Steevo

Hi,
I am currently considering buying a Novak or Hacker brushless system for my car....
I have the basic understanding of how the brushless system works etc but one thing that I have not read any where is whether or not a brushless motor is prone to the overheating/burning problems of under or over gearing.
I would imagine that a brushless motor would probably be more tolerant of under or over gearing???
Can anyone shine some light on the subject???

Steevo

Neil Rabara

The reason you haven't read anything is probably because none has been done. Even though the brushless is new to RC Cars, it's not new technology. You might find articles in the RC Airplane community and magazines.

Steevo

Yes I do understand that this is not new technology but planes are not geared like cars are, to my knowledge, so I don't think the gearing problem would apply.
I am sure somone out there has got some Idea of whether or not under or over gearing in a brusless motor is an issue.
I mean, Wouldn't it be great if you could choose just about any gear ratio with no fear of ruining your motor!! I imagine that this is probably not the case but they might be able to handle over or under gearing better than a brushed motor could....

Any other theories/facts????

Steevo

Steevo

???

dalem

My $.02... from personal experience with the brushless systems in other peoples' cars.

1. ESC is an on/off switch. Even playing with radio throttle exponential doesn't help much. Novaks' system is much more controllable than the others (hacker & lehner (sic?)).

2. Some of the ESC's are about the size of two servos (end to end).

3. They suffer from 'cogging'. They 'pulse' coming out of a turn after a minute or two of running. Novak was 'quietly' having trouble with this on press day at SoCal.

The upcoming Tamiya 4 hour enduro should be the perfect shakedown for brushless motors since there is no way to take a brushed motor on a 4 hour drive. I'll report back after the race.

Steevo

They have been using brushed motors at the Tamiya endurance races for years. Sure a brushless would be a huge advantage there but before the brushless came along what do you think they used?? I have no doubt though that the winning team WILL have a brushless system Installed though....

Looks like my original question has every one stumped!!!!

Steevo

dalem

Wow, I sure missed it with my original post. Forgot to add this on the end...

The systems I have seen are the equivalent of a 10-12 turn brushed motor. They are geared up a few teeth from what you might run with a 10-12 turn brushed motor and don't even get hot (warm maybe). General opinion is that they don't overheat from overgearing, just run slow and 'cog' REAL bad coming out of turns.

What I was trying to say about Tamiya enduro is that because a brushed 10 turn can't go 4 hours w/o replacement (and lots of them) that everyone will (probably) use brushless in order to spend less time in the pits.

I should wait until after 2nd cup of coffee before posting.

Steevo

Ahhhhh Excellent!!

Thats what I was looking for... I know what its like when you're half asleep

I know that most racers know how to gear their cars anyway so it wouldn't be that much of an issue but knowing how sensitive brushed motors are to over or under gearing I wondered how the brushless would cope...
As far as the Tamiya Endurance race goes, I had some stats somewhere on how many times the guys had to change motors/cut comms etc from previous 3 hour races.. It was Interesting reading, I'll see if I can find it.....

Here's an interesting one not concerning motors but the cars themselves..
In the "3 Hours of Tamiya" race held a couple of years ago the "TRF Team" chose to run a TA04R chassis over the TRF414X, or TB Evolution I....
Heres the top 10 finishers in the A Main
1. TEAM TRF/ TA04
2. TA04
3. TA04
4. TA04
5.TRF 414X
6. TB01
7. TRF 414X
8. TA04
9. TA04
10. TB Evolution I


Steevo

Nightbreed

it up or what. Why would the mags do that for Novak? Do you think Novak fixed the problem? I'm interested keep going.

dalem

Steevp

I would except most if not all of the cars to be EVO's & TA04's just because of how much easier it is to change a side x side pack as opposed to a saddle pack (414x). With a 4 hour race you would need an entire group just to handle battery issues.

* know each packs avg runtime & track it during a run
* charging additional batteries
* cooling & repeaking just before pitting
* repairing damage during pitting

Should be fun to watch.

Nightbreed
Before Novak's press day at Socal (Wedn, 11/13 - I think) I had heard others complain about cogging w/other brushless systems. The problem tends to start about 2 minutes into a run.

When press day began the runs were short (under 2 minutes), probably just to give everyone a chance to play & setup their cars. Even for a press event these guys were pushing the cars hard.

Eventually runs became longer and some of the testers started experiencing cogging. It was especially apparent when Kinwald & a few of his buddies were out there. Coming out of turns the brushed guys were getting away from the brushless. Some of the brushless cars started cutting out mid-straightaway.

Maybe press day wasn't an indication of things to come. Maybe it was just a bad day. I don't know, but before I spend $350 for one (motor & ESC) I'm going to watch the Tamiya race closely.

I'm also interested in what gets written about Novak's press day. I believe it will be in the 03/03 issue of RC Car Action.

Nightbreed

better keep working on it. Novak where are you? Speak! Is this true? I can't beleive it, they won't comment until 03/03. Smells like a cover up.

dalem

Looks like I believe wrong. 03/03 issue is out and doesn't include an article on Novak brushless.

newracer

the latest isue of R/C Car has an article on it. March Issue I believe. I need to re-read it but I basically think they said it had no problems.

Besercoe

iTrader: (9)

Since when have any of the RC Magazines given a true and fair report on a product? every product tested is awesome, except sometimes for some puny reason like instructions lacking.

Nightbreed

if the would inform people of what to expect. I would respect Novak for coming out with the truths. Otherwise, if I read it in a mag? Humm.... Either way people are going to know.