Happy Cinco de Mayo!

I just released a new version of the calculator with a couple of requested features. There’s also the usual long list of minor changes that I won’t bother to mention.

I’ve exposed the propeller n100WRPM of the propeller when it is absorbing 100 watts of power. Defined to be measured at zero airspeed and standard atmospheric conditions. Note that this is not the power going into the motor, but the power available to the propeller. and n10N input values. They were there all along, but I wasn’t sure how valuable they would be. A website user recently gave me a great use case for these. Anyway, they are used to tune the performance of a propeller to match real world test data. I believe Aero-Naut is the only manufacturer that provides this data with their propellers. But if you have a test stand, it’s not too difficult to measure these yourself.

The other new feature is harder to explain. Suppose you are working on a power system. Have you wondered what the input voltage and current to the motor are with the current power system knob settings? Well, if you turn to the motor editor, it will have the motor from the power system selected and the knob settings will match the values used by the power system. The same applies to the other components such as the propeller and batteries.

Note that the current filter settings will be honored. So if the motor filter excludes the motor used by the power system, only the motor knobs will be updated.

The tutorials are coming along very well. The beta testers have given me some fantastic feedback. Expect them to be released in a couple of days.

I just completely replaced the website search feature. The new search box will look for your search terms on RCadvisor.com and a select set of RC discussion forums, retailers and manufacturers. You can filter the search results to only include results from one of these sets. I like it a lot - I hope that you do too.

I just released a new version of the calculator with the power system optimizer. After a week of testing, I’m very happy with its performance and robustness. My original plan was to wait until the end of the month, but this is such an important new feature that I didn’t want to wait.

The ToolTipA ToolTip is a small text box that appears when the mouse pointer is hovered over a screen object. The box disappears when the mouse pointer is moved away from the object or after a specified period of time, usually a few seconds. help on the ‘Opt’ button summarizes how it works. It uses the filters on each component to narrow down the combinations that it will consider. The power system filter is used as a final filter on the good candidates found. It is extremely fast - it can analyze over 40,000 power systems per second on my computer. But if you don’t use the filters and you have one billion combinations to test, it will take a while. The optimizer craves CPU cycles.

You can stop the optimizer at any time and keep the best combination found so far. It tests the more promising candidates first so that you get some results fairly quickly.

Right now it rejects power systems that weigh more than half of the total airplane weight. I may change this in the future (what do you think?). You can use the power system filter to limit this even further.

This feature has so much power that it begs for a tutorial. I plan to put one together soon.

A new release of the calculator is ready for your enjoyment:

- The European data server is finally here! For the website users from across the pond, the calculator should load twice as fast as before. New users get prompted at the registration page. If you already have an account, you may change your default user data server (United States) by going to My Account -> Edit -> User Information. Confused? Let me know. I copied the data for current users to the European server, so they can switch servers without losing any work.

- the components database grew dramatically:

• 500 pre-analyzed airfoils
• 300 airplanes
• 100 battery packs
• 30 speed controllers
• 250 motors
• 350 propellers
• 30 full-size airplanes
• 40 locations

- There is a fantastic new filter on every component editor tab. Click on the button next to the component name to bring up the window. Now you have a customizable sort order and a very powerful filter that can work against the input fields or the result fields. Just like the rest of the calculator, it is extremely fast. Frankly, I’m still learning all the possibilities that this new filter opens up.

- I rewrote the formulas for computing the airplane Climb Rate. The calculations are now more accurate, but you also get a new warning when you have a rocket instead of an airplane and the equations no longer apply.

- As always, there are many other improvements. The airfoils are now in a separate file (almost 1MB). If you don’t want them, don’t load them.

It took me over 100 hours to put the new filter together (I have thousands of hours invested in the calculator and website). I hope you enjoy the new features!

Help! Have you used the calculator? How about giving me some feedback by taking the Survey on the website? It only takes about a minute to fill out and the information it provides me is invaluable.

In the next week or two I will be releasing a new version of the calculator. As usual, it will contain more preloaded components (motors, airfoils and others). I’m also working very hand on a new very nice component filter.

But the most exciting new feature will be a data server based in Europe. From looking at the web site logs, a large number of the visitors are from across the pond. This data server will be selectable from your user profile on the web site. The calculator file will be loaded from your chosen location (United States or Europe) and your edited components will be saved there as well. Our overseas users can expect a dramatic increase in network performance.

With RCAdvisor, you can:

• put your model airplane through its paces in our virtual wind tunnel
• easily put together efficient electric power systems
• get advice from our smart calculator on how to improve your models
• visualize the results on graphs that are updated in real-time
• save your working data onto our distributed server network
• run electric motors on the virtual test stand to find their weaknesses and strengths
• analyze propellers to discover their optimum flying airspeed
• see the dramatic difference that a simple change in airfoils can make
• create an accurate scale flying model and learn the trade-offs involved
• realistically take into account altitude and temperature effects

Why did I create the calculator? While designing a power system for a new model, I was very disappointed in the quality of the available tools. Many were HTML forms, which necessitated a lengthy page reload for every recalculation. I found the spreadsheets very limited, hard to use, and not very attractive. Paying for and installing a Windows desktop application struck me as quaint. I also found that the programs were continually asking me for data I didn’t have, and giving me results I didn’t care for. And don’t get me started on the inaccuracies in the programs and all the misinformation out on the Internet!

I just released a new version of the calculator, the first update since the website launch at the beginning of January. It includes the much anticipated airplane editor and an entirely new charting module. There are too many other smaller changes to mention.

RCAdvisor is one month old! Thank you for all the great feedback. I appreciate it all, both positive and negative.

The next major release of the calculator is scheduled for later this month. Here are the highlights for the features planned for that release:

• A brand new airplane editor will be here. It will allow you to enter the basic information from a manufacturer and predict it’s performance with a given power system.
• Expect a lot more preloaded data. Locations, airfoils and motors are already in the works. Others will be next.
• There are some features (*cough* bugs *cough*) in the charting library that I’m using now that are getting in the way of what I want to do. Expect an entirely new charting module. The new charts are more attractive and contain some nice touches, such as an indicator for the maximum point on a line.
• Many other small changes too numerous to mention. Numbers will be easier to read, performance will be better, etc.

Not all of the pieces for this new release are under my direct control, so it is very hard to predict exactly when it will be ready. There’s a very good chance I’ll be making an interim release in mid-February.