Does any Aussie own a ZZ SE?
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- This topic has 13 replies, 6 voices, and was last updated 20 years, 6 months ago by
oldtamiyaphile.
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October 15, 2003 at 2:20 pm #11394
I’m keen on getting one of these. Does anyone have one yet? Any ideas, comments?
ta,
ph2t.
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October 15, 2003 at 7:23 pm #28972
Yep got one running around the kitchen, love them.
Propo control is good in both throttle and steering. They are faster in forward than reverse due to some transistor stacking on the pcb.
Could do with some more speed and torque (i’m working on that atm), but unfortunatly they are not able to be dual celled or mosfetted.
Still they are a good little car, worth the purchase ph2t, do it.
:)uA -
October 15, 2003 at 8:37 pm #28866
I’ve got two on the way to see if I can sort out the steering problems.
A lot of people in the US are really disapointed with them and they are moving up to ‘real’ micros, at long last.
I only chipped in $7 for the two, otherwise I wouldn’t have bought any.
Epoch, Epoch, Epoch 😀
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October 16, 2003 at 5:47 am #28881
I am not an Aussie but I have one and I love it. There are a few mods out there now that will greatly improve the cars performance. Right now mine is in the middle of gettin fets 🙂
The fets dont do a great deal of improvment but they do help.
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October 16, 2003 at 1:18 pm #28895
Only very slightly, the vlotage to the motor is actually reduced with fets but because they flow more current they are a tiny bit torquier, but are SLOWER. And the torque is only a TINY bit higher, not worth paying for IMO.
:)uA -
October 16, 2003 at 7:00 pm #39145
uA, I take it you’ve tried the MOSFET mod already?
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October 16, 2003 at 8:45 pm #28572
Micro is good like that. =o)
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October 17, 2003 at 12:36 am #28575
CrazyDave has modded an SE with FETs, see here:
http://bitpimps.lixlink.com/pages/phpForum/viewtopic.php?t=2140
Hey Micro, what model do you have?
ph2t.
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October 17, 2003 at 5:44 am #28581
Yes OTP, I have fet modded these, but there are fet mods and there are fet mods. This fet mod does nothing to enhance the performance of the car.
This is what I wrote in reply to the bitpimps thread………
I’ve fet modded these things, and the result is dissapointing to say the least. The problem is that the design of the control signals to the H-bridge (yes there is a full H on the pcb, 2 of them actually) only raises the gate voltage of the transistor (or fet) to a pulsed 900mV, barely enough to turn the fet on at all. The designers have tried to overcome this “half turn on” by stacking the negative transistor in the forward circuit, which helps, but comes no where near the potential speed that this car should be running at. To fully turn on a tranny/fet at least 2 volts, preferably 5 is needed. The IRLML2502 fets start turning on at 700mV, so at only 900mV they are only just turned on, and still in a high resistance state, thats why they dont conduct like they do in a BCG or Gen1 ZZ that has 3.3 volts available to turn on the transplanted fets.
I am still working on a couple of ideas (transistor combinations) to get a decent voltage across the motor from this H-bridge, but it looks like this 900mV issue is going to be the biggest hurdle to overcome now.
BTW, I tried running my ZZ SE on 3.6 volts (simulating a 3 cell) and there was no increase in speed, for the same reasons as above.
I dont know why they have done it, but they are using a 3 volt DC-DC converter to power up the control chip, which keeps the output driving signals at exactly the same values regardless of the battery voltage.(Oh well, thats probably why they have done it) You could run this car on 12 volts and it wouldnt go any faster.
I will keep trying, I want to see performance like that of a fet modded BCG coming from this car.More work needs to be done on these, just because a fet goes into a circuit and it works, doesnt call for “I have fet modded a car, yahoo” .It has to be a decent improvement, and in this case so far its not.
ph2t I have an Efini RX7, and 2 extras here for modding.(hopefully)
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October 17, 2003 at 6:27 pm #28559
Micro, would you reccomend the EFini RX7 vs. the others available?
Thanks man,
ph2t.
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October 17, 2003 at 6:52 pm #28560
It is said to be the one with the least steering problems, but I dont know how much diff a shell is going to make. It sound like they just need a bit of tweaking anyway.
:)uA -
October 22, 2003 at 7:32 pm #27349
oh well…even thoguh fets won’t work that well on the SEs, at least they are the closes thing to proportional bits…
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October 22, 2003 at 7:32 pm #27651
oh well…even thoguh fets won’t work that well on the SEs, at least they are the closes thing to proportional bits…
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October 22, 2003 at 8:00 pm #27990
Just thought I’d update my comments on the ZZ SEs and FET modding them.
I HAVE HAD EXCELLENT SUCCESS FET MODDING THESE BABIES NOW.
They fly and have as much power as a fet modded bcg or Gen1 ZZ.
Check my website for more details, but they are stacks of fun once they start screaming around the place at 15kmh (10mph)
Couldnt be happier with these now, I cant put them down.
:)uA
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