Can I ask a non baot related question of the technical savvy among us.

What do i do if i am tired of using yahoo mail as my mail service due to the pop-up adverts and so on.

What does it cost to pay for a non-advertisement financed mail service?

Which sort of ones are there?

DOug

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From: Rob Denney <harryproa@gmail.com>
To: harryproa@yahoogroups.com.au
Sent: Wednesday, 14 September 2011 8:25 AM
Subject: [harryproa] electric drive on 18m harry

 

From Rick.

After the lessons from the first test I have a few more thoughts as follows:
1. A single 4kW Mars 3001 motor is likely to be good enough (we
initially thought two would be best):
http://kellycontroller.com/mars-3001etek-comparable-pmsmbldc-motor-p-29.html
2. It makes sense to have the thrust line closer to the ww hull as
this has the most drag as well as windage and is possible to use the
rudders in braking mode to spin the boat on itself as long as there is
a moment arm from the line of the rudders and the prop thrust line.
3. Having the drive leg steerable is considered unnecessary complexity
for Peter's application - it will be locked in line for the next test
but can be tilted up out of the water.
4. I have determined a 900mm diameter prop will be about right for
Peter's 4t boat. At rated power it will get 8kts with this and 5kts at
economic cruise. The big prop also has the ability to generate enough
thrust to make way against strong winds. I expect I will have to
make a suitable prop. It is bigger than any model aircraft prop but
smaller than ultra-light props.
5. I have proposed a 4:1 reduction from motor to the prop. This will
be achieved with a belt reduction. The bottom box will be 1:1 right
angle sized for the torque and the thrust from the big prop.
http://www.mitrpak.com/product_datasheet.php?product_id=55
6. The leg will tilt up when not in operation. It will have an
angled strut to take the thrust as it will be longer than 2m overall.
7. Peter is getting two new lead/acid batteries for the next test as
the ones he has on board were old batteries he salvaged for starting
his outboard.
8. I have proposed 48V for the final system and suggested a lithium
battery. I found a supplier of nice batteries and low cost solar
panels:
http://lithbattoz.com.au/?page=about-us
http://www.aidesolar.com/
The 48V 30Ah battery is AUD2085 - weighs 20kg
The 250W panels are AUD569
9. A single 30Ah battery allows full power from the motor for about 15
minutes and 5kt cruise for about 1 hour. Peter would need 4 panels to
maintain his cruise in good sunlight. He has the room on cabin top
for these.
10. The long slender hulls have low wave drag but lots of wetted
surface so any hull fouling seriously impairs performance. Peter will
clean his hulls before the next test - it has sat around for almost a
year now without anti-foul near the waterline.

All up cost about AUD7000 without labour. All up weight around 100kg.
Basically infinite range as long as the sun continues to rise; no fuel
bills; no fumes; little noise and little added fire risk.