Nagini | Build Journal



Just documenting a few thoughts.

I may mount an old phone to the front of the deck to act as a low budget Davega so I can see my battery charge, speed, distance etc. All it would need is a waterproof case and 3D printed mount.

Once my printers up and running I intend to print some covers for the belt drive and underside of the motors to prevent stones coming and knocking things about. It’s also become apparent that I need a better carry handle solution than just holding the trucks, and nose/tail bumpers to prevent scratches.

Still planning to mount some lights as well…

Also, a carry handle. Probably machined aluminium.

Before:

After:

Details

Since I was already replacing my damaged BMS, I figured it would be worth just redoing some other aspects of the pack as well.

I was feeling quite dissatisfied with how messy my shitshow of kapton tape is, and also I had already managed to damage some of the shrink wrap. Those combined certainly didn’t give me much confidence that the pack will be able to hold up to any vibration, especially with all the air pockets between layers of tape. I decided to strip the battery back to P-group level.

Much happier with the way the pack looks and feels now :slight_smile:

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I’m so frustrated with myself.

I got home from work early with the intention of getting a bit more done from home to catch up on some stuff that’s behind. Instead, I saw the Amazon package for blue foam and got excited and decided to work on my enclosure.

The first mistake is not giving myself enough time.

I knew this would be a lengthy, messy process, yet realistically I only had about 2 hours before it was time to make dinner, do the chores, spend time with my fiancé and get a good night sleep.

I started off working carefully but as time started to run out I felt more and more rushed.

I began with some cardboard as a base:

Then cut some blue foam to size and with double sided tape, attached it:

It was at this point I was concerned that I cut the foam too small across the width of the board. I decided to go ahead anyway.

I set up some bin bags as dust sheets:

Then began shaping the enclosure.

Because of how lightweight the foam was, I tried using the double sided tape to stick it to the deck. However because of the heavy duty velcro I previously added to hold the battery in place during testing, this didn’t work.

I still decided to carry on.

The final shape of the enclosure mould was decent. It’s not perfect, and I didnt take the time to make proper measurements and markings for the two height levels and rounded edges. I eyeballed it.

I then haphazardly wrapped it in packing tape. Completely ruining all the work I did to make the surface nice and flat to provide a good internal finish for the fibreglass.

Then I laid out the battery and ESC on top and realised it was going to be too tight of a fit for all of the wiring, especially the loopkey circuit which I haven’t made yet.

I realised I’d need to buy more foam and start from scratch. That’s fine. What’s not fine is the sticky tape residue on my deck.

So with a combination of heat gun, a plastic scraper and isopropyl alcohol I began chipping away at the tape. I was making frustratingly slow progress, and then this happened:

Some of the epoxy on the deck completley chipped off. Now, not only have I wasted time and energy on the enclosure, but I’ve made myself more work because I need to repair the deck once I’m done removing the adhesive. I don’t have enough epoxy left for a full coat of the underside so I’m going to try to patch it up, but I’m worried it’ll be obvious and look shit.

I’m covered in blue dust. My desk is covered in blue dust. The floor is covered in blue dust. All my tools are covered in blue dust. Even the kitchen has somehow got blue dust. Everywhere I walk is getting covered in blue dust. I need to make dinner. I need to tidy up before I work from home tomorrow. I’m pissed off with myself.

Rant over.

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I’ve been there too man, just take a breather for a while then knock one thing out at a time. Feeling like you’re tripping over yourself is one of the most frustrating things

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I’m sorry to hear that man, feeling like you’ve only gone backwards after a ton of work is never fun. When you do end up starting again though I recommend goo gone to get rid of the tape residue. It has always worked wonders for me.

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Yeah man. I guess its all a part of the learning process, especially with this being my first time. Im just itching to ride this board at this stage and want it done so badly. I’ll try again, but make sure i take my time with it.

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Thanks man, glad you get me. I’ll look into that goo gone stuff, sounds like it’ll work a treat :slight_smile:

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Yeah dude. Modest goals and lots of easy, achievable little steps is the way.

Wanting to finish so that you can ride it is the hardest thing. Avoid that any way possible dude, cos it makes you rush shit. Borrow a board, push skate, whatever.

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Great advice here… your first build is especially tough for this reason- you’re itching to ride like a junkie and it enables compromises on quality and/or shoddy work. This will also lead to a board that’s not gonna hold up very long… or at all.

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Bro I could kiss you rn

That goo gone stuff worked its magic and the deck is completely clean.

Thank you :slight_smile:

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Glad it worked out man! Excited to see how everything turns out in the end.

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Wash that shit off tho. It will fuck up your epoxy if you leave it on afaik…

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I used some kitchen spray because I figured a degreaser would be best as the goo gone felt and smelt like lemon flavoured WD40. Got most of it off but wasn’t very thorough. Will clean it off properly when I get home.

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I think it’s about time I post an update. Lot’s has happened over the past couple of weeks. Let’s start with the enclosure…

This part of the project had me stumped for a long time and is the cause of an excessive amount of procrastination. I see now why it is best to pick an enclosure and deck combo first, and work the rest of the build around it!

There are many options out there when it comes to enclosures. I could have bought one, but it would never have fit perfectly to the contours of my deck, and it would never look quite like my idea of perfect. So that was out of the question.

There are three main options when looking to build an enclosure.

  1. 3D printed
  2. Vacuum formed thermoplastic
  3. Composite

Due to the cost and labour associated with options 2 and 3, I initially planned to go with a 3D printed enclosure. The plan was to 3D scan the deck, clean up the mesh and work from there. The enclosure would be printed in multiple parts, joined with adhesive or hardware.

The problem with taking this apparent path of least resistance is that a 3D printed enclosure is not as simple as it initially sounds. I’m pretty good when it comes to CAD so that wasn’t going to be a problem, but the 3D scanning would take much more work than anticipated. I would require an NVIDIA Cuda enabled GPU for meshroom, which immediately bumps up the cost (there are ways around it, or other 3D scanning softwares that may be used but truthfully I just couldnt be arsed to spend a few weeks learning a whole new software package and workflow) The I would need to try out different settings and iterate the 3D reconstructuon process until finally producing a mesh close enough to the shape of my deck.

Then my 3D printer mainboard blew for the third time and I was PISSED. So I threw this idea out of the window entirely. Besides, waterproofing it, applying filler, sanding and painting would still have taken just as much time as any other enclosure build and at the end of it all, would not be as strong as composite or vacuum forming due to the weak inter-layer bonding (even if designed in such a way to optimise the print direction). I considered fibreglass reinforcement but at that point why not just fibreglass the entire enclosure?

Vacuum forming was out of the question because I dont have a shop vac, or the money to buy one, or space to store it, or the equipment to put a vacuum former together, or know anyone who has one. Plus, it would not be as strong as composite.

So I settled for fibreglass composite, which from my research appeared to be the cheapest and most robust method. There are so many ways you can make an enclosure with fibrelgass, using directional sheets at altenating angles, applying finishing layers, gelcoats, negative moulds, positive moulds, the list goes on. I settled for the cheapest and most crude method available which was to use polyester resin, 450gsm chopped strand matt and a mould made from blue foam, covered in sellotape to act as a mould release.

My first attempt at making the mould was a huge failure. You can read all about it above. My second attempt however, went much better.

I began by laying out the battery, ESC and wiring on top of some blue high density foam, on top of my deck. This enabled me to cut out the bounding box of the enclosure mould and stick the foam blocks together with double sided tape. I also made sure there would be enough clearance on the flange which will host the deck mounting holes for some neoprene backed domed washers I brought which will help waterproof the enclosure.

Then with a contour gauge, I traced the curvature between the platform of the deck and the truck mounting holes. I cut the excess with a utility blade.


I wanted to add a nice chamfer around the edge, so with my crappy plastic geometry compass I marked 3cm all around the top surface and approximately 1.5cm around the sides. I tried using a handheld sander to shape the foam before but it gummed up the discs and dust collection so quickly, and made a huge mess, so this time I opted to use a steak knife. I was going to use a bread knife originally, but it was too long and imprecise. Im hindsight i don’t know why I didn’t consider using a coping saw… but this worked perfectly. I sanded the chamfer by hand to make it smooth:


Once I was happy with the finish and shape, I applied sellotape to the deck, then double sided tape on top. This would prevent the double sided tape from ripping more epoxy from my gorgeous deck. I still need to fix that…

I carefully positioned the mould, and painstakingly applied overlapping layers of double sided tape to the mould and deck. This took a while as I didn’t have any filleting wax for the transition, so the tape had to sit perfectly betwen the foam and the deck.

I couldnt be fucked with taping each end, but they still needed protecting, so I used some plastic gloves. Some duct tape was also applied to even out the transition between mould and deck, and prevent any polyester resin leaking through gaps in the tape.

Once everything was protected it was time for the fibreglass.

I got suited in my finest work trousers, respirator, old shirt and safety goggles, opened all the windows, and laid out the newspaper.

I accidentally mixed up way too much resin. Off the top of my head I think I calculated I would need 300ml per fibreglass layer. I mixed up 500ml. I guess it’s better to have too much than too little?

I thoroughly wetted the sheet with a chip brush, then as it began to cure I went around with some metal fibreglass rollers to keep the flange fillet nice and tight and remove air bubbles. The wide rollers were absolutely crap and just kept ripping up the fibres so instead I used the end of the chip brush to dab any air bubbles down. The thin seam roller was fantastic for the fillet though.

After about 10-15 mins the first layer was tacky and holding shape, so I applied the second layer. That went well, and after I was confident it would hold shape I hit it with my heat gun to make it cure faster so I could get this over and done with. It was 1AM and I needed to get to sleep.

I applied the third layer and all seemed to go well. I could see there were some air bubbles, and knew it wouldn’t be perfect in the absence of a vacuum bag and finishing layer, but was happy to take on board the challenge of sanding.

I demoulded it the next day which was incredibly difficult. But once it released from the tape I was extremely glad to see that there was no immediate damage. The heat during curing has deformed the edges of the foam mould so that can’t be used again, but apart from that, everything was in working order.

I marked where to cut with a sharpie, and got to work with the dremel.

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This took a long time. At first, I kept sending broken cutting wheels flying across the room. I’m extremely glad I wore my eye protection because there were some close calls. I realised I needed to set the speed to maximum, and make slow, shallow cuts. Slowly but surely I removed the excess matting.

In hindsight it would have been a hell of a lot easier to cut off the excess before it fully cured, or to fully impregnate the entirety of each layer. Areas of the matting which hadn’t been impregnated with resin were easy but messy to remove. Areas which had only been partially impregnated delaminated and created gaps that required multiple cuts at weird angles to get through.

I then took it outside to sand and this is where the trouble began. The material was fairly easy to work with, and sanded nicely without gumming up the discs. I spent about 4 hours shaping the deck with 60 grit, and went through about 15 discs. It was a strangley relaxing process, just turning your brain off and embracing the never ending vibration and noise. Where the air bubbles had formed, gaps and weak spots appeared in the enclosure:

I’ve ordered some more matting and will need to add layers to both the inside and outside of the enclosure to fully repair these sections. Then, the lengthy process of sanding will begin again.

Unfortunately I can’t do this until two weeks time as I am on holiday next week (first world problems eh?). Once it is done, I will need to make the cutouts for the loopkey and charging ports, as well as the phase wires, and drill out the deck mounting holes. The enclosure will be mounted to M4 threaded inserts. I also have some rubber grommets to help prevent water ingress at the phase wires.

Once all the cutouts are done, I will spray some primer, give it a light sanding, then use a matte black spray paint to make it look nice. I will then use some satin clear coat to add some protection and a mild gloss.

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Aside from the enclosure, I have also been working on the loopkey and new motor mount clamps for some BN 220 hangers. I’m being told to go and pack my suitcase now, so unfortunately those updates will have to wait but here’s a few pictures to satiate your primal desires:




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So I added more fibreglass. One patch on the interior and one on the exterior of each area that needed reinforcement.

Unfortunately, where I had been using my orbital sander at weird angles to shape the corners, the velcro backing pad has been gummed up with cotton and all the hooks are bent.

Fortunately, this gave me a perfect excuse to buy a detail sander…

A lovely old lady down the road who I sometimes help out with shopping let me use her shed while it was raining to do some more sanding. The detail sander did a fantastic job as opposed to the orbital when it came to flatening the side walls and getting the angles correct. However, more gaps began to appear.

I’m pretty sick of fibreglassing at this point. I’ve gone through loads of brushes, the resin stinks, and it always makes a huge mess that takes ages to clear up. So I decided to use some general purpose outdoor filler to hopefully seal the gaps and any imperfections in the surface before priming and painting. I’m a bit worried about how well it will bond to the fibreglass but worst case scenario it all comes off and I just need to add more fibreglass. Also, it’s marketed as shrink resistant so hopefully any flex in the enclosure won’t cause the filler to fall out.

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What is the plan once it’s all smooth? Final layer of fibreglass/ skin it to look pretty?

What’s the filler type? Water based or polyester (2 part?). I’d be more nervous about adhesion for a water based one…?

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Spray primer and matt black paint with a clear satin coat to help protect it.

I can’t find any info on the filler base. It’s called “Diall Exterior White Ready mixed Filler” so I’d assume it’s water based…