Picking Yeti parts, please help and suggest

[Antsiranean]

Hi,

knowing nothing about RC:s and having good fun with an Arrma 2WD SCT, I have pondered and asked and now decided to get an Axial Yeti. Reasons to get the Yeti and not a Bomber or a Rock Rey are not completely rational, but boils down to the following:

1. I want a good all round vehicle, capable of high speeds, some jumping and easy crawling.
2. I love the looks of the Yeti
3. This forum rocks
4. I want a kit
5. I want large aftermarket support
6. I want 2 speed, because it's cool

In the end I want a vehicle that doesn't break all the time, since every breakage means waiting a week or two for parts, so I intend to build it sturdy from the start. Since I am in no hurry, I intend to buy all the pieces over a couple of months and then getting the actual kit in January, to celebrate that I will get a new job then. In addition, I live in Sweden, and as long as I keep the individual orders rather cheap and small size, some 50-80$, they tend to be ignored by customs. And that is a very good thing, since customs will add 30% to the price. In addition, ordering from Tower Hobbies I get 12$ off the next order over 50$, which works out at a saving of 20-25% if I order 50$ at a time. Complicated and time consuming I know, but quite fun.

If you live in the U.S., you're lucky. At least as far as ordering RC-parts go...

So, on my list of things to get is the following. Please have a look and tell me if I have made any mistakes, or should get anything more, anything less, or anything else. I will spend a lot of money on this baby, so all help is very, very much appreciated.

Motor and ESC, I intend to run it on 3S
Castle Creations Mamba X 25.2V WP ESC +1406-3800kV Comb, 193$
or
Tekin PRO4 Heavy-Duty Brushless 2-3S 3000kV Motor with a Castle Creations Mamba X Sensored 25.2V WP ESC, 145$ + 145$

Steering servo
Hitec HS-7955TG High Torque, 100$

Servo for 2-speed transmission
Suggestions, please, I just don't get this.

Aluminum parts from STRC. Is there any reason to go for Vanquish or SSD instead?
Steering bellcrank set, 42$, to tighten up steering a bit
Steering posts again for improved steering. The posts on my Arrma just broke.
Aluminum shock caps
Front skid plate, 18$, seems to be popular
Front caster block, 26$
Steering knuckles, 35$, almost a must if I've gotten it right

Axial aluminum parts (because these particular parts are cheap)
Machined Shock Mount Plates, 8$
Machined Adjustable Motor, 30$
Front Shock Tower, 9$
Servo horn 24T, 14$

Rear end stuff
MIP X-Duty Rear C-Drive Kit, 34$, seems a must have
SSD wide rear axle, 110$, one long piece has to be better than a couple of short ones.
SSD rear trailing arms, 35$, because as someone said, the rod ends defines a break point and they are cheap to replace. Therefore not Vanquish.
SSD Titanium rear upper links, 18$

Wheels and tires - please tell me if this is not OK, since I find this very confusing. Are the wheels and tires compatible?
Vanquish method 2.2 Race wheel (1.2" WIDE) 105, 120$, because they seem to be the best. Expensive though. Do you think ProLineDenali 2.2", 66$, will do?
Pro-Line BFGoodrich Baja T/A KR2 2.2" G8 Rock Terrain Truck Tires, 60$, As I said, I know nothing. At least they seem to fit on the wheels...
Deuce's wide single stage 2.2" tall foams, 24$, do they fit, or should I have the standard foams instead of the tall?

Gears, bits and pieces
Axial Heavy Duty bevel gears 38T/13T, 26$ (times two for front and rear)
SSD 2-speed transmission, 65$. For more power and control at low speeds.
KNK stainless steel screws, 25$

That's about it. Should I upgrade idler gears and pinions as well?
Robinson Racing X-Hard Idler Gear One-Piece 32P 15T | TowerHobbies.com
Robinson Racing X-Hard Diff Output Gear One-Piece 32P
Robinson Racing Gen3 Slipper Unit 56T Spur w/Ridged Hub

If I am right, all of the above should sum up to a very expensive, rock hard, do-it-all, killer Yeti. With some room to upgrade shocks later...

[magic_yeti]

Steering posts Not needed kit came with upgraded ones
Axial Heavy Duty bevel gears 38T/13T not needed incl. in kit version may consider a spool for the rear
The new kit version has now steel steering and chamber links so no upgrade needed

Aluminum shock caps no issues with the plastic ones
MIP X-Duty Rear C-Drive Kit the wb8hd are very reliable just order the plastic parts as spare

Steering ballcrank set may consider the adj. version from hot racing
Machined Shock Mount Plates Machined Adjustable Motor GPM makes some cheap alternatives (but don't use the screws of them)

That's about it. Should I upgrade idler gears and pinions as well?
only a spare metal spur maybe
but before test with cheap plastic ones which gearing you like put some pinions of different size for testing in your order
also some different springs and varies of shock / diff oil for setup as orientation here are many threads about setup in this section

As motor esc i would go today with the mamba x and 1410 3800kv 5mm sensored version
The yeti is too heavy for the 1406 just my opinion and i like my castle setup especially the aux function (rock racer / rock crawler mode)

U will need a radio with more channels th/st/2spd/aux so may consider to hack an gt3b/c gives u up to 8 channels
Don't forget hubs for the wheels

Also you can get a screw set here in 3 different versions (i use 12.8 harden steel torx) they add 50% more as listed in the manual so u have spare
The ssd parts you can order in europe within the eu for a good price
Lipo's you can order also for cheap in Europe
pm me for some links if u want saves shipping and customs

Have fun building and driving it.

[shiftauto]

Your off to an expensive heavy yeti build for sure. I personally don't like all the weight of the method wheels on the yeti but to each his own. I've had great success with the CI 6hole glue on wheels but am in the process of swapping them out for the newer VP SLW wheels. Less rotating mass than 105's. I'd actually recommend the MIP driveshaft over the WB8 also. Plenty of people do fine with the new WB8 but I torched a couple. Look forward to seeing a build thread on this rig in a few months

[Shinchu]

very good pointers from magic, he has helped me before also.

doesn't the kit come with the upgraded icons dampers? I would say no for shock caps also if that is the case.
my father in law has 1406 with sidewinder 3 and it moves very quick! faster than my RTR with stock vanguard stuff.
everyone swears by the mamba X though. I think its a better idea for just a bit more money.

also look into stonger front A arm hinge pins. there are tips here how to sleeve them. I thought mine are ok but pulled them out and looked like the stick from the movie WILLOW.

I laughed when you said you don't want something that will break often. this yet will attempt to DESTROY ITSELF every time you take it out hahaha but you will have a blast and gladly throw more money at it for fixing it. this is a rare thing that makes me smile when I buy parts.

very fun and its my first serious off-road rig also. now I am building a "go slow" rig and looking forward to not breaking stuff so much, but the yeti is still a blast!!!

[Antsiranean]

Originally Posted by magic_yeti

Axial Heavy Duty bevel gears 38T/13T not needed incl. in kit version may consider a spool for the rear
The new kit version has now steel steering and chamber links so no upgrade needed

So it does come with HD gears? On the homepage, it says it does, but in the manual an HD option part is suggested, one that has a different parts number from the one supposedly included. Confusing.

Originally Posted by magic_yeti

Steering ballcrank set may consider the adj. version from hot racing

I've seen it, but have no clue why I would choose one over the other. Anyone with experience with either one?

Originally Posted by magic_yeti

test with cheap plastic ones which gearing you like put some pinions of different size for testing in your order
also some different springs and varies of shock / diff oil for setup as orientation

Good idea, will do.

Originally Posted by magic_yeti

As motor esc i would go today with the mamba x and 1410 3800kv 5mm sensored version
The yeti is too heavy for the 1406

The 1410 has more torque than the 1406, right? If so, getting the 1410 would make sense I guess.

Originally Posted by magic_yeti

Don't forget hubs for the wheels8

I thought hubs were included?

Originally Posted by magic_yeti

Also you can get a screw set here in 3 different versions (i use 12.8 harden steel torx)

Where can I tet them?

Originally Posted by magic_yeti

The ssd parts you can order in europe within the eu for a good price

Where?

[Antsiranean]

Originally Posted by shiftauto

newer VP SLW wheels. Less rotating mass than 105's.

Makes sense, with less rotating mass. Very important on race bikes. I guess you mean these? I can wait for them, I'm in no hurry... What tires and foams will you run on them?

[shiftauto]

Yes, those are them. I'm running Crawler innovations deuces wild single stage foams with the Voodoo U4 tires. Totally forgot about the hinge pin upgrade shinchu mentioned. It's pretty important to do. I know the bomber kit comes with HD gears and didn't think the yeti kit did. It's fairly easy to tell by looking @ the cut of the gear. If they're straight they aren't HD, if they're helical they are the HD version

[mikemcE]

I'm still running the stock a arms , with the mod. Arms are beat up, but stay square, and work well for me.


Hang up and Drive

[magic_yeti]

the hr adjustable version why i choose it was for crawling you can lock the servo saver spring and for go fast you can enable it.

[Antsiranean]

Originally Posted by Shinchu

also look into stonger front A arm hinge pins. there are tips here how to sleeve them. I thought mine are ok but pulled them out and looked like the stick from the movie WILLOW.

Thanks for the reminder, I've seen this is a common problem. I've checked out and contacted Strong Arms for a set of hinge pin sleeves. No idea what they cost, but can't be very expensive I guess.

On the other hand, six Axial hinge pins costs 3$, so they are really cheap to replace. A bent, cheap hinge pin means power wasn't transferred anywhere else, which it would be with a strong, sleeved hinge pin. I need to think about this.

[mikemcE]

All you need is a 3/16th drill, 3/16 SS tube and a dremel. Bore out the arm and push in the tube. Cut to
length and deburr.
Cost me about $6.00 for the tube.



Hang up and Drive

[shiftauto]

Yep. It's a simple cheap mod and you won't have to replace them anymore. I thought the same thing about the $3 pins and then went through em on consecutive days. Save yourself the bs and do the mod yourself. Like mike said, you can do it with the stock arms and be fine. I chose to do the mod to the rpm arms

[mikemcE]

Originally Posted by shiftauto

Yep. It's a simple cheap mod and you won't have to replace them anymore. I thought the same thing about the $3 pins and then went through em on consecutive days. Save yourself the bs and do the mod yourself. Like mike said, you can do it with the stock arms and be fine. I chose to do the mod to the rpm arms

These are my original rtr arms, never needed to do my replacements. The RPM arms are stiffer

[DavidH]

Originally Posted by Antsiranean

Hi,

knowing nothing about RC:s and having good fun with an Arrma 2WD SCT, I have pondered and asked and now decided to get an Axial Yeti. Reasons to get the Yeti and not a Bomber or a Rock Rey are not completely rational, but boils down to the following:

1. I want a good all round vehicle, capable of high speeds, some jumping and easy crawling.
2. I love the looks of the Yeti
3. This forum rocks
4. I want a kit
5. I want large aftermarket support
6. I want 2 speed, because it's cool

In the end I want a vehicle that doesn't break all the time, since every breakage means waiting a week or two for parts, so I intend to build it sturdy from the start. Since I am in no hurry, I intend to buy all the pieces over a couple of months and then getting the actual kit in January, to celebrate that I will get a new job then. In addition, I live in Sweden, and as long as I keep the individual orders rather cheap and small size, some 50-80$, they tend to be ignored by customs. And that is a very good thing, since customs will add 30% to the price.

Hobby parts to Canada are duty free but if it is over a US$20 threshold, it can be hit with both a 12% sales tax charge and a $35 brokerage fee. That takes the shiny off of your new parts. :( Good reason to support the lhs.

In addition, ordering from Tower Hobbies I get 12$ off the next order over 50$, which works out at a saving of 20-25% if I order 50$ at a time. Complicated and time consuming I know, but quite fun.

If you live in the U.S., you're lucky. At least as far as ordering RC-parts go...

So, on my list of things to get is the following. Please have a look and tell me if I have made any mistakes, or should get anything more, anything less, or anything else. I will spend a lot of money on this baby, so all help is very, very much appreciated.

Motor and ESC, I intend to run it on 3S
Castle Creations Mamba X 25.2V WP ESC +1406-3800kV Comb, 193$

As much as I appreciate magic-yeti is using the 1410-3800kv motor, that the manufacturer rates it for 4 lb vehicles while the yeti is double that makes me hesitant.

or
Tekin PRO4 Heavy-Duty Brushless 2-3S 3000kV Motor with a Castle Creations Mamba X Sensored 25.2V WP ESC, 145$ + 145$

I just ordered the ROC412 HD 3100kv, for its low end control, vs the Pro4 HD rock racing bias. Depends how you intend to use it.

Steering servo
Hitec HS-7955TG High Torque, 100$

Here on the wet coast of Canada, everything gets wet. I won't buy another non-waterproof servo.

And I won't buy one that is not rated to run at (at least) 7.4 volts.

Switching servo
Suggestions, please, I just don't get this.

Dunno. Switching power supply, yes. Switching servo I am not familiar with.

Aluminum parts from STRC. Is there any reason to go for Vanquish or SSD instead?

My local store has both. Pick as appropriate.

Steering bellcrank set, 42$, to tighten up steering a bit

Put a 1/16" shim under the spring in the servo saver to tighten it up.

Spray the spring - and every other piece of exposed metal on the kit - with Corrosion-X before the rust sets in.

Steering posts again for improved steering. The posts on my Arrma just broke.

Steel posts included n the kit.

Aluminum shock caps
Front skid plate, 18$, seems to be popular
Front caster block, 26$
Steering knuckles, 35$, almost a must if I've gotten it right

Depends how you drive it. Mine are intact.

Axial aluminum parts (because these particular parts are cheap)
Machined Shock Mount Plates, 8$
Machined Adjustable Motor, 30$
Front Shock Tower, 9$

I wouldn't add this weight until I saw a need for it.

Servo horn 24T, 14$

The number of teeth depends on the servo.

Rear end stuff
MIP X-Duty Rear C-Drive Kit, 34$, seems a must have

Not a must have from what I have read. They are not without their own issues, and the factory one is very good.

There is also option the using T-Maxx parts to build a rugged drive shaft for less than $20.

SSD wide rear axle, 110$, one long piece has to be better than a couple of short ones.

I stayed with the factory axle, as I intended (and did) add rear-steer to my yeti. That may not appeal to you.

If I'm not mistaken, with that axle in the yeti you'll need to install the front differential flipped left-to-right and the driveline reversed from the kit directions.

SSD rear trailing arms, 35$, because as someone said, the rod ends defines a break point and they are cheap to replace. Therefore not Vanquish.
SSD Titanium rear upper links, 18$

Your kit will include lower control arm reinforcement plates. This should do you for a while.

Wheels and tires - please tell me if this is not OK, since I find this very confusing. Are the wheels and tires compatible?
Vanquish method 2.2 Race wheel (1.2" WIDE) 105, 120$, because they seem to be the best. Expensive though. Do you think ProLineDenali 2.2", 66$, will do?
Pro-Line BFGoodrich Baja T/A KR2 2.2" G8 Rock Terrain Truck Tires, 60$, As I said, I know nothing. At least they seem to fit on the wheels...
Deuce's wide single stage 2.2" tall foams, 24$, do they fit, or should I have the standard foams instead of the tall?

Depends on how you use them. The standard factory foams are pretty useless at anything resembling speed.

I put 1.9" proline dual stage foams in my kit tires since it was a better fit for how I used them (a bit of crawling). For speed I have some 2.8" wheels and tires.

Gears, bits and pieces
Axial Heavy Duty bevel gears 38T/13T, 26$ (times two for front and rear)

In the kit.

SSD 2-speed transmission, 65$. For more power and control at low speeds.

I believe the SSD kit may need some parts the axial kit includes. I used the axial kit as it was stocked locally.

You'll need a servo saver (in the axial kit), a >80 oz-in digital servo, and a extra channel on the radio.

KNK stainless steel screws, 25$

That's the best kit from what I have read, but you need to be careful of the softer metal, that the screw heads will be easier to strip. Expensive to ship cuz of the weight. Still tempting though.

That's about it. Should I upgrade idler gears and pinions as well?
Robinson Racing X-Hard Idler Gear One-Piece 32P 15T | TowerHobbies.com
Robinson Racing X-Hard Diff Output Gear One-Piece 32P
Robinson Racing Gen3 Slipper Unit 56T Spur w/Ridged Hub

Not until they give you trouble.

If I am right, all of the above should sum up to a very expensive, rock hard, do-it-all, killer Yeti. With some room to upgrade shocks later...

There are upgrade parts for factory shocks, rebuild parts, etc. The proline powerstroke shocks, meant for lighter short course trucks, seem to sag under the weight of the yeti.

Looks like it'll be a fun truck. Take it slow, don't be afraid to ask questions.

[DavidH]

Originally Posted by Antsiranean

Thanks for the reminder, I've seen this is a common problem. I've checked out and contacted Strong Arms for a set of hinge pin sleeves. No idea what they cost, but can't be very expensive I guess.

On the other hand, six Axial hinge pins costs 3$, so they are really cheap to replace. A bent, cheap hinge pin means power wasn't transferred anywhere else, which it would be with a strong, sleeved hinge pin. I need to think about this.

Sleeved the factory arms on my kit for $2. You still have the flex of the arm to ease the stress on the other components.


Cuts easily with a typical pipe cutter, and press into place once you have drilled out the arms. A countersink bit cleans up the ends.

[Antsiranean]

That sleeve fix seems a breeze, thanks for all the pics. I'll definitively do it myself. Including shipping it would cost some 60$ from StrongArms.

Originally Posted by DavidH

As much as I appreciate magic-yeti is using the 1410-3800kv motor, that the manufacturer rates it for 4 lb vehicles while the yeti is double that makes me hesitant. I just ordered the ROC412 HD 3100kv, for its low end control, vs the Pro4 HD rock racing bias. Depends how you intend to use it.

I too have been thinking about the CS ratings, and that's why I consider the mor expensive Tekin. Looking at some of your videos, it seems as terrain around where you live in New England is pretty similar to my place in Sweden. As much as I would like a top speed of 35-40 mph, I don't think I'll find the space to run it faster than 30 mph. Do you have any idea of what top speed could be expected of a ROC412 HD 3100kv on 3S, or how to calculate it?

Originally Posted by DavidH

Here on the wet coast of Canada, everything gets wet. I won't buy another non-waterproof servo.

I thought the Hitec HS-7955TG was waterproof, but see that I was mistaken. It says "Splash proof" on the manufacturers homepage. Since I don't intend to submerge my car, that might do? Otherwise the Xpert 7000 Series Mega Torque might be an alternative? What do you think of that one? 380 oz-in @ 7,4V; 0,158sec/60 @ 7,4 volts.

Originally Posted by DavidH

And I won't buy one that is not rated to run at (at least) 7.4 volts.

This I do not understand, please explain. I guess you are right and therefore put either the Xpert or the Hitec 7954SH in the list instead of the 7955TG

Originally Posted by DavidH

Dunno. Switching power supply, yes. Switching servo I am not familiar with.

I was unclear. I mean a servo for the gearbox. I'll edit that in the first post.

Originally Posted by DavidH

Steel posts included n the kit. [...] In the kit.

So, if two people say that the kit includes the Heavy Duty 38/13 Bevel gears, I guess it's gotta be true. But then the manual is wrong. Saves me 50$, great!

Originally Posted by DavidH

I believe the SSD kit may need some parts the axial kit includes. I used the axial kit as it was stocked locally.

You'll need a servo saver (in the axial kit), a >80 oz-in digital servo, and a extra channel on the radio.

If that is so, I'll go Axial. Doesn't seem to be any noticeable quality difference anyway. Suggestions for a servo are most welcome. It's a jungle out there.

Originally Posted by DavidH

That's the best kit from what I have read, but you need to be careful of the softer metal, that the screw heads will be easier to strip. Expensive to ship cuz of the weight. Still tempting though.

Magic-Yeti suggested these from a german company. Includes 40-50% more screws than needed and has the option of torx heads. Seems nice. I'll get the torx version for 46€, shipping 7.50€. Not too bad.

[magic_yeti]

the mamba x can be setup to 7.4 V, but this also goes than through your receiver and the 6ch for the gt3b is only rated upto 6V. Check this in advanced otherwise you need a bec for the servo. I'm very happy with the savöx 1210SG on 6V and this is the only really from manufacturer rated as IP67 servo i found (all others just say waterproof), maybe it could be a little stronger but sofar i didn't miss more torque). Other option shv500 waterproof direct from the 3s lipo powered or as discussed in the electronic section the pro modeler but getting it in/to europe
Also which is the weight measure for the tekin roc412hd can't find info on their website also a nice option. would be interesting cause the other sepc. are very similar except the kv. nothing against tekin just interest. also i like the HH 3500kv puller pro XL in combo with the mamba x would be also nice.

i use a savöx0231 for shifting way over powered but fast strong and IP67 and most important with correct endpoints it shifts smoooooth.

regarding speed it depends what gearing the motor can handle.
i liked 64/19 with the 3800kv which gives the max speed my little monster can handle on my go fast surface wide open grass if our local farmer cuts it also in just a few seconds it's a little point on the horizon in this combo. after killing my plastic spur i chanced to 56/16 which is similar cause i also switch the gearing for 2. gear to the high speed option. no temp issues with up to 36°C outside temp even with >5kg weight (using fans on both esc and motor)

trail crawl in testing but for this still with same gearing but i think i will go down to 56/14 to see what change it will do. maybe also sometime 56/19 but not for crawling

the torx version of the screw kit that i mentioned are 12.8 grad hardened steel i don't know stronger screws in this size

[Antsiranean]

Thanks for pointing me towards the Savox servos, I checked the specs on the 1210SG and it seems indeed to fit the bill, rated for 7,4V too. And the bill is a bit smaller than for the Hitec 7954SH as well.

I have a FlySky GT3B for my Arrma, and since I am happy with it I intend to get one for the Yeti too. Had no idea I would need a BEC to run 7,4v, so good that you pointed that out. But if the receiver of the FlySky only is rated at 6,0V, I guess that means can only run the servos at 6,0V, even if I have a BEC? Or do I put the BEC, like this one, between the receiver and the steering servo to raise the voltage from 6,0 to 7,4?

Or do I need a receiver that can handle 7,4V, like the Futaba R203GF 3-Channel, and then skip the BEC? I guess I can bind any receiver to my FlySky radio?

I've never understood electronics and would hate to fry something on the first run, so please help me get this right. Do both of the following alternatives work, or none of them?

Alternative 1:
steering servo rated at 7,4V
receiver max output voltage 6,0V
BEC (between receiver and servo to up the voltage from 6,0 to 7,4?)

Alternative 2:
steering servo rated at 7,4V (Savox 1210SG)
receiver max output voltage 7,4V (Futuba R203GF)

As far as motors go, after looking around I think I'll settle for the Tekin Pro4 HD. It's getting late so I actually can't really remember the arguments I picked up in a couple of forum threads, but the Pro4 fit the bill. Anyway, doesn't seem to be much difference between that one and the ROC412 and price is the same.

Also, I looked into top speeds and the RC calculator. 3000 or 3100kV on 3S should make me happy, theoretical top speed 43,7 mph with 4" tire diameter. In fact, I will have to get myself a 12T pinion not to make it kill cats and small dogs. And yes, the manual is clear on that HD bevel gears are in the kit. My mistake, please excuse me for any confusion caused.

Edit: got it wrong. Theoretical top speed 25mph on 3S and 16/64. Not very exciting. 17/56 should push it to 31 mph. I guess I just have to get some alternatives and try it out for myself eventually.

[DavidH]

Originally Posted by Antsiranean

I too have been thinking about the CS ratings, and that's why I consider the mor expensive Tekin. Looking at some of your videos, it seems as terrain around where you live in New England is pretty similar to my place in Sweden.

British Columbia, actually . The local crawling spot has lots of challenging terrain, and trails go out into the surrounding forest.

As much as I would like a top speed of 35-40 mph, I don't think I'll find the space to run it faster than 30 mph. Do you have any idea of what top speed could be expected of a ROC412 HD 3100kv on 3S, or how to calculate it?

You could use the kv rating times the battery voltage and the transmission and bevel gear ratio to calculate it (taking into account the overdrive gearing added by the 2-speed upgrade), but math hurts my head.

I expect the Tekin 3100kv motor to give me the similar wheelspeed as the factory motor. As pictured here, on 5" tall Super Swampers, with the factory 3150kv motor, I measured 53 km/h on the GPS in my phone in high gear with the factory 16/64 gearing. These tires are on 2.8" wheels and use closed cell foams, so they are more for speed, handling and bashing and some trail use than crawling.



For me the yeti is about versatility. There are better choices for speed and handling, or for crawling, but few that can cross purposes.

The 3800kv motor may work for flat out speeds on flat ground, but in talking to someone outside these forums yesterday, she said that her yeti just "melted" a castle 3800 on 3s.

4s + an 8th scale/kv motor sounds like fun, but I don't want to be one of those complaining that Axial only put a tenth scale driveline and axles in their tenth scale truck.

I do expect that the Mamba esc and the Tekin motor will be more versatile than the factory combo, able to handle the heat of being geared up a bit, for a bit more wheel speed, while the sensored operation will reduced the cogging down low (especially with the 2-speed). We'll see.

I thought the [URL="http://hitecrcd.com/products/servos/ultra-premium-digital-servos/hs-7955tg-high-torque-titanium-gear-coreless-servo/product"]Hitec HS-7955TG[/URL ] was waterproof, but see that I was mistaken. It says "Splash proof" on the manufacturers homepage. Since I don't intend to submerge my car, that might do?

I have found that bashing in wet snow is almost as bad as submersion. I lost a "splash resistant" servo this last winter. Even with an internal "snow guard" the snow gets packed it.

Otherwise the Xpert 7000 Series Mega Torque might be an alternative? What do you think of that one? 380 oz-in @ 7,4V; 0,158sec/60 @ 7,4 volts.

Looks good. The Savox is stocked locally for me. Speed(@7.4V sec/60): .13, Torque(@7.4V oz-in): 319.4

This I do not understand, please explain.

Bumping up the voltage for the bec gets the more speed and power out of the servos, and I don't want to have to have a separate circuit for the lower voltage stuff.

I guess you are right and therefore put either the Xpert or the Hitec 7954SH in the list instead of the 7955TG

I was unclear. I mean a servo for the gearbox. I'll edit that in the first post.


So, if two people say that the kit includes the Heavy Duty 38/13 Bevel gears, I guess it's gotta be true. But then the manual is wrong. Saves me 50$, great!

The PDF of kit manual I am looking at says AX30395.

Axial Racing - Heavy Duty Bevel Gear Set - 38T/13T

If that is so, I'll go Axial. Doesn't seem to be any noticeable quality difference anyway. Suggestions for a servo are most welcome. It's a jungle out there.

I use a Traxxas 2075 because its happy with 7.4v, its quick, powerful enough, waterproof, can be found for CAN$22, and the potato-chip gears won't be a problem in this application.

Magic-Yeti suggested these from a german company. Includes 40-50% more screws than needed and has the option of torx heads. Seems nice. I'll get the torx version for 46€, shipping 7.50€. Not too bad.

I'd be cautious about mixing hex and torx on the same truck. You might accidentally strip something and be kicking yourself as you are digging the screw out of your truck.

Whatever you do, make sure you coat every factory metal bit in Fluid Film or Corrosion-X, before the rust sets in. That was one of my biggest disappointments with the axial product. Looks like crap.

[DavidH]

Originally Posted by Antsiranean

Thanks for pointing me towards the Savox servos, I checked the specs on the 1210SG and it seems indeed to fit the bill, rated for 7,4V too. And the bill is a bit smaller than for the Hitec 7954SH as well.

I have a FlySky GT3B for my Arrma, and since I am happy with it I intend to get one for the Yeti too. Had no idea I would need a BEC to run 7,4v, so good that you pointed that out. But if the receiver of the FlySky only is rated at 6,0V, I guess that means can only run the servos at 6,0V, even if I have a BEC? Or do I put the BEC, like this one, between the receiver and the steering servo to raise the voltage from 6,0 to 7,4?

To be clear, there is a BEC in in the ESC, and there are external BECs; I use an external Castle 10A BEC (to get to 7.4v) that will be removed when the Mamba ESC is installed. The Mamba will do what that external bec can do (up to 8A).

Or do I need a receiver that can handle 7,4V, like the Futaba R203GF 3-Channel, and then skip the BEC? I guess I can bind any receiver to my FlySky radio?

I've never understood electronics and would hate to fry something on the first run, so please help me get this right. Do both of the following alternatives work, or none of them?

Alternative 1:
steering servo rated at 7,4V
receiver max output voltage 6,0V
BEC (between receiver and servo to up the voltage from 6,0 to 7,4?)

Alternative 2:
steering servo rated at 7,4V (Savox 1210SG)
receiver max output voltage 7,4V (Futuba R203GF)

this is simply a matter of figuring out the wired diagram for what you want. But, getting everything compatible with 7.4 makes it far simpler.

Futaba would be my first choice, but I found a used Spektrum DX4C; the two extra channels for shifting and rear-steer, and the rx is fine with 7.4v.

As far as motors go, after looking around I think I'll settle for the Tekin Pro4 HD. It's getting late so I actually can't really remember the arguments I picked up in a couple of forum threads, but the Pro4 fit the bill. Anyway, doesn't seem to be much difference between that one and the ROC412 and price is the same.

Also, I looked into top speeds and the RC calculator. 3000 or 3100kV on 3S should make me happy. And yes, the manual is clear on that HD bevel gears are in the kit. My mistake, please excuse me for any confusion caused.

While similar in power output, the pro4 is biased for racing, the ROC412 for low speed control.