Have tech questions? Will answer.

[ovidiugm]

Originally Posted by JayHawk

Looking for an SCX24 battery extension. Searched multiple times using various ways (MCPX JST, micro battery, and everything else in between). Anybody know where I could pick one up, outside of buying a plethora of pigtails and soldering them together?

I don't have a SCX24, but maybe have a closer look at this:
https://www.ebay.com/itm/1-E-Flite-B...-/232060296492

[Ninomaniac]

Quick question... a couple of us crawl with budget TRX4 sports builds but now and then we put up a short track and race them around (yeah, I know). Is a 3 slot or a 5 slot less bad for this kinda behavior?

So, would a 21t 550 TM sport or a 12t 550 CM sport be more efficient at 3s full throttle, geared relatively high (11t pinion, 2nd gear)? Which would give less heat, and moar battery and motor life?

[usert_l]

In the days when brushed motors were still used for RC racing (before brushless took over), 5 slot armature was not used. Not sure if the racing rules didn't allow it, or because 3 slot simply worked better. In any case, 3 slot was the typical armature for a racing motor.

[Ninomaniac]

Good point.

[Voodoobrew]

Originally Posted by Ninomaniac

Quick question... a couple of us crawl with budget TRX4 sports builds but now and then we put up a short track and race them around (yeah, I know). Is a 3 slot or a 5 slot less bad for this kinda behavior?

So, would a 21t 550 TM sport or a 12t 550 CM sport be more efficient at 3s full throttle, geared relatively high (11t pinion, 2nd gear)? Which would give less heat, and moar battery and motor life?

Your thinking about this all wrong. The most important thing is that your trx4 has lights and sirens that go woo-woo-woo NEE-eu NEE-eu!

Keep it fun, smiles win every race.

If you really need an answer, crawling is the opposite of racing, and you use different motors for each. Pretty much all the stuff that makes a crawler motor good, makes for a bad race motor. It also make for a bad drag brake. Because the strong magnetic field that makes a good race motor and drag brake hold the rotor in place at low power. So low rpm is difficult.

For extra giggles in a trx4 with a 2 speed, puller pro/mamba x/6s/9tpinion it will crawl really good, or you can do wheelies and back flips. You should probably order like 100 extra side mirrors because they don't last long.

[Ninomaniac]

LOL. 2 of the 4 of us are Puller and Mamba X equipped. We make the brushless bastards dial them down to our poor people top speed, but I have a feeling they're cheating. Either that, or I keep losing cause of that funny green tobacco one of the guys keeps bringing to the party. That stuff greatly increases my transmitter delay!

Anyway. I swap between 21t motor, 12t pinion on 3s for "racing" and 5 pole 10t on 9 pinion, 4s for cwarling and it's good.

If any of you want to spend an amount of money on brushed motors in a month that could've bought tou a nice brushless system, come to me for advice!

[Voodoobrew]

Originally Posted by JayHawk

Looking for an SCX24 battery extension. Searched multiple times using various ways (MCPX JST, micro battery, and everything else in between). Anybody know where I could pick one up, outside of buying a plethora of pigtails and soldering them together?

PS. I don't have a soldering iron yet, and don't really wanna buy one for a 3 inch extension.

Sent from my SM-F916U1 using Tapatalk

I actually cut the battery wires in the middle and add a XT30 plug. Then I get XT30 batteries.

But thats not what you asked,
you want this link https://www.micronwings.com/Products...ns/index.shtml ?

[King Dork]

Originally Posted by Ninomaniac

Either that, or I keep losing cause of that funny green tobacco one of the guys keeps bringing to the party. That stuff greatly increases my transmitter delay!

That’s great!

[Hypn0t1q79]

I'm looking to add a BEC to my rig. Both the steering and Dig servo can handle up to 8.4v. I am wondering if this is the correct adapter for that application? https://www.amainhobbies.com/holmes-...ssdual/p541702

I'm using a 1080 ESC and a Spektrum SR300 receiver.

[natsb]

I use a Prodigy 680 battery charger, which works great by the way.

Can the USB port on the side actually be used for anything? I plug it in, but nothing happens other than a driver being loaded on my system. The manual says the USB port is for firmware updates and PC monitoring, but as far as I can tell, there is no software available to do these task.

[Voodoobrew]

Originally Posted by Hypn0t1q79

I'm looking to add a BEC to my rig. Both the steering and Dig servo can handle up to 8.4v. I am wondering if this is the correct adapter for that application? https://www.amainhobbies.com/holmes-...ssdual/p541702

I'm using a 1080 ESC and a Spektrum SR300 receiver.

That bec can handle a lot, are you having issues that makes toy think you need a bec?

I use the castle bec, its the blue $20 one. you can set it to any voltage using castle link.
most of the other ones are only 5A or less so no real point in using them. set your endpoints right and its rarely an issue any more.

[SurlyBurly]

Here's a genuine newb question. Is there a universal metric to describe a motor in the hobby? Like in automotive engines, regardless of how they're marketed, they have certain metrics that will always relate, no matter if its NA or Forced induction or displacement is described in liters, or CCs or cubic inches, there is a way to boil the specifications into a common denominator.

I get the general gist of turns and KV, but I also see motors described as 130, or 370 or 540 or 550, and I have a loose understanding of what that mean relative to each other, but do those numbers actually represent anything? I've also seen 1/5 scale motors and 1/8 scale motors and so on, clearly describing their intended use but is that all it means?

What do I need to know to look at a motor and understand what it really is.

[Hypn0t1q79]

Originally Posted by Voodoobrew

That bec can handle a lot, are you having issues that makes toy think you need a bec?

I use the castle bec, its the blue $20 one. you can set it to any voltage using castle link.
most of the other ones are only 5A or less so no real point in using them. set your endpoints right and its rarely an issue any more.

No issues at the moment just upgrading to better servos that can handle more than 6v from my research I planned on using the regular castle BEC and that adapter to power 2 servos as both the steering and dig servo can handle the higher voltage. From what I read that adapter I linked should do what I want but i'm new to BECs and wanted to doublecheck before I bought it.

[mikemcE]

Originally Posted by SurlyBurly

Here's a genuine newb question. Is there a universal metric to describe a motor in the hobby? Like in automotive engines, regardless of how they're marketed, they have certain metrics that will always relate, no matter if its NA or Forced induction or displacement is described in liters, or CCs or cubic inches, there is a way to boil the specifications into a common denominator.

I get the general gist of turns and KV, but I also see motors described as 130, or 370 or 540 or 550, and I have a loose understanding of what that mean relative to each other, but do those numbers actually represent anything? I've also seen 1/5 scale motors and 1/8 scale motors and so on, clearly describing their intended use but is that all it means?

What do I need to know to look at a motor and understand what it really is.

Your numbers 380,540,550 relate to the physical can size. Then you can get into KV/turns.....
think of can size as the “block”
Small, big, ProMod. KV/turns are the HP / torque ratings .
If you go to Holmes Hobby site, he has a chart showing Kv/turns vs speed

Bigger rig needs more motor, weight is the key
Hang up and Drive

[Voodoobrew]

Originally Posted by Hypn0t1q79

No issues at the moment just upgrading to better servos that can handle more than 6v from my research I planned on using the regular castle BEC and that adapter to power 2 servos as both the steering and dig servo can handle the higher voltage. From what I read that adapter I linked should do what I want but i'm new to BECs and wanted to doublecheck before I bought it.

That servo adapter will work, but you need to figure out how to plug a bec into that red and black Dupont connector.

In the crawler world we like to use the red jst plugs for that power instead.
Just be sure to triple check the wiring so you not sending the red wire to the receiver or where it doesn't belong.

It worth the $10 for a cheap Weller 40w soldering iron and some heat shrink. Its not a difficult skill to be good at and will save you lots of problems in the future.

[Den72]

Originally Posted by Voodoobrew

It worth the $10 for a cheap Weller 40w soldering iron and some heat shrink. Its not a difficult skill to be good at and will save you lots of problems in the future.

Its worth noting that good heat shrink is worth its weight in gold. The cheap version from Harbor Freight has no adhesive in the tube and don't hold the best in certain applications. Heat Shrink with adhesive inside ensures that the tubing stays in place.

[smc-93]

I've always had a decent understanding of what motor goes where. But I like your comparison to 1:1 engine though. It's a good way to simplify it for someone new to the hobby or is only experienced in 1:1.

Originally Posted by mikemcE

Bigger rig needs more motor, weight is the key
Hang up and Drive

I do have a question here though, but I understand it might be difficult to answer without being hands on with the truck. My TRX-6 weighs 12-13 pounds (don't fret, it's intentional), right now I'm running the 2800kv HH 540XL motor and the HH Trailmaster BLE (iirc) and a 9t Traxxas pinion. When I give it very little throttle the first time I power up the truck, it sounds like the motor might be struggling until I give it a quick punch. I can't seem to narrow down the issue.

Is this a result of not enough motor for my trucks weight? Is it just the nature of the rotor/stator in that specific motor? Or is it simply the TRX drive train was never meant to weigh so much and is struggling until the rotor is "located"?

If my chassis is just to heavy for the drivetrain to easily move, I'll just have to deal with it as is. It's going to be a trail truck/light duty crawler so perfect throttle resolution isn't to important




Sent from my LM-V600 using Tapatalk

[mikemcE]

Did you set a throttle curve with castle link? The BLE is a castle MMP, slight differences, but quite tunable with the link
I actually run an 11# wraith with the BLE and a 3500 PullerPro, no issues

Hang up and Drive

[smc-93]

Originally Posted by mikemcE

Did you set a throttle curve with castle link? The BLE is a castle MMP, slight differences, but quite tunable with the link
I actually run an 11# wraith with the BLE and a 3500 PullerPro, no issues

Hang up and Drive

I originally set up a custom throttle curve but after discovering the issue I set it back to linear. I figured the stock traxxas TX throttle resolution, combined with the weight of the truck, was just to low to effectively run the HH combo. I couldn't tell what the rest of my ESC settings are off the top of my head, I haven't messed with CL since the initial set-up.

Sent from my LM-V600 using Tapatalk

[SurlyBurly]

Originally Posted by mikemcE

Your numbers 380,540,550 relate to the physical can size. Then you can get into KV/turns.....
think of can size as the “block”
Small, big, ProMod. KV/turns are the HP / torque ratings .
If you go to Holmes Hobby site, he has a chart showing Kv/turns vs speed

Bigger rig needs more motor, weight is the key
Hang up and Drive

Thanks for that, its pretty much inline with my understanding thus far so if I'm following you correctly the "380" and "540" is not some unit of measurement or rating or anything, the only information the numbers convey is relative size and power to the arbitrary numbers used by other motors?