glass". I love the *idea* of glass. And for the inner tube, that'd be no prob (just fine something right diameter). Windows are more of a problem tho! Figure I can always clearcoat it all when done; that'll help with scratch resistance a bit I guess.

Watch this space! Order was from aliexpress. So I might get it this year

I've started the rest of the prints, so I can at least begin this build thread soon "properly"

 

[scornflake]

Initial prints are done. I've mildly filed down the "iris" end cap. Not done anything with the main cylindrical body yet. I decided to try printing cylinder with full supports; just to get a nicer edge at its top. Note the all important coffee!

 

[scornflake]

Starting a primer/sanding process.

I've some left over epoxy rub-thru primer (in a can) from doing the D9 gun repair. Starting with that. It's not as thick as the primer I was using before, but I also don't have to setup a mini-booth to handle the overspray (of which there was LOTS using a regular paint gun).

This is 3-4 coats + sanding.
I think I should probably have sanded the main cylinder some more. You can see some obvious print marks there. Oh well, gives me something to do!

 

[scornflake]

Next morning, more sanding back after 2 coats of primer last night.

I've gone straight to 600 grade as these are small parts and the primer isn't that thick. I'm using a mix of cork + hard sponge block, very very lightly.

I think I might actually fill some of the obvious gaps with something before the next primer pass. Especially on the top of the hex cyliner bit (see single shot on brown kitchen table)

I had tried to put some insets into the cylinder and also one of the "rings" that fits on the end, as per the concept art.
I think at least with a 3d print like this, I prob want to double the depth of those; as it'll make sanding it "more possible" without entirely removing it.

 

[Movie Magic]

Wow. You did a great job on this! Excellent work!

 

[scornflake]

Wow. You did a great job on this! Excellent work!

Why thank you sir!