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Old Sep 27, 2012, 03:29 AM
I don't like your altitude
Stupot46's Avatar
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Quote:
Originally Posted by Knoll53 View Post
If I'm keeping up correctly, you have not chosen a wing yet.

As far a speed goes, one thing that I have learned from the Manatee project is that a very thick wing simply will not fly fast. Happily, it makes tons of lift at the modest airspeed that it cruises at.

Kent
Hi,Kent,no the whole wing/ airfoil thing is very much open to debate.I've read a lot of threads on the effect of sweep etc,but am in no way qualified to make an informed choice.
Would I be correct in thinking that whatever airfoil is used it will become effectively stretched ie thinner as the sweep is increased?
Regards Stuart
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Old Sep 27, 2012, 10:11 AM
less is more
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United States, CA, Marina
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By inspection, you can see that the chord increases as the wing swings back, thus changing the ratio of chord the the measured thickness, which is the definition of thickness. Of course the measured thickness does not change.

Kent
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Old Sep 27, 2012, 01:42 PM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,379 Posts
Quote:
Originally Posted by Knoll53 View Post
By inspection, you can see that the chord increases as the wing swings back, thus changing the ratio of chord the the measured thickness, which is the definition of thickness. Of course the measured thickness does not change.

Kent
Bad choice of words,should have left it at stretched.
What I was thinking was that as the sweep angle increases the thickness ratio of the airfoil parallel to the airflow decreases.
Will this be a beneficial effect?Higher ratio with wings extended for slow flight,lower ratio for swept higher speed.
Regards Stuart.
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Old Sep 28, 2012, 03:32 AM
I don't like your altitude
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Displaying my total lack of electrical knowhow.The motor has only two wires,so I presume I can't use the servo tester to drive it.Direct connection to the battery and reverse the polarity to reverse the direction?
Regards Stuart.
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Old Sep 28, 2012, 09:38 AM
Just call me crash for short
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United States, OH, The Plains
Joined Jan 2011
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Quote:
Originally Posted by Stupot46 View Post
Displaying my total lack of electrical knowhow.The motor has only two wires,so I presume I can't use the servo tester to drive it.Direct connection to the battery and reverse the polarity to reverse the direction?
Regards Stuart.
You are correct Stuart, just the battery is all you will need to run the motor. From their web site, anything between 3 and 12 volts will run it. If your using a LiPo, 1S to 3S will work, or 2 - 8 cell standard battery. Reverse the polarity to reverse the direction.

Mark
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Old Sep 28, 2012, 10:16 AM
I don't like your altitude
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Thanks Mark.The local electronics shop will probably have a switch I can put in the circuit.
Regards Stuart.
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Old Sep 28, 2012, 04:15 PM
I don't like your altitude
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Busy this week,so not much done.Put the top slide in place,the height of the unit is 45mm.I think I can reduce this a bit,but it'll suffice for now.
Templates cut for the roots,I'm going to make these 42mm thick.
Stuart
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Old Sep 29, 2012, 05:34 AM
I don't like your altitude
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Blanks cut.Next some study as to how to fit the bits and pieces."It needs a coupla cowts o' looking at"(yorkshireism)
Stuart
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Old Sep 29, 2012, 11:17 AM
less is more
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United States, CA, Marina
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Being a sailplane pilot, the idea of having a motor on board is....well...new.

So have you fired up that monster yet???


Kent
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Old Sep 29, 2012, 11:48 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
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Quote:
Originally Posted by Knoll53 View Post
Being a sailplane pilot, the idea of having a motor on board is....well...new.

So have you fired up that monster yet???


Kent
No,not as yet Kent.I need to get to the shop for a suitable switch,see what sort of connecters I need etc.Monday hopefully.
Stuart
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Old Oct 03, 2012, 05:38 AM
I don't like your altitude
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Bit of progress.Cut out a pair of blanks for the wing roots.The series of holes are to take tubes/rods to aid compressive strength(they'll also stop it squashing:-) ) After a lot of trials with heating and sharpening brass tube I drilled them with a 6mm router bit.
Next I put the cores back in the blanks and fitted templates to cut slots for the brass wing box.I arranged them this way so there are no corners to trap the wire.
Any suggestions as to fixing the box(with hindsight I had no need to cut this deep:-( )
To hand I have epoxy and micro balloons,also a gorilla type glue.
I've had the drive running-I remembered I had an old Hornby train controller stashed away.Perfect for the job.Unfortunately the coupling wasn't good enough so I've got a neat alloy one on the way. Otherwise it ran fine,at 12v it was moving really fast,I'll post a vid when I get the new parts.
Regards Stuart
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Old Oct 04, 2012, 02:26 PM
I don't like your altitude
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Bit more progress.The brass boxes cut and fitted,very snug fit.The tube ends showing on the edges are to take the drive arms,one above and one below the shaft centre.All the tube here will be replaced with carbon;I've ordered a length of 6mmx4mm and one 4mmx3mm to fit inside it.These two,along with a piece of 3mm steel shaft will enable me to try the direct link I speculated about earlier,or form attachment points for the rod ends.
Stuart
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Old Oct 05, 2012, 12:35 PM
I don't like your altitude
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Marked the laminate ready for cutting.I'll cut these out with circular/jigsaw,outdoors tomorrow.
Placed the drive and roots to see how they look.One job I can do whilst waiting for the bits is to figure out how to mount the slide rails.
Stuart
Pics didn't come throughBack in a mo'
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Old Oct 05, 2012, 12:42 PM
I don't like your altitude
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Whew!
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Old Oct 05, 2012, 01:10 PM
I don't like your altitude
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On the subject of slides I received an unexpected parcel the other day.From igus.co.uk.Amongst the samples was the piece of rail and slide.I asked for a quote on it,1m of rail and two slides for £15.I think these may find there way into the final version.
They do a wide variety of slide rails,bearings,chain cables etc.May be of interest to our cnc man.
Stuart
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