Earthstar Forums

Posted: **Fri Mar 13, 2020 4:55 pm**

We still have frost overnight and a few flurries, but in a few weeks the
weather will be tame enough to reassemble the Quark and start the flying
season. We are both ready and eager!
I am still wondering what would happen if I shut off power (key switch)
while in flight. Can the prop overspin in a dive?
But let's talk about the normal power modes: ECO, Sport, Custom (2014 and
later). From the "Unofficial Service Manual":

Default mode settings

Mode

Max Speed

Max Torque

Max Regen.

Max Regen Brake

ECO

70mph

40%

66%

100%

Custom

70mph

100%

40%

66%

Sport

98mph

100%

40%?

66%?
*Max Regen Brake probably does not apply to us, since we don't use the
brake.**Max Speed* is tricky: depending on how the controller gets its
speed reading (probably simply the motor rpm), Max Speed may actually limit
power if it is set too low. Mark reports there is surprisingly good
correlation between the speed reading on the dash and the airspeed, likely
by accident. I don't see any need to deliberately go faster than 98mph, but
70mph may not be fast enough in some situations.*Max Torque*: 40% (ECO
mode) may not give you enough torque on short-field take-offs. We are not
likely to gratuitously gun it - I usually keep my take-off power below 35
kW - but in a pinch, I'd like to know I have the torque available right
now, not after switching mode and throttling down first. That said, the
amazing torque our motors can produce are bound to take a toll on the belt
and bearings (the margin is better with the wider belt), so for my Custom
mode, I think I'll set Max Torque to 80%. If I really need all she's got
for a short take-off, I can switch to Sport mode.*Max Regen* should be
simple: I see no good reason to use anything less than 100%. If my normal
approach setting of 5kW is too shallow, I can back off on the throttle and
use the prop as a speed brake. This allows me to set the flaps at some
point, and then keep my hand on the throttle.So, my Custom mode will be:Max
Speed = 98mphMax Torque = 80%Max Regen = 100%(Max Rege Brake = 100%)
Does anyone see a hole in my logic?
Martin & the Quark

Posted: **Fri Mar 13, 2020 7:21 pm**

Hi Martin,

My understanding is that propeller speed when freewheeling is less than when being powered. If 120 mph
(Vne) under power does not overspeed the engine, overspeeding when freewheeling will not either.

I have been told that 100% regen braking will stop the prop, at least temporarily. I guess it is the
equivalent of locking your wheel on a motorcycle. I have not experimented with this yet but, if so, a lower
setting will be my choice.

--Ray

Posted: **Sat Mar 14, 2020 11:01 am**

Thanks, Ray. What you say about overspinning makes sense, and I will not
worry about it.

We discussed prop drag in an earlier thread. I think the consensus was that
a stopped prop offers the least drag, even less than if the prop spun at
just the right speed to produce neither thrust nor regen. So, if I want to
get the maximum glide distance, I should stop the prop, right? Regen is so
inefficient that the bit of energy we could be putting back into the
battery would not compensate for the shorter glide distance.
I have not (deliberately) stopped my prop in flight. With 100% Regen, the
prop should come to a stop once I go slow enough, right? And it will start
spinning again in a dive or once I apply power.

Martin & the Quark
*** practice social distancing: fly solo! ***

Posted: **Sat Mar 14, 2020 3:42 pm**

Hi Martin,

Here is another wrinkle to think about. Assuming you can permanently stop the prop, battery power will
be consumed to do that (because we do not have a mechanical lock). Setting the prop to have a null effect
will also consume some battery power. How much for either case I do not know. It is possible that the
maximum glide consumes more of this battery energy than the other case. I have no idea if this is true or if
the numbers are so small as to be irrelevant.

It could very well be that this effect is overshadowed by not flying at the best speed for current air mass
lift vs sink, and wind if you are doing a 'final glide'.

When I get back in the air I plan to do some instrumented flights to determine the glide characteristics at
different speeds so a 'speed to fly' curve can be obtained... just like they do for sailplanes.

--ray

Posted: **Sat Mar 14, 2020 6:55 pm**

I plan to do some testing along those lines, myself, and this discussion is
intended to nail down the variables and guess at the outcome.
As long as the battery contactor is closed, the controller will move energy
back and forth. What happens when the contactor is open?
And, what is the behavior in Sport mode, where we have little regen? Or in
Custom mode with regen set to 0%? Theoretically, the prop will spin as fast
as its drag allows.
I have been flying the Quark for 4 seasons now, and am still finding new
wrinkles to explore! Eventually, all our findings should make it into a
Wiki or the manual Richard started.

Posted: **Sat Mar 14, 2020 9:48 pm**

RE: prop over-spin in dive
Suggest you use Vne and prop pitch to calculate rpm with zero slip for
worst case analysis. If that result is terrifying, try stall speed.

ie: At a given pitch your prop will advance a calculated distance for each
revolution.

Posted: **Sat Mar 14, 2020 10:38 pm**

RE: Max Speed

Now that we're limited to 10,000ft, this may be moot, but with my 20' wing
a 70mph airspeed limitation would also create an altitude limitation,
because stall speed increases with altitude. I can't quantify it for your
plane, but you could do a max altitude flight test.

Otherwise, I have wanted to go faster in a pattern, to avoid delaying a
faster plane.

Posted: **Sun Mar 15, 2020 7:52 am**

The free Zero app with an Android or IOS device can display the rpm.

--ray

Posted: **Sun Mar 15, 2020 11:58 am**

I cannot find motor rpm anywhere in the app screens. I would have expected
to see it as one of the items to display on the ride screen. However, motor
rpm can be displayed on the dash. That's OK with me, even though my dash is
mounted off to the side, not in the panel; rpm is not that important
outside calibration and test runs. I assume all this data is also available
in logs that can be extracted after the flight, but I have not been
successful in downloading those to my laptop (via diagnostics cable or
wireless).
I remember tachometers in my sportier cars, where you would use it to shift
at the right point. But on the motorcycle, the motor is directly coupled
with the wheel and revolutions are proportional to speed, which is the more
useful item to display for most riders.

Dave: with my 28 ft wing, I don't think I would stall at 70mph in legal
airspace. But you are right, there are situations in which you may want to
fly faster than 70mph in the pattern (even Ultralights can legally do so in
an emergency). That is where the 70mph speed limit (in ECO mode) may get in
the way. Richard, if you are listening: I understand you have been flying
in ECO mode almost exclusively. Did you ever feel you would like to go
faster, but the controller wont let you?

Posted: **Sun Mar 15, 2020 4:05 pm**

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
</head>

<body style="background-color: #fff;">
<span style="display:none"> </span>


<div id="ygrp-mlmsg" style="position:relative;">
<div id="ygrp-msg" style="z-index: 1;">


<div id="ygrp-text" >

<p><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<div>
<div align="left">
<span style="font-family: Arial;font-size: 14pt;"><em> </em></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: 14pt;"><span style="font-family: Arial;"></span></span>
<div>
<span style="font-size: 12pt;">Oops. You are right Martin. The dash gives rpm while the app shows power. Power is negative when in regen. Don't remember prop rpm when power is zero in a glide.</span>
</div>
<span style="font-family: Arial;font-size: 12pt;"><span style="font-family: Arial;"><em><span style="color: #888888;"><span style="color: #888888;"></span></span></em></span></span>
<div>
<span style="font-size: 12pt;"> </span>
</div>
<span style="font-family: Arial;font-size: 12pt;"><span style="font-family: Arial;"><em><span style="color: #888888;"><span style="color: #888888;"></span></span></em></span></span>
<span style="font-family: Arial;font-size: 12pt;"></span>
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>________________________________________</em></span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>To:</em></span></span>
<span style="font-family: Arial;"><span style="font-size: 12pt;">                            Earthstar_Aircraft@yahoogroups.com</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>From:</em></span><span style="font-size: 12pt;">                       "Martin Koxxy martinkoxxy@gmail.com [Earthstar_Aircraft]" <Earthstar_Aircraft@yahoogroups.com></span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Date sent:</em></span><span style="font-size: 12pt;">               Sun, 15 Mar 2020 09:58:16 -0700</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Subject:</em></span><span style="font-size: 12pt;">                   Re: [Earthstar_Aircraft] eGull: Mode</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Send reply to:</em></span><span style="font-size: 12pt;">         Earthstar_Aircraft@yahoogroups.com</span></span>
</div>
<p style="margin-left: 0mm;margin-right: 0mm;text-indent: 0mm;margin-top: 1.76mm;margin-bottom: 1.76mm;"><span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;">  </span></span></p>
<table style="table-layout: fixed;border-collapse: collapse;width: 619px;" cellpadding="0" cellspacing="0">
<colgroup>
<col width="619">
</colgroup>
<tbody>
<tr>
<td width="619" align="left" valign="top"><span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">I cannot find motor rpm anywhere in the app screens. I would have expected to see it as one of the items to display on the ride screen. However, motor rpm can be displayed on the dash. That's OK with me, even though my dash is mounted off to the side, not in the panel; rpm is not that important outside calibration and test runs. I assume all this data is also available in logs that can be extracted after the flight, but I have not been successful in downloading those to my laptop (via diagnostics cable or wireless). </span></span>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">I remember tachometers in my sportier cars, where you would use it to shift at the right point. But on the motorcycle, the motor is directly coupled with the wheel and revolutions are proportional to speed, which is the more useful item to display for most riders.</span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">Dave: with my 28 ft wing, I don't think I would stall at 70mph in legal airspace. But you are right, there are situations in which you may want to fly faster than 70mph in the pattern (even Ultralights can legally do so in an emergency). That is where the 70mph speed limit (in ECO mode) may get in the way. Richard, if you are listening: I understand you have been flying in ECO mode almost exclusively. Did you ever feel you would like to go faster, but the controller wont let you?</span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">On Sun, Mar 15, 2020 at 5:52 AM 'Ray St-Laurent' </span></span>
<a href="mailto:raystl@nbnet.nb.ca"><span style="color: #0000ff;font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"><span style="text-decoration: underline;">raystl@nbnet.nb.ca</span></span></span></a>
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"> [Earthstar_Aircraft] <</span></span>
<a href="mailto:Earthstar_Aircraft@yahoogroups.com"><span style="color: #0000ff;font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"> <span style="text-decoration: underline;">Earthstar_Aircraft@yahoogroups.com</span></span></span></a>
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;"> > wrote:</span></span>
</div>
<table style="border-collapse: collapse;width: 584px;" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td colspan="15" width="584" align="left" valign="top" bgcolor="#ffffff">
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;">  </span></span>
</div>
<div align="left">
<span style="font-family: Liberation Serif;"><span style="font-size: 12pt;">The free Zero app with an Android or IOS device can display the rpm.</span></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Liberation Serif;"><span style="font-size: 12pt;">--ray</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>______________________________________________</em></span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>To:</em></span><span style="font-size: 12pt;">                            </span></span>
<a href="mailto:Earthstar_Aircraft@yahoogroups.com"><span style="color: #0000ff;font-family: Arial;"><span style="font-size: 12pt;"><span style="text-decoration: underline;">Earthstar_Aircraft@yahoogroups.com</span></span></span></a>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>From:</em></span><span style="font-size: 12pt;">                       "DaveB </span></span>
<a href="mailto:dave.bonkowski@gmail.com"><span style="color: #0000ff;font-family: Arial;"><span style="font-size: 12pt;"><span style="text-decoration: underline;">dave.bonkowski@gmail.com</span></span></span></a>
<span style="font-family: Arial;"><span style="font-size: 12pt;"> [Earthstar_Aircraft]" <</span></span>
<a href="mailto:Earthstar_Aircraft@yahoogroups.com"><span style="color: #0000ff;font-family: Arial;"><span style="font-size: 12pt;"> <span style="text-decoration: underline;">Earthstar_Aircraft@yahoogroups.com</span></span></span></a>
<span style="font-family: Arial;"><span style="font-size: 12pt;">></span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Date sent:</em></span><span style="font-size: 12pt;">               Sat, 14 Mar 2020 19:48:18 -0700</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Subject:</em></span><span style="font-size: 12pt;">                   Re: [Earthstar_Aircraft] eGull: Mode</span></span>
</div>
<div align="left">
<span style="font-family: Arial;"><span style="font-size: 12pt;"><em>Send reply to:</em></span><span style="font-size: 12pt;">         </span></span>
<a href="mailto:Earthstar_Aircraft@yahoogroups.com"><span style="color: #0000ff;font-family: Arial;"><span style="font-size: 12pt;"><span style="text-decoration: underline;">Earthstar_Aircraft@yahoogroups.com</span></span></span></a>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div style="margin-left: 0mm;margin-right: 0mm;text-indent: 0mm;margin-top: 1.74mm;margin-bottom: 1.74mm;" align="left">
<span style="font-family: Arial;font-size: small;"> <span style="font-size: 10pt;"> </span></span>
</div>
<table style="border-collapse: collapse;width: 584px;" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td width="584" align="left" valign="top" bgcolor="#ffffff">
<div align="left">
<table style="border-collapse: collapse;width: 579px;" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td width="579" align="left" valign="top" bgcolor="#ffffff">
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">RE: prop over-spin in dive</span></span>
<span style="font-family: Arial;font-size: small;"> <span style="font-size: 10pt;"> </span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">Suggest you use Vne and prop pitch to calculate rpm with zero slip for worst case analysis. If that result is terrifying, try stall speed. </span></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Georgia;font-size: small;"><span style="font-size: 10pt;">ie: At a given pitch your prop will advance a calculated distance for each revolution. </span></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<div align="left">
<span style="font-family: Arial;font-size: small;"><span style="font-size: 10pt;"><br> </span></span>
</div>
<table style="border-collapse: collapse;width: 16px;" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td width="16" align="left" valign="top" bgcolor="#ffffff"> </td>
</tr>
</tbody>
</table>
<table style="border-collapse: collapse;width: 579px;" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td colspan="2" width="579" align="left" valign="top" bgcolor="#ffffff"> </td>
</tr>
<tr>
<td colspan="2" width="579" align="left" valign="top" bgcolor="#ffffff"> </td>
</tr>
<tr>
<td colspan="2" width="579" align="left" valign="top" bgcolor="#ffffff"><..snip..></td>
</tr>
</tbody>
</table> </td>
</tr>
</tbody>
</table>
</div> </td>
</tr>
</tbody>
</table> </td>
</tr>
</tbody>
</table> </td>
</tr>
</tbody>
</table>
</div>

</p>

</div>


<div style="color: #fff; height: 0;">__._,_.___</div>

<div style="clear:both"> </div>

<div id="fromDMARC" style="margin-top: 10px;">
<hr style="height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3E3;">
Posted by: raystl <raystl@nbnet.nb.ca> <hr style="height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3E3;">
</div>
<div style="clear:both"> </div>

<table cellspacing=4px style="margin-top: 10px; margin-bottom: 10px; color: #2D50FD;">
<tbody>
<tr>
<td style="font-size: 12px; font-family: arial; font-weight: bold; padding: 7px 5px 5px;" >
<a style="text-decoration: none; color: #2D50FD" href="https://groups.yahoo.com/neo/groups/Ear ... 664">Reply via web post</a>
</td>
<td>•</td>
<td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;" >
<a href="mailto:raystl@nbnet.nb.ca?subject=Re%3A%20%5BEarthstar_Aircraft%5D%20eGull%3A%20Mode" style="text-decoration: none; color: #2D50FD;">
Reply to sender </a>
</td>
<td>•</td>
<td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;">
<a href="mailto:Earthstar_Aircraft@yahoogroups.com?subject=Re%3A%20%5BEarthstar_Aircraft%5D%20eGull%3A%20Mode" style="text-decoration: none; color: #2D50FD">
Reply to group </a>
</td>
<td>•</td>
<td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;" >
<a href="https://groups.yahoo.com/neo/groups/Ear ... QzMDYzNDc-" style="text-decoration: none; color: #2D50FD">Start a New Topic</a>
</td>
<td>•</td>
<td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;color: #2D50FD;" >
<a href="https://groups.yahoo.com/neo/groups/Ear ... NJZAM0NjU1" style="text-decoration: none; color: #2D50FD;">Messages in this topic</a>
(10)
</td>
</tr>
</tbody>
</table>






<div id="ygrp-vital" style="background-color: #f2f2f2; font-family: Verdana; font-size: 10px; margin-bottom: 10px; padding: 10px;">

<span id="vithd" style="font-weight: bold; color: #333; text-transform: uppercase; "><a href="https://groups.yahoo.com/neo/groups/Ear ... QzMDYzNDc-" style="text-decoration: none;">Visit Your Group</a></span>

<ul style="list-style-type: none; margin: 0; padding: 0; display: inline;">
</ul>
</div>

<div id="ft" style="font-family: Arial; font-size: 11px; margin-top: 5px; padding: 0 2px 0 0; clear: both;">
<a href="https://groups.yahoo.com/neo;_ylc=X3oDM ... MwNjM0Nw--" style="float: left;"><img src="https://s.yimg.com/ru/0.9.12/min/css/ya ... 101x21.png" height="21" width="101" alt="Yahoo! Groups" style="border: 0;"/></a>
<div style="color: #747575; float: right;"> • <a href="https://info.yahoo.com/privacy/us/yahoo ... tails.html" style="text-decoration: none;">Privacy</a> • <a href="mailto:Earthstar_Aircraft-unsubscribe@yahoogroups.com?subject=Unsubscribe" style="text-decoration: none;">Unsubscribe</a> • <a href="https://info.yahoo.com/legal/us/yahoo/utos/terms/" style="text-decoration: none;">Terms of Use</a> </div>
</div>
<br>



</div> 



<div id="ygrp-sponsor" style="width:160px; float:right; clear:none; margin:0 0 25px 0; background: #fff;">


<div id="ygrp-reco">
</div>


</div> 

<div style="clear:both; color: #FFF; font-size:1px;">.</div>
</div>

<img src="http://geo.yahoo.com/serv?s=97359714/gr ... 1584306347" width="1" height="1"> <br>

<img src="http://y.analytics.yahoo.com/fpc.pl?ywa ... o&resp=img" width="1" height="1">

<div style="color: #fff; height: 0;">__,_._,___</div>


</body>


<head>
<style type="text/css">

</style>
</head>


</html>

Earthstar Forums

eGull: Mode

eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode

Re: eGull: Mode