RCCrawler Forums

RCCrawler Forums (http://www.rccrawler.com/forum/)
-   Electronics (http://www.rccrawler.com/forum/electronics/)
-   -   Have tech questions? Will answer. (http://www.rccrawler.com/forum/electronics/590281-have-tech-questions-will-answer.html)

JohnRobHolmes 10-04-2017 01:15 PM

Have tech questions? Will answer.
 
1 Attachment(s)
Post up electronics tech questions and I'll do my best to answer them until I burn out. It would be great to have some distractions from the circus of memes on facebook.



I'll start first. HOw are the electronics on the TRX-4?


answer: Servos are easy to burn out, steering servo is undersized for the weight, needs at least 300oz/in. ESC and motor are adequate, but don't have much control getting through a bind.

CREEPERBOB 10-04-2017 01:23 PM

Re: Have tech questions? Will answer.
 
Do I need a BEC? ;-)

Thanks for your dedication John "thumbsup".

Bob

JohnRobHolmes 10-04-2017 01:26 PM

Re: Have tech questions? Will answer.
 
If you are running anything except an SHV500 servo, yes you do :lol:


Just got v2 SHV which is 2s through 4s direct power compatible. Its super quick on 4s.

realsickclown 10-04-2017 02:00 PM

Re: Have tech questions? Will answer.
 
What is the best way to break in brushes that are NOT from HH? In a glass of water?? Do I just run the motor and then break it down and clean the can and armature?

JohnRobHolmes 10-04-2017 02:48 PM

Re: Have tech questions? Will answer.
 
If they are serrated face, 3 minutes at 3v and then spool it up once on pack voltage.

If they are curved face, same thing but keep checking the face every minute until broken in. If the curve is wrong it may take a little while.

If they are flat face and you don't have a brush shaper , go ahead and pull out the cup of water and be prepared to dry and reoil after.

Pushjerk 10-04-2017 03:31 PM

Re: Have tech questions? Will answer.
 
An old myth I have heard among flyers:

Running a brushless motor at partial or lower throttle is harder on the motor, making the esc/motor work harder and hotter, than higher or full throttle.

Example here, If I'm running my Puller Pro Standard 2700 KV at a little under 1/4 throttle for an extended time, it is harder on the motor than running it at higher throttle, around 50-60% for a while.

Any truth to this?

HumboldtEF 10-04-2017 03:44 PM

Re: Have tech questions? Will answer.
 
I've also heard that electric motors are happiest when they are spinning faster.


Quote:

Originally Posted by JohnRobHolmes (Post 5754104)
Just got v2 SHV which is 2s through 4s direct power compatible. Its super quick on 4s.

Very nice! Being able to get down to 2S is a nice feature ( I usually bring a 2S battery around for backup but I'm afraid to use it with the SHV500 V1 in my wraith)

What does it take to get the broader range in voltage?

JohnRobHolmes 10-04-2017 04:19 PM

Re: Have tech questions? Will answer.
 
Quote:

Originally Posted by Pushjerk (Post 5754137)
An old myth I have heard among flyers:

Running a brushless motor at partial or lower throttle is harder on the motor, making the esc/motor work harder and hotter, than higher or full throttle.

Example here, If I'm running my Puller Pro Standard 2700 KV at a little under 1/4 throttle for an extended time, it is harder on the motor than running it at higher throttle, around 50-60% for a while.

Any truth to this?

Motors like spinning faster for any given load, but it's not much issue to run motors at half throttle. The item that really hurts under part throttle is the esc unless it has synchronous rectification, which no car controllers use. Part throttle loads without SR utilize body diodes to deal with rectification, which makes a lot more heat than the FETs would.

Quote:

Originally Posted by HumboldtEF (Post 5754140)
I've also heard that electric motors are happiest when they are spinning faster.




Very nice! Being able to get down to 2S is a nice feature ( I usually bring a 2S battery around for backup but I'm afraid to use it with the SHV500 V1 in my wraith)

What does it take to get the broader range in voltage?

Just do it. It wasn't officially stated, but v1 handles 2s.

White cobra 10-04-2017 05:32 PM

Re: Have tech questions? Will answer.
 
http://www.rccrawler.com/forum/elect...nnections.html
I posted that thread and then found this 1 and thought as owner of HH, who better to ask questions!

Motorider 10-04-2017 07:24 PM

Re: Have tech questions? Will answer.
 
In the brushed world, where would the puller 400 compare to a brushless?

Sent from my SM-N920V using Tapatalk

Motorider 10-04-2017 07:36 PM

Re: Have tech questions? Will answer.
 
What is the difference between your waterproof version and regular puller pro? I bought this 3500 used and was told it's not the water proof version, but the sensor boards looked coated when I pulled it apart to silicon conformal coat them.

Sent from my SM-N920V using Tapatalk

realsickclown 10-05-2017 09:11 AM

Re: Have tech questions? Will answer.
 
2
Quote:

Originally Posted by JohnRobHolmes (Post 5754126)
If they are serrated face, 3 minutes at 3v and then spool it up once on pack voltage.

If they are curved face, same thing but keep checking the face every minute until broken in. If the curve is wrong it may take a little while.

If they are flat face and you don't have a brush shaper , go ahead and pull out the cup of water and be prepared to dry and reoil after.

Can I make a brush shaper or buy one for reasonably cheap? I'm looking now.

Edit: during the break in , the motor in or out? Is it best connected to the drive line or no?

Hardcoretam 10-06-2017 11:05 AM

Re: Have tech questions? Will answer.
 
Apart from the bearing on shaft output end of the motor, what are the differences between the Trailmaster Sport 550 motors and the Traxxas Titan 21t 550 motors?

JohnRobHolmes 10-06-2017 02:23 PM

Re: Have tech questions? Will answer.
 
Quote:

Originally Posted by Motorider (Post 5754177)
In the brushed world, where would the puller 400 compare to a brushless?

Sent from my SM-N920V using Tapatalk

There isn't anything very close that works. A little 2215 outrunner would be similar.

Quote:

Originally Posted by Motorider (Post 5754179)
What is the difference between your waterproof version and regular puller pro? I bought this 3500 used and was told it's not the water proof version, but the sensor boards looked coated when I pulled it apart to silicon conformal coat them.

Sent from my SM-N920V using Tapatalk

You may have gotten a freebie upgrade. The boardmaker puts a little bit of conformal, but we lay it on thicker in house.

Quote:

Originally Posted by realsickclown (Post 5754293)
2

Can I make a brush shaper or buy one for reasonably cheap? I'm looking now.

Edit: during the break in , the motor in or out? Is it best connected to the drive line or no?

No load for break in. In the vehicle with no pinion is fine.

This is what we use to shape brushes-

Fussy Brush Kit - Parts and Accessories - Motors

Quote:

Originally Posted by Hardcoretam (Post 5754674)
Apart from the bearing on shaft output end of the motor, what are the differences between the Trailmaster Sport 550 motors and the Traxxas Titan 21t 550 motors?

Much better magnets. The Trailmaster stalls less and handles more predictably in a bind.

karajabola 10-06-2017 03:44 PM

Have tech questions? Will answer.
 
Can the little 0.5A BEC on the TorqueMaster mini BR support a small light bar like this: https://www.horizonhobby.com/product...20-p-los230005

If not, how about the two BECs together with the Mini BR Dual?

(Iím using the Nightcrawler body for a MOA build )

Thanks!

Ascenderbender 10-06-2017 05:08 PM

Re: Have tech questions? Will answer.
 
What can you run 4s on in your puller brushless motor series?


Sent from my iPhone using Tapatalk

JohnRobHolmes 10-06-2017 10:43 PM

Re: Have tech questions? Will answer.
 
Quote:

Originally Posted by karajabola (Post 5754782)
Can the little 0.5A BEC on the TorqueMaster mini BR support a small light bar like this: https://www.horizonhobby.com/product...20-p-los230005

If not, how about the two BECs together with the Mini BR Dual?

(Iím using the Nightcrawler body for a MOA build )

Thanks!

Depends on a few too many factors to say outright, but... Two mini BRs going into an ESC would probably work since they are linear and won't fight as much. No problem on 2s. 3s may make the main regulator run warm or even hot. Wouldn't recommend 4s whilst powering leds.

Quote:

Originally Posted by Ascenderbender (Post 5754804)
What can you run 4s on in your puller brushless motor series?


Sent from my iPhone using Tapatalk

3500kv is awesome on it, racing or otherwise. 4500 hasn't been tested on the track running 4s, it would be pretty uncontrollable power though.

bilinvic 10-06-2017 11:48 PM

Re: Have tech questions? Will answer.
 
What's the improvements / differences on the v2 500 series servos vs. v1?

maverick67 10-07-2017 03:36 AM

Re: Have tech questions? Will answer.
 
Dear JRH:

For a scale crawling application, everything else being equal, which setup would give more torque?

1) Puller Pro 2200kv,

OR

2) Puller Pro 2700kv geared down to operate at approximately the same vehicle speed as the 2200kv.

Bulldog 10-07-2017 09:43 PM

Re: Have tech questions? Will answer.
 
JRH,

I usually gear down my drivetrain (axles, spur and pinion) for better torque and smooth startup. I always use a shallow throttle curve with high startup. Typically using puller pros and ble. I always get confused on KV though. Given the previous...what would be better for torque and slow crawling? 2200, 3500 or negligible difference? Would a 3500/2700 with throttle EPAs shortened feel the same as a 2200 wide open at startup? Thanks in advance."thumbsup"

Just reread Mav's post...kind of similar...edit: Does a throttle curve significantly change the amount of power or torque to a given KV motor?


All times are GMT -6. The time now is 04:35 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO ©2011, Crawlability, Inc.
Copyright 2004-2014 RCCrawler.com