Multi wing fan blades...

[Hovercrafters]

Has anyone tried those multi wing adjustables fans in a UH craft? I am
talking about the ones typically used in a sevtec. I have the opportunity
to buy one and think it would be a good replacement for my wood one.

Brendin

[bruce einarson]

Hi Brendin, to add to your question I would be interesting in seeing some
performance comparison charts for the different fans. I do not think I have
ever seen anything for the UH fans.

I assume that the Multi wings do not need any reductions ???

Thanks
Bruce

"Hovercrafters" <you....@spammersgotohell.com> wrote in message
news:%ql4e.48$vt1.40@edtnps90...

[Hovercrafters]

I don't think they need reductions as you can vary the angle of the blades.
I think I'll just buy the 26" one and give it a shot.

"bruce einarson" <hein...@mts.net> wrote in message
news:wum4e.2999$Mj.2...@news1.mts.net...

[Ken Roberts]

I think I heard a whisper about using one for lift. I don't see why that would
be a problem, the only thing is you'd have to get the load right.

Another interesting tidbit you might think about is the low rpm characteristics
of UH lift fans vs the MultiWing ones. UH designs their fans so that the craft
loses its lift in a certain range.

If you mess with the "solidity" of your fan (the amount of the duct area covered
by blades at any instant) you will change the rpm of when your craft goes on and
comes off bubble. That assumes you're using the same engine in direct drive,
and have similar blade characteristics.

In other words, there will be some necessary experimentation in order to get
things right.

[Hovercrafters]

I need the 26" fan for my Surveyor build anyways so if it doesn't work well
not a big deal

"Ken Roberts" <k...@kroberts.in.9ci.com> wrote in message
news:slrnd55bc...@kroberts.in.9ci.com...

[Troels Larsen]

I've got a Multiwing pressure/rpm/efficiency/etc program - If you'v got the
data I can find the right prop.

As far as I remember the 26" one is about $100

/Troels

"Hovercrafters" <you....@spammersgotohell.com> wrote in message

news:nFy4e.178$7Q4.117@clgrps13...

[Ken Roberts]

Really?!

That's a lot cheaper than I thought. This is for an entire fan? Bolt it on,
adjust it and fly?

Brendin, I think if you need one anyway then you can't lose. Try it out and see
what happens.

[Neil Medcalf]

I've written to UH for flow rate for their smaller 24-14N fan and all I've
gotten sofar is a runaround. The guy keeps trying to get me to buy plans for
a craft or a constructors guide. All I want is an airflow rating! Does
anyone have the airflow rating for the 24-14N @ 9lbs/ftsq cushion pressure?
Neil

"bruce einarson" <hein...@mts.net> wrote in message
news:wum4e.2999$Mj.2...@news1.mts.net...

[Fanman_UK]

On Tue, 12 Apr 2005 13:02:41 -0700, "Neil Medcalf"
<zo...@pacificcoast.net> wrote:

>I've written to UH for flow rate for their smaller 24-14N fan and all I've
>gotten sofar is a runaround. The guy keeps trying to get me to buy plans for
>a craft or a constructors guide. All I want is an airflow rating! Does
>anyone have the airflow rating for the 24-14N @ 9lbs/ftsq cushion pressure?
>Neil

If you already know the cushion pressure Neil you can calculate the
volume flow required for the craft. Easier still, contact me direct
and I can send you a spreadsheet (excel) which will do it for you with
some input about your skirt.

I suspect that you may have to make some small additional allowance
for the pointed bow. :o(

Fanman_UK

To reply by email remove the "fanman"

[Neil Medcalf]

Thanks Fan man- My requirements are as follows -
Length 8'5" Width-5'11" Area- Aprox -49 ft/sq
AUW- 450lbs- CP- 9.18 Lbs/ft sq
current est. airflow- 65 cubic feet/sec.
Skirt- a simple Segmented design

As I would like to bleed thrust off of this as well I would like to obtain
130 cu feet/sec from a fan of 24 to 30" dia.
The ultimate question is- are the UH fans capable of this airflow? And if so
what HP rating are we talking about to get this airflow.
I currently have a 4hp Tech engine I can use..
Please note this is a LOW PERFORMANCE craft for kids and "beginning adults"

Thanks again- Neil Medcalf

"Fanman_UK" <pa...@fanman.commark.freeserve.co.uk> wrote in message
news:h7lo515ob0849lgm9...@4ax.com...

[Sonerai]

What does the N in the fan designation stand for? I don't see it in the
prop templates.
Randy

"Neil Medcalf" <zo...@pacificcoast.net> wrote in message
news:115oa97...@corp.supernews.com...

[Neil Medcalf]

Don't know what the N stands for but that's how it's listed on the UH site
for the preshaped fans....
Neil

"Sonerai" <rpr...@mit.midco.net> wrote in message
news:RLudnQqCIqZ...@midco.net...

[Marquis Songer]

"N" stands for narrow blades. They are made from 1x4 material. The other
fans are made from 1x6 material.

As far as getting a flow rate from UH goes, the only way you will probably
get that information is to talk to Bob Windt directly. I've never seen that
information published in any of the material I've ever seen during my
affiliation with them.

Best regards,

Marquis Songer

"Sonerai" <rpr...@mit.midco.net> wrote in message
news:RLudnQqCIqZ...@midco.net...

[Ken Roberts]

The issue, if I understand correctly, is that flow rate for a lift fan depends
as much on external parameters as it does on the fan itself. So wouldn't the
flow rate for a hovercraft lift fan depend on the individual machine (area
covered, mass, rpm, etc) such that you would need to punch all the other info in
in order to get even semi-accurate flow rates?