CTC email

Jon Senior wrote:


Just needs wings. Apparently, someone has done the maths, and concluded
that it is possible to build a HP Helicopter. The only requirement is a
person capable of producing 400W for 45 seconds (The time constraint is
required to prove that the vehicle is airbourne and not just bouncing!).

Two HP helichopters have already been built and "flown" - one in Japan
and one at Cal Poly. However, they only go up and down, and not very
far at that. The HP helichopter which can actually go places is
considerably less likely than, say, jet packs for all, meals in pill
form or the return of the Austin Maxi.

--

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
================================================== =========
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
================================================== =========

Jon Senior wrote:


Just needs wings. Apparently, someone has done the maths, and concluded
that it is possible to build a HP Helicopter. The only requirement is a
person capable of producing 400W for 45 seconds

.... and a 300ft cliff ;-)

Tony

Jon Senior wrote:

I can build the frame myself, I also then have the option of USS and
front suspension.

Front sus on its own isn't that much of a win, it appears. Most designs
that only do one wheel usually favour the rear. Another alternative,
probably better, is to suspend the seat to some extent which is how the
PDQ and the new Windcheetahs do it. The Wavey has optional front sus,
but in a review (in C+ IIRC) the folks doing the tests reckoned the seat
sus on the PDQ was rather better.
If you avoid a hard shell seat there's less need for sus anyway (plus
it's generally cheaper and lighter). Never particularly missed it on
the old Orbit Crystal, and what goes for some sort of standard pattern
on US 'bents is soft seat and no sus.

Pete.
--
Peter Clinch University of Dundee
Tel 44 1382 660111 ext. 33637 Medical Physics, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

Jon Senior wrote:

: 400W is actually very close to possible at the minute. A suitable guinea
: pig and some serious steroids should make it a reality.

400W is perfectly possible - Lance Armstrong can produce 400W for an
hour. As did Chris Boardman during his hour record.

I can't mind.

Arthur

--
Arthur Clune

Arthur Clune wrote:

400W is perfectly possible - Lance Armstrong can produce 400W for an
hour. As did Chris Boardman during his hour record.

I can't mind.

"Nothing is impossible for the man who doesn't have to do it himself" ;-/

Pete.
--
Peter Clinch University of Dundee
Tel 44 1382 660111 ext. 33637 Medical Physics, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

In article ,
says...
Jon Senior wrote:

I can build the frame myself, I also then have the option of USS and
front suspension.

Front sus on its own isn't that much of a win, it appears. Most designs
that only do one wheel usually favour the rear. Another alternative,
probably better, is to suspend the seat to some extent which is how the
PDQ and the new Windcheetahs do it. The Wavey has optional front sus,
but in a review (in C+ IIRC) the folks doing the tests reckoned the seat
sus on the PDQ was rather better.
If you avoid a hard shell seat there's less need for sus anyway (plus
it's generally cheaper and lighter). Never particularly missed it on
the old Orbit Crystal, and what goes for some sort of standard pattern
on US 'bents is soft seat and no sus.

The plan was rear sus a la Dutchbikes, and front sus from a cheap (To be
replaced one day) 20" fork (See Kinetics). The reason for not just
suspending the seat was a concern over power. I didn't want the seat to
move when bracing the shoulders. A small amount of thought (I do manage
it occasionally), suggested making the pivot point at the shoulders.
That way I can maintain a more rigid frame (Easier to build) and get the
seat closer to the rear wheel. The reasoning behind front suspension is
the observation (from others) that small wheels do not perform so well
over rough ground (ie. any of the roads in Scotland!). I was hoping that
even a cheap unit, might smooth out the bumps and thus improve the
handling.

I'm also toying with the idea of the decoupled chain. Single ring at the
front, triple (or quadruple) behind the rider which links via a separate
chain to the rear. The other possibility, depending on costs is SRAM
Dualdrive, but I'd really like to see one in action first. I was never a
big fan of twistgrip shifting.

Jon (There is occasionally a method in my madness!)

In article ,
Jon Senior writes:

Just needs wings. Apparently, someone has done the maths, and concluded
that it is possible to build a HP Helicopter. The only requirement is a
person capable of producing 400W for 45 seconds (The time constraint is
required to prove that the vehicle is airbourne and not just bouncing!).

Nah. It wants a bigger vehicle that can pool the energy of several
people, at significantly less output per-person. That way even a
middle-aged, pot-bellied lump like me can have a go:-)

--
Nick Kew

Nick's manifesto: http://www.htmlhelp.com/~nick/

Jon Senior wrote:

The other possibility, depending on costs is SRAM
Dualdrive, but I'd really like to see one in action first. I was never a
big fan of twistgrip shifting.

After tests in the NL both Roos and I came out quite favourably
impressed with the DD, and it is nice being able to change down stood at
lights or the like as you can't honk your way out of it on a 'bent if
you stopped in too high a gear.

You don't /need/ to use a twist (I think they're a Work of Stan, Roos is
more underwhelmed with them than I am), it should be possible to set it
up with a pair of bar ends (as on the Grasshopper, and indeed on the
Fiero that should arrive for Roos later this month). Even if you do
like gripshifters they're the wrong way up/round on underseat bars, but
bar ends actually work better than on the drops they were designed for.

Pete.
--
Peter Clinch University of Dundee
Tel 44 1382 660111 ext. 33637 Medical Physics, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

In article , says...
Jon Senior wrote:

: 400W is actually very close to possible at the minute. A suitable guinea
: pig and some serious steroids should make it a reality.

400W is perfectly possible - Lance Armstrong can produce 400W for an
hour. As did Chris Boardman during his hour record.

Apologies... I had my figures wrong. The actual value is nearer 800W.
Apparently the "output" of most sprinters is around 600W. Back to
steroids I think!

Jon

Jon Senior wrote:

: Apologies... I had my figures wrong. The actual value is nearer 800W.
: Apparently the "output" of most sprinters is around 600W. Back to
: steroids I think!

Max output of sprinters is rather more than that. ~2000W for a couple
of secs for track sprints.

Arthur

--
Arthur Clune