Have tech questions? Will answer.

[Benp]

I really like rc reviews servo test videos. I’ve learned a lot.

Here’s his video describing the actual servo tester that you see.


https://youtu.be/ONnbbiON610

[bexline]

Originally Posted by bexline

7.4lb Capra with 4ws and SuperShafty Axles
Crawlmaster 16t Pro
Mamba X
3s 50C
9T Pinion

Watched your video on setup.
Current Settings
Brake Amount 100%
Drag Brake 100% Crawler Full-On
Drag Brake Ramp Disabled (Intantaneous)

Brake will not hold the truck. It isn't any better than the HW1080 I just replaced.

I have an AXE 550 2700kv in a 9lb TRX and if the tires will stick, the brake will hold. Hoping for the same performance in the Capra.

Any suggestions? Appreciate it.

So, I put the 550 2700 Axe in the Capra so that solved the problem there. I moved the Mamba X and the Crawlmaster into my Trx and it holds it on all but the steepest hills. Even though it's a couple lbs heavier, I'm guessing it's the much lower transmission gearing in the Trx vs the relatively high transmission gearing in the Capra.

[ScaleLifeNewbie]

Originally Posted by JohnRobHolmes

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.

Hey John, I have a trx4 Bronco. The steering on it doesn’t turn right when on the ground. But when lifted up, it turns fine. Do I need a servo? If so, what’s the best servo that’s not a budget killer? TIA

[Voodoobrew]

If the servo isn't turning then you probably have a broken gear in the servo. If the servo turns but the wheels don't then check the linkage. The set screw on the servo horn can get loose and the teeth strip out. Tighten that up.

__________________________
Handy gearing spreadsheet

[Ninja77]

Question: Will the 0° timing mark need to shift if set up for CW if originally set up for CCW? This is for skewed slot motors only.
I found 2x different points of lowest amp draw when running my skewed motor in opposit directions, its about 10° difference

[King Dork]

Does anyone have an opinion on the following? I have 2 motors, a Holmes Puller Pro V2 Stubby 2200kv and a Holmes Revolver V2 (standard) 2200kv. One will find a home in my Capra, the other in a trail truck build. I totally understand one sensored, one sensorless. Just curious how these 2 compare torque-wise? Thanks gents.

[mikemcE]

The revolver is a incredible motor, vs my PullerPro’s. I have 2700stubby, regular and 3500regular. The 2200 revolver puts them to shame torque wise and creep ability. The pullers take a throttle curve for incredible speed with torque. The curve for revolvers makes it literally creep gear tooth by geartooth. Downside is the noise factor. On a crowded trail, the whiners do complain, I usually drive past or over them and stay ahead.


Hang up and Drive

[King Dork]

Thanks Mike! That’s what I was assuming but glad to get confirmation. Looks like the Revolver will end up in the Capra and the Puller Stubby is going in the Gmade.

[JohnRobHolmes]

Originally Posted by Ninja77

Question: Will the 0° timing mark need to shift if set up for CW if originally set up for CCW? This is for skewed slot motors only.
I found 2x different points of lowest amp draw when running my skewed motor in opposit directions, its about 10° difference

Technically it wont shift, but.... The brushes will shift a little bit from forwards to reverse and will cause the minimum point to change. A skewed arm doesn't have "virtual zero" at different points, its the same for both directions.

[King Dork]

My friend got a Crawlmaster Sport 550 8t motor and wanted me to install it in his rig. By hand I could not turn the motor shaft. I put a pinion on and could turn it by hand but with a ton of resistance (this is a brand new motor). I keep my old Ice charger around because it has a motor run in feature. Hooked the motor up and got an error reading as if one of the leads wasn’t hooked up which was not the case. Fast forward to today. He got another of the same motor, brand new as well. Same thing. Couldn’t turn the shaft by hand and barely with a pinion. Hooked it up to the Ice and got the same error reading and the motor did nothing. Took one of my Holmes motors and a Traxxas motor and hooked them up to see if the charger was defective. Both of these motors worked fine. Was there a issue with these motors? I know the 8 turn was just recently released so thought I’d ask if there was something going on with them that I haven’t heard. Thanks

[ScottyM]

Motor question here. I have a castle slate 3800kv combo on my TRX4. What determines motor speed on these? It says on the can it has a 100,000 RPM limit but data logging says it exceeds that using 3s(assuming the parameters are set correct for the motor type). For instance if I were to get a Holmes puller pro v2 which has an rpm limit of 50,000, would it exceeds that limit on the same 3s battery? Does the ESC have any limiting capabilities to keep it check?

I don't wanna void any warranty I have with my castle system!

[robert@castle]

Originally Posted by ScottyM

Motor question here. I have a castle slate 3800kv combo on my TRX4. What determines motor speed on these? It says on the can it has a 100,000 RPM limit but data logging says it exceeds that using 3s(assuming the parameters are set correct for the motor type). For instance if I were to get a Holmes puller pro v2 which has an rpm limit of 50,000, would it exceeds that limit on the same 3s battery? Does the ESC have any limiting capabilities to keep it check?

I don't wanna void any warranty I have with my castle system!

The RPM in the datalog assumes a 2 pole motor. Divide by 2 to get the actual RPM of a Castle motor.

The max unloaded RPM of a motor should be the KV * Number of Cells * Max charge per cell; so 3800kv * 3 cells * 4.2v/c = 47880 RPM.

[Fishcharger]

Yes!!! Now I’m not lying when I tell girls I use a Magnum;) That being said, generally I use the leads you guys solder on and connect them to the ESC via bullet connectors (in this case, HW1080). If I’m correct, really the best practice would be to solder the ESC leads direct to the motor right? In looking to really get a sense of how great this motor is, should I do as such, or being a layman is the difference negligible?



Sent from my iPhone using Tapatalk

[JohnRobHolmes]

negligible to direct solder in a crawler.


Thanks everyone for keeping this thread going. I'm back in a point where I can be hanging around again. Not down a few employees any longer.

[rag6]

Is the crawlmaster 550 15t too hot in a trx6 on 3s 2200 spektrum smart packs? I have 5000 50c packs, but really like the difference when running the small packs with the 21t trailmaster.

I can gear down to 9t pinion if need be

[stimpy]

Hi there John,

Have been looking at the SWM2 and wondered if it would be man enough to power a snub nose in a lightweight comp rig?

I had a thread about this a while back but no definitive, pmd Robert and he thought it may be possible but recommended asking if you had tried this combo and your thoughts?.

Thanks

[Voodoobrew]

Originally Posted by rag6

Is the crawlmaster 550 15t too hot in a trx6 on 3s 2200 spektrum smart packs? I have 5000 50c packs, but really like the difference when running the small packs with the 21t trailmaster.

I can gear down to 9t pinion if need be

It is unlikely you will see a temperature difference.

My guess is Technically the smaller pack probably has a lower C-rating which means there could be more voltage sag, lower voltage means you need more throttle to reach the same speeds, thus requiring more amp draw, this the possibility of higher temps. But really you would have to already be bushing the motor the its thermal limits for this to push you over. But I could be wrong.

[ScaleLifeNewbie]

Why does my Savox servo on my TRX4 only turn right and not left?

[ScaleLifeNewbie]

Originally Posted by ScaleLifeNewbie

Why does my Savox servo on my TRX4 only turn right and not left?

Originally Posted by JohnRobHolmes

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.

Why does my Savox Servo on my TRX4 turn right but not left?

[Voodoobrew]

Originally Posted by ScaleLifeNewbie

Why does my Savox servo on my TRX4 only turn right and not left?

Could be something in the servo gears, TX settings, binding on the links... Most like the servo is dead or needs new gears. Stock servos in crawling don't have servo savers so they take some heavy apuse that stock plastic traxxas gears can't withstand.

__________________________
Handy gearing spreadsheet