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After three years, things have changed apparently, few questions if you don't mind

After three years, things have changed apparently, few questions if you don't mind

Old 01-29-2017, 09:00 PM
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Default After three years, things have changed apparently, few questions if you don't mind

Chargers:
  • Are the cheapy single channel 6A turnigy type chargers up to the task anymore? I see there is a whole slew of functionality new chargers seem to have. Are any of them a must have? I see they are monitoring IR, some can apparently do some type of motor specing, some can do servo testing? I'm not sure what these options are but any feedback on these would be helpful. When I raced last I had a fairly cheap AC/DC 4 port charger which was sub $100 which did the job very nicely. I won't be running multiple classes so a single channel charger will work.
  • Is charging at high current really a thing again? Back in the NiCd days it was but it destroyed batteries in short order. Same deal today? Worth it?
  • Just like above, is discharging really a thing again too? Is it beneficial really. I don't know all of the physics behind lithium cells but I'm not sure I'm buying into that just yet.

Motors
  • I'll be running the 25.5 F1 class more than likely, Is there a decently prices but competitive 25.5 motor? They were in the $60 range last I raced but I was shocked to see them around $90-100 now. I was shocked to hear Novak had gone away also.

Radios
  • Seems not a lot has changed here at least. Are there any must have options (Aside from the obvious, trims/EPA adjustments, etc.) that the newer generations have? Someone told me today that you can use a telemetry sensor in one of the futaba radios that will vibrate when motor temp is above a preset temp. Anything else like that? Do you guys find any of these things useful or just superfluous? I had a DX3s before which was more than enough and I may just go back to what felt right but any input would be great.

ESCS
  • This may have changed the most for me. It seems the Chinese brand ESCS have started to become serious contenders. I was always a Tekin guy ever since the 410K days. The hobbywing were just for the bashers when I left but they are being recommended now. Was looking at the JUSTOCK one. Opinions on these guys, good manufacturer these days? Competitive? On their site they have a XR10 and a Legacy. One is 60A and the other 45A, current draw is a new way to rate and ESC to me so what do these 25.5 motors draw at peak/continuous? Anyone have any idea if that cheapy legacy 45A would be ok for 25.5?

Anything else you'd like to add for someone who's been out of racing for 3 years?

Sorry for the seemingly basic questions but the trip to the LHS today sent me home with more questions than answers. I went in figuring I had a solid gameplan, I was wrong.
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Old 01-29-2017, 09:51 PM
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The answer to everything is: it depends. In speculiar class the Uber serious guys are discharging and charging at high amps, yes. Is it necessary? Depends. It does lower the internal resistance and the newer lipos seem to be more apt to handle it. But until you're racong consistent laps, putting your batteries through that won't really yield better results. A good idea is to keep an eye on the for sale section here for deals on an icharger duo, they come up sometimes. As far as esc's. If you're running f1 then the hobbywing justock speedos are perfect. Motors are always a matter of opinion but you won't go wrong with schuur speed, team powers, or team scream. But you'll get more answers from people here who swear by others as well. It'll just come down to doing some research and going with your gut. As far as radios, there's not really a lot that has changed and widely used. The temp and telemetry features arent really used a lot and not really worthe the extra money for you right now. If you're just getting back in to it there's going to be a lot to learn. You just need track time.
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Old 01-29-2017, 10:09 PM
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The learning curve won't be bad. I've not forgotten what i've learned in 30 years and I'll be running fairly consistent laps very quickly once I get the setup right. I've left the hobby before and it's like riding a bike, you don't ever forget it from my past experiences.

For those who have charged at high current and also discharge, what would you gestimate your lap times being reduced by? Do you notice more punch, top speed, both, etc?

I was looking some more at cheap chargers and this came up. Can charge at 10A and they say it can report IR. Is Ir something to monitor these days w/ LIPOS? I'm certainly not going to spend $350 for a charger any time, not because I cannot afford it but because I cannot justify it knowing what I know about charging circuitry, voltage monitoring and design.

More on the ESCS, anyone have a comment on these 45A vs. 60A ESCS, what do these motors draw at peak/continuous and will I notice getting a 60A vs. a 45A?

Thanks
Dave
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Old 01-30-2017, 12:46 AM
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Originally Posted by TT_Vert
The learning curve won't be bad. I've not forgotten what i've learned in 30 years and I'll be running fairly consistent laps very quickly once I get the setup right. I've left the hobby before and it's like riding a bike, you don't ever forget it from my past experiences.

For those who have charged at high current and also discharge, what would you gestimate your lap times being reduced by? Do you notice more punch, top speed, both, etc?

I was looking some more at cheap chargers and this came up. Can charge at 10A and they say it can report IR. Is Ir something to monitor these days w/ LIPOS? I'm certainly not going to spend $350 for a charger any time, not because I cannot afford it but because I cannot justify it knowing what I know about charging circuitry, voltage monitoring and design.

More on the ESCS, anyone have a comment on these 45A vs. 60A ESCS, what do these motors draw at peak/continuous and will I notice getting a 60A vs. a 45A?

Thanks
Dave
I don't really know what a 25.5 actually draws, but I can tell you that a Justock(either Legacy or XR10 version, I have one of each) will handle it just fine & you will NOT notice a difference from the more expensive ESC's. When I got my first Justock, I had been using an original Novak GTB(the early Spread Spectrum ones, could handle most ANY motor, had VERY low IR & good throttle feel, it's only issues were its size & weight) & was given a Justock(was a prize at a VTA/F1 event), & since in that event I had noticed a LOT of guys using it(& running very well with it) I decided it'd be worth a try. So by the next race at that track I had installed it & was AMAZED at how well it ran, NO difference in laptimes, no difference in throttle feel, & at the same time, it fit MUCH more easily in my car & shaved around 20 grams of weight as well. Now, I run Hobbywings in ALL of my cars, & have not regretted it one bit, I think they're the best value in ESC's, & I don't feel I'm giving up ANYTHING to anyone else I race with(aside from my driving, of course, you can't buy that still, unfortunately). My other Justock(the XR10) I'm using in a Mini with a 21.5 motor, & it's the same deal, when I built my mini, I didn't have my XR10 yet, so I used whatever ESC I had available, which happened to be the HW V3.1(that was their top of the line model before the XR10 Pro), & then when I could get ahold of the Justock, I got one & installed it, & again, I saw NO difference in throttle or brakes, nor in heat or laptimes, the XR10 Justock was all I needed in the mini. I'd predict that you will NOT be disappointed....
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Old 01-30-2017, 08:24 AM
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Thanks. My biggest question on the justock now is the Justock legacy (45A) vs. the Justock XR10 (60A). Has anyone gone from one to the other? I'd hate to get the legacy to find out that i'm leaving something on the table. it is so cheap though (The legacy) i'm having a hard time passing it up.
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Old 01-30-2017, 09:11 AM
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High current charging and discharging a LiPo battery isn't going to make much difference if you are using a 25.5 motor. The motor resistance is so high compared to the battery IR that I don't think you will ever notice the difference. Save the money you would spend on the equipment to do high current charging and discharging, and use it for something more important, or save it for when you finally need another battery (which may take quite a while!).

The same goes for ESCs; the motor resistance is so high that even cheap ESCs give excellent performance.
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Old 01-30-2017, 10:32 AM
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Thanks. Any idea where I may find a spec sheet for these 25.5s? I'm particularly interested in current draw of these things to figure out the ESC question I had above.

Dave
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Old 01-30-2017, 12:29 PM
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Originally Posted by TT_Vert
Thanks. Any idea where I may find a spec sheet for these 25.5s? I'm particularly interested in current draw of these things to figure out the ESC question I had above.

Dave
I don't know of any spec sheets, but ROAR rules specify a minimum stator terminal resistance of 101 milliohms at 25C. That gives a stall current of about 83A at 8.4V, which works out to about 42A at peak power (at 1/2 of the free-running RPM).
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Old 01-30-2017, 12:49 PM
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Thanks. I would assume you'll rarely have high current at high RPMs (Unless there is some rolling resistance or other binding issue) so I'm not sure that 25.5 would ever even see near 40A given that data. I wonder if anyone have ever done a current vs. load (measured by TPS) vs. rpm type of graph for these things.
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Old 01-30-2017, 01:56 PM
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Originally Posted by TT_Vert
Thanks. I would assume you'll rarely have high current at high RPMs (Unless there is some rolling resistance or other binding issue) so I'm not sure that 25.5 would ever even see near 40A given that data. I wonder if anyone have ever done a current vs. load (measured by TPS) vs. rpm type of graph for these things.
It will still pull the stall current when given full-throttle from a standing start, but that only lasts for a fraction of a second. Over a 6 minute run, I don't think I've ever used more than 1200mAh. That works out to 12A average.
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Old 01-30-2017, 02:30 PM
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Ok so the only topic not touched really, aside from getting a very expensive charger, has anyone used any of those cheaper china chargers recently? I know the B6As and the like worked great and not it looks like there are 20 knock offs of this touch screen charger. Tenergy and many other companies have one. The Tenergy is the TT6080AC 80W AC DC Balance Charger with Touch Screen LCD . Shockingly i searched everywhere under this model # and a few others I found very little information, only one post here actually but the search function here seems to leave a bit to be desired even when using quotes.


And i just stumbled upon the fact that there are now android based radios. Not sure how nobody felt that was something worth noting. With that, anyone using one? Like it?
Dave

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Old 01-31-2017, 04:39 PM
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Anyone??
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Old 01-31-2017, 04:57 PM
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Originally Posted by TT_Vert
Ok so the only topic not touched really, aside from getting a very expensive charger, has anyone used any of those cheaper china chargers recently? I know the B6As and the like worked great and not it looks like there are 20 knock offs of this touch screen charger. Tenergy and many other companies have one. The Tenergy is the TT6080AC 80W AC DC Balance Charger with Touch Screen LCD . Shockingly i searched everywhere under this model # and a few others I found very little information, only one post here actually but the search function here seems to leave a bit to be desired even when using quotes.


And i just stumbled upon the fact that there are now android based radios. Not sure how nobody felt that was something worth noting. With that, anyone using one? Like it?
Dave
As far as chargers go, I usually stay away from the off brand models just because the warranty process is a little easier when you get something from a name brand. I pay more but I feel better having the peace of mind.

As for the android based radios, I have not tried any but I do use my android to make setup changes on my Tekin RX8 gen2 and I absolutely love that feature. It makes trackside setup changes a breeze.
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Old 01-31-2017, 05:18 PM
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I can get the chargers on amazon and i have prime so returns aren't a huge issue. At the price I would see them as disposable even if they only work for a year each. I was hoping given their price point someone would have tried them. Searching rctech i can't find much of anything on these things. I've watched youtube reviews but I figured I'd see something around here on them. **EDIT** I found another rebrand of it which has a thread on it, the Protek Prodigy 680

What I like about android based systems if I can mess w/ the file system, root and reverse engineer I just don't know what they can do aside from send PWM signals via the receiver to the ESC/servo. I could have a ton of fun w/ one of those things but I'm not even sure how long I'll be in the hobby as there are only a few months left of winter for me to race and by the time I get everything together i'll have even less time.

Last edited by TT_Vert; 01-31-2017 at 05:42 PM.
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Old 01-31-2017, 10:04 PM
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Originally Posted by EbbTide
As far as chargers go, I usually stay away from the off brand models just because the warranty process is a little easier when you get something from a name brand. I pay more but I feel better having the peace of mind.

As for the android based radios, I have not tried any but I do use my android to make setup changes on my Tekin RX8 gen2 and I absolutely love that feature. It makes trackside setup changes a breeze.
Same here, I tried the knock-off route many years ago(a couple of Integy chargers, had a decent feature list), but they didn't last long & their customer service was exactly NIL, so that kinda soured me on off-brand stuff. I've been using Thunder Power chargers for about 10 years now, & have been overwhelmingly happy with them, all the features I've wanted & dead-solid reliable, so far(newest one i have is their TP-820HVC, absolutely loving it).
Oh, & about radios, I'm the same way, I care MUCH more about the feel, control & reliability of a radio than any gimmicks like an Android OS. There may be some great potential for goodies in the future, but that alone won't sell me a radio. I was a hardcore KO Propo guy for a long time(about 23 years) until I was at a ROAR Carpet Nationals about 5 years ago & my TX died on me(& they didn't have a KO at the shop to replace it with), so I tried a Futaba 4PL, & I've been using it & the 4PLS ever since, excellent value for the price(& their new 4PV looks like a really good choice, as well)....
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