AE .15 engine oddities

[Gary Smith]

Ok, I figured that I would just post this just in case someone is
interested.

Last year I took my RC10GT out to the lake with me. We ran it for
some time and then the RX batteries died. For some odd reason it got
stuck full throttle and the stupid spring didn't pull it to the close
position. After getting my bike and going about a 1/8 mile to get it
the car was upside down just going full bore. It was hot. It must
have been running for about 4 minutes until we got to it.

We, the connecting rod basically melted. As this was the first day of
the 1 week vacation we ran to town (the lake is only 5 miles from the
town of Oakdale) and it had a hobbie store.

I took the poor connecting rod with me and went through all of the odd
parts they had behind the counter. It was odd. They only carried the
RC10T3 car and zero additional parts. Everything was special order...
Go figure. But they were really into the TRaxx and everything big. I
managed to find the Traxxas #3224 connecting rod in what the called
the "odd bin". Coincidentally it was identiacal to the AE .15. In
fact it was $3 cheaper.

I have been looking for many little parts for my RC10GT and found a
bunch of little parts that look identical online but in many cases
cheaper...

I'm sure the reverse is also true. It seems that many of these
companies though competing use a lot of the same structures.

Does anyone have any experience with using different parts on the AE
..15 engine (like the traxxas sleave and piston combo)? Electric start
system?

Any feedback would be greatly appriciated. I'm also interested in any
stories as well.

BTW, the engine still ran great after the fact even though it's inner
bearing was toast. It was a little rought but it ran. This year I'm
putting new bearings in it and putting a different RX unit (as the
other was a 4 channel aviation) and switching from the dead nicad
rechargables to duracell or something...

Gary Smith

[hydro@antispam.net]

Interesting story, Gary. My understanding is that the use of the
throttle return spring is widely misconstrued. Its main application is
for when the throttle linkage becomes loose - not for when the RX
batteries die. Makes sense to me as there is no way my stock Assoc TR
spring could overpower my throttle servo.

But there is a solution - they're called failsafes. Dynamite's Race
Guard and Venom's failsafe are two popular models in my area. At my
local race track, everybody uses them. Failsafes put your throttle
servo into a position of your choosing (usually idle) when it detects
poor radio signal -or- a dying RX battery. The failsafe typically has
a voltage threshold of around 4.0V, so when you RX pack drops below
that, the failsafe kicks in. They're very small and worth the rougly
$30 cost.

So keep your rechargeable batteries and try a failsafe. A good
investment, IMHO.

[Gary Smith]

That makes sense... I have been playing around with some other
oddball solutions. I have a little motor connected to the flywheel
using a hardrubber wheel. It generates about 3-25v's (low-high) when
the engine is running. Using a diode network I have been playing with
it will power the vehicle as long as the engine spins. It will cut a
small amount of power off the top of the engine but not enough for me
to notice (as I don't race).

But the other item also looks interesting as well. I will probably
put one of those in as well just to be on the safe side.

Awesome Gary that sounds cool. I would like to try that too. Can you give me
more info. I would like to do this to my Traxxas Rustler. Awesome, an
alternator like a real car.

"Gary Smith" <gary.smith@primeexalia.com> wrote in message
news:2e75b13e.0304211218.7ef9fb12@posting.google.c om...
> That makes sense... I have been playing around with some other
> oddball solutions. I have a little motor connected to the flywheel
> using a hardrubber wheel. It generates about 3-25v's (low-high) when
> the engine is running. Using a diode network I have been playing with
> it will power the vehicle as long as the engine spins. It will cut a
> small amount of power off the top of the engine but not enough for me
> to notice (as I don't race).
>
> But the other item also looks interesting as well. I will probably
> put one of those in as well just to be on the safe side.

[Gary Smith]

Once I'm finished I will take some pic's and put them on my web site.
I am thinking of a better way to do it because the space is tight. I
was thinking of other solutions such as polarizing the flywhere and
putting a coil around it as this would create a zero load solution but
I'm not sure what the output would be and it would become the
collection point for metalic trash...

As the motor is the optimum place for this (because it has movement
even when idle) I have been focusing around there. It's much easier
to mount it on the drive tran but then you only have power when the
vehicle is running. Even then this may be enough.

My goal is to hook an X10 style (or something with slightly better
range) to the car and also power this as well (and record to the
laptop while crusing around). Just some odd ideas.

The final and biggest problem that I have yet to overcome is fuel...
I don't race so why do I need a small 75cc tank. Has anyone seen
something like a 200cc or so tank that with fit the RC10GT? I know
this sounds odd but it's beyond fast so I will sacrafice 20% of the
speed to extend the play life of the car 3x.


I am also interested in hearing what other people have done...

> Awesome Gary that sounds cool. I would like to try that too. Can you give me
> more info. I would like to do this to my Traxxas Rustler. Awesome, an
> alternator like a real car.
>

[Justin Mahn]

Depending on your setup, you could either mount the driving magnet on the
far side of the clutch bell, or create a stepped flywheel with the coil
around the inner step. You could also create a toothed flywheel. The
tricky part is regulating the voltage to 6 volts.

--
Justin Mahn
remove Panties to reply


"Gary Smith" <gary.smith@primeexalia.com> wrote in message
news:2e75b13e.0304212208.5641fd34@posting.google.c om...
> Once I'm finished I will take some pic's and put them on my web site.
> I am thinking of a better way to do it because the space is tight. I
> was thinking of other solutions such as polarizing the flywhere and
> putting a coil around it as this would create a zero load solution but
> I'm not sure what the output would be and it would become the
> collection point for metalic trash...
>
> As the motor is the optimum place for this (because it has movement
> even when idle) I have been focusing around there. It's much easier
> to mount it on the drive tran but then you only have power when the
> vehicle is running. Even then this may be enough.
>
> My goal is to hook an X10 style (or something with slightly better
> range) to the car and also power this as well (and record to the
> laptop while crusing around). Just some odd ideas.
>
> The final and biggest problem that I have yet to overcome is fuel...
> I don't race so why do I need a small 75cc tank. Has anyone seen
> something like a 200cc or so tank that with fit the RC10GT? I know
> this sounds odd but it's beyond fast so I will sacrafice 20% of the
> speed to extend the play life of the car 3x.
>
>
> I am also interested in hearing what other people have done...
>
> > Awesome Gary that sounds cool. I would like to try that too. Can you
give me
> > more info. I would like to do this to my Traxxas Rustler. Awesome, an
> > alternator like a real car.
> >

[Gary Smith]

The voltage isn't much of a problem. You can build a simple 6v
regulator using the LM317 circuit and it'll be fairly reliable. The
parts are under $10 to make it if you have some eletronics experience.

Here's some tech info on the chip:
http://www.jameco.com/jameco/Products/ProdDS/23579.pdf

I think that they also stock this part at radioshack.

I proposed the idea to my dad regarding weather or not I should put
this on the flywheel or on the rearend. His recommendation was on the
rear end and use nicad batteries, build a diode seperate for the
bettery to the control and have the engine run the motor to charge the
batteries while it's running. This idea seems a little simpler at it
will ensure that you don't offbalance the flywheel but it's a more
complex electronic strucutre to design.

Gary

"Justin Mahn" <gabrilPanties@tcainternet.com> wrote in message news:<vaaas3rr24ef4e@corp.supernews.com>...
> Depending on your setup, you could either mount the driving magnet on the
> far side of the clutch bell, or create a stepped flywheel with the coil
> around the inner step. You could also create a toothed flywheel. The
> tricky part is regulating the voltage to 6 volts.
>

[Justin Mahn]

So your circuit would be between the receiver pack and the reciever. It
would let a regulated 6volts to the receiver power supply. At idle, the
circuit would allow the NiCD's to power the circuit, but on power, the
charger would power the circuit and dump the extra volts back into the
battery? Sounds extremely promising! A little complex though, as you would
need to regulate the charge voltage to keep from overcharging the NiCD's
also. Fun project for a Electrical Engineering major. Of course you'd have
to make it small and light enough to keep the performance up. Maybe
something about the size and weight of the Traxxas EZ Start. Hell, you
could probably run it off the EZ start gears and lock the one way bearing,
but it would be much more drag than a toothed flywheel.

--
Justin Mahn
remove Panties to reply


"Gary Smith" <gary.smith@primeexalia.com> wrote in message
news:2e75b13e.0304221233.4dabc810@posting.google.c om...
> The voltage isn't much of a problem. You can build a simple 6v
> regulator using the LM317 circuit and it'll be fairly reliable. The
> parts are under $10 to make it if you have some eletronics experience.
>
> Here's some tech info on the chip:
> http://www.jameco.com/jameco/Products/ProdDS/23579.pdf
>
> I think that they also stock this part at radioshack.
>
> I proposed the idea to my dad regarding weather or not I should put
> this on the flywheel or on the rearend. His recommendation was on the
> rear end and use nicad batteries, build a diode seperate for the
> bettery to the control and have the engine run the motor to charge the
> batteries while it's running. This idea seems a little simpler at it
> will ensure that you don't offbalance the flywheel but it's a more
> complex electronic strucutre to design.
>
> Gary
>
> "Justin Mahn" <gabrilPanties@tcainternet.com> wrote in message
news:<vaaas3rr24ef4e@corp.supernews.com>...
> > Depending on your setup, you could either mount the driving magnet on
the
> > far side of the clutch bell, or create a stepped flywheel with the coil
> > around the inner step. You could also create a toothed flywheel. The
> > tricky part is regulating the voltage to 6 volts.
> >

[SBlackfoot]

> Interesting story, Gary. My understanding is that the use of the
> throttle return spring is widely misconstrued. Its main application is
> for when the throttle linkage becomes loose - not for when the RX
> batteries die. Makes sense to me as there is no way my stock Assoc TR
> spring could overpower my throttle servo.

Properly set up a TRS can close the throttle of a vehicle if power (or the
signal for that matter)is totally lost, unless you have a freakishly strong
throttle/brake servo. My NMT and my Rampage (a cleaner TRS setup than my
NMT, it worked out great) are both testaments to that. Of course, the only
time I've needed one was when my throttle servohorn broke on the Rampage.
;o)

[Gary Smith]

Performance isn't that much of a problem. The EZstart motor would
actually be overkill. Those little motors you get in the $1.00 kids
toys would generate enough power to push the battery back up and also
keep the RX working. The charge cutoff for the battery pack would be
the main concern though.

"Justin Mahn" <gabrilPanties@tcainternet.com> wrote in message news:<vabcfuj5gcmka1@corp.supernews.com>...
> So your circuit would be between the receiver pack and the reciever. It
> would let a regulated 6volts to the receiver power supply. At idle, the
> circuit would allow the NiCD's to power the circuit, but on power, the
> charger would power the circuit and dump the extra volts back into the
> battery? Sounds extremely promising! A little complex though, as you would
> need to regulate the charge voltage to keep from overcharging the NiCD's
> also. Fun project for a Electrical Engineering major. Of course you'd have
> to make it small and light enough to keep the performance up. Maybe
> something about the size and weight of the Traxxas EZ Start. Hell, you
> could probably run it off the EZ start gears and lock the one way bearing,
> but it would be much more drag than a toothed flywheel.
>
>

[Gary Smith]

I'm using the 605BB's for the servo. I'm currently resetting up the
car right now and the servo is not being pulled back. I'm going to
try it with a different spring though.

I do thing that the battery cutoff idea would be the best...


> Properly set up a TRS can close the throttle of a vehicle if power (or the
> signal for that matter)is totally lost, unless you have a freakishly strong
> throttle/brake servo. My NMT and my Rampage (a cleaner TRS setup than my
> NMT, it worked out great) are both testaments to that. Of course, the only
> time I've needed one was when my throttle servohorn broke on the Rampage.
> ;o)

[SBlackfoot]

> I'm using the 605BB's for the servo. I'm currently resetting up the
> car right now and the servo is not being pulled back. I'm going to
> try it with a different spring though.
>
> I do thing that the battery cutoff idea would be the best...


Both would be ideal.

Remember, a battery cut-off would be of absolutely no use if you suddenly
lose all power (dislodged battery, broken wire, switch taking a hit, etc..).
The only thing that could possibly save the model if the power goes out is a
properly set up TRS, or a lucky catch. ;o)

[hydro@antispam.net]

On Tue, 22 Apr 2003 22:06:24 -0400, "SBlackfoot"
<trypticon@sympatico.remove.ca> wrote:

>
>Properly set up a TRS can close the throttle of a vehicle if power (or the
>signal for that matter)is totally lost, unless you have a freakishly strong
>throttle/brake servo. My NMT and my Rampage (a cleaner TRS setup than my
>NMT, it worked out great) are both testaments to that. Of course, the only
>time I've needed one was when my throttle servohorn broke on the Rampage.
>;o)
>

I think in the case of the RC10GT, AE"s intent was for their TRS to
act only in case of linkage failure. I have their stock TRS and have
it installed per their manual - it definitely would not be able to
pull the throttle to idle if the throttle servo became unpowered. So
at least for the GT, its not an issue of proper setup but rather
design intent.

However, Jodi Grein has rigged up a TRS for his GTthat will work in a
sudden power cut situation:

http://www.rc10gthobby.com/~mystracing/Nitroind.htm

[Seajj2]

Just wanted to add that most racing organizations require you to have a TRS.
Get the losi ones and cut to fit. It has no problem shutting down my digital
servo.

[hydro@antispam.net]

On 05 May 2003 02:40:03 GMT, seajj2@aol.com (Seajj2) wrote:

>Just wanted to add that most racing organizations require you to have a TRS.
>Get the losi ones and cut to fit. It has no problem shutting down my digital
>servo.

Good point about the race req.

I've been told by a very seasoned racer (10+ years) that only certain
expensive types of servos can be overridden by the TRS. Your digital
servo is probably one of them. He tells me that for the common servos
most people have, the TRS won't budge them.

[SBlackfoot]

> I've been told by a very seasoned racer (10+ years) that only certain
> expensive types of servos can be overridden by the TRS. Your digital
> servo is probably one of them. He tells me that for the common servos
> most people have, the TRS won't budge them.


Who told you this? My Losi TRSs work fine with the generic Airtronics servo
in my Rampage (saved it once too) and the higher torque Futaba (I forget the
model number) in my NMT. The TRS on either chassis will close the throttle
to an idle. Anyone who tells you otherwise doesn't know how to set them up
or is using a very beefy throttle servo.

[SBlackfoot]

> My RC10GT uses a Futaba S3004 throttle servo (S3003 with bearings). The
AE
> spring is attached to the outermost hole in the throttle arm, and the
other
> end goes to the rear engine mount. The spring is NOT strong enough to
> return the servo to idle when I cut the Transmitter's power.


Then you need a stiffer spring, or move the mount from the engine mount to a
point further away. On my Rampage the spring goes from the carb to the rear
shock tower (inline engine), and on the NMT it actually loops around the
shock tower to a convienent screw, in order to have sufficient tension.

What's more likely, a broken throttle linkage or some electrical problem?
Both can be safeguarded against with a properly set-up TRS. Work on yours, a
TRS should easily close an S3004.