caster rtr truggy ..

[BRS]

Ok so how important is that "C" rating whats that about?

And as it will be a kid playing with this what happens when when he runs out of battery power can he kill the cells by running it flat?

[Marvin]

The Hobbywing ESC (the one it comes with) has an LVC (low-voltage cut-off), which should cut out when the cells reach ~3V per cell. This is a safe level. You can tell the cut-off has come on when it sometimes refuses to move.

The C rating is the level of discharge that the battery can sustain. E.G. a 5000mAh pack is rated for a continuous 25C. This means that the pack can discharge at a level of 25 x the packs capacity in Ah (divide the capacity in mAh by 1000). Meaning that 25x5 = 125A continuous. This is about the minimum level of discharge that I'd run on 4S. Therefore, the capacity and C rating must be 'balanced'. If you are only using 3000mAh packs, the C rating must be higher so it can discharge at a high rate.

Packs come in anything from 15C up to 45C, and with 1/8 it is best to go for at least 25C as a rule of thumb. The higher the C-rating, the longer the cells generally last (life cycles), the more useable capacity they have (so a 5000mAh 40C pack will actually give slightly longer run times than a 5000mAh 30C pack) and as they are not pushed as near to their limit anyway, they will last longer again.

[BRS]

Good stuff Marvin your a mine of usefull infomation

[BRS]

Originally Posted by steelie600

Sam youve gone to the dark side!!!! NOOOOOOOOOOOOOOOOOOOOOOOOOOO

Anyway the lipos are lasting a lot longer now you should get atleast 300 charges out of them (early ones you were lucky to get 100!!) and the small connector your describing is the balance lead, which enables all the cells to be charged at the same rate and to exactly the same voltage. One thing i will say tho is get the best batteries you can afford, i run Kong Power in my 6s heli and they are awesome, and have over 250 charges on one of them and its still as powerful as ever. One thing i have noticed about flightpower/trackpower, is the seem to be peaky, ie give out more power at the start of the useage and peter off, where as the Kongs i use are very consistant through out the charge.

Hello Kev I've not quite gone to the dark side dont worry....

I maybe be dreaming but I'm imagining the lad can come along to meetings with me at Pendle and race that when he fancies, as well as playing at home with it. Hoping thats easier than another nitro vehicle as it should be a switch on and through it down job for him..(sure it wont be that easy)

Need to find a good source for these bloody expensive batteries now, £250 for a nitro motor no problem, more than 20sheets for a battery come on now lol

[BRS]

I presume these would be the Interllect lipos you mentioned Marvin?

http://cgi.ebay.co.uk/Intellect-7-4v...item19b652195f

Whats the pitfalls of ordering from that place any experience?

[Marvin]

Yep, they're the ones.

That's a good price actually! Just run it on them.

You say that a good nitro engine is £250. How often do you need to replace that? Every two seasons if you're lucky! These packs (say 4 in total) will last around 4 seasons, but cost £170 from the source you used.

Not to mention fuel costs (£30 a gallon).

[BRS]

The Nitro motor / battery comparision was very much tongue in cheek ;o)

I've ordered from that link so we'll see how delivery goes....

[Marvin]

True though...

Hope it goes well for you!

[rc_dan]

where did you order the truck from bud, got a link ? its between this kit or the one from ansamann

[BRS]

Was Stwbald earlier on in this thread mentioned he had one for sale new and unwanted...

[BRS]

Quick update to this is the Intellect cells arrived yesturday from HK and all seems good. So if you are looking for much cheaper good lipos its a good choice.

UK - £90 Delivered from HK - £47, not a bit of sense.....

[shaun m]

i also bought some zippy lipos from hk , i ordered them last monday and they turned up last thursday ( 2-1/2 days from hk ) ..

they were 5000mah and 40c .. and they seem spot on .. it cost me £93 delivered for 4 ...... from hobbycity.com

[BRS]

With all the terrible weather my lads not had chance to give the Caster rtr Truggy a good run. Hes had a little mess under cover in an area too small really. It seems bloody quick but we'll see once on a proper track.

The pinion was wearing very fast (even only after 5min use), didnt look like it had been hardened so I replaced it with a Losi one off ebay.

The servo saver is to soft you end up with no steering even with what looks like a decent tension on the spring, had to wind it right up.

Many of the screws on the car were loose & no lock tight so thats something to do if you have one before you run it.

The body is like toffee, practicaly split from nose to tail on his first bump

Thats all for now will report back once its been used in anger

[BRS]

We managed to give the Caster rtr Truggy a decent run last night he got about 20min run time from it with the 2x5000mah packs. It wasnt on a track but we drove it as hard as we could and I have to say I'm pretty impressed with it.

I think if anything its under geared as standard, its a wopping 62T spur and a 12T pinion seemed a little short on top speed and the motor and esc never got more than warm the hole time.
I'll leave the gearing for now as its better for him to control till he gets into it but I'm thinking it should be more like 14T/15T with the 1880kv motor?

I must admit after what Marv had said I expected the motor and esc to be cooking after 5min of full stick but so far so good, maybe thats the gearing though.

[rc_dan]

is the esc 6c capable ? the kv is about right for 6cell

[BRS]

Its running 4S at the moment do you mean 5S, 5S would be wild 6S sounds like puff of smoke time

Its the Hobbywing 80A esc not sure of the specs

....


Been and got them

1 Specification
1.1 Output: Continuous current 80A, burst current 270A.
1.2 Input: 6-12 cells NiMH/NiCd or 2-4 cells LiPo.
1.3 BEC Output: 5.75V/3A (Switch mode built-in BEC).
1.4 Resistance: 0.0018 Ohm.
1.5 Motor Supported: Sensorless and sensored brushless motors
1.6 Suitable Brushless Motor: 8T and > 8T
1.7 Suitable Car: 1/8 on-road or off-road cars / trucks for sportful race and RTR application.
1.8 Size: 68mm(L) * 55mm(W) * 45mm(H).
1.9 Weight: 150g(Without wires)


4S limit then.....

[Marvin]

80A Hobbywing has a 4S limit - probably bound by the BEC.

1800KV is by no means a 6S motor. 1400 is a 6S motor. 1700 is a 5S motor. 2000 is a 4S motor. 2500 is a 3S motor.

If the ESC and motor aren't getting warm then it's in its sweet spot. When one component is hotter than another, or it's all running hot - that's when you need to worry.

Remember, it only uses buggy gearing in the diffs - hence the massive spur (like the original X1-CRT).

[adrictan]

For the 1880kv motor, u can try to push up to 14t and try. monitor the temps then if it's constant, you can try to go higher.

[BRS]

Quick update now for you on the Caster Truggy....

First time driven in anger on the track on dry Astro, 2nd lap of practise my son did a 6 ft double jump hit the break to hard flipped the truck over it landed square on its roof. Nothing you havent done before it got marshalled and had lost all drive. Took it back to the table and the front centre drive shaft was rolling around loose inside...strange?

Chassis bent like a bananna!! Must be made of lead I bent it back over the edge of the table as best i could and re fitted the drive shaft. He managed to do a couple of heats before the truck slowed, batterys charged no power, either the Hobbywing esc or motor is gone...

NO MATTER HOW CHEAP DONT BUY ONE

[steelie600]

Sam on the flipside to this PM wizardking on NNRC forum, he MAY sell you his MBX5t if you wanted. Basically the same car with decent electrics already installed. Im only saying this cos he never uses it. May be an idea???