Noob question thread! 2020_Summer

How-Tos & Esk8 mechanics Esk8 Mechanics
#15610

TS100 is a good one.
I’ve also been eyeing the Pine64 Pinecil, which is a very similar design to the TS100 except it’s less expensive, and it has both a barrel jack, and a type-C port so it can run off of DC or a usb-PD (or QC) power supply.

Basically anything that has tips with a heater cartridge built right into the tip will serve you very well as long as it’s at least 60-80 watts.
Hakko makes the fx-950/951 stations which are excellent.
You can also get a Chinese knockoff station that takes standard Hakko T12 cartridges, which is what the 950/951 uses, for about $30-60 from the usual scumbags.

Also make sure you get a couple different sizes of tips. A big fat chisel or truncated cone like a D-4 or C-4 is great for putting lots of heat into a stubborn joint.

2 Likes
#15611

i have the ts100, and i only use it at 400C, its been great for 10awg, xt90 should be no problem as well. the ts100 body does get a bit hot after awhile, so just be ware if u plan on doing non stop soldering, might wanna take a coffee break once in a while.

also, tips matters, i have 3 tips just for different use

3 Likes
#15612

While discharging one p-group always gets out of balance even after replacing it, could I work around this somehow if I go charge only?
If I go charge only, I would have to change the load+ to pack+?
Or is definitely something wrong with the balance wires/a balancing part on the bms?

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#15613

my diebie did this, but when doing nothing. does this also happen if you just leave the board sitting overnight?

#15614

yes

1 Like
#15615

so yeah…

#15616

Need to remove a thick bit of conformal coating off a boosted battery pcb. I’ve dremeled some with a small cone grinding bit, I’ve tried soldering iron melting it, in about to (carefully) try heat gun next.

Any pointers?

1 Like
#15617

Please can someone give me some advice on motor kv and gearing for offroad, I’ve read a ton, but I’m still confused?

I want to build a trampa for offroad exploring. Priorities: getting difficult places > torque > range > top speed.

Building it from Trampa available parts my plan was 2wd Spur Drive (metal helical) with 9 inch back wheel, 8 inch front and a 21700 12s7p 2x VESC6.

I have the choice of 160kv or 185kv motors (6374) and 1:57 or 1:7 gearing.
According to the gearing chart @ 9inch:

  • 160kv @ 1:57 = 31.5 mph
  • 185kv @ 1:7 = 29.8 mph (calculated)

Which of those is going to be optimal? Most efficient, most torque?

Either is more top speed than I need. I suspect I’ll be averaging ~15 - 20mph (lower when out with the kids on their bikes) so that’s the zone I’d like to target for efficiency (i.e. not flat out top end all the time).

Range I don’t need to max, i’m assuming the 21700 is going to give me plenty. I’d rather higher torque than slightly higher range, unless the torque is going to be unusable, which I’m assuming a 160kv @ 1:7 might be?

For reference I’ve had a bamboo GTR for a year, I have knobbly off road wheels and average 15-18 mph on light off road (woods etc.). Anything faster and my feet move around too much when I hit tree roots etc. considered adding bindings, but it can’t cope with mud, rain or anywhere horses have churned up either.

I love GTR for carving on the road (initial purpose, although I’d like more punch accelerating), but it’s not capable of much offroad.

Battery wise I have the choice of
40T @ 4000 mAh
48G @ 4800 mAh
p42A @ 4200 mAh

I’m leaning towards the molicel p42As (amps look rubbish on 48G, better amps and capacity than 40T)?

Sorry for the essay, not sure what’s relevant to leave out.

2 Likes
#15618

Acetone should break it down but I would try my best to keep it where you need it since it may damage the silk mask.

edit: but you would have to be pretty confident its an acrylic based conformal coating and not another base.

1 Like
#15619

In reply to @uberteck :

Higher gearing ratios will give you more torque, and theoretically more range due to less load on the motor, but in practice higher gear ratios will give you worse free-roll. I don’t know how important free-roll is or isn’t on a mountainboard, but I would definitely go with the higher gear ratio. Then pick the motor with the lowest kv that still gets you your desired top speed. (Sure, a higher kv motor might be slightly more efficient / powerful, but if your motor is large enough that doesn’t matter. Lower kv will mean less current required from your ESC, which will be good for efficiency in its own right)

Might be safe to assume that on a 2WD mountainboard you can never have too much torque :grinning_face_with_smiling_eyes: On 9" tires you’re gonna want that torque for sure

For 90% of esk8 use those are the best 21700 cells currently due to their low voltage sag + relatively large capacity. 40T is a close second; if you get a good deal on them then they’re not a bad option either.

2 Likes
#15621

Awesome, thank you!

Good point about the extra torque on 9 inches.
160kv @ 1:7 gives 25.7 mph

Realistically I’d be unlikely to want to go faster than that, but probably would go up to that which means I’d be using most of the speed range.

3 Likes
#15622

Yeah like @rusins said, gear reduction is more important for torque than lowering motor kv.
You can have two combinations which result in the same top speed, but the one with higher gear ratio would give more torque and range.

So, if you have too low a gear ratio you cannot sufficiently compensate with a low kv choice. You will still be lacking torque. I suspect the opposite thing happens. Let’s say you have 5:1 with 6’’ tires, which is a pretty torquey setup. I suspect if you put there 210kv motors you will still get a lot of torque with the advantage of reaching speeds above 50km/h.

2 Likes
#15623

Are you sure it’s conformal coating and not epoxy?

2 Likes
#15624

I suppose I can’t be 100% sure…

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20210427_1828144032×2268 1.53 MB

Looks 1.5-2 mm thick. Dremeled off fairly easily. Soldering iron had some resistance melting through it.

1 Like
#15625

That looks more like hot-melt-adhesive to me than conformal coating.

6 Likes
#15626

Yeah I saw you mentioning before when i searched on the forum for XT90 mounting tools. Unfortunately i’m not from the US. So shipping out of china to europe will be cheaper for me.

#15627

@SabreDynamics will have some soon (couple of weeks i think)

2 Likes
#15628

So hot re-melting might be worth trying?

1 Like
#15629

Getting ready to start finding room for stuff In my enclosure, which is METAL. I love that, because it is a giant heat sink with great airflow, but looking at the bottom of my anti-spark, I see this.

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That’s the side where the batt comes in…I probably need to insulate that, no?
Seems like I’d short it out mounting it to the inside of a metal enclosure…

#15630

Yes, you definitely need to insulate that. Use something abrasion resistant like fishpaper or thick plastic, and make sure it is secured very well. Shorting those two points together would be very bad.

1 Like