Have tech questions? Will answer.

[pmiller]

Originally Posted by HumboldtEF

When you hooked up the BEC did you disconnect the red wire on the ESC plug going to the ESC? You need to do this so you're not powering the ESC twice unless you use a bypass adapter (which routes the BEC power directly to the steering servo instead of going through the receiver). Heres a link to a bypass adapter for reference https://holmeshobbies.com/electronic...s-adapter.html


You also mention heat which could be an issue though it should take much longer top get so hot its an issue. How hot does it get, can you hold your finger on the motor and ESC without getting burned?

Thnx for your reply...

ESC RED WIRE:
Yes, I removed the red wire from the connector on the ESC cable.

REST OF WIRES (This is all steering so I don't know if it matters to my issue of freezing up & not moving):
On the rest of the wires I didn't have any Y-cables at the time, so I kind of ended up with a less than professional soldering job where I actually Y'd the BEC wires & servo wires onto the pins of the same single connector plugged into RX steering port. But I THINK the connections are working ok. And correct? Although it doesn't look exactly like the bypass adapter you linked (thnx btw). I have one side of BEC hooked to battery + & - . I have the other BEC BLACK wire Y'd into Servo BROWN, and BEC RED wire Y'd into Servo RED (both actually soldered into back of the RX steering connector as described above).

* Do I need to remove the red BEC wire from connecting to the RX steering port? (That appears to be what the adapter linked above does, right? That would leave just 1 wire from BEC connected to that RX port).

HEAT:
It has gotten to where about 5-10 mins is all I can drive without it "freezing up." The other day I had been driving off & on for probably 20+ mins, pushing thru the freeze ups. When I picked it up I noticed ESC didn't seem too warm but motor was very warm. I could put my finger on it but didn't leave it too long. I didn't think to hit it with the infrared thermo.

ADDITIONAL THOUGHTS:
The Losi design with the worm drive axles sure seems to put a good deal of strain on the motor. I have wondered if that combined with the added wheel weights is just too much for it?

Thnx for any help,
-Paul

[Voodoobrew]

Originally Posted by pmiller

Hey guys, newbie here. I know just enough to be dangerous. Need some help diagnosing what to repair on my Losi.

(I'm savy on general electrical. Have a real-life 67 Bronco crawler been driving for years. Have 2 younger boys with Baseltek / Monoprice crawlers, we just drive recreationally on our backyard rock pile & parks etc).

I picked up a used original Losi Nightcrawler a couple years ago, worked fine. Believe it to be all original. After a while, I added wheel weights, a ZTW 6A UBEC, & a steering servo (20kg red Amazon special, works great, love it). All that also worked great for several months.

BUT - I am recently having issues with it randomly not moving once I have been driving a few minutes. Seems to happen worse as it gets hotter (at least in my mind). Steering works fine. But it freezes or "hangs" and won't move forward/backward. Sometimes after a few seconds or working the throttle it will start going. But once it starts freezing up it doesn't go away, and seems to get worse & worse. I've had plenty of experience with bad electrical connections, & this seems more like a component failure.

** What does this sound like the problem is? And how can I test it?

(Does it sound like the motor (my guess)? Or the factory ESC? Or something about the UBEC I added?)

Thanks in advance!
-Paul

The motor brushes are probably worn out, if you can see springs on the back of the motor its rebuildable and can get brushes for a few dollars at a local hobby store. if you cant see springs buy a new motor, no springs is a less then 20$ motor. Unless its brushless, then IDK.

[Jboucher]

John are you going to revisit your hobbywing AXE video when the new 550 motors come out?

Just out of curiosity i want to see if they improved anything.

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[westerlycarrot9]

How do I choose an appropriate motor for a specific ESC? For example the Hobbywing 1080.

[durok]

Originally Posted by westerlycarrot9

How do I choose an appropriate motor for a specific ESC? For example the Hobbywing 1080.

Their specification sheet shows compatibility:

Brushed Motors
540/550/775 Series
2S LiPo or 6S NiMH: ≥10T or\RPM<3000@7.4V


3S LiPo or 9S NiMH: ≥16T or RPM<2000@7.4V

For general crawler use, what is very popular is the Holmes Hobbies Trailmaster Sport 550 21t, or get a 540 somewhere between 27t-35t.

[Jboucher]

Originally Posted by westerlycarrot9

How do I choose an appropriate motor for a specific ESC? For example the Hobbywing 1080.

All you need is a trailmaster sport 550 21T (fast) or 27T(slow).

Your wallet will thank us

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[mikemcE]

Originally Posted by westerlycarrot9

How do I choose an appropriate motor for a specific ESC? For example the Hobbywing 1080.

Best way is start at the Holmes homepage .
Scroll way down and find the motor recommendations link and that will show what motor you will want speed wise, Then match it by Holmes What they’ve recommended here earlier or what they sell as combos. I chose a 13t Crawlmaster on 3s. I was going to get a 1080 for this until I found a MMP at home, and it’s working fine.


Hang up and Drive

[westerlycarrot9]

I'm not sure if Holmes Hobbies products are available in EU. By the way is it better to use a brushless system on a scale crawler than a brushed one?

[HumboldtEF]

Crawlers are really the only RC's left that a brushed motor is still the best fit... but brushless has come a long way and its perfectly fine as well and requires less maintenance. But you might ask yourself if you want to go slow or fast, Brushed motors will chill you out while peppy brushless motors tend to goad you on to do a bit of bashing and to get silly now and then.

I prefer a slow crawl and go for brushed motors, my favorite being the Holmes crawlmaster 550.

And if you plan to get wet a brushed motor doesn't care about water while most all brushless motors need waterproofing. Brushed is much less expensive for the motors and ESC's.

[JohnRobHolmes]

Originally Posted by Jboucher

John are you going to revisit your hobbywing AXE video when the new 550 motors come out?

Just out of curiosity i want to see if they improved anything.

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maybe. I'm more interested in testing the latest firmware updates. judging by the weakness of the 540, the 550 will be equally gutless for the size of the motor. I'll throw it on the dyno if I do test.

Originally Posted by westerlycarrot9

How do I choose an appropriate motor for a specific ESC? For example the Hobbywing 1080.

Most important is to ensure you get the correct wheelspeed and stay within your budget. Pretty much anything for crawling will be compatible. See the previous posts for people's recommendations.

[JohnRobHolmes]

Originally Posted by pmiller

Thnx for your reply...

ESC RED WIRE:
Yes, I removed the red wire from the connector on the ESC cable.

REST OF WIRES (This is all steering so I don't know if it matters to my issue of freezing up & not moving):
On the rest of the wires I didn't have any Y-cables at the time, so I kind of ended up with a less than professional soldering job where I actually Y'd the BEC wires & servo wires onto the pins of the same single connector plugged into RX steering port. But I THINK the connections are working ok. And correct? Although it doesn't look exactly like the bypass adapter you linked (thnx btw). I have one side of BEC hooked to battery + & - . I have the other BEC BLACK wire Y'd into Servo BROWN, and BEC RED wire Y'd into Servo RED (both actually soldered into back of the RX steering connector as described above).

* Do I need to remove the red BEC wire from connecting to the RX steering port? (That appears to be what the adapter linked above does, right? That would leave just 1 wire from BEC connected to that RX port).

HEAT:
It has gotten to where about 5-10 mins is all I can drive without it "freezing up." The other day I had been driving off & on for probably 20+ mins, pushing thru the freeze ups. When I picked it up I noticed ESC didn't seem too warm but motor was very warm. I could put my finger on it but didn't leave it too long. I didn't think to hit it with the infrared thermo.

ADDITIONAL THOUGHTS:
The Losi design with the worm drive axles sure seems to put a good deal of strain on the motor. I have wondered if that combined with the added wheel weights is just too much for it?

Thnx for any help,
-Paul

If it's a rebuildable motor then it might just be the brushes hanging by the shunt. Otherwise, I can't actually guess as to the problem. Seems its not internal BEC browning out, which would be the other main cause.

[Voodoobrew]

Originally Posted by JohnRobHolmes

maybe. I'm more interested in testing the latest firmware updates. judging by the weakness of the 540, the 550 will be equally gutless for the size of the motor. I'll throw it on the dyno if I do test.







Most important is to ensure you get the correct wheelspeed and stay within your budget. Pretty much anything for crawling will be compatible. See the previous posts for people's recommendations.

Because the axe system has terrible acceleration and feels like it has more torque at low speeds because the esc applies more power, the dyno will show it in a very poor light since your dyno is based off acelleration alone.

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[Voodoobrew]

It you had a true Dyno that had a break it would be very interesting to see indeed. But this test would exploit the flaws of the motor as well as the dyno. I mean you get raw numbers and quantitative data but it can't measure the benefits that the axe was specifically designed for.

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[JohnRobHolmes]

Weak is weak. It has terrible acceleration because it has low torque. 100% throttle will be all the power it can give regardless of whether the throttle is velocity based or voltage based. If some internal throttle damping is occuring, using a heavier flywheel will get around it. Even the lightest flywheel accelerates slower than the axe can spool itself. A break or universal dyno would not give different information about the power curve, just more flexibility of testing range without reconfigure and less unaccounted for parameters.

[Voodoobrew]

I'm not saying it isn't weak, I definitely agree it is. But the idea behind the axe setup where it "appears to have more torque then it actually does" will only be visabe with a break. That whole applying more power when the motor meets resistance at x-rpm won't be viable on your dyno.

As weak (in actual torque) as it is imo It just feels like a high torque motor with shitty acceleration. This is all when at realy low rpm's. The motor dosent bog down as much as other motors.

I feel if you want it to bog down that's cool, to each their own. But i like to double down in my 1:1 toyota where it's geared so low it will just go when you hit the gas until something snaps. As the driver you feel the truck and the steering wheel to know when your loaded up. Same with my scale crawler, I don't want it to bog down on a rock, I watch the tires crush, suspension shift and steering tension to let me know when it's loaded up. At the low speeds I drive it has never failed me and left me with broken parts.

This is why I gear my rigs down to 100:1, taller gears bog down more, and with the axe I don't feel the need to gear down as low to avoid the bogging down and surging forward when the tires unload.

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[Jboucher]

When you buy an Mamba X, what other cables do you need that are not included?
There is the Bluetooth, the castle link, the quick connect, the sensor cable...

Good god make it 30$ more and include everything!

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[brimdogg]

Originally Posted by Jboucher

When you buy an Mamba X, what other cables do you need that are not included?
There is the Bluetooth, the castle link, the quick connect, the sensor cable...

Good god make it 30$ more and include everything!

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You get a coupon for a free Castle Link, and the sensor adapter comes with it.

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[JohnRobHolmes]

Would you agree that the axe attempts to hold constant speed equally under acceleration loads and deceleration loads? A dyno tests power, not throttle response, so it is assumed that the “feel” of a system is completely ignored from dyno information. . All that a dyno will show is that the input throttle is not proportional to output power with the axe. 50% throttle will have the same torque and power curve as 100% throttle, it will just truncate and roll off at 50% rpm. A typical system would have half the torque and 1/4 the power when tested at 50%. As long as a dummy isn’t trying to interpret the data it will be as applicable to the axe as any other system.


I don’t want my systems to be boggy, hence why I make nicer motors and live by “volt up gear down”. But I also don’t want my systems to be absolutely inelastic in rpm. I suppose the axes saving grace is that it’s too weak to break most rigs.

In an ideal world I would make the rpm lock controllable and programmable. Make it as soggy or stiff as you want. Put the choice back into the hands of the user.

[Jboucher]

Originally Posted by brimdogg

You get a coupon for a free Castle Link, and the sensor adapter comes with it.

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Ok so I need the quick access y-cable because opening the receiver box every time is dumb...

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[brimdogg]

Originally Posted by Jboucher

Ok so I need the quick access y-cable because opening the receiver box every time is dumb...

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Honestly I just use a regular y-cable for mine, it was way cheaper than the Castle cable.

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