Could OpenRocket developers please consider switching to metric units

[Charles_McG]

I will never be happy, unless the developers change the whole program to Furlong per Fortnite.

I can't understand why not.

Roy

And density in stones per firkin.

I have a classic American book on apple trees and hard cider that measures specific gravity in pennyweights per pint compared to water.

 

[prfesser]

And density in stones per firkin.

I have a classic American book on apple trees and hard cider that measures specific gravity in pennyweights per pint compared to water.

Hmph. Rookie units...

PROPEL workbook, Version 3.1 will express propellant densities in batman per hobbit.

(See here, scroll down to "Other" )

 

[Reinhard]

I’m following the Chinese Balloon thread, and I’m wondering if future releases of Open Rocket could have an option to express length in School Buses, area in Football Fields, and mass in Elephants.

Thanks!

Is the OpenRocket team currently accepting high quality pull-requests?

UNITS_LENGTH = new UnitGroup();
UNITS_LENGTH.addUnit(new GeneralUnit(0.001, "mm"));
UNITS_LENGTH.addUnit(new GeneralUnit(0.01, "cm"));
UNITS_LENGTH.addUnit(new GeneralUnit(1, "m"));
UNITS_LENGTH.addUnit(new InchUnit(0.0254, "in"));
UNITS_LENGTH.addUnit(new FractionalUnit(0.0254, "in/64", "in", 64, 1d / 16d, 0.5d / 64d));
UNITS_LENGTH.addUnit(new GeneralUnit(0.3048, "ft"));
//Medium sized school bus (25 ft to 35 ft)
UNITS_LENGTH.addUnit(new GeneralUnit(0.3048 * (25.0 + (Math.random() * 10.0)), "School bus"));

Reinhard

 

[JimByrne]

As an American, I like our (SAE) system, metric is for foreigners

 

[Charles_McG]

ooohhhh - them's fightin' words.

I see the tension even within one company. In my secret life (petrochem), research is [nearly] all metric, and the engineers across the street talk about degrees Fahrenheit and MM barrels/year.

In home conversation, I call a thousand dollars a 'kilobuck' - I really kinda loathe the MM = 1 million thing.

I won't understand the resistance to metric/SI units if I live to be C.

 

[dhbarr]

Everyone has their limit on metrification. I don't hear anybody arguing for redefining hours and minutes, or banning 360 degree circles in government publications. All the arguing is somewhere on a continuum between there and rods per hogshead.

 

[jsdemar]

If you really want to horse around, there are furlongs per fortnight. The rate varies by how many fingers you pilfer from a firkin.

 

[Steve Shannon]

ooohhhh - them's fightin' words.

I see the tension even within one company. In my secret life (petrochem), research is [nearly] all metric, and the engineers across the street talk about degrees Fahrenheit and MM barrels/year.

In home conversation, I call a thousand dollars a 'kilobuck' - I really kinda loathe the MM = 1 million thing.

I won't understand the resistance to metric/SI units if I live to be C.

Every good engineer that I know can easily use either SI or English units.
I prefer metric if I’m starting engineering calculations, but in real life most of the data presented to me to solve problems is in English units. The greatest risk is changing from one to the other.

 

[rocket_troy]

I've only just recently converted to pretty much all metric. I still really like psi and how lbs can be both weight and force and it's taken me the good part of 2 decades to get there from English to hybrid to metric.

TP

ps. Hybrid included doing calcs in both systems in parallel to verify.

 

[bad_idea]

Everyone has their limit on metrification. I don't hear anybody arguing for redefining hours and minutes

Ahem.

I for one welcome the new three metric hour workday.

 

[cls]

In home conversation, I call a thousand dollars a 'kilobuck' - I really kinda loathe the MM = 1 million thing.

I too use kilobux, that's a good one, because it's calibrated in BOAT-units. One BOAT = Break Out Another Thousand.

But MM for mega, ooooh, that one really grates, like nails on chalkboard. I know where it comes from, Roman numerals, so it's exactly horrible in an SI prefix context. We already have M for mega and m for milli, so just use those.

 

[JohnCoker]

@MetricRocketeer I think you're doing your cause more harm than good at this point. Please recognize that a choice of units is a matter of preference, and nearly all software will give you options.

 

[MetricRocketeer]

Thank you @JohnCoker for your message. I only intended to impart thoughtful information. However, I will heed your advice and refrain from commenting on the metric system for a good long time.

Incidentally, I enjoyed and learned a lot from your recent presentations at vNARCON 2023.

Stanley

 

[JohnCoker]

Incidentally, I enjoyed and learned a lot from your recent presentations at vNARCON 2023.

Thanks for the kind words.

 

[samb]

@JohnCoker ... I only intended to impart thoughtful information. However, I will heed your advice and refrain from commenting on the metric system for a good long time.
…

@MetricRocketeer Honestly with your handle and declared affiliation I don’t think that’s necessary. Maybe just accept the diversity in our little internet sandbox.

 

[Cape Byron]

I really like the flexibility I have in OR to have the default as metric and then just change the units on the component I'm working on to Imperial. If your cloning something and it says 1/8" balsa you can input the thickness as Imp without converting it.

 

[cls]

NASA and consequently SLI use imperial units. I was surprised by this, but the SLI team explained yes it's imperial units, says so in the SLI instructions.

I usually have OR set for SI units, but I'm comfortable with both.

I don't think imperial units will disappear, so best to get comfortable with both systems.

 

[Buckeye]

NASA and consequently SLI use imperial units. I was surprised by this, but the SLI team explained yes it's imperial units, says so in the SLI instructions.

I usually have OR set for SI units, but I'm comfortable with both.

I don't think imperial units will disappear, so best to get comfortable with both systems.

My hidebound, Rust-Belt industry has used SI units for 40 years. I am surprised rocket scientists at NASA would still use English units.

I'll go out of my way to convert a dataset to SI before working with it.

Now for the next argument. "Metric" vs. "SI" and "English" vs. "Imperial!"

 

[cls]

I should be more specific: NASA at Marshall SFC, sponsors USLI. I don't know about other NASA centers and departments.

Now for the next argument. "Metric" vs. "SI" and "English" vs. "Imperial!"

Hoo boy! That might go on for a while ;^)

 

[TomMcKeown]

Hi TRF colleagues, and here especially OpenRocket developers,

I am a big fan of OpenRocket. But I do wish that you would switch to metric units. Doing so would make things much easier not only for me but for metric users around the world.

Please consider this:

• If you try it, you will find that metric units are much easier to work with.
• The fact is that the rest of the world uses metric units. OR fans in continental Europe, Australia, and everywhere else would appreciate the change.

I understand, of course, that as a user I can change the default units in settings. But all your expamples and tutorials use foot-pound units, and this makes things difficult.

As always, I remain an OR devotee. However, please consider my suggestion.

Thank you.

Stanley

Under Edit, Preferences, Units...

 

[Steve Shannon]

I should be more specific: NASA at Marshall SFC, sponsors USLI. I don't know about other NASA centers and departments.


Hoo boy! That might go on for a while ;^)

SI is required except where impracticable and legacy projects. https://www.nasa.gov/offices/oce/functions/standards/isu.html

I don’t know why USLI uses imperial units, but it doesn’t reflect what goes on within NASA engineering. USLI requirements may just be as simple as the fact that most of us still have inch measuring tapes.

Rocketry has always been a mixed bag with average thrust and impulse usually described in metric terms, motor case diameter always described in metric terms except for Kosdon, and lengths, weights, and altitudes usually described in imperial units.

 

[cls]

Rocketry has always been a mixed bag with average thrust and impulse usually described in metric terms, motor case diameter always described in metric terms except for Kosdon, and lengths, weights, and altitudes usually described in imperial units.

so, just like tires: 225/70R15. gah!

 

[dhbarr]

so, just like tires: 225/70R15. gah!

I am not aware of a more widely used less sensible system. If there is one, probably I don't want to know.

 

[RocketScientistAustralia]

I’m following the Chinese Balloon thread, and I’m wondering if future releases of Open Rocket could have an option to express length in School Buses, area in Football Fields, and mass in Elephants.

Thanks!

When I use OR, my dimensions are set to mm, my altitude is in feet and speed is set to Mach. That's the way I like it.

 

[rharshberger]

I am not aware of a more widely used less sensible system. If there is one, probably I don't want to know.

"so, just like tires: 225/70R15. gah!" (the quote dhbarr was responding too).


It actually imparts a lot of information its a tire 225mm wide with sidewalls 157.5mm tall (70% of width) on a 15" rim, the old way would have been a 27x9.0x15.

 

[Jowayen]

NO. NO. NO
Please, stay with the english system

 

[RocketScientistAustralia]

NO. NO. NO
Please, stay with the english system

The British one, The Australian one, The New Zealand one, The Canadian half one or the American one??///

 

[cls]

"so, just like tires: 225/70R15. gah!" (the quote dhbarr was responding too).


It actually imparts a lot of information its a tire 225mm wide with sidewalls 157.5mm tall (70% of width) on a 15" rim, the old way would have been a 27x9.0x15.

Yes, we understand. It's the mix of 225mm and 15 inches that grates.

 

[rharshberger]

Yes, we understand. It's the mix of 225mm and 15 inches that grates.

Doesn't bother me, but then I have worked around tires for the last 40 years.

 

[Cape Byron]

so, just like tires: 225/70R15. gah!

Metric wheels and tyres have been done.

Michelin TRX - Wikipedia

en.wikipedia.org

The Renault Fuego was one of the first cars to use this system. Michelin's extortionate pricing forced almost all owners to jump to a more conventional alternative. If you ever decide to restore a Fuego I'd worry about your sanity check to see if the owner has the original wheels. In many cases they are worth more than the car.