klims
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do you mean the pad is no longer at 0v? GND and 0v can be different…
that pad should change from 0v when the motor is not spinning to 3v when the motor is supposed to be spinning if i remember correctly (may be 3v when in reveserse).don’t quite understand what “metering” means but i have noticed that the 7317 FET’s seem to keep their last gate signal, as in if you turned them on then disconnected the wires they would stay on and would sometimes change state while soldering. i never worked out why but the mosfets still worked afterwards so i don’t think thats your problem.
for a bit of troubleshooting you should make sure you have connectivity from the board all the way up to the gates on the FET’s (pin 4). if thats not your problem then make sure all the wires are soldered to the right pads, and if that doesn’t solve it then try turning the car on for a second and only a second! if you have wired it incorrectly you could blow up the FET’s. make sure the RX is on and then turn the car on the steering kicks to the centre. this will let you know if you have power to the PCB. if it doesn’t react then maybe you should check that its all hooked up right.
i should mention that i have a mini z, but i think it should all work the same.
Andrew.
yeah i noticed it wasn’t mentioned in the description. don’t really care about the gyro though. sounds like a bit of a cop out.
P.S: sorry for hijacking the thread…
i picked mine up about 4 months ago when they had just come out on toyeast.
that looks pretty mental. hope you guys are right about the belt drive.
sounds like i’m gonna have to start saving again!drifting pretty much. although my preffered surface would be road so i was worried about pebbles getting into the belt drive and ruining it.
i know this is a litle off the topic, but have you guys ever had any problems with the belt drive system? that really the one thing holding me back from getting one. i much preffer the shaftdriven 4WD
WOW. thats pretty impressive. i’m not into the Bit’s, but that looks like a fair amount of skill went into making it.
how exactly do you make something like that? did you just paint it? i’d love to see some stage by stage shots if you’ve got em.
so over the summer break i finally took the plunge and went the Li-Po upgrade.
not wanting to spend 60+ USD on polyquests, i went the low budged chinese knock off brand Li-Pos seen here.
I know the dimensions aren’t exactly right, but for $40 bucks delivered i was willing to give it a shot.when they arrived i found they didn’t exactly sit too well in the battery holders but with some imagination it actually worked out ok… lol it looks like it has wings! it all fits pretty neatly under the body as can be seen, and the body actually holds the Li-Pos in place pretty well. haven’t fallen out on me yet!
the only thing really holding me back atm is the spider. it really doesn’t seem to be up to the challenge. was running fine on nimh but just giving it a little squirt on the floorboards with the Li-Po setup and they are quite warm. i’m trying to order in some more efficient MOSFETS but am so far unsuccessful.
i don’t suppose anyone wants to part with a nelly do they?[ATTACH]269[/ATTACH]i have one. they are awesome! bought mine off toyeast for just under $60AUD.
i was most surprised with the maneuverability of the little suckers. considering they are 2 channel you can get them doing exactly what you want with a little practice.the only problem i had was letting other people have a go and have both my tail props snapped…
anyway i would definitely recommend one if you have 60 bucks to waste on a toy.
i don’t suppose anyone will be able to post the part numbers of the nelly mosfets?
doesn’t matter what model, i’m just having trouble finding low resistance p-chan’s in an SO-8 package. best i can find are the Si4453DY at 6.5 mOhm.hey Aaron,
i have a spider flying lead turbo and noticed the other day that after much use and even more amperage my motor spins faster in the reverse direction.
is it possible for the mosfets to “waste”? do you know if the high amperage can cause an increase in mosfet resistance? the forward direction N-chan has a higher voltage drop across it than the reverse. i didn’t check it when it was new so i’m not exactly sure about it.do you sell the mosfets used in the turbo separately?
side note…
so as a result of my investigation i ended up just drowning the tracks that were visible with solder and noticed an INCREASE in speed! thought this might be of interest to you in your never ending quest for increased performance.Andrew.
any news/updates?
so i pulled my iwaver pro to piece thinking i was gonna “modify” it only to find that its a 20t motor! no wonder why it was killing my pn anima (33t).
i’ve been running this with my spider 2.1 with no problems. it doesn’t even get hot! does anyone know at what number of turns i’m pushing the limit of my spider? i’m happy to test it, but i really dont want to blow it up in the processi’m in for 3 or 4, depending on the total cost (inc shipping to melbourne). i’d be willing to spend $50 bucks all up.
what is the ETA in these beasts? before christmas?i scored a couple of the 0.47 farad super capacitors that jaycar sells. i had 2 hooked up in series (0.235 farad total) and it is CRAP!!! they drain way too much battery power. i have it hooked up across the battery terminals because i figured that when i gas it it will be drawing most current so the cap could help out. it takes a good 10-15 sec to charge up which means when i take off its good but kills acceleration afterwards. i wouldn’t recommend going higher than 0.1 Farad, but i guess that depends on how you like to drive
P.S i should mention that i was running that in my mini z
oh sorry i guess i didnt explain myself too well. i haven’t actually run the setup with LiPo. i only tested my circuit and found that the mosfets (7317 from the shop) were shorting for some unknown reason. i guess i’m gonna have to buy some more and keep testing.
also the two mosfets running at 7.2 volts was supposed to be a crappy representation of my spider…
i’m interested. what price range are we talking?
ok, so i figured out that my circuit doesn’t work when a heap of smoke escaped from one of the mosfets.
does anyone have any thoughts or suggestions? anyone at all????anyone????????
thanks for that PH2T
Suspension is a big thing. It can just be too fast to dampen well.
i just got in my kyosho oil damper from hobbyjapan. it kicks arse! i noticed both you and BETTYK had one without a spring. works wonders.
Grip is also an issue. You need some really nice soft n sticky foams to get that power to the ground and keep it there.
i have a pair of medium foamies on the back so thats not too bad. the setup i like best is getting the pinion gear right so that at full throttle from stand still i dont spin out. its getting some great speed. im not really to good at handling it though. today i turned my 0 deg knuckles into 10 deg knuckles with the help of those reflectors on the road lol. got some serious air!
That won’t work. The reason why is that the mosfet gate voltages don’t fully alternate between GND (0v) and Vcc (4.8v for 4 cell nimh). Whilst I won’t go into the full details, you will find that both the p-chan mosfets on your turbo will always be on. When you apply throttle you will create a short circuit along one path of the h-bridge and blow the turbo.
yeah this is one of the few things i remembered about transistors from 2nd year lol.
I use MOSFET drivers on my nelly deluxe to achieve a similar (but more effective) result. (MOSFET drivers are suited to turning on MOSFET really well, really fast, really hard!)
yes i like the sound of that! that is originally what the electronics guy was telling me to do. he didnt like the idea of using a p and n chan mosfet though. what mosfets do you use? im not too sure how you feel about sharing your hard work but if you were willing to tell me how exactly you set it up i would really appreciate it.
and about those polyquests. i have been doing some research and found these. they dont seem to be the same as yours though. are the dimensions the same?
thanks for all the help
Andrew.
so i figured by the overwhelming response that either no one knew or i asked a stupid question… so i started doing some hunting around. i now see the error of my ways.
BETTYK i see what you were saying. i’ve done some more mods and its fast enough, although i guess it can always go faster lol.
so anyway i was talking to the electronics guy at work who tells me that it is possible to run a load of 7.2v with a 5v gate voltage, however it does require some circuitry. i’ve been trying to figure something out using a configuration like this one (does’t seem to be up), but to adapt it to 4 input signals. what it does is use transistors and some pull up resistors to trigger the gate. i’ve been told that the right combination of resistors can make it happen, but i’d need to do some circuit analysis.
Has anyone tried to do something like this? is it a waste of time trying to get it to work?thanks for the input guys.
Andrew.
i know this isnt really a lipo question, but if i had a 6 cell setup with 4.8v running to the pcb and 7.2 running to the turbo would this work? i figure its the same as having a voltage reg on the turbo isnt it?
PH2T have you seen these? waht do you think? they seem pretty sweet at a max 13C (6.5A) continuous discharge. the guy seems to think they will fit in an mr02 but after measuring mine i dont know how…
i have also been looking at these but they have a max discharge of 2C each so about 2.5 A with 2s2c. any advice would be greatly appreciated
sounds good. i dont have a speek checker so i have no idea how fast i am going. would probably be a good inverstment.
i guess if you actually have a decent place to race 30-40 is plenty, but seeing as i am down at my local factories thrashing it around the car park i wanna see more speed… and besides the mm i have only allows me to go to 12T.
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