NESE modular jumper - 🐉 Dragon MTB build

#Data


Final jump weight: 15.4 kg (33.9 lbs)

I could reduce this a few pounds if I removed the Davega, swapped the DV6 for the Xenith, put on 6" tires, and maybe lost the nanuk case entirely. Maybe get to 14kg / 30lbs. But I can’t see how anyone can really go lower. I specifically choose all the lowest weight mtb components for this build.

But otherwise, it’s pretty light with that 12s2p P42A pack. Somehow it feels lighter than my landyatchz 10s4p P42A / BN M1 gear drive / TB110s at 12.6 kg (27.8 lbs) - maybe because the bro + matrixII is so much longer and wider.


Started the 12s3p pack. Time to wire.

7 Likes

Never seen phase resistance this low :hushed:

Large 190kv motors. So this is fairly normal.

2 Likes

#Battery

Test fit the 12s3p range pack. Fits nicely above the makerx on some 100% solid printed angles. I need to add some padding, but I think this will work well.


9 Likes

Shoot, that’s a really clever battery layout! I ordered a box the other day for my 12s6p and it is definitely not as small as yours lol

1 Like

I wouldn’t call this Nanuk 905 small, haha, but it’s a nice size. I’m sure I could pack a bigger spot-welded battery than this NESE setup, but it’s fun to assemble these.

Mainly, I didn’t want to have to run wires up the lid for a lid-mounted esc. I also wanted the potential to add a bottom mounted aluminum plate for rigidity and heat dissipation, if necessary. And I wanted a nice little electronics & wiring compartment, so I didn’t have to agonize over routing like on a bottom-mount enclosure.

1 Like

#Battery

Finished the batteries!

Look at this ridiculous parallel harness




Watching the silicone squeeze out as the heat shrink tightened was quite satisfying.

Padded the range pack area. Nothing moves when the lid is locked. :ok_hand:



What a beautiful fit. Added a couple fibertape pull tabs to lift the range pack.

Just waiting for the new footpad to finish printing and then it’s off for a real test ride

8 Likes

next time try out the adhesive lines heat shrink! has hot glue on the inside so it has a nice clean waterproof setup.

5 Likes

Oh that’s the only stuff i use! so satisfying to see the adhesive bubble out and know the connection is extra protected.

On this harness i was worried that the large change in diameter from two jacketed 12awg wires down to one xt90 terminal would be too much for this size heat shrink, so i filled it with silicone as well.

2 Likes

This is my preferred method as well.

Some sealant under the shrinkwrap, whether silicone or conformal coating or epoxy, whatever. Then squeeze it down

edit Oct 2022: I prefer inserting pieces of unmelted HMA (hot glue) in there

3 Likes

LOL…it is definitely cool to watch.
One thing to consider is that the silicone needs moisture to cure and the silicone inside the connector might take days and days, even weeks if ever, to finally cure.

2 Likes

:face_with_raised_eyebrow: Do you mean air? Or am I about to learn something…

2 Likes

lube

It needs the water vapor in the air.
No air = no moisture = no cure. Inside the heat shrink it’s essentially the same environment as inside the original tube of silicone.

There would be verrrrry slow migration of water vapor through the silicone exposed to air but I think that significantly slows down or stops after a while when the exposed silicone fully cures.

2 Likes

there probably isn’t much left inside since heat shrink kinda fills in most of the gaps

Can confirm, tried to do a similar thing between two small, nonporous surfaces and the center was still liquid after a week

The figure of merit is the distance the volatiles need to travel through the bulk material, I think. So maybe half an inch in this case. That’s pretty far by silicone standards

2 Likes

Still a long way for moisture to go to make it into the center of the heat shrink tube though.

You do have less silicone to cure but the smaller opening at the end, because the shrink collapsed down, limits the amount of moisture that can get in at any one time. I think there might be some balancing each other out (silicone volume vs moisture entry speed) going on here.

1 Like

This is a great point. So you’re saying I should water test these connections asap! :wink:

2 Likes

Lol the lesson here might just be to use hot glue or 5 minute flexy epoxy

:grin:
Actually, putting silicone in a very humid environment or in water forces the surface to quickly skin over and seal out moisture that is needed to seep into the rest of the silicone. It significantly lengthens the cure time.

It all needs to happen very slowly.

3 Likes