HPI Savage Flux XL FLM FTC + CC 1717?

[Nard Cox]

Hi guys,

Currently
HPI Savage Flux
FLM Forward Tranny Conversion
Flux Blur 2200kv diameter : 44mm can and 48mm fins
Gearing : 44/20
Pinion diameter : 21.5mm
LiPo space : 37mm, +4mm (41mm) when I would use the supplied TVP spacers.
LiPo's I run : 4S 5A
RC calc : 34mph/55kmph

Goal
40mph/65kmph

Planning
HPI Savage Flux
FLM Forward Tranny Conversion
CC 1717 HELI 1580kv diameter : 49.5, less on the shaved surfaces Bondo click
Gearing : 44/25
Pinion diameter : 26.5mm
LiPo space: 37mm - (1.5mm/2) + (26.5mm-21.5mm/2) = 38.75mm + 4mm (42.75mm) when I would use the supplied TVP spacers.
LiPo's I plan on running : 5S 4A or 5A
RC calc : 40mph / 65kmph

Questions

1. Am I overlooking something or doing something wrong?
2. Will 5S 4A give me about the same runtime as 4S 5A? (4S * 3.7v * 5000mAh = 74000 vs 5S * 3.7v * 4000mAh = 74000)
3. Will a 5S 4A 40C be sufficient for this animal?

RC Calc data

[pinkpanda3310]

In 'planning' you've got a 'CC 1518 heli' I think you mean 1717.

My understanding is the 5s set up will have a slight edge over the 4s because of the higher V it will be relying less on the amps and not working the battery as hard (geared for the same speed).

Why do you want the same run time anyway. It's going to take more power to push that thing to 40mph.

[Nard Cox]

Wh00ps, fixed it thanks!

Yep, higher V = less A = less heat, atleast that's what I believe is the general assumption.

[pinkpanda3310]

Yes, general assumption but you will be gearing to go faster. The 1717 I think will be more efficient generally speaking as well but I still think it's going to take more power to go faster.

[Bmr4life]

With that gearing you will definitely hit 40mph on 5s.

[Bondonutz]

I've run my 1717 on 5s and the 35C packs were to warm for my liking even tho I was geared for 38mph in my XXL. The packs got hot and swelled a little, they recovered but The 1717 was to much for them. I would seriously consider useing no less than 40C in 5s, higher the better(Nano 50-90C?) . 6s I think is the basic sweet spot for the motor, It's a amp hungry pig and on 6s the packs stay ambiant temps.

You have to figure AT LEAST a 1/4" for tire balloning, 0.1 aint enough.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 22
Total Voltage: 22.2
Motor KV: 1580
Tire Diameter (inches): 5.84
Tire Ballooning (inches): 0.25
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2 : 1
Total Ratio: 14.65491 : 1
Tire Circumference (inches): 19.92 inches (505.91 mm)
Rollout: 1.36:1
Total Motor Speed: 35076 RPM
Vehicle Speed: 45.14 mph (72.52 km/h)
Effective KV Value: 1580
KT constant: 0.86 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

[Nard Cox]

6S is indeed the sweet spot. The problem is $$. I also bought new motors for my MBX6e (which I still need to buy) and MBX6Te. So I also have to buy LiPo's for them since I will have to switch to running on 5S instead of 4S. But for some matches I need 4S, so I need to buy a few of those as well. All in all my $$ is just flying out of my hand atm.

Perhaps I will store the 1717 and just run my 2200kv for now. Than buy some decent 6S packs when I have a job and an income. Being a full time student can suck @ times :D

I assume a 5S 4A 40C pack is enough for a MBX6e RCM with CC 1512 1800kv and for a MBX6Te RCM with a 1520 1600kv?

[Bmr4life]

Yeah. I need to order some 6S batteries. How many amps do I need? Is 100 enough?

[nitrostarter]

I have a brand new Hyperion 6s 5000 45C for sale if your interested. Would be plenty amps for this motor. PM me if interested.

[Nard Cox]

Bmr4life, 100A is not enough. I would aim at atleast 150A after hearing stories about this power hungry motor ;)

@ nitrostarter, I'm sure that what ever youa sk for them is a fair price, but I'm afraid it's too much for me at this time. After 6 new motors, a MBX6e and some 5S LiPo's I'm done. Really need to take is slow with my $$ :(

Originally Posted by Bmr4life

Yeah. I need to order some 6S batteries. How many amps do I need? Is 100 enough?

The problem with 6s batteries is the space to fit them in the FLM chassis.

In my FLM forward chassis Savage, using a Castle 1520 (its diameter is about 9mm lower than the 1717) with a spur of 52 and pinion of 25 (so the motor is as far as it possibile from the left chassis plates), I have about 46mm width to mount batteries, just enough to mount 6s Lipo of 4.000 / 4.500 Mah.

If You have no more than 42,5 mm (with the spacers), I guess you will be in trouble to find 6s pack of that width (maybe something can be found, but with no more than 3.000 Mah).

Bye, Andrea.

[Bmr4life]

Yeah, I understand that. Not trying to brag, but the DB17 has a ton of room inside the rails for mounting batteries.

[Nard Cox]

andreazinno, very true. There are even 4 and 5S packs which don't fit.

Bmr4life, the DB17 does have tons of rooms, will not be a problem for you :)