Two questions: Trakpower LiPo running time and what servo's?

[dirtrider]

Hi,

've been out of the RC world for ages now but I'm thinking of starting again... especially the ZX-5 SP attracts me because when I was young I had a Optima MID SE and I really really loved that car (too bad I don't have it anymore )

I was thinking about using a brushless system (e.g. Mamba Max?) but other tips are welcome. Low maintenance is important and ease of installation.

As for battery, LiPo attracts me more then NiMh, but what are the running times with a battery nowadays? I remember with my Optima you had 10 - 15 minutes of fun maximum and that was it...

For servo's I still have a S3003 I can use but tbh this is not my first choice, does the ZX-5 require a metal gear servo or is this overkill?

Thanks for any advice from you pro racers

Cheers,

Dom, Belgium

[Alfonzo]

Can't comment on the ZX5, but pretty sure it's a reasonable bet. Brushless all the way, although you can probably pick up a very good brushed setup second hand very cheaply nowadays. Lipo is the future, much longer run times although 10 - 15min is still what you can expect, difference being the cars nowadays are much quicker. I think that S3003 servo will be fine for now.

Be aware - check your local club (assuming you are actually going racing) for Lipo acceptance, as it isn't widespread yet.

Good luck and enjoy it.

[markwilliamson2001]

Depends on what you are doing... bashing or racing?

For bashing, it maybe worthwhile looking at a medium to slow sensorless brushless system (e.g. Tekin etc etc). With a decent sized Lipo (Trakpower 5400) you could get around 20-25 minutes from it, but make sure you get a speedo (not sure on the tekin) with a lipo cutoff. This prevents damage to the battery.

[dirtrider]

Hi again,

Thanks for the input. Hmm I think at first it won't be much racing yet... clubs are not widely available here but the whole 'bashing' idea of just running a truck into a park and seeing what brakes first isn't my thing either

What times would I get from normal battery packs? I expect I won't have the cutoff thing then?
What motor is best, I see you got 7700kv but from what I read that's unusable due to way oevrpowered. I thought the mid range was ok, but maybe that's even aimed too high?

As for the servo, great, thank god I can reuse some stuff from a nice 2nd hand bargain I did (bought a road car, refurbished it a bit and sold it with major profit... so there's the funds for my ZX

Cheers,

Dom

[Chrislong]

If you get a new Novak brushless then it comes with Lipo cut off.

Without Lipo cut, you just need to time your own runs and don't run til it starts to slow down - as the cells will be too flat then and although it isn't as bad as some people may think, it isn't adviseable to flatten a Lipo below 5v.

With Nimhs and 5.5R you should get 8-10 minutes.

With Lipo and 7.5R (equivalent speed) you should get 15-20 minutes.

With Lipo and 5.5R (mental power) you should get 10-15 minutes.

If you are going to run cells, make sure to get the latest cells off the 2008 cell list. As although you may not need to be BRCA legal, the 2007 cells went bang and have a short life. Im yet to see any 2008 cells go bang and i'll go out on a limb and say the lifespan will be better - it can;t be worse.

Lipo will work out far cheaper for you, as you won't need as many, lifespan will be far far longer and you don;t need equaliser, chargers cheap, etc..

Chris

[dirtrider]

Hi Chris,

Thanks for the info. LiPo it is then... but sorry to ask a noob question, what is the 5.5R and 7.5R you talk about?
I always thought 7.5R was more powerful? I don't get it how can you get more time out of a more powerful motor? or am I barking up the wrong tree here?

Thanks,

Dom

[Chrislong]

Ah no, sorry. Novak motors are rated in winds. 4.5, 5.5, 6.5, 7.5

The smaller the number, the faster the motor.

LRP, Nosram, orion and Peak work by the same way. But the Mamba way is a rating which means X amount per volt.

A rule of thumb is that LRP & Nosram motors are rated 1 number higher than Novak. So an LRP 6.5 is equivalent to a Novak 5.5.

Also with Novak, there are 'R' and 'L' motors. The R is the main brushless motor which responds like a brushless motor should - very quick top speed, very quick aggressive acceleration. Where-as the 'L' is a Light version, and it accelerates a bit smoother.

So the R is like running a single wind brushed. The L is like running a triple or quad wind brushed. Top speed is the same.

So a 5.5R with Nimh's will be very fast, and a 7.5R with Nimhs will be steady and controllable.

a 5.5R with Lipo is crazy fast and faster than anyone will need, but 7.5R with Lipo is very fast and more controllable.

Hope this helps

Chris

[mark christopher]

Originally Posted by Chrislong

Ah no, sorry. Novak motors are rated in winds. 4.5, 5.5, 6.5, 7.5

The smaller the number, the faster the motor.

LRP, Nosram, orion and Peak work by the same way. But the Mamba way is a rating which means X amount per volt.

A rule of thumb is that LRP & Nosram motors are rated 1 number higher than Novak. So an LRP 6.5 is equivalent to a Novak 5.5.

Also with Novak, there are 'R' and 'L' motors. The R is the main brushless motor which responds like a brushless motor should - very quick top speed, very quick aggressive acceleration. Where-as the 'L' is a Light version, and it accelerates a bit smoother.

So the R is like running a single wind brushed. The L is like running a triple or quad wind brushed. Top speed is the same.

So a 5.5R with Nimh's will be very fast, and a 7.5R with Nimhs will be steady and controllable.

a 5.5R with Lipo is crazy fast and faster than anyone will need, but 7.5R with Lipo is very fast and more controllable.

Hope this helps

Chris

chris he is in belgium why would he need to use the brca list?

[dirtrider]

Thanks for that decent explanation, now I understand it.
True I don't need the BRCA specs but it clarifies that you can't just put whatever you want in a car

Thanks so far, I'll keep you up to date on what I bought!
THis forum is by far the best I came across for buggy stuff... most of the forums I visited were cluttered with crappy posts.

Dom

[Alfonzo]

This is THE only forum you need visit my friend .

Get yourself along to your nearest club and get involved. In my opinion there is little satisfaction from running these RC cars without racing them on track.