SR-71 Bluebird | Hummie | 110 Artic Blues | 12s7p 30Q

Progress progress. Kind of anyway, got some stuff ordered!

Mounts and the second hanger

Random but I needed heatshrink for my battery, so I ordered some 80mm ID stuff from Ali

image

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More updates. I’m still waiting on a good amount of stuff, but I’ve started planning out the battery layout, and I’ve decided to go with a 12s7p instead of a 12s6p because I felt bad leaving so much real estate that I would regret not using later.

I used the 3D servisas calculator and it estimated 20 miles of range with the 12s6p and while I believe I will get more than that, having another parallel set doesn’t hurt either. No one really cares how heavy they are anyway.

Anyway, with a 12s7p in the hummie deck, you can actually come together with a pretty nice layout that allows for a little bit of flex. I plan to arrange the cells like this, with 7 cells in parallel and run the nickel as shown:


In this orientation, there should be plenty of contact for parallel cells. The series connections will be done with 12 awg silicon wire or copper braid, I haven’t decided yet. I think the wire is better since I have room to run all of the series connections down the center channel between the cells. I am aware that if I wired the series wires in this picture as it is, that it would not be as I expect lmao, I just set them in there for visual purposes, obviously in the actual build, they would be alternating orientations with positive into the center and negative into the center.

I used paint to draw on the wires, in this orientation, it should allow for some flex and plenty of current draw from 12 awg wire.

I still have plenty of space for the bms in the back with the Go-FOC Retro, and if need be, stuff in that area can be stacked since it’s a DS enclosure. I don’t really know exactly how much horizontal room @BigBen 's DS hummie enclosure has but I don’t think it should have any issues with the cells being all the way at the edges. With each individual P group covered in heat shrink, I shouldn’t have any reason to use fishpaper (that I see anyway).

If anyone has constructive criticism or comments, let me know, nothing is welded or soldered yet.

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Special delivery from the Kevin delivery service came in today @Boardnamics

Probably gonna get this stuff installed tomorrow.

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Good ol Kevin delivery service. This time, done NOT at 3am!

Hope to deliver more packages to your in the future.

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I think 11s9p might fit :stuck_out_tongue_winking_eye::smirk:

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Ew oh no 11s? The horror :joy:

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Lol thank goodness. Any yeah I imagine you will be at some point :sweat_smile:

You can also use 25 x 0.15 mm nickelstrips takes less time to weld them plus you dont have to round and cut all the tabs, and the extra surface area can handle the amps so you dont have to add another layer on top.

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Hmm that’s a good point. Like the super wide ones that cover two sets of cells?

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Got the @Boardnamics mount system on today, and I have to say I am happy with how easy it is to install and the overall quality of it. I am concerned about clearance between the idler and the wheel with the 110mm wheels when I get them, but I will tackle that problem when the time comes.

The belts also feel a bit long but the final drive train will have 15-40 instead of 16-36. That should help the idler stay at a more normal spot.

The top-down and back views of the drivetrain look pretty great. I am quite concerned about ground clearance, and while I might try to notch the mounts angle up one spot, I think it might have a collision with the deck and the motors. Hopefully the 110mm wheels will give me enough ground clearance for comfort. As @KaramQ suggested I could just do top mount but I kind of wanted to do drop-through because it looks nice and enhances stability.

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Exactly, also less chance of a tab coming loose since its just a single layer. Of course nickel should never come loose with a good welder but ya never know. Board is looking awesome btw :ok_hand::ok_hand:

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That is true I agree, I don’t want to wait long enough to get that nickel type but it is a good suggestion.

Thanks! It’s starting to get exciting, I placed my order for my Hummie DS BigBen special yesterday, that will look super clean on here.

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Yeah and shipping times suck atm, better use whats at hand.

And looking very clean already, gonna be one sexy board when its done then :star_struck:

True true. Right now I’ve got my 0.2x 10mm nickel which I think will be perfectly fine, except cutting the corners will be time consuming.

I have some 0.15x12mm somewhere between china and here too. I got impatient and bought the 10mm from a US ebay vendor lmao

Indeed, I plan on carbon fiber skinning the enclosure with some cool vinyl wrap as well. Not sure how I want to do the design yet, but I want to somehow incorperate the SR-71 Blackbird design angles and stuff.

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Clearence is scary, it’s low on mine but it doesn’t budge at all. What I suggest is you put ur tb110’s on that build

Honestly I’m just going to buy a set of the 72a ones. Just haven’t done it yet

They’re so good on my other board that I figured I should just have 2

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Whahaha I know the feeling I often order something from china but get impatient and end up ordering it another time locally. And the wrapping sounds cool maybe design and 3D print some angled pieces you can epoxy onto the enclosure and wrap on top of to incorporate the angled surfaces.

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Ya that’s kinda what I was thinking, I was looking for a good graphic of the jet but it’s hard to come by

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Maybe some models help? https://grabcad.com/library/tag/sr-71

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Hmm good idea maybe I can crank out a render from a good angle