Snowman (the Abominable) - born as a beast, Yeti build thread

[TAT76]

I've been thinking about building a yeti and your build is giving me the itch. Keep it coming.

 

[Antsiranean]

Very slow progress. I got the RPM A-arms on, as well as the steering linkage. Here are some pics, just to keep it itching.

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[Antsiranean]

I've spent the evening soldering (first time in 25 years!) and trying to get the wiring right, but I just can't figure it all out. This is what I've got:

ESC (Mamba X)
BEC
Rx bypass adapter
Y-harness with servo reverser
Steering servo
Servo for gearbox

BEC goes into the Rx bypass adapter, which in turn is connected to the steering servo and the receiver, right? And then I use Castle link via the ESC to set the BEC output voltage, right again? Do I need to have a battery connected to program the ESC and BEC?

The Y harness has two female contacts, I guess the Aux wire goes into one and the gearbox servo goes into the other? The male then goes into Rx channel 3? I then use Castle link to set the the aux wire to switch between rock racer and crawler mode as I change between second and first gear. Should the servo be reversed, so that crawler mode is enabled in high gear, I just switch places of the aux-wire and servo contacts going into the Y harness/servo reverser?

Bypass adapter from steering servo then goes into rx channel 1?
Brown-red-yellow wire from ESC goes into rx channel 2?
Wire from Y-harness goes into rx channel 3?
One slot (top one, called VCC) on rx is left empty?

Please give me a helping hand, I feel rather lost.

On the slightly more practical side, where to stuff away all those wires? And where to put the on/off-switch?

 

[DavidH]

I've spent the evening soldering (first time in 25 years!) and trying to get the wiring right, but I just can't figure it all out. This is what I've got:

ESC (Mamba X)
BEC
Rx bypass adapter
Y-harness with servo reverser
Steering servo
Servo for gearbox

BEC goes into the Rx bypass adapter, which in turn is connected to the steering servo and the receiver, right?

I've not seen the pinout on this adapter, but that sounds right.

And then I use Castle link via the ESC to set the BEC output voltage, right again? Do I need to have a battery connected to program the ESC and BEC?

You don't need the battery connected for programming of the esc or bec.

The Y harness has two female contacts, I guess the Aux wire goes into one and the gearbox servo goes into the other? The male then goes into Rx channel 3?

Sounds right.

I then use Castle link to set the the aux wire to switch between rock racer and crawler mode as I change between second and first gear.

You would have already done this previously when you set the mamba's bec voltage, updated the firmware (if required), and set the aux wire for the rock racer/crawler mode switch.

Should the servo be reversed, so that crawler mode is enabled in high gear, I just switch places of the aux-wire and servo contacts going into the Y harness/servo reverser?

No, you connect the esc to the rx, then set the endpoints to engage/disengage the rock race/crawler mode to your liking, reversing the servo direction at the tx to get the switch working in the direction you want (up for high gear, down for low?) and then connect the servo using the (reversing) y-harness.... then if the servo does not move in the 'right' direction to engage the hi/lo gear to match the esc you then remove the (reversing) y-harness and put in a 'plain' y-harness.

Lastly, you install the servo horn and linkage to the 2-speed, so that the shift lever moves to fully engage the gears but is not stressed at the endpoints.

Bypass adapter from steering servo then goes into rx channel 1?

I'd need to see the pinout on the connectors.

Brown-red-yellow wire from ESC goes into rx channel 2?

yes.

Wire from Y-harness goes into rx channel 3?

yes.

One slot (top one, called VCC) on rx is left empty?

yes.

Please give me a helping hand, I feel rather lost.

On the slightly more practical side, where to stuff away all those wires? And where to put the on/off-switch?

I managed to get rx and castle bec and the spare wire into the fuel cell. I had to cut a larger horizontal slot to accommodate the wires and add some weatherstripping to keep the crap out.

I have a waterproof rx and I made the castle bec waterproof myself.

 

[DavidH]

...

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Did you add a spacer under the spring?

 

[magic_yeti]

for the on/off switch is a holder on the back of the chassis, beside the upper link mounts.
i put all extra electronic in the fuel cell, as davidh mentioned. very crowdy in there.

BEC goes into the Rx bypass adapter, which in turn is connected to the steering servo and the receiver, right?
The Y harness has two female contacts, I guess the Aux wire goes into one and the gearbox servo goes into the other? The male then goes into Rx channel 3?
Bypass adapter from steering servo then goes into rx channel 1?
Brown-red-yellow wire from ESC goes into rx channel 2?
Wire from Y-harness goes into rx channel 3?
One slot (top one, called VCC) on rx is left empty?

correct "thumbsup"

Do I need to have a battery connected to program the ESC and BEC?

no is powered by the usb port over castle link

you never forget how to solder if you have learned it once, like riding a bike:mrgreen:

 

[DavidH]

...
you never forget how to solder if you have learned it once, like riding a bike:mrgreen:

I don't recall burning myself so often when riding my bike.

 

[Antsiranean]

Thanks a lot for helping me get this sorted! Seems as if I knew what to do (or rather just made some good guesses) , but didn't know that I knew, and then it's no real use knowing anyway.

Here's the Rx bypass and planned wiring to and from it.

I'll leave the BEC outside the rx-box and waterproof it by squirting some silicone into it. That ought to make it at the very least splash proof and that should be enough. I plan to drive Snowman as a car, not a submarine.

 

[magic_yeti]

be carefully with silicon and electronics, if not special for electronics some silicon can destroy your electronics. your wiring is correct "thumbsup" in the pic.
i use balistol seal spray (liquid PVC) from hornbach (german homedepot) and plastidip (liquid rubber) to waterproof.

 

[Antsiranean]

Didn't know silicone can destroy electronics. I'll go hunting for liquid PVC instead. Or just use a balloon.

 

[Nastyman211]

Put a couple coats of this on and you’re good to go man.

Cheers!!
NastyMan


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[DavidH]

Thanks a lot for helping me get this sorted! Seems as if I knew what to do (or rather just made some good guesses) , but didn't know that I knew, and then it's no real use knowing anyway.

Here's the Rx bypass and planned wiring to and from it.

Looks good. Use it as you have it labeled.

I'll leave the BEC outside the rx-box and waterproof it by squirting some silicone into it. That ought to make it at the very least splash proof and that should be enough. I plan to drive Snowman as a car, not a submarine.

I never fully submerse my cars but I find that snow can be just as bad, the way the snow clings to the relatively warm electronics, and the water still gets in there.

Back in the 80s I learned that silicone rubber is not a great water-proofing substance. While it does block liquid water, it can pass water vapour, and can be acidic; back when we needed big antennas on the (real 1:1) cars and truck radios, it was found that the metal would rust around and under the silicone rubber sealant.

Link

What you want to apply to the electronics is a conformal coating, such as this:

https://www.rpelectronics.com/422b-55ml-silicone-conformal-coating-liquid-55ml.html

I've also used a squirt of Fluid Film inside of a bec or servo, then sealed the seams with liquid tape, or larger openings with Goop. I would not rely on plasti dip or liquid tape by itself, as I consider it to be fragile. Goop is removable if one is careful, unlike silicone rubber.

 

[Antsiranean]

Another night spent soldering and trying to get a semblance of order among all the wires. In the end I think it turned out alright. I led all the wires under the receiver to the back right hand corner of the chassis, and then used a fair amount of heat shrink tubing to bundle up excess lengths of wire. The switch was just taped to the side of the ESC.

And with all that done, I just found out that my FlySky tx didn't come with a battery, so I'll have to order one in order to try it all out. Frustrating. Certainly lots of things ordered to get this beast running.

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[magic_yeti]

the gt3b tx uses normal batteries you can get in normal stores. but could be upgraded with a 3s lipo with some soldering:mrgreen: i use a zippy compact 1500mAh 3s 25c from Hobbyking. fits perfectly if the battery tray is removed.

 

[Antsiranean]

It's a GT3C, not a B, and that one needs a specific 800 mAh LiPo battery. Well, there are things to build while waiting, so it won't really delay finishing.

 

[magic_yeti]

It's a GT3C, not a B, and that one needs a specific 800 mAh LiPo battery. Well, there are things to build while waiting, so it won't really delay finishing.

yes the c uses a lipo, but it should be included if you purchase it. I would email the vendor why it was not incl. in your package.
Nice and clean wiring, reminds me that my wiring is still test mode and has to be cleaned up. right now it's a mess.

 

[Antsiranean]

Glad you like my wiring, all the more reason to be satisfied myself. Concerning the battery I mailed the vendor yesterday, so I hope it will be sorted.

 

[Antsiranean]

The roof is ready, with a portrait of the Abominable Snowman himself.

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[Antsiranean]

9And now I've run into a most unexpected problem. In the kit there was two left side 4 link mounts, and no right side one. Annoying. Both were lying loose in their plastic bag. I have written Axial and hope they'll send me a new parts tree. Or a pair of machined mounts.

What's the word on Axial customer support?

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[magic_yeti]

If they don't set you up i can send you my one, but will take till next weekend, if've changed to gpm alloy ones.
https://www.asiatees.com/display?Axial-Yeti-Parts-Hop-Ups&brand=Axial&model=Yeti&id=103331
they also came in blue 8)