Double Agent EMTB

[SirVesa]

Hey fellas,

I’ve been collecting parts for a new build over the past couple months or so. Enough stuff has showed up to get started on the build and I need something to do while these mandatory Linkedin learning videos play so it’s time to get a build thread started.

Parts List
-Agent Deck with Pro Grip Pads, F5 bindings & heel straps from @MBS
-MTB Duality trucks from @Titoxd1000
-6495 Reachers @170kv from @Skyart
-Second version of SKP Solos & VX4 remote from @Skyart
-Custom herringbone gear drive @ reduction of 5
-Phatlad hubs (hydrodipped by my 6 year old with the usual 9" pneumatics
-Battery is DIY 18s4p of P45B cells with JBD smart BMS (charge only)

The goal of this build

I wanted to try something a little different from our usual builds without going too far from what’s tried and true for our group. This one will probably take another month or so to finish since I’m waiting on the V2 of the Solos and some other parts that will take awhile to make.

The battery is my first build that isn’t 12s. It’s kind of pussyfooting into higher voltage but the layout works perfect for the enclosure so that was the major deciding factor.

That Agent deck just looks awesome in every way. I love all of the deck inserts, the wider stance and wider sections of the deck to stand on. It also has inserts for both regular and goofy riders so I’ll be able to let the two goofs in our group give it a shot.

I’m new to using Reacher motors and don’t see myself ever going back to Flipsky with new builds. The 6485s on my chain drive are great, but I do overheat them occasionally so decided to put 6495s on this one.

Everyone on here seems to be in love with the Duality trucks. I’m really looking forward to having a setup on something other than the Airs like on my other two builds. Clearance on the Dualities might exclude this build from some of our rockier runs, but there are plenty of other spots that they should handle no problem.

Artem asked if I was OK waiting to receive the second variation of Solos. This seemed like a no brainer. The first version I’m running in in the chain drive have been flawless so very excited to get to try out the next gen.

Prepping the Deck

The first minor hiccup is with the size of the wireway provided in the deck. It’s a perfect width for two #10 wires, but can not fit four of them.

Since each Solo needs a dedicated set of conductors, I had to widen the channel a bit. I’m in absolutely no rush and could have waited a day to grab a panel saw from work to make a perfect cut, but decided to cave man it with a circular saw and a multi tool. The cut came out good enough to be covered by grip tape. The cut is pretty shallow so not too worried about structural integrity but I’ll be sure to let you guys know if If my 200lb ass snaps it on a landing.

Mounting the Trucks

@Titoxd1000 suggested that I mount the front hanger in reverse to increase ground clearance. This is probably great advice, but I didn’t like the look with the front hanger not matching the back. If this causes me to break a truck and have to order a new one it will be my own dumbass fault for ignoring good advice.

I did want to do something to help with clearance a little so I de-wedged the front base plate and increased angle in the back with the included 5* wedges. This combined with 9" pneumatics should give me plenty of clearance for the trails in mind for this board.

Battery Build

Per advice from you guys, I decided to build an 18s pack. The 14s battery described below now lives in my chain drive.

Sooo, first 14s pack! Also the first time using the Malectrics spot welder at the advice of @Skyart. This was definitely a good buy. My brother and I were able to get two packs built in the time it normally would have taken to build one with the old Sunko. I didn’t get many pictures of the build, just the general layout and part way through welding the series jumpers on.

So now that the battery box is mounted, along with the trucks, grip pads and bindings, it’s going to be a waiting game for the Solo V2s, 6495 motors and my straight cut gears. I don’t want to mount the jump drives until everything else is in to make sure there aren’t any angle issues. For now this thing will sit on the bench taunting me, but all good things are worth waiting for! Happy to hear anyone’s thoughts or criticism.

[CarelessAquarist]

Cool looking build and it’s set to perform fantastically with some of those parts, one thing though don’t we normally add angle in the front and de-wedge the back for stability, more turning in the front less in the back? I could have gotten something wrong thought

[SirVesa]

I think you’re right. My hope was that adding 5* in the back would compensate for the 5* removed from the front but I could be way off base. I haven’t even stood on this thing yet, but just applying pressure to the deck with my hand makes me thing it will still turn better than Airs would, even with the angle changes.

[Shadowfax]

@SirVesa

Battery is DIY 14s5p of P45B

This build looks sick. My only comment is I’d strongly recommend going to 18s4p. Switching boxes would be easy right now too. Pelican 1200 I think will fit great for 18s4p, and it’s a medium / smallish box. Going with 14s is leaving power on the table somewhat unnecessarily. 18s will be great for a high power street board.

[SirVesa]

Oh man, I almst did! That was the other “perfect fit” option for this enclosure. The lowest KV 6495 motor that SKP sells is 140kv and I thought that would be too high for 18s. Turns out I had a gross misunderstanding of how KV and torque are tied together. I’ll make an 18s for the next pack.

[Shadowfax]

140kv is perfect for 18s. You could even do 151kv or 170kv with no issues.

[SirVesa]

Pretty sure I have a better understanding of how KV and battery voltage interact now. I was concerned with having too high of a top speed and not enough low end power. Artem kind of explained to me how low KV does not = more torque. The funny thing is, I used to teach a night class about electric motors, but we didn’t cover much with DC or permanent magnets in the curriculum.

The way I understand it now, a higher KV results in a faster rotating magnetic field. When the board is not moving and you apply power, the “faster” rotating magnetic field cuts more lines of flux from the permanent magnets in the housing resulting in higher current and more power generated of the line. Top speed would still be higher than I would need, but not at the expense of torque.

Hopefully that’s a somewhat accurate description of how it goes down…

[Shadowfax]

The best way to figure out how kv, amps, and voltage result in torque and force is to play with the ultimate esk8 calculator. Search the forum for it and plug in your numbers.

Generally speaking, you’re going to have more torque/force with an 18s setup, because you’re able to use a higher gear reduction and maintain an acceptable top speed.

18s / 5.5 / 140-170kv is a pretty normal HV setup.

[JustNeL]

@SirVesa

game for the Solo V2s, 6495 motors and my straight cut gears. I don’t want to mount the jump drives until everything else is in to make sure there aren’t any angle

Dope setup. I have an 18s6p with 6486 151kv motors. SKP was helping me set them up and they run very responsive… still have some tweaking to do before shes fully running. I still have to do some loctite before i feel 90% sure shes good to go. good luck on the build. those trucks

[SirVesa]

I should have played with it more. The top speed number is what scared me away. Hopefully I’ll get another pack built this spring. Appreciate your input.

[SirVesa]

Sounds sick. SKP was very helpful setting everything up on my other builds too. Do you have a build thread going or waiting for it to be completed first?

[Shadowfax]

Oh I didn’t realize you had already built the pack. I thought you were more in the planning stage for the build.

In that case, yeah definitely run the 14s pack. 170kv with 14s and lots of amps will be pretty ridiculous amounts of power.

[Venom121212]

Damn dude this is like 95% of my ideal build right now. Please hate it and sell it to me at a steep discount

[AlexB]

I loved my 18S setup with 151kv motors, but the 14S setup with 173kv was a super fun and capable setup. I always thought of it as sort of the ideal street power setup (for ‘most’ people)

[JustNeL]

Hehe i am still new to this so not sure if i will make a thread for it or not(extremely introverted). Will def post a photo of the board.

[SirVesa]

That’s a huge relief! I was weighing the marital conflict vs buying shit for an 18s pack. Love my wife but the battery was winning .

[SirVesa]

Let me guess, the other 5% is an 18s battery

[SirVesa]

It’s crazy how many different directions you can go with a build to dial it to exactly how you like it. This one probably won’t see too much asphalt but I’ll put in enough rip tide orders to get her set for my riding style.

[SirVesa]

Ok, you guys talked me into it. Decided to build an 18s 4p using p45B cells. The 14s that I had originally planned to use for this now lives in my chain drive. This is the first pack I’ve built without making a bunch of copper jumpers and it was much easier to put together. Big thanks to @Pecos and @Skyart for the advice.

It went a little slower than it could have because my right elbow is immobilized in a splint, but with two fully functional arms and a helper the next one is going to be a breeze.

Would you trust a battery built by a one armed man?

It really wasn’t too bad using the Malectrics without moving my elbow. Tear test on some spare cells went well so decided to go for it.

I ordered an LLT BMS, wired everything in and was getting bad readings on the first two P groups. Checked voltage at the JST connector from each P group back to the first wire that lands on the pack negative. Everything was testing right so no clue what the deal was with the BMS.

Only ordered that thing because I had given up on the Daly I ordered ever actually showing up. Ironically it came in the mail right after trying to troubleshoot the LLT. Removed the LLT and installed the Daly, now everything is working as it should.

Pack is ready to go. Just need motors and Solos to show up and this thing will be ready to go.

Side note, the guy I know with a fab shop is just getting started and doesn’t have a CNC yet. He’s planning to get one later this year and agreed to make my straight cut gears. If any of you have a quicker solution it would be greatly appreciated, otherwise be riding helical for awhile.

[Shadowfax]

@SirVesa

ordered an LLT BMS, wired everything in and was getting bad readings on the first two P groups. Checked voltage at the JST connector from each P group back to the first wire that lands on the pack negative. Everything was testing right so no clue what the deal was with the BMS.

With LLT you need to bridge pins to get the configuration correct for the number of cells you have in series.

This photo is what happens if you don’t bridge the pins or bridge the wrong ones.

Also possible that you did everything correct and the bms is bad, but I’d start with checking the bms pin bridging diagram to confirm.