Savage XL-E

[Janezki]

Short introduction to my brushless Savage XL, if you have questions don't hesitate to ask.

motor: Feigao 540XL10 in TeknoRC motor mount
esc: LT-6S-150A (by lutach)
batteries: 2x3S Zippy 5000mAh in series

Total weight for the truck in driving conditions is 6.28kg (13.85lb).

Transmission locked to 2nd and using 47t spur, 16t pinion. Selfmade battery trays (from freezing bottles, aluminium angle and epoxy), bolted to TVP's.
Ofna T/E-Maxx 17mm hex adapters (had them lying around for a while with no use), modified to fit Savage axle.

Otherwise the truck is stock - atleast for the time being...

Short video on snow can be seen here.





More pictures of the project can be found from here.

[rhylsadar]

hi

i like this conversion. its simple and functional. locking the tranny is imo the way to go. nice work!
pay attention to the lipos in very low temperatures. did you warm them before using?
maybe you can use the battery holders of the flux when it comes out to make it look a bit more "factory style". i always used aluminium U-profiles for the battery holders.

bye
rhylsadar

Like ^ says; Simple and Functional!

Nice truck, and I like that snow over there.. =)

[Janezki]

Thanks.
Actually I didn't warm lipos in any way, just very slow driving for about 10 minutes, then the rest was a little over half throttle max. They seemed to warm in use a bit, just to melt the snow slightly - didn't feel warm to hand though.
Temperature was around -4 degrees Celsius.

I have noted the Flux battery trays and am planning to get them as soon as they became available.

[Savage03]

Thats awesome! Got a few questions if you dont mind. I am converting mine right now just waiting for castle to ship the combos. How is your drivetrain holding up and gears? Was locking into 2nd difficult? also are you using stock brakes or when you locked it can you have reverse?
Thanks!

[MTBikerTim]

I'm curious about your motor mount. Did you have to do anything special to use the tekno motor mount?

[BL_RV0]

Very very nice truck. Finland is purrty....

[Janezki]

* Added some detailed pictures to project pics.

Savage03: After the somewhat total destruction on test drive #2 on 3 speed (which lasted about 30 secs and trashed idler & main gear), I locked the transmission to second with super epoxy. Also, all the unused gears and excessive sideplay from the remaining ones was removed, so I suppose it'll hold up now...
Using motor brake and have reverse now.

pic of the mishap:



here's the current state of the tranny (that's not water, it's grease):



locked gear:



47t spur gives plenty of gearing options, with the stock spur I could fit only 15t pinion max.





MTBikerTim: No special tricks, I just drilled few 4mm holes to the original motor plate and widened them so I can adjust the mesh.
I'm using only two screws to hold that mount on it's place, mainly because the center rear driveshaft and the openings at the motor plate came into way.

BL_RV0: Thanks. Beautiful but COLD, if I may say...

[Savage03]

wow cracked that gear didnt it. Guess while im waiting for the monster max to ship I could lock the gear, like the idea of reverse.
No ones answered in my thread on this but which pinions do I use mod1? or im guessing these 32 pitch, dang spendy pinions to.
Thanks for the reply and pics.

[Janezki]

Cracked idler and two teeth missing from the main gear :(
Mod1 pinions are the way to go.

Speedwise, how is electric compared to nitro?

[Savage03]

Got my 3 speed cluster out and wondering did you use something specific for the spacers?

[Janezki]

clowkoy: I'm not the speed freak, but I think the truck should go just fine and accelerate faster than nitro version.
Should - because there will be snow and ice in here for atleast next three months, so not much grip available for serious testing...

Anyways, this is what I got from the top speed estimator:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.8894009216589862
Other Ratio: 1
Spur Tooth Count: 47
Pinion Tooth Count: 16
Total Voltage: 22.2
Motor KV: 1668
Tire Diameter (inches): 6.69
Tire Ballooning (inches): 1
Motor Current Draw: 66
Motor coil Ω: 0.0114
Spur/Pinion Ratio: 2.94 : 1
Total Ratio: 18.35807 : 1
Tire Circumference (inches): 27.3 inches (693.43 mm)
Total Motor Speed: 35774.6 RPM
Vehicle Speed: 50.38 mph (80.93 km/h)
Estimated Adjusted Speed: 47 mph (75 km/h) - 7% loss
Effective KV Value: 1611.47
KT constant: 0.81 oz-in/A
Motor Torque: 0.28 ft-lbs
Final Torque: 5.12 ft-lbs
Final Power: 1465.2 watts (2 HP)


Savage03: There are three spots that you should check:



- to keep left bearing on it's place, use something that fits the axle and is the right lenght.
I used inner part of E-Maxx front driveshaft, which was cut to right lenght.
It is possible to use the clutch from 3rd gear, just remove all the moving parts.
- to remove sideplay from the axle, I used two 6mm shims between bearing & c-clip
- to remove sideplay from maingear axle, I used one 8mm shim behind right bearing
Shim could also be put to the left side, depends from the position of idler & main gear, the goal is to get them "inline".

The amount of shims may vary between transmissons, so just check that you remove excessive play and the gears still roll smoothly.
Can't remember from where I bought the shims, but atleast the 6mm ones do have a HPI part number.

First gear can be removed completely.
I left all three gears to the input shaft (where slipper & spur are) - it could also be reduced to one gear with proper spacers, but seemed a little too much hassle...

[doo540]

Nice write up on the locked tranny!
I'm still using the stock 3 speed with Neu 1515 1y on 4s with the mmm
Top speed right know is 48 mph (radar) with Losi Bolt-On tires.
I went thru 3 stock diffs, now I'm running Cen Gen ring and pinion conversion.
My motor mount is up high (kershaw design) and my lipo is inside the frame above the driveshaft and below the motor. Nothing hanging on the outside of the frame. Still using stock brakes, seem to work ok for me. I like watching the truck move around as it shifts thru the gears. I haven't done a speed run with the new gears, I think they are 10% faster then teh stock rear end ratio.

[BrianG]

Nice improvisation using the plastic for the trays! Did you happen to have them, or did you do what I do and wander around Wal-Mart looking for ways to hack up everyday items for R/C use?

Yes, I actually do that.