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Old Jun 06, 2009, 06:42 AM
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Mölnlycke, Sweden
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CarbonFibre Rowing?

I have just started to build a Minimum and have a small question:
When you apply tha Carbon Fibre Rowing and Epoxy at all joints, do you drench the rowing first or do you wrap the rowing "dry" and then drench it in epoxy?
I have tried the "drench first" method and thinks it is difficult to lock the last loose end, it sort of unwinds all the time.

Per
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Old Jun 06, 2009, 10:58 AM
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Per,

I put some resin on the parts to be joined, then drench the strand of cf with resin and wrap it around the joint. That done, I drench the finished wrap with resin until I get a sort of glossy surface.

To secure the loose end, I start by placing the cf strand against the joint, a few centimeters distant from its actual end. Then I turn the cf strand back on itself, leaving some kind of loop, and do the wrap. At the end of this, I put what's left of the strand through the loop and pull the loop tight with the starting end of the cf strand.

I hope I made myself understandable.

Jochen
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Old Jun 06, 2009, 03:13 PM
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Quote:
Originally Posted by seipean
I have just started to build a Minimum
Quote:
and have a small question:
When you apply tha Carbon Fibre Rowing and Epoxy at all joints, do you drench the rowing first or do you wrap the rowing "dry" and then drench it in epoxy?
I have tried the "drench first" method and thinks it is difficult to lock the last loose end, it sort of unwinds all the time.
Per
I found that once the epoxy had started to cure it was easier to get the loose end to stay where you wanted it to go.
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Old Jun 07, 2009, 04:32 AM
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Thanks you Jochen and Peter, I believe I understod what you ment.
I will try this!

/Per
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Old Jun 07, 2009, 05:10 AM
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Quote:
Originally Posted by seipean
Thanks you Jochen and Peter, I believe I understod what you ment.
I will try this!

/Per
I'm sure you will have found it already, but my Minimum build log is on my web site.
http://www.peteronion.org.uk/Autogyr...mum/index.html

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Old Jun 09, 2009, 02:54 PM
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Well Mike I have put the Binford on hold for a while and have been gathering valuable information ,Sometimes you have to step back and look at the BIG PICTURE. I have been fallowing Rich and his progress with the Tempest and taking in all the knowledge that has come from his project and this is my 3rd version of the redneck build. It looks promising but it is only a driveway test what I do like is that the blades spin up with just forward speed and no wind at all, The on question I would have for Rich or anyone else who does ground takeoffs is the nose seemed to pull up on its own and then turn right Is that the norm and do I have to correct for that somehow maybe with ruder Hey give it a look see and leave me any thoughts Thanks BILL http://www.youtube.com/watch?v=Uhow7gaZBnw
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Old Jun 09, 2009, 03:13 PM
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Quote:
Originally Posted by Mud Duck Bill
, The on question I would have for Rich or anyone else who does ground takeoffs is the nose seemed to pull up on its own and then turn right Is that the norm and do I have to correct for that somehow maybe with ruder Hey give it a look see and leave me any thoughts Thanks BILL
Roll to the left is indicative of the rotor not being up to flying speed. Can you get a video where the model is closer to the camer as it lifts off so we can get a better look at what is happening ?

Right roll can be caused by a problem with the flapping hinges but I can't remember if it means they are too stiff or to floppy (and I'm too tired this evening to try and work it out).

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Old Jun 10, 2009, 12:57 AM
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Hi Bill,
It looked more like right yaw to me than roll. Did you do a hang test with power applied to verify your thrust line? Like Peter mentioned, if someone could get a closer shot as it begins to lift it would be helpful. The Binford certainly looks good! Press on Bill!
Regards,
-Mike
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Old Jun 10, 2009, 02:01 AM
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Quote:
Originally Posted by PeterO_UK
I'm sure you will have found it already, but my Minimum build log is on my web site.
http://www.peteronion.org.uk/Autogyr...mum/index.html

PeterO_UK
Peter, I had a look at your build log. Very nice and detailed :-)

With the size of rudder you have, does it give you enough "ground steering" capability? It seems rather small?

/Per
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Old Jun 10, 2009, 04:19 AM
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Originally Posted by seipean
Peter, I had a look at your build log. Very nice and detailed :-)
Thanks
Quote:
With the size of rudder you have, does it give you enough "ground steering" capability? It seems rather small?
/Per
It is easily big enough to keep it going straight during a ROG takeoff, and it is big enough to taxi to and from the pits, but you need to plan ahead as it won't do tight turns. A free/castoring front wheel would probably help a lot, but the Minimum sits very close to the ground which makes it difficult to achive.
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Old Jul 21, 2009, 06:42 AM
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Per,

Any news on your Minimum build ?

PeterO_UK
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Old Jul 28, 2009, 05:27 AM
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Quote:
Originally Posted by PeterO_UK
Per,

Any news on your Minimum build ?

PeterO_UK
I'm done building, now it's more repairing

I've done three flights:

The first was a hand launch, once airborne it had a lot of heads up and was tilting to the right. It was also very difficult to control. It felt as tilting the rotor had almost no effect. But with rudder and throttle I kept it flying.
Unfortunally the wind made it go to far away, finally it "landed" in a three. Not to much damage.

I went home for some repair and a lot of thinking and forum-reading, mainly your's, Jochen's and mnowell129's threads.
Conclusion: to much backtilt of the rotor, I adjusted i forward approx. 5degrees and went for a new test flight.

ROG-launch this time, still to much heads-up and some right tilt. But clearly lesser then last time. The crasch this time was propably due to lost the orientation due to quite a long take of.

Home for more repairing and thinking.
The rotor head I have comes from a PT Profile kit i've built an flew (once) last autumn: I did a quite long ROG, approx 70-80 meters, but it took off nicely. I did a left turn, flew over me an started a right turn. But a combination of to much bank and to little throttle made it clip(?) and "land" vertically on a asphalt road. The only parts left to use was the motor, radio equipment and the rotor except from the plastic hinge. So I made a new plastic hinge out of 0,5mm GF and used this rotor for the Minimum.

This time I thought that maybee I shall look at the rotor-angels from the PT Profile also. And according to the plans it is more or less 0 degrees when the stab is horizontal.

Test flight three: still i little less back tilt. Also a little left tilt. ROG that takes off quite nicely. This time it actually feels that I have some kind of control. But also this time the gyro is to far away, I loose orientation when I try to turn it back to me.

Next time I believe that I will keep the settings and do hand launches. Maybee even do just a launch and land it before makeing any turns, just to see how it behaves.

/Per
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Old Jul 28, 2009, 07:30 AM
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Originally Posted by seipean
The rotor head I have comes from a PT Profile kit
/Per
You havn't actually built a Minimum! I'm not surprised it didn't fly at first

If you had built a Minimum as per the plans I'm sure you would have enjoyed many successful flights by now.

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Old Jul 28, 2009, 11:54 AM
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Per,

can you post a picture of the head you're using?

If your c.g. is in the position specified in the instructuions and you have practically zero rotor back tilt to get the gyro to fly, then it looks as if your hinges are far stiffer than the original ones. Stiff hinges result in asymmetric lift, which in turn makes the gyro take up its nose and automatically tilts the rotor backwards.

With the original Minimum head and zero rotor back tilt there'd be no chance of her ever flying.

Jochen
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Old Jul 29, 2009, 11:28 AM
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Quote:
Originally Posted by JochenK
Per,

can you post a picture of the head you're using?

Jochen
Here are some pictures of my mimimum together with som drawings.
I have not been on zero tilt, but maybee somewhere between zero and the angle recomended for Minimum. The tilt seen on the photos is what I will use next test.

Do you have an idea of how measuring the stifness of the hinge? Since the original PT-Profile-hinge broke when I crached it I've made a 0,5mm GF hinge as you have used in yours. Could they have different stiffnes?

/Per
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