JoaoCaldeira
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 posted on 26/1/07 at 10:09 PM |
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Electric reverse
Is there such thing as an electric reverse off the shelf?
IIRC there was one big manufacturer developing one, but can't remember who...
Joćo
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stevec
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| posted on 26/1/07 at 10:57 PM |
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Just push it Joćo or even better get your passenger to push it.
But there is one here at the bottom of the list.
http://www.stuart-taylor.co.uk/phoenix.html
Steve,
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BenB
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| posted on 26/1/07 at 11:22 PM |
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If it's the unit STM were using a few years back its a nice bit of kit.... Lots of bearings, ali brackets etc....
The main problem with reverse systems is that there can't be a "one size fits all" system. Most setups will need a fair bit of work
to install them... It all depends upon prop clearances etc...
Also bare in mind that BEC engines tend to have fairly low ampage alternators and low amp-hour batteries which don't take too well to having the
amount of current required for a starter motor to move a car for ten seconds or so being drawn..... On most setups you push the reverse buttons and
the dash lights go out!!!! Okay for the occasional reverse (e.g. on a race car to satisfy scruteneering) but not best for regular use unless
you've got a chunky deep-discharge battery and a powerful alternator. Alot of BEC drivers are wary of giving jump starts to other drivers due to
the risk of knackering the battery. 2 second jump-start vs 10 second reverse with higher current draw.... not a good proposition....
Mind you, some bike engines have an electronically adjustable idle speed (dependant upon clutch position, light switch and gear selection etc). This
makes the situation a lot better, you frig it so that you can significantly raise the idle speed (to get more alternator output) when in reverse. You
can, of course, do this with the right foot but with a small flywheel and a revy engine this is easier said then done whilst trying to reverse at the
same time....
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Bob C
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| posted on 27/1/07 at 04:02 PM |
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Hi JC,
Shouldn't be anywhere near as hard on the battery as starting a reluctant engine. General reverse load is 2m back into a parking space, your
battery will laugh at it, especially as 7s are so light anyway. Check out thread
http://www.locostbuilders.co.uk/viewthread.php?tid=48832
for the saga of power electronics development by a newcomer to the game ;^) It includes some excellent advice from MikeRJ.
I'll be making a controller for mine in a few months & if it goes well I'll try to document it properly, but it's difficult to
do an effective brain dump on a forum like this in a scenario where a 4iinch bit of wire can be a vital active circuit element.... The alternative
which I assume other folk have used is just to slam 12V on the reverse motor & hurtle backwards everywhere!!!!!
I think pre-engaged starter motor is the way to go as it conveniently takes itself out of gear when not used & can be interlocked via the neutral
switch on the bike for safety.
cheers
Bob
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