Lyle,
Guess I don't follow you 100%.
My transmission uses two different sets of sprockets between two jackshafts.
A sprag (overrunning clutch) for 1st gear. Was 1.54:1 ratio. Currently
1.82:1 ratio. I engage an electric clutch with a 1:1 ratio. This causes
the gearing on the sprag to overrunn. It's like a ratchet.
Make sense? Can you expand on what you just said.
Later,
Darin
----- Original Message -----
From: "lyle sloan" <[EMAIL PROTECTED]>
To: "ElectricMotorcycles" <[email protected]>
Sent: Saturday, October 28, 2006 12:19 PM
Subject: Re: [ElectricMotorcycles] Latest on the BadFish Drag Bike
For the Pirahna, you have a 2 motor design. Could you
use the second motor as drag during the transition?
Essentially, switch the second motor to reverse to
provide drag (with just the right voltage, of course)
and switch gears. Then put to normal and accelerate.
The reason I say this is I think when the motor
transitions to 2nd gear it is too close in speed to
mesh if it hits wrong.
I want to ask what kind of clutch you got but I am
afraid that might be a trade secret. :)
Lyle
--- BFRListmail <[EMAIL PROTECTED]> wrote:
Hi all,
Well, Mike asked for a report on how the gear
changed worked on my bike, so
here goes.
Went Wednesday to the Milan Dragway Test/Tune
session. I'd only been to one
other wednesday nite race, and it was pretty packed.
This nite was the
same, and the last one for the year. Even the 40
degree nitetime temps
didn't scare anybody off. Guess those gassers make
big power in the cold,
but I was definately down on power. I can always
squeak 600 amps out of
each string of Hawkers, but this time I could only
pull about 500.
Launches were OK. I geared 1st gear just a tad
taller than my last time to
the track where I was getting quite a bit of wheel
spin. The track was
definately cold, but was also sticky. 2nd run I
made I thought I pulled the
front end up, at least stroked the shocks out, but
maybe didn't lift the
wheel. One guy commented on how the bike launched
really good, but just
quit a few hundred feet out. I can't even feel the
clutch pull in. Not at
all. Looking at the data confirmed what that guy
said. You can see the
volts drop and amps spike when the clutch comes in.
But the amps take
forever to drop back off. The volt take forever to
come back up. I was
clearing the 1/4 mile at about 2000 RPM. I can run
about 2900 RPM in 1st
gear.
Analysis? That larger split between 1st and 2nd
gear is bogging the motors
down. But mathmatically, I don't know why I went
with such a steep 2nd
gear. At 2900 RPM I'd be turning probably 90 MPH.
Not going to happen.
So then I did some homework. I read that a shunt
motor (mostly the same as
a PM motor) doesn't respond well to changes in load.
I guess I've proven
that. A shunt motor won't make the torque to
reaccelerate the load. A
series motor is the answer for that, or at least a
compound motor.
So I'm looking at a few options:
A) Change the gearing so 1st gear is 1.375:1 and 2nd
gear is 1:1. This will
put a smaller load change on the motors, and should
hit just over 70 at 2900
RPM.
B) Lower the voltage way down on the clutch (voltage
yet to be determined)
so that the clutch actually slips and bring on the
added load slowly. Might
tear up the clutch though?
C) Toss the transmission and see if I can get it
running as quick as I did
before the transmission.
Oh yea, Suncoast can ignore the preceeding as this
is all in an attempt to
dominate at the upcoming Battery Beach Burnout.
Later,
Darin
BadFishRacing
----- Original Message -----
From: "Mike" <[EMAIL PROTECTED]>
To: "ElectricMotorcycles"
<[email protected]>
Sent: Friday, September 22, 2006 10:44 AM
Subject: Re: [ElectricMotorcycles] Harley Drags
> >About the only thing I haven't tried is changing
the gearing between 1st
> >and 2nd gear. What are you guys with 2 speeds
running for gear ratios?
> >Or if you're running 2nd and 4th gear? I don't
think I've got enough
> >leap from 1st to 2nd, as I can't seem to SUCK
AMPS when I grap 2nd gear.
> >Any thoughts?
>
> Darrin, Did you find any answers since you posted
the above? I'm always
> curious.
>
> Mike
>
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