Nagini | Build Journal

[That_Jamie_S_Guy]

I’ve been feeling quite burnt out on the deck design since having to sand it back, so I decided to move onto other part’s of Nagini.

Firstly, I got my 3D printer back up and running by replacing the mainboard. This meant I could print the second 60T pulley:

Ignore the red 3D printed motor mount. It’s an older prototype from when I envisioned using my Globe deck and PU wheels, and had no idea what pulleys or belts I’d be using. I just figured I’d fit it to see where the main issues lie with the design before my next printed prototype. The end goal is to either waterjet cut the mounts or to CNC machine them, and hopefully anodise them afterwards.

I’ve also moved on to battery building. I ordered 50x Samsung 40T cells from Fogstar, which came a couple of days ago. After my whole fiasco around how to pay for them, I realised I had missed the PayPal option on the checkout screen…

I spent some time this evening measuring the voltages of each cell to ensure they are equal, attaching the insulator rings, and hot gluing them together.

I knew I wanted the pack to be completely flat as I am using a drop down deck, but I had no clue what orientations the P groups should be in. I laid them out on my board to figure things out:

And then produced the following, highly advanced, top of the range PowerPoint schematic:

To combat my burnout I figured more retail therapy should do the trick. I popped over to everybody’s favourite Chinese website, Aliexpress, and ordered some 70mm wide fish paper, some 0.12x8mm Nickel (reviews state that it is pure, however I will confirm upon receipt) and 50mm kapton tape.

Originally I was planning to rent or borrow a spot welder, but I caved in and bought this bad boy:

I’m hoping it will do the trick. It has a number of good reviews and although it is by no means a KWeld, it is spec’d to my needs.

While I was on Amazon I perpetuated my financial troubles further by ordering some ebony flavoured wood dye for the deck. The plan once my pyrography is complete, is to dye the entire rest of the deck outside the perimeter of the graphic, before coating with polyurethane and fine glass frit. I will test different timings for when to add the frit to the PU to ensure it provides good grip without sinking beneath the coating, yet is unable to fall off.

[That_Jamie_S_Guy]

A few more things came to mind that I would like to document before I forget.

I am planning to add lights to the board, but not wire them in. I am going to buy some cheap and cheerful flashlights off amazon and design a 3D printed mount to the front of the deck for shredlights-style lighting. I will use a cheap rear bike light or reflector strip on the rear also.

The enclosure I haven’t really figured out yet, so this is going to be a bit of a word vomit. I figure I am going to deck mount my components, likely with 3D printed brackets that screw into place, such that the enclosure simply acts as a waterproof and protective shell. To make it as waterproof as I can, I will 3D print a custom TPU gasket (in multiple parts, joined together with thoughts, prayers, and a lighter) which will be bonded to the enclosure’s outer flange with superglue. I’ll give the deck mounted components some foam sheet to help with vibration. The enclosure itself I am thinking maybe fibreglass? Using a 3D printed, filled, and sanded mould. I’m not very confident about the idea of working with fibreglass, so alternative suggestions are welcome.

I think that’s all for now. I’m procrastinating a lab report for my thermodynamics module, due at midnight today. Wish me luck…

[rosco]

@That_Jamie_S_Guy

enclosure itself I am thinking maybe fibreglass?

It is a good choice for this purpose , but quite a lot of work and a bit of learning for a first timer.

After making a few enclosures, I’m gonna suggest buying a fibreglass enclosure that is close to fitting (ebootsed?) might give best bang for buck (time/effort and cost). What’s the concave like? Alan may have a generic enclosure which is close to the right size. Custom is best, but loooots of work.

Butyl tape is a good gasket because it can be installed to be pretty waterproof. Ali express has some rolls of 6-8mm dia stuff which are pretty economical.

(NZ$ 15.10 45％ Off | 1Pcs 4m Butyl Rubber Glue Headlight Sealant Retrofit Reseal Hid Headlamps Taillight Shield Glue Tapes Car Door Seal Accessories https://a.aliexpress.com/_ms0rvWc)

[Bavioze]

I believe this model welds until . 15mm nickel, just so you know

[That_Jamie_S_Guy]

I’ll have a look and see if there’s anything out there that fits but I’m quite keen to try my hand at making it myself.

The concave isn’t very aggressive, but enough to be significant. I’m not sure how i can measure it other than by buying or printing a contour gauge.

That’s a good shout for the gasket, it’ll make life much easier.

[That_Jamie_S_Guy]

Thanks, I’ve ordered some 0.12 nickel which should do the trick

[That_Jamie_S_Guy]

@Plurf

Cool you already look

Thanks!

[That_Jamie_S_Guy]

Figured I’d draw up the deck (Indy 42" x 9.5" Slant) in Fusion 360 to help with designing the enclosure later down the line.

It was a struggle to model the concave, but eventually I figured it out with planes and lofts. I can’t guarantee it’s 100% accurate, but the main dimensions are there:

This then led to me making a really rough mockup of the Haggy Bergmeister wheels and putting together a half-assed assembly of the build:

God I’m so excited to eventually finish this beauty.

[That_Jamie_S_Guy]

3D printing some custom motor mounts to satisfy my impatience:

These are only temporary. A proof of concept if you will. I’ve stolen @ZachTetra idea for a Vernier indexing system. Although not really necessary as my mounts will only ever be in one position, I just had to try it out.

[ZachTetra]

If you sell these I expect soda money as royalties

What hole pattern count on each sides is it?

[That_Jamie_S_Guy]

I wasnt thinking of selling them, but if thats something you’d be okay with (with appropriate compensation of course.) Ill have a think later down the line

It’s 16 & 20. Took me a good few minutes to wrap my head around how that equates to 80 positions but I got it eventually. I honestly dont see why it hasnt become the mainstream for adjustable motor mounts. It eliminates the tradeoff between size/strength/adjustability very elegantly.

[That_Jamie_S_Guy]

Your drunk ass never got back to me!

[Common_good]

@That_Jamie_S_Guy

some 0.12x8mm Nickel

This nickel is a tad undersized for what you’re planning, bruv. Unless of course you plan on building bus bars with the nickel which is gonna take you a very long time… ask me how I know lol. Even still, that nickel will run hot if you pull even modest amps across your pack.

Will that spot welder do 0.15mm nickel? If so, I’d source some 25 or 30mm in that thickness or the stuff they fabricate that’s already cut into bus bars.

[Flyboy]

Yes, it will take 9A, or maybe 15A peak. You could maybe get away with soldering a series wire for every cell, to split the currents in half, but it will still be hard to avoid hot spots.

[That_Jamie_S_Guy]

@Common_good @Flyboy After some discussions in battery builders I realised the whole design of the pack is a failure waiting to happen. So I’m trying to find some 30mm x 0.15mm Nickel as seems to be the standard

[That_Jamie_S_Guy]

While I procrastinate finishing the deck and wait for more battery building supplies Im focusing on the motor mounts.

I 3D printed some ABS prototypes and put together the board:

It’s 2AM so I should probably go to sleep now…

[That_Jamie_S_Guy]

Finally getting back to working on the deck. Its taken a while to get the motivation back. That, combined with Christmas, a godawful fever and flu that has lasted two weeks now, and a series of exams, have absolutely crippled me this month.

But it’s 2023 now! Happy new year everyone. Fingers crossed this is the year that Nagini comes to life

A few weeks ago I applied the wood dye to the back of the deck, just for some practice. As you can see there are some blemishes as it was a bit of a rush job, I was marginally wankered, and I forgot to give it a quick sanding first. So I’m planning to sand it back and give it another go:

Last week I made some progress: after the blowtorch and shit shading incident, I was left with patchy linework, shoddy shading on the compass points, and no scales through the majority of Nagini’s body. I couldn’t seem to sand back all of the blowtorch marks or the areas where I’d accidentally gone too deep with the burner, without stripping the whole thing back to a fresh slate. I figured I’d salvage what I’ve got and find a way to hide my mistakes.

I started by reburning the block shading on the compass points. This took a good few hours. I then spent a number of hours sketching out the scaffolding for the scales to get them proportioned somewhat correctly:

Because I had too much coffee today in an attempt to combat my awful fatigue, I haven’t been able to sleep. Instead, it’s almost 7AM now and I’ve spent the last 5 and a half hours fixing the linework and redoing the scales while listening to a Vice documentary about psychedelic frogs:

As you can see, I’ve changed my method of shading (definitiely not to hide all my fuck ups) and I’m really happy with how it’s starting to look. There was a phase after I had re-outlined the scales that I was stsrting to wonder whether this whole thing was a mistake, but now things are going in the right direction.

The next steps are as follows:

1. Finish shading the scales, and add shading to the edges for more of a 3D effect.
2. Shade the underbelly.
3. Outline the head and tongue
4. Shade the head and tongue
5. Sand down the back of the deck, and lightly sand the bare sections on the front
6. Apply wood stain
7. Apply polyurethane coating
8. Test polyurethane and glass frit on scrap
9. Pray to all things holy that I don’t screw up massively again

[Common_good]

@That_Jamie_S_Guy

Pray to all things holy that I don’t screw up massively again

It’s gonna happen bruv so I think the key is just to expect it and be as zen as u can about the inevitability. Your first build is a steeeep learning curve. I just about binned my first diy a half dozen times for that reason and that was after already building a bkb kit.

It’s all part of the journey, mate

[That_Jamie_S_Guy]

Don’t scare me like that! It’s slowly but surely getting there. Being as patient and careful as possible to avoid binning it…

[Common_good]

Patience is a virtue, so they say

You’ll be just fine if u work with the expectation that problems will occur as will frustration. Ultimately, when u finally finish it the sense of accomplishment is just that much more profound.