DG-100 vs Std Libelle - opinions wanted

Hi Martin, read your notes, under handling point 3, you suggest that differential makes the down going aileron travel further than the upgoing one.
That is the opposite of normal differential, which has the upgoing aileron travel more than the downgoing one. The downgoing aileron produces more drag than the upgoing one.
This is why rudder is required to prevent adverse yaw.
Just sayin.
Regards
Dave L

On Tue, 03 Apr 2018 17:07:47 -0700, davidlawley wrote:

Hi Martin, read your notes, under handling point 3, you suggest that
differential makes the down going aileron travel further than the
upgoing one.

Yep - and I was wrong. Just looked at the data sheet, which shows a lot
of differential, but in the other direction: 20 degrees up, 12 down.
Moral: trust the data sheet, not ones imperfect recollection.

Thanks for spotting it. I've just updated the page by removing the
reference to aileron differential, but the rest of the comment about the
occurrence of aileron stalls matches my experience.

This is why rudder is required to prevent adverse yaw.

Indeed, and its still needed because even a 12 degree downward deflection
adds more drag than 20 degrees of upward deflection.

However, I still think that this year I'll fit a set of 35mm wingtip
skids. Mine has 12mm rubber blocks fitted which are a bit too short: a
fully deflected aileron can touch the ground.


--
Martin | martin at
Gregorie | gregorie dot org

If you think of differential in terms of a ratio, yours is a bit less than 2:1, my DG202 is 2:1.
In my days of F3B model flying, I used up to 4:1 for thermalling, and still got adverse yaw, reqiring rudder mixed in.
For the speed task, flown at a very low angle of attack, no differential. With electronic control mixing, a lot of options open
such as flap to elevator (cruising) and elevator to flap (Thermaling) mixing.

On Wed, 04 Apr 2018 05:24:09 -0700, davidlawley wrote:

If you think of differential in terms of a ratio, yours is a bit less
than 2:1, my DG202 is 2:1.
In my days of F3B model flying, I used up to 4:1 for thermalling, and
still got adverse yaw, reqiring rudder mixed in.

You were obviously involved with another part of the model world than I
was. Flew C/L when I was a kid and then moved in to single channel RC. I
gave up RC just about the time that proportional radios appeared because
I'd got involved with competitive Free Flight, mostly F1A gliders and
1/2A / F1J power.


--
Martin | martin at
Gregorie | gregorie dot org

Op woensdag 4 april 2018 23:57:57 UTC+2 schreef Martin Gregorie:
On Wed, 04 Apr 2018 05:24:09 -0700, davidlawley wrote:

If you think of differential in terms of a ratio, yours is a bit less
than 2:1, my DG202 is 2:1.
In my days of F3B model flying, I used up to 4:1 for thermalling, and
still got adverse yaw, reqiring rudder mixed in.

You were obviously involved with another part of the model world than I
was. Flew C/L when I was a kid and then moved in to single channel RC. I
gave up RC just about the time that proportional radios appeared because
I'd got involved with competitive Free Flight, mostly F1A gliders and
1/2A / F1J power.


--
Martin | martin at
Gregorie | gregorie dot org

I have no clue where this is going to be honest

I have no clue where this is going to be honest

To bring this back to the original thread: before settling on the DG, look into the service contract aspect surrounding older DG/LS models. Streifeneder still provides service, advise and parts to Libelle owners without a binding service contract.
I know because I owned a H301 for 30 years....

Uli
'AS'

Op donderdag 5 april 2018 13:01:09 UTC+2 schreef AS:

I have no clue where this is going to be honest

To bring this back to the original thread: before settling on the DG, look into the service contract aspect surrounding older DG/LS models. Streifeneder still provides service, advise and parts to Libelle owners without a binding service contract.
I know because I owned a H301 for 30 years....

Uli
'AS'

I have been told to stay away from the H301 Libelle because of many reasons, is this true? As you have owned one for 30 years you could probably have the best opinion on this.

On Thu, 05 Apr 2018 02:35:30 -0700, Senna Van den Bosch wrote:

Op woensdag 4 april 2018 23:57:57 UTC+2 schreef Martin Gregorie:
On Wed, 04 Apr 2018 05:24:09 -0700, davidlawley wrote:

If you think of differential in terms of a ratio, yours is a bit less
than 2:1, my DG202 is 2:1.
In my days of F3B model flying, I used up to 4:1 for thermalling, and
still got adverse yaw, reqiring rudder mixed in.

You were obviously involved with another part of the model world than I
was. Flew C/L when I was a kid and then moved in to single channel RC.
I gave up RC just about the time that proportional radios appeared
because I'd got involved with competitive Free Flight, mostly F1A
gliders and 1/2A / F1J power.


--
Martin | martin at Gregorie | gregorie dot org

I have no clue where this is going to be honest

Just a slightly technical model flying discussion, mainly about the
differences in desirable control response between remotely flown models
and full-size gliders. Adverse yaw is something that is easy to deal with
in full-size if your rudder is powerful enough: by and large we just do
it without needing to concentrate on flying a coordinated turn, but when
you're flying an RC glider thats almost specked out above you, its easier
if you can thermal using just one stick instead of juggling both of them.

OTOH, my view, with my F1A freeflight hat on, is that since the model is
doing its own thing (no external control allowed or closed-loop control
systems) I must set it up to automatically centre and stay centred in the
thermal I launched it in. Fortunately, we know how to do this (CG at 55%
chord, minimal fin area, crossed controls with the rudder balanced
against wash-in on the inner wingtip in the turn, trimmer to fly at min.
sink).


--
Martin | martin at
Gregorie | gregorie dot org

Op donderdag 5 april 2018 13:04:20 UTC+2 schreef Martin Gregorie:
On Thu, 05 Apr 2018 02:35:30 -0700, Senna Van den Bosch wrote:

Op woensdag 4 april 2018 23:57:57 UTC+2 schreef Martin Gregorie:
On Wed, 04 Apr 2018 05:24:09 -0700, davidlawley wrote:

If you think of differential in terms of a ratio, yours is a bit less
than 2:1, my DG202 is 2:1.
In my days of F3B model flying, I used up to 4:1 for thermalling, and
still got adverse yaw, reqiring rudder mixed in.

You were obviously involved with another part of the model world than I
was. Flew C/L when I was a kid and then moved in to single channel RC.
I gave up RC just about the time that proportional radios appeared
because I'd got involved with competitive Free Flight, mostly F1A
gliders and 1/2A / F1J power.


--
Martin | martin at Gregorie | gregorie dot org

I have no clue where this is going to be honest

Just a slightly technical model flying discussion, mainly about the
differences in desirable control response between remotely flown models
and full-size gliders. Adverse yaw is something that is easy to deal with
in full-size if your rudder is powerful enough: by and large we just do
it without needing to concentrate on flying a coordinated turn, but when
you're flying an RC glider thats almost specked out above you, its easier
if you can thermal using just one stick instead of juggling both of them.

OTOH, my view, with my F1A freeflight hat on, is that since the model is
doing its own thing (no external control allowed or closed-loop control
systems) I must set it up to automatically centre and stay centred in the
thermal I launched it in. Fortunately, we know how to do this (CG at 55%
chord, minimal fin area, crossed controls with the rudder balanced
against wash-in on the inner wingtip in the turn, trimmer to fly at min.
sink).


--
Martin | martin at
Gregorie | gregorie dot org

Ah that explains it.

Would it be all right to buy a glider with just over 3000 hours with 3000h check done, in good condition, and still be quite sure to be able to fly it without issues? (When taking good care of it of course)