Taking off with heading hold will get the plane to rotate (usually) but if you leave the sticks at neutral when doing so once it rotates it will apply control surface movements to get back to the heading that was last remembered by the Guardian. I take off in 2D, 3D and off. You just have to remember if you have heading hold on you have to change the heading with the sticks. 2D is harder to do when climbing out because it will level out every time you center the sticks.

Originally Posted by jedorme

Have been flying my PZ foam T-28 almost entirely in 3D mode with great results, particularly if there is much wind. Recently I started turning on 3D for takeoffs & have noticed that as the plane starts to rotate on the ground, the nose often will abruptly dip down even past level unless I catch it before it starts. A few takeoffs have resulted in the nose gear almost hitting the ground before it starts its climbout.

Would a solution for this be to feed in a bit more up elevator even before it is at takeoff speed? I've been taking off with some nose down on the initial roll out to ensure nose wheel steering but trying to judge when to come off of it to let the plane rotate, which without the Guardian it pretty much does on its own when its ready to fly. Any ideas most welcome. Thanks,

Jed

I've had great success with my Formosa taking of in 3D heading hold. I set 3D mode, point the plane where I want it to go, stir the stick to lock it in, put the plane on the ground. Then just max the throttle and watch while Guardian executes a beautiful takeoff literally hands-off, auto-correcting any turbulance! This wouldn't work in 2D mode as Guardian would keep the plane level and probably stuck to the ground depending on the level setting.

Originally Posted by choochoo22

You're right. Last night I was catching up on a weeks worth of posts and missed that, sorry.

If it was me, I'd rather have the available channel for mode than gain. Once a working gain is established, it shouldn't need much tweaking.

I figured that was the case.

Originally Posted by choochoo22

You're right. Last night I was catching up on a weeks worth of posts and missed that, sorry.

If it was me, I'd rather have the available channel for mode than gain. Once a working gain is established, it shouldn't need much tweaking.

Originally Posted by Prof100

I fugured that was the case.

When flying on my own, I would agree that it would be more fun to use the free channel for MOD.
But when training you will fly 2D anyway and the GAIN channel pot lets you "challenge" the student progressively. Therefore I wanted to assign the free channel to GAIN but then I lose the neat switch-flicking trim reset function.
BTW, I found that setting the initial trim calibration with the PC was quite challenging (in the end I used a spirit level) to achieve no control surface movement between Guardian ON and OFF.

Originally Posted by Galand

When flying on my own, I would agree that it would be more fun to use the free channel for MOD.
But when training you will fly 2D anyway and the GAIN channel pot lets you "challenge" the student progressively. Therefore I wanted to assign the free channel to GAIN but then I lose the neat switch-flicking trim reset function.
BTW, I found that setting the initial trim calibration with the PC was quite challenging (in the end I used a spirit level) to achieve no control surface movement between Guardian ON and OFF.

Thinking about it, there are some very good reasons to set it up either way depending on the plane, transmitter, pilot, and objective.

Originally Posted by ricoalonso

When you say 3D, which Submode (Heading Hold or Direct Rate) are you using or, had you tried both with the same result?

I should have clarified that I'm using Heading Hold as I'm using the T-28 as a test bed before I install a second Guardian & 2 more on order in some tail draggers that are a bit squirrelly on takeoffs. The HH works quite well to steer a straight line; it is just the problem of wanting to flatten out the rotation that is giving me the problem.

But for the T-28, taking off with it turned off is certainly possible. For a tail dragger, I haven't really thought out the issue of rotation, as maybe once the tail is up & the Guardian is happy with the level flight position, it will just fly off with some added up elevator. Has that been the experience of those using 3D HH when taking off a tail dragger with the Guardian on?

Jed

Originally Posted by jedorme

For a tail dragger, I haven't really thought out the issue of rotation, as maybe once the tail is up & the Guardian is happy with the level flight position, it will just fly off with some added up elevator. Has that been the experience of those using 3D HH when taking off a tail dragger with the Guardian on?

Jed

With my Formosa taking off in 3D HH it pretty much drags the tail until lift-off. (I pre-set it to climb out attitude.) Not very scale, but the fastest way off for a plane with plenty of power. Taking a small plane off rough gravel, keeping it on the ground for a long roll with the tail up gaining speed isn't going to look prettier or work better, it just beats the plane up and isn't necessary.

I can see, however, where someone with a larger, more scale plane taking off asphalt may want a longer roll with the tail up for aesthetic reasons or if the plane needs to gain speed. In that case it seems like 2D HH would work better if you can get the level attitude set right, then a gentle pull on the stick for lift-off.

When I tested the Guardian in my 41-inch Edge 540 (tail dragger) I always take off in 3D Direct Rate and I let it take off with a long roll along the runway and did not notice any issue.

Originally Posted by jedorme

I should have clarified that I'm using Heading Hold as I'm using the T-28 as a test bed before I install a second Guardian & 2 more on order in some tail draggers that are a bit squirrelly on takeoffs. The HH works quite well to steer a straight line; it is just the problem of wanting to flatten out the rotation that is giving me the problem.
Jed

jedorme,

To help with the take-off you can program some up elevator into a mix on a switch. This will tell the Guardian to maintain a climb angle for take-off. The mix can also be used in flight to either climb or to maintain altitude when the throttle is reduced. Test it at altitude to check how much up elevator to program into the mix. When the amount is correct the plane will lift off by itself and look very scale.

I program three switches where each adds about 5% up elevator. Then I can decide how much I want by using one or more switches.

Just before the take-off run move the aileron/elevator stick to set the Guardian heading hold. That will help keep the take-off straight. You can still use the rudder to keep it straight.

Steve

Originally Posted by Floater73

To help with the take-off you can program some up elevator into a mix on a switch. This will tell the Guardian to maintain a climb angle for take-off.

This is mode dependent. In 3D Direct, the up elevator will be telling the Guardian to maintain a mild rate of loop! It will feed in as much elevator as it needs to achieve that rate, most likely resulting in a stall if you don't correct it first.

When flying on my own, I would agree that it would be more fun to use the free channel for MOD.
But when training you will fly 2D anyway and the GAIN channel pot lets you "challenge" the student progressively. Therefore I wanted to assign the free channel to GAIN but then I lose the neat switch-flicking trim reset function.

Someone want to try an experiment , I would but I am to tied up in other projects at the moment.

Normaly Rudder is or can be set to full servo range as in full CW ,full CCW and ofcourse cetered. These are the same outputs required to reset Trims on Guardian 2D/3D so...........

Seems one could disconnect Rudder signal from Guardian to receiver and plug Guardian Mod. lead into Receiver make Trim Reset and then switch leads back. Yes it is a pain bvut should work I believe.

It seems one could also use a spare receiver and receiver battery and connect this receiver to the Guardian 2D/3D Mode channel and along the same lines a servo tester should work also.

Perhaps Bill or John will comment on these ideas.


Charles

Originally Posted by everydayflyer

Someone want to try an experiment , I would but I am to tied up in other projects at the moment.

Normaly Rudder is or can be set to full servo range as in full CW ,full CCW and ofcourse cetered. These are the same outputs required to reset Trims on Guardian 2D/3D so...........

Seems one could disconnect Rudder signal from Guardian to receiver and plug Guardian Mod. lead into Receiver make Trim Reset and then switch leads back. Yes it is a pain bvut should work I believe.

Charles

How about a Y connector and a SWITCH on the arm going to Guardian mode channel. No fumbling with connectors just the switch. You would need to be anal about checking switch is in the correct position before flight.

Steve & choochoo22 - When taking off in 3D Heading Hold mode, I'm a bit confused by your reference to "stirring the sticks" or moving the "aileron/elevator control" just before take off to set it. Can you clarify this? Thanks,

Jed

Originally Posted by jedorme

Steve & choochoo22 - When taking off in 3D Heading Hold mode, I'm a bit confused by your reference to "stirring the sticks" or moving the "aileron/elevator control" just before take off to set it. Can you clarify this? Thanks,

Jed

Every time you "stir the sticks" the heading is reset with heading hold turned on.

Also, when in heading hold turn off the Guardian when retrieving your plane or stir the sticks if you change heading .

Originally Posted by jedorme

Steve & choochoo22 - When taking off in 3D Heading Hold mode, I'm a bit confused by your reference to "stirring the sticks" or moving the "aileron/elevator control" just before take off to set it. Can you clarify this? Thanks,

Jed

What Prof said.

To elaborate; You are getting ready to fly. You have the plane in your left hand and the tx in your right hand, preferably on a neck strap. As part of your pre-flight you turn on 3D mode. As you walk to your launch point, Guardian is moving the surfaces trying to maintain the attitude that was locked in when you turned 3D on. This is most likely not a useful attitude as you were carrying the plane, possibly straight up, down, or sideways.

When you are at your launch point, you are ready to set the plane down for a ROG or toss the plane for a hand launch. As a final pre-flight step, you point the plane in the direction and attitude you want for climb out and "stir the stick". Any movement of the aileron or elevator will reset the locked-in attitude in G to the current position. Now you are ready for takeoff. On the ground or by hand, all you need do is apply throttle and G will fly the plane where you had it pointed.

You could just wait until you have the plane in climb-out attitude before activating 3D. I find it more convenient, however, to set all my switches ahead of time. Since I'm holding the plane in my left hand, it's easier to reach the right stick with my right hand than the mode switch on the left side of the tx.

In any case your pre-flight after setting the climb-out attitude should include wiggling the plane around and observing that G is moving your surfaces properly. You don't want to hit full throttle for launch and discover, for instance, that your gain was all the way down and G isn't flying the plane

As Prof suggested, it's generally not good to carry the plane around much before or after flight with G active. It will be trying to "fly" the plane and will be moving the surfaces, probably to maximum. It could overdrive a servo doing this. I haven't found this to be a problem on any of my planes so I have become somewhat careless on this point. If you are careful to verify the limits when installing G and, if necessary, set the G travel limits with a PC (not the tx travel limits) it should never be a problem.

Hope this helped clarify things.