New Rocketry App for iPhone and iPod Touch

[Gus]

Useful new rocketry app for the iPhone.

Good writeup on Rocketry Planet (http://www.rocketryplanet.com/content/view/2749/29/) with some useful comments from those who've downloaded the program.

Website of the app is http://ipowerrocket.othello.ch/

It's great to see someone writing new rocketry software.

[Brent]

Is there anything out there that operates on windows mobile? I use a Motorola Q.

[Andreas Müller]

Update to version 1.1 has been posted in the App Store. Includes

additional motors
cluster mode: rockets can have multiple motor mounts, and they remember what motors were last used
on the fly simulation, allows to see simulation results already in the motor selection list (this is rather CPU intensive, and slows down scrolling in the motor selection menu)
bug fixes

[troj]

Update to version 1.1 has been posted in the App Store. Includes

additional motors
cluster mode: rockets can have multiple motor mounts, and they remember what motors were last used
on the fly simulation, allows to see simulation results already in the motor selection list (this is rather CPU intensive, and slows down scrolling in the motor selection menu)
bug fixes


I'd like the ability to switch between English and Metric units of measurement. I can do Metric, but I don't "think" in it.....

-Kevin

[Porthos II]

I'd like the ability to switch between English and Metric units of measurement. I can do Metric, but I don't "think" in it.....

-Kevin

You turn it on and off in Settings on your iPhone. Nice feature, as I don't think in metric.

[Andreas Müller]

I'd like the ability to switch between English and Metric units of measurement. I can do Metric, but I don't "think" in it.....

Oh yes, I forgot to mention this.

[aerospike]

Ok, that does it, I'm getting an i-phone.

[Gus]

Andreas,

Why did Lukas choose to implement the units choice in Settings, rather than in the program itself? I don't have any other apps that do this so I wouldn't have thought to look there. Most other apps include a little "i" (for "info") button within the program to change settings. Lukas' implementation is not wrong, just unusual, and I'm curious as to why he chose to do it that way.

But let him know I really like the update, and the ability to choose units is very helpful to me. This is a really nice program. Well worth the price.

And, yes, it is another good reason to own an iphone. As far as I know no other cellphone has rocketry apps.

[Andreas Müller]

Why did Lukas choose to implement the units choice in Settings, rather than in the program itself? I don't have any other apps that do this so I wouldn't have thought to look there. Most other apps include a little "i" (for "info") button within the program to change settings. Lukas' implementation is not wrong, just unusual, and I'm curious as to why he chose to do it that way.
If you do settings it in the app, then you have to make sure the settings are saved when the app terminates. Also you have to design a screen and write a controller class to process the events on that screen. The iPhone settings do all that for you. You specify the items you need in an XML file (there is useful XML editor in the iPhone software development kit to help you with this), and the iPhone does everything else for you. So this is certainly the easiest way to get a "settings" functionality. And it is also the way recommended by Apple, which is why the Apple apps (mail, phone, safari, iPod, iPhoto) always use that mechanism. So you can say that the programmer here was lazy. Some consider this a virtue (don't reinvent the wheel ;) ).

The little i is the way to go in Mac OS X widgets or single screen iPhone apps, for this special case, it's even recommended by Apple. And if you port an application from some other plattform to the iPhone, you probably already have all the infrastructure for settings in the app, so you'll just use the little i to show users where they can find the settings. Also if you want your app to have a distinct look and feel, then the settings screens are probably too bland for you. iPowerRocket settings don't qualify for the "single screen app" category, currently the settings span about three pages, that would be quite some coding.

iPowerRocket does not try to be smart about graphics, it uses standard components wherever possible. The rocket components, the thrust curves and the 3D rocket are the only places where graphics operations are used directly. And where they are used, simplicity and reusability is very important. All 2D rocket drawings are done by exactly the same method (in Objective-C speak: the controller, after setting up what "here" means, sends each rocket component a message to draw itself "here"). After all, this is not a game, it is a technical application, and hopefully you are using it because of the results, not because of its cool graphics ;)

[Andreas Müller]

Ok, that does it, I'm getting an i-phone.

... or an iPod touch. Of course, if you want to use iPowerrocket to convince someone that you really, absolutely need an iPhone, you'll not mention that it also runs on the iPod touch (without any service fees) ;)

[troj]

You turn it on and off in Settings on your iPhone. Nice feature, as I don't think in metric.

Ah, cool.

That got added in the latest update, which I didn't have yet.

I've got it now....

[troj]

... or an iPod touch. Of course, if you want to use iPowerrocket to convince someone that you really, absolutely need an iPhone, you'll not mention that it also runs on the iPod touch (without any service fees) ;)

In the US, you do want to make sure AT&T's coverage is good in your area. Where I live, their coverage isn't the best, so there's no way I'd switch to AT&T.

Now, if the iPhone comes to Verizon, my wife isn't gonna be happy....

[Gus]

...So you can say that the programmer here was lazy. Some consider this a virtue (don't reinvent the wheel ;) ).Andreas,

Thanks for the great explanation. The difference between a single-screen and multi-screen app never occured to me. Very interesting.

[Andreas Müller]

Update 1.2 has been sent to Apple for publication in the App Store. It includes the following
- Improved precision of trajectory calculations: the ballistic modell now uses a simple transsonic drag model. Transsonic flights are flagged red in the trajectory view.
- Performance of on the fly simulations has been improved considerably. Trajectory integration in on the fly simulations use slightly larger time steps, and are done in a background thread and saved in a cache, so they don't slow down the user interface as they used to do in 1.1
- Bug fixes: due to heavy rounding in the GUI, the mass of small rockets was sometimes stored inaccurately, leading to imprecise trajectory calculations.
- Some motors were not offered in the motor list because some part of the motor selection code had not been updated to all the new motors, this has been fixed.
- Other bug fixes

In the mean time, iPhone OS 3.0 has been announced, which includes accessory support. We will use this to add the capability to iPowerrocket to read trajectory data from altimeters when iPhone OS 3.0 is released.

[Gus]

Andreas,

A suggestion for some future release. I do way more low power than high power flying and one thing I'd really like to have access to at the field, particularly for contest flying, would be a list of the real impulses of black powder motors. As you know, unlike high power motors, labeling for black powder motors is notoriously fanciful. Nobody actually produces a C6 motor yet there are several with that label including the new Quest "long burn" C6.

So what I'd like is an easy way to access the following for all currently certified black powder motors:

Total Impulse:
Peak Thrust:
Burn Time:
Average Thrust:
Propellant Mass:
Mass after Firing:
Contest Certified: Y/N

I don't know if it's something you'd consider adding, but I'd really like it if you could.

[Andreas Müller]

Update: iPowerrocket 1.3 hast just been sent to Apple and is awaiting approval. New features:

- New checklist subapplication allows you to put together a check list and work through it on the range or at the pad. Especially useful for complex projects
- Rockets can be a little more complicated: fin sections and transitions can be combined, motor mounts can be canted. Also the fin span is now measured from the surface of the rocket, which is much easier to measure in the field.
- The log subapplication can now get the launch position from GPS.
- The motor database can be updated automatically over the Internet (must be enabled manually, so iPowerrocket will not surprise you with a large mobile bill, motorfiles are not very large, Aerotech, by far the largest file, is only 250kB).
- Support for the high resolution "Retina" display of the iPhone 4.
- Complete german localization (italian is planned for 1.4).
- Despite all the new features, iPhone OS 3.1.3 is still fully supported, so you can still run it on your old iPod that you just kept for rocketry purposes ;-)

Also all known bugs have been fixed:

- Deleted rockets don't show up again when the app is restarted
- The no longer crashes when you switch from motor view to flight view in the motor selection (this was caused by semantic change in the thread API between iPhone OS 3 and 4)
- Some memory leaks caused the App to crash after longer usage. This is important because in iPhone OS 4, iPowerrocket is no longer terminated when you leave it, it stays alive in the background.
- Most restrictions on rocket names removed, in particular you can have a slash in the rocket name.

iPowerrocket is a free update for 1.2 users. The first time you run it after it has been installed, it will automatically upgrade all your rocket files to the new version.

[mperdue]

Good news. I'm looking forward to trying it out again. Now we need a version that runs at iPad resolutions.

[WillMarchant]

Yes, thanks for the updates, Andreas!

[Andreas Müller]

Good news. I'm looking forward to trying it out again. Now we need a version that runs at iPad resolutions.
iPowerrocket does run on the iPad, but it does not make use of its resolution. When working with a large rocket (e.g. like my 1:10 Atlas Centaur), the small screen of the iPhone is somewhat finicky. So when we launched the Atlas Centaur at ALRS XI, and worked through the checklist using iPowerrocket, I was more comfortable with the iPad.

A UI that uses the full iPad screen area would probably look very different, and would consequently be a lot of work. As it is now, iPowerrocket already has ab 23000 lines of code.

[ScrapDaddy]

In the US, you do want to make sure AT&T's coverage is good in your area. Where I live, their coverage isn't the best, so there's no way I'd switch to AT&T.

Now, if the iPhone comes to Verizon, my wife isn't gonna be happy....

Their coverage in NY is certainly substandard, NYC is a terror to have AT&T in...
Because of this, my iphone is basically a glorified iPod Touch with a microphone.


About the app:
Its a great app, its no Rocsim or Openrocket, but its certainly great for last minute on the field calculations

[Andreas Müller]

iPowerrocket 1.3 has just been approved by Apple and can now be downloaded from the App Store. Have fun.

Andreas Müller

[Andreas Müller]

A suggestion for some future release. [...]
So what I'd like is an easy way to access the following for all currently certified black powder motors:

Total Impulse:
Peak Thrust:
Burn Time:
Average Thrust:
Propellant Mass:
Mass after Firing:
Contest Certified: Y/N

The first four are contained in the motor selection list when you select a motor for your rocket in the Trajectoy subapp. The two mass numbers are on the motor detail page. And wether or not a motor is contest certified I have no idea how to find out. The information is not contained in the ENG files we use as the basis for our motor database.

[mperdue]

The new version is much improved. Thanks.

[Oliver]

About the app:
Its a great app, its no Rocsim or Openrocket, but its certainly great for last minute on the field calculations

Well, I guess it wouldn´t make too much sense to run a calculation program on a small smartphone with a tiny screen. I do not buy Apple products for some reasons but I use Android and there is an application named Rocket Sim from Madcow. It is helpful on the field to determine which engine is best for example.

[Andreas Müller]

Well, I guess it wouldn´t make too much sense to run a calculation program on a small smartphone with a tiny screen. I do not buy Apple products for some reasons but I use Android and there is an application named Rocket Sim from Madcow. It is helpful on the field to determine which engine is best for example.
Why not? I know some people who have iPowerrocket as their only software to design and simulate their rockets. It has much longer battery life than a notebook computer, you always have all your "files" with you, and not having to carry a notebook computer to the range simplifies the trip to the range greatly. Also working through a checklist on a notebook at the pad looks a bit strange. And by the way: IIRC the idea to display simulated flight data for each motor to simplify motor selection goes back to iPowerrocket 1.1 (first screenshot published on Feb 2, 2009). Of course, iPowerrocket is limited to what Barrowman can do, and it currently cannot handle staging. But judging from what I see at a typical launch, I would say iPowerrocket already covers more than 95% of all flights. I think that's pretty good for such a tiny screen ;)

[Oliver]

I agree, I do not like the idea to carry a laptop (or even a smaller netbook) to a flight field. A small smartphone is the utimate device for that. However, I never met anyone who actually constructed a rocket on a field ;-)

So I think there are a lot of useful features for mobile rocketry apps such as motor selection and even a checklist. Personally I wouldn´t miss a full construction module. On the other hand, having all the data storaged for altitude measurement etc. is a smart idea.

Unfortunatly I never heared about iPowerrocket until a few days ago. I use only Android and recently discovered Rocket Sim searching the market. So I asked in our Modellraketen Forum for more apps when someone mentioned it. Since Android now hypes in the US and Europe, it wouldn´t be a bad idea to offer more apps for this platform.

[Andreas Müller]

I agree, I do not like the idea to carry a laptop (or even a smaller netbook) to a flight field. A small smartphone is the utimate device for that. However, I never met anyone who actually constructed a rocket on a field ;-)
Well, I did. Twice already I have conducted "incentive workshops (http://www.eurocketry.org/forum/german/viewtopic.php?t=826)" (in german) in rocket building. Teams of employees of two of my customers were invited to the ARGOS launch site in Kaltbrunn, to build and fly a rocket (usually from PML parts). If two people work together, and with some preparations (motor retainers, rail guides, tools), it is quite possible to get a midpower rocket flight ready in a day, and launch it in the late afternoon. At the first workshop; we used the trajectory nomograms to sim the flights. At the second workshop, most participants had iPhones with iPowerrocket ;)


Unfortunatly I never heared about iPowerrocket until a few days ago.
It was announced in all open german and italian forums, on rocketry planet and the rocketry forum, the australian rocketry forum, and was on the main page of the ARGOS (http://www.argoshpr.ch) website for several weeks when it came out more than two years ago. The EUrocketry forum (http://www.eurocketry.org/forum/german) (our home base) has an extensive thread with discussions of new ideas and implementation steps, and www.raketenmodellbau.org also has a thread with all updates.

[Oliver]

Well, I did. Twice already I have conducted "incentive workshops (http://www.eurocketry.org/forum/german/viewtopic.php?t=826)" (in german) in rocket building. Teams of employees of two of my customers were invited to the ARGOS launch site in Kaltbrunn, to build and fly a rocket (usually from PML parts). If two people work together, and with some preparations (motor retainers, rail guides, tools), it is quite possible to get a midpower rocket flight ready in a day, and launch it in the late afternoon. At the first workshop; we used the trajectory nomograms to sim the flights. At the second workshop, most participants had iPhones with iPowerrocket ;)

Ok, in this scenario (many people, individual designs), it make sense. My picture in mind was the typical rocketeer constructing his model at home, using the PC to design his rocket :)


It was announced in all open german and italian forums, on rocketry planet and the rocketry forum, the australian rocketry forum, and was on the main page of the ARGOS (http://www.argoshpr.ch) website for several weeks when it came out more than two years ago. The EUrocketry forum (http://www.eurocketry.org/forum/german) (our home base) has an extensive thread with discussions of new ideas and implementation steps, and www.raketenmodellbau.org also has a thread with all updates.

Well, I almost never check Italian or Australian forums. Same goes for club websites (there are just too many).To be honest, I even do not have time to check the US forums regulary while it is quite a pleasure to read them. I never found an announcement in the oldest German-speaking public model rocketry forum, the Modellraketen Forum (http://www.modellraketen-forum.de) (online since 1998), which I read regulary. And even not in the European Rocketry Forum at www.europerocketry.com (http://www.europerocketry.com) (which sounds a little bit like eurocketry.org - since europerocketry.com was founded in 1996 this affinity is only accidentially?). So pls. excuse my ignorance.

Oliver

[Andreas Müller]

Well, I almost never check Italian or Australian forums. Same goes for club websites (there are just too many).
Well, let's see: ARGOS is the organizer of ALRS, the oldest and largest continental european high power launch. So it's quite a good platform to promote iPowerrocket, as all european HP rocketeers often come here for news about ALRS. And there are only two german forums that have high power rocketry. So I guess you are not into high power.


I never found an announcement in the oldest German-speaking public model rocketry forum, the Modellraketen Forum (http://www.modellraketen-forum.de) (online since 1998), which I read regulary.
The problem with that forum is that it is completely closed, it is impossible to look at the forum without registering. At that point, one has already accepted the forum terms and conditions, which prohibit to post a link to iPowerrocket. So what's the point? Furthermore, the forum seems not to be about high power, so it's not of any interest to me.


And even not in the European Rocketry Forum at www.europerocketry.com (http://www.europerocketry.com) (which sounds a little bit like eurocketry.org - since europerocketry.com was founded in 1996 this affinity is only accidentially?).
This forum is even more extreme. You cannot even see what this forum is about. How should I know that there really are people interested in a software like iPowerrocket? You are not even allowed to see the terms and conditions without registering. So you don't know what you are getting yourself into. It could well just be a scam to collect Email addresses of people interested in model rocketry, to later spam them. No thanks. Anyway, as both forums are run by the same people (by you, among others, as your signature shows), I conclude that the terms will again disallow a link to iPowerrocket.

[Oliver]

Well, let's see: ARGOS is the organizer of ALRS, the oldest and largest continental european high power launch. So it's quite a good platform to promote iPowerrocket, as all european HP rocketeers often come here for news about ALRS. And there are only two german forums that have high power rocketry. So I guess you are not into high power.

I cannot confirm if this is true or not. I just remember that I saw many HPR flights and events here in Europe over the past decades. And as far as I can remember, ALRS is a more recent event, about 10 years old (my first Aerotech flight dates back in the late 80´s, for example).

But anyway, I didn´t get aware that iPowerrocket is just a program for HPR flyers? When it´s true, since most rocketeers fly low- or midpower rockets, it would be useless for them. Then Rocket Sim would be a better choice I guess?



The problem with that forum is that it is completely closed, it is impossible to look at the forum without registering. At that point, one has already accepted the forum terms and conditions, which prohibit to post a link to iPowerrocket. So what's the point? Furthermore, the forum seems not to be about high power, so it's not of any interest to me.

No, the Modellraketen Forum is public, just a free registration is required. You may even login into it as a guest viewing the terms and conditons. It´s open to anyone who accept the terms - but is that different to any other forum? Even the Swiss forum you mentioned has terms I need to accept and has many completly closed areas. Different to any other German-speaking forums, it´s the only one which does not belong to a club. It`s even not true that you cannot place links. And, it is also about Highpower - there is no restriction to exclude HPR topics. If you have no account and cannot read the terms, as you say, how can you verify what you are telling here?



This forum is even more extreme. You cannot even see what this forum is about. How should I know that there really are people interested in a software like iPowerrocket? You are not even allowed to see the terms and conditions without registering. So you don't know what you are getting yourself into. It could well just be a scam to collect Email addresses of people interested in model rocketry, to later spam them. No thanks. Anyway, as both forums are run by the same people (by you, among others, as your signature shows), I conclude that the terms will again disallow a link to iPowerrocket.

As the name says, the European Rocketry Forum it is about rocketry in Europe... How could you determine in other forums if people are interested in your program if you never asked? You cannot see terms and conditions? Have you ever looked before you posted this? Just click here (http://www.europerocketry.com/index.php?id=forum_help) to view it. And if you do not thrust a website that is in business for almost 15 years - how could you thrust a forum like yours being in the web for just 3 years or so?

But I believe this discussion tends to get offtopic? I just explained why I (among many others) never get aware of your software. It´s up to you if you would like to promote it or not...

[Andreas Müller]

You cannot see terms and conditions? Have you ever looked before you posted this? Just click here (http://www.europerocketry.com/index.php?id=forum_help) to view it.
Well, I stand corrected. I would never have expected the terms under "help", though, that's probably the only place I didn't look.


... a forum like yours being in the web for just 3 years or so...
Correction: I have no forum.

[cwbullet]

Nice attempt, but to be honest, the imperial units are not complete enough. I tried it out and it used 1/2 imperial and 1/2 metric when set to use imperial only.

[Andreas Müller]

Nice attempt, but to be honest, the imperial units are not complete enough. I tried it out and it used 1/2 imperial and 1/2 metric when set to use imperial only.
There was some discussion with the requestors of the imperial units feature back when it was added about which units should be imperial, and which metric. E.g. motor mount diameters are never imperial, imperial wouldn't make sense, as motor manufacturers specify motor diameters in metric only, and some even name their product lines after the metric diameter (RMS-38, Pro38). That discussion mostly covered the Rocket and Trajectory subapplications. What was implemented is the result of that discussion. As a consequence, it is possible that some less discussed parts do not use the units an "imperial" person would expect. I'm a "metric" person, all those imperial units look equally strange to me, I have no clue where to use inches and where feet. And even in the well discussed parts, some users may disagree about unit choices. So if you disagree with some of the choices, or have found an outright omission, please be more specific so that we can change it in the next release (version 1.4, free upgrade planned for march, containing italian and french localizations, rocket templates and scaling feature). Technically, there is no problem displaying any system of units: The app contains a whole unit conversion layer between the models (they implement the physics and are always metric) and the views you see on the screen. But that layer only does what it is told to do...

[Andreas Müller]

Hi Chuck,


Nice attempt, but to be honest, the imperial units are not complete enough. I tried it out and it used 1/2 imperial and 1/2 metric when set to use imperial only.
Today I went through iPowerrocket screen for screen chasing down places where non-imperial units were used. The only values that are displayed in metric units are

Forces are displayed in Newtons. The alternative would be pounds, but that's not a unit of force
Impulse in Ns, which is what everybody uses: manufacturers in their product docs (e.g. AT, in its high power reloads, does not even mention the equivalent value in lb-sec, just N-sec), TMT certification documents, the safety code.
Times, there is no different imperial unit of time.
Motor diameters in mm: the motor and kit manufacturers also use mm, so talking about 3.9" motors would probably more confusing than it would help.
The size of the the ejection charge in g, this also seems to be what people are using. E.g. see http://www.vernk.com/EjectionChargeSizing.htm

So I really don't see how you get at "1/2 metric". The only item we could discuss is the thrust. So let me sollicit your opinion: Do imperial users want to see the thrust in pounds?

Andreas

[SAC of MMMSClub]

Andreas,

For me personally, I do not need Thrust in pounds, Newtons is fine. Having correct motor data is the most important thing.

Metric is ok too, my phone has a conversion function.

Will your app work on other platforms i.e. Android or others(forgive my lack of knowledge on apps and phones I'm OLD) as I am looking for a new phone?

Have all the bugs been worked out, as there were some sour reviews?

Thank You,

Scott
NAR#91379 L0

[troj]

Do imperial users want to see the thrust in pounds?

No. We're used to seeing it in Newtons, so having it in pounds would be odd for us.

-Kevin

[Andreas Müller]

Will your app work on other platforms i.e. Android or others
Android is an option I'm considering. Unfortunately I cannot do it myself, so I hope to find a student at my university who could do the port as a semester or bachelor thesis. One young rocketeer in our club (ARGOS (http://www.argoshpr.ch), the swiss TRA prefecture) happens to be a student at my university (http://www.hsr.ch), so he would have the necessary rocketry background. He also is a very good student (got a straight A in my rather tough course on the theory of computation), unfortunately he also has lots of other ideas that he could do as thesis projects. But I'm working on it....

Other platforms:

Symbian has just died (well, it will survive for some time, but will hardly get new developers)
WebOS: is there really a market?
Windows Phone is not my world: I'm a Unix or Java person

BTW, we still test each release of iPowerrocket on iOS 3.1.3 on a first generation iPod touch, which means all iPhone OS devices, including the first generation iPod touch and the original iPhone can run iPowerrocket (3.1.3 is the last version supported in those devices). Also, since an iPod does not need a phone contract, it could be cheaper alternative.

[eggplant]

Android is an option I'm considering. Unfortunately I cannot do it myself, so I hope to find a student at my university who could do the port as a semester or bachelor thesis. One young rocketeer in our club (ARGOS (http://www.argoshpr.ch), the swiss TRA prefecture) happens to be a student at my university (http://www.hsr.ch), so he would have the necessary rocketry background. He also is a very good student (got a straight A in my rather tough course on the theory of computation), unfortunately he also has lots of other ideas that he could do as thesis projects. But I'm working on it....

Other platforms:

Symbian has just died (well, it will survive for some time, but will hardly get new developers)
WebOS: is there really a market?
Windows Phone is not my world: I'm a Unix or Java person

BTW, we still test each release of iPowerrocket on iOS 3.1.3 on a first generation iPod touch, which means all iPhone OS devices, including the first generation iPod touch and the original iPhone can run iPowerrocket (3.1.3 is the last version supported in those devices). Also, since an iPod does not need a phone contract, it could be cheaper alternative.

I happen to be an android dev... :D

[Andreas Müller]

Have all the bugs been worked out, as there were some sour reviews?
1.3 fixes all known bugs. No new bugs have been discovered so far. There is currently just one report open that a certain motor sims much lower than on Rocksim. Usually the results are quite close, the differences can usually be attributed to differences in the Cd used. We are investigating whether the motor data for that motor may be incorrect (we pull motor files from vendor websites and convert them to a format that is easier to parse in the iOS software environment, we have seen some broken .eng files, and it is possible that this problem report cited could be such a case). Of course, if the motor data is faulty, we will publish a corrected version of the motor file, which 1.3 can update without the need to update the app.

[cwbullet]

I downloaded the new version and figured it out. I was incorrect on the units. Is it possible to add an way to also calculate papacute descent by ccd?

[Andreas Müller]

Is it possible to add an way to also calculate parachute descent by cd?
Do you mean the option to enter a custom Cd for the parachute calculator? The current implementation has two implicit values, borrowed from a book an parachute systems, selected when you select the parachute shape.

The problem is where to place that in the UI, screen area is so limited... Some implementation ideas:

I simple implementation would be to add a third shape "Cd", and add an option in the iPowerrocket settings where you can set the custom Cd to use. Changing the Cd would be awkward, however
In the seetings, one could add an option "Use implied Cd" under the title "Parachute". If this is turned off, then instead of the shape selection, you would get a slider to change the Cd. The problem is that you will loose the
ability to use the shapes without leaving iPowerrocket to go to the settings
Tapping the "Shape:" label turns it to "Cd:", and the shape choice is replaced by a Cd slider. The disadvantage is that you normally don't expect any action when you tap on a label.

What do you prefer, or do you have other suggestions?

[Andreas Müller]

Ok, for the parachute Cd thing, I came up with the following solution, which will be in 1.4. In the corner on the upper right, you get a button that says "Cd". If you tap it, you'll get a slider to set the Cd instead of the two options X/Spherical. The approximate Cd values of X/Spherical shape parachutes are marked with appropriate icons, see the screenshot (of course, your english speaking iPhone will display it in english).

[dixontj93060]

Ok, for the parachute Cd thing, I came up with the following solution, which will be in 1.4. In the corner on the upper right, you get a button that says "Cd". If you tap it, you'll get a slider to set the Cd instead of the two options X/Spherical. The approximate Cd values of X/Spherical shape parachutes are marked with appropriate icons, see the screenshot (of course, your english speaking iPhone will display it in english).

Nice.

[Andreas Müller]

Lukas just uploaded version 1.4 of iPowerRocket to Apple, the app is now awaiting review. It offers the following new features:

- italian localization: there is a very active italian Tripoli prefecture, they have their big annual launch MIR (Meeting Italiano di Razzimodellismo) in two weeks, so 1.4 is just in time for their meeting.
- the parachute calculator can now accept arbitrary Cd values, not just the shapes cross and hemisphere (features suggested in this forum)
- transitions can now be ogives
- rockets can now be copied, scaled and renamed
- a database of popular kits from Estes, Aerotech, PML and LOC simplifies simulating rockets built from these kits: just copy the kit, give it a name, add mass and Cg, and start simulating.
- the database also contains 10 templates of rockets popular among scale rocketeers. If you want to build an Arcas in 6", just pick the Arcas template, give your rocket a name, e.g. 'Arcas 6"', select scale to 6" and tap 'done'. There's your Arcas ready for simulation.
- the rockets in the database also can have arbitrary polygonal shapes, but in this release, you cannot edit them yourself (yet).

For users of iPowerRocket, 1.4 is a free upgrade available as soon as Apple approves the app.

Furthermore: you'll find iPowerRocket on Facebook, just search for IPowerRocket.

[GregGleason]

Thanks for the update.

Greg

[Gus]

Good news, Lukas! Thanks for continuing to make this product even better.

[Andreas Müller]

iPowerrocket 1.4 has just been approved by Apple and can now be downloaded from the App Store. Have fun.

[Andreas Müller]

We have just finalized and uploaded version 1.5 of iPowerrocket. It fixes some minor bugs, and includes two new features:

1. a simplified method to rename a rocket

2. a subapplication to design ellipsoid parachutes. Enter the dimensions of the parachute in the application, and it will produce the sewing pattern as a PDF file. It also figures out how to optimally place the individual panels of the parachute on the cloth. Just print out the PDF, cut out the panels, sew the together, and get a perfectly shaped ellipsoid parachute. For an example of a large parachute using this design have a look at the 4.5m main chute of my Atlas Centaur, especially the opening at 5:20 (http://www.youtube.com/watch?v=keweeQdMAFM).

Unfortunately, PDF generation is a feature that only became available in iOS 3.2, it cannot be used on the oldest supported devices (3.1.3). And printing via AirPrint is even more recent, and requires a printer supporting AirPrint. But you can always send the PDF via Email, and print from your PC.

[Andreas Müller]

iPowerrocket version 1.5 has been approved by Apple and can now be downloaded from the App Store. Have fun!

[Andreas Müller]

We are currently preparing release 1.6 of iPowerrocket. It will include some great new features:

Flight data import for the Louis Schreyer's Altimax altimeter
Emailing, printing and opening PDF files in other apps (like iBooks): rocket plans, checklist, flight data and flight cards
some bug fixes

More information about the data import feature in the article on the ipowerrocket website: http://ipowerrocket.othello.ch/index.php?option=com_content&view=article&id=12&Itemid=12.

If you have some whishes/bugreports that you would like to have included in 1.6, please send email to ipowerrocket@othello.ch

[Andreas Müller]

Lukas today has prepared release 1.6 and has uploaded it to Apple. As soon as it has passed the review process, it will be available as a free upgrade to current users.

[UPscaler]

request: Android :wink:



Braden

[Andreas Müller]

request: Android :wink:

As I explained in a post on the rocketry planet, you are requesting a complete rewrite of an application with over 27000 lines of code for a market that is way too small to ever pay for it and with no benefit to the existing user community, including it's developers. Find an Android Dev who is also a rocketeer and has too much spare time, or buy an iOS device :wink:

[BayouRat]

Has anyone tried the Android ap "Rocketry Tools" ?

http://www.androidzoom.com/android_applications/tools/rocketry-tools_bjlyx_screenshots.html

[Oliver]

No, but I´ve installed the Model Rocket Calculator on my Droid:

http://de.androidzoom.com/android_applications/tools/model-rocket-calculator_tqsc.html

But I guess it is a little bit offtopic here?

Oliver