Speed Calculator

[BrianG]

OK, new version uploaded with the final lipo page. Whole new menu system and minor changes to layout as well.

@cemetary gates: I used both CF and the RCM logo. Although it did take a while to wipe out the background...

@MM: I used some of the code from the BEC & Wiring page to show how to connect multiple packs. I hope this is sufficient.

As usual: R/C Calculations

Looks really good!:027: I'll have to bookmark the new version...

Bye:018:

[jhautz]

SLICK!!! I like it! Its looking as good as the info it contains now!!!

[pinolelst]

A bug IMHO..I tried inputting values for a xxx-t 2.43:1 tranny ratio 16 tooth pinion and 86 tooth spur 11.1 volts (3s lipo) mamba max 7700 kv motor and got a warning that my motor might overheat due to a 40k rpm limit on brushless motors and no top speed estimate was given...castle rates their motors at 65k and even then I'd exceed that but rather than get a warning and no output why not have the warning and give the user the option to proceed with the top speed estimate??

We all know there are a few of us who throw the warranty cards away in the interest of destructive testing for empirical data for the masses :005:

hope this helps

pinolelst

[crazyjr]

Originally Posted by pinolelst

A bug IMHO..I tried inputting values for a xxx-t 2.43:1 tranny ratio 16 tooth pinion and 86 tooth spur 11.1 volts (3s lipo) mamba max 7700 kv motor and got a warning that my motor might overheat due to a 40k rpm limit on brushless motors and no top speed estimate was given...castle rates their motors at 65k and even then I'd exceed that but rather than get a warning and no output why not have the warning and give the user the option to proceed with the top speed estimate??

We all know there are a few of us who throw the warranty cards away in the interest of destructive testing for empirical data for the masses :005:

hope this helps

pinolelst

click on the ok in bubble and it will show the values. BTW your combo with 4.2" tires(off road) is 81.76 MPH

[pinolelst]

Originally Posted by crazyjr

click on the ok in bubble and it will show the values. BTW your combo with 4.2" tires(off road) is 81.76 MPH

Silly me didn't think to scroll down :007: :007:

Was waiting for another pop up window to give me the estimates :007:

LOL

Thanks

pinolelst

edit:A friend of mine clocked it at 55 mph with a cheap bushnell gun but I suspect he shot it from an angle and not straight on so I could assume 60 or so but 81 mph ??

[BrianG]

Thanks jhautz! I like the interface better too. Although, this started as a single page and it sorta grew as I just tacked on more stuff. It did need an overhaul.

Originally Posted by pinolelst

A bug IMHO..I tried inputting values for a xxx-t 2.43:1 tranny ratio 16 tooth pinion and 86 tooth spur 11.1 volts (3s lipo) mamba max 7700 kv motor and got a warning that my motor might overheat due to a 40k rpm limit on brushless motors and no top speed estimate was given...castle rates their motors at 65k and even then I'd exceed that but rather than get a warning and no output why not have the warning and give the user the option to proceed with the top speed estimate??

We all know there are a few of us who throw the warranty cards away in the interest of destructive testing for empirical data for the masses :005:

hope this helps

pinolelst

Thanks for the feedback! First of all, crazyjr is right, it will still figure out the values, it just warns you that the rpm is over the recommended limit.

Next, which page was this in?

If it's the "top speed estimator" or the "solver" page, then you have to select the motor from the list because there are seperate max rpms based on manufacturer ratings. If you type in "7700" the program uses the baseline 40k rpm as the limit. The program does not try to look up a matching motor since that would be a possibly incorrect assumption. I just tried it by picking the MM 7700 motor and it said it exceeded the 65k rpm limit, which is correct. But it still displayed the results regardless.

If it's still giving you something you don't think is right, post a screenshot of the error along with the values chosen and I'll see what I can do to correct it... or at least explain it.

[BrianG]

Originally Posted by pinolelst

...edit:A friend of mine clocked it at 55 mph with a cheap bushnell gun but I suspect he shot it from an angle and not straight on so I could assume 60 or so but 81 mph ??

After a certain speed, wind resistance starts to become a serious limitation. Unfortunately, without all the aerodynamic figures from all the different vehicles, it is extremely difficult to factor this in.

For a while, I was toying with the idea of calculating in some type of speed derating after a certain speed, but don't know what I should use. A MT will have a steeper derating than a pan car so it would still be quite difficult. I ended up not doing it so people can get a more accurate ideal calculation. Although I did add in a disclaimer on the "top speed" page:

Originally Posted by R/C Calculations - Top Speed Estimator

...Also, at speeds over 50mph, wind resistance becomes a serious factor and may reduce the accuracy of the calculations further. Just keep in mind that the result is the maximum theoretical speed based on ideal conditions. Most likely, the actual speed will be a little less.

[coolhandcountry]

That is phat brian. I like the new page.
You not trying to make others look bad are you. ;)

[BrianG]

Originally Posted by coolhandcountry

That is phat brian. I like the new page.
You not trying to make others look bad are you. ;)

Thanks!

What do you mean by trying to make others look bad??

[crazyjr]

After a certain speed, wind resistance starts to become a serious limitation. Unfortunately, without all the aerodynamic figures from all the different vehicles, it is extremely difficult to factor this in.

I agree, when my T4 was being speed tested with a 3s lipo and a mamba max 5700, it was a little windy and even with a tailwind, my T4 would flip at 40 to 45 no matter how I pulled the trigger

[coolhandcountry]

It was a joke brian.

[BrianG]

Originally Posted by coolhandcountry

It was a joke brian.

Oh. :) I was just confused. :confused:

[BrianG]

Does anyone have a decent AVI showing tire ballooning? I want to use it in the R/C calculator and turn it into an animated GIF. I can crop out unecessary parts of the "movie" as needed...

Originally Posted by BrianG

Does anyone have a decent AVI showing tire ballooning? I want to use it in the R/C calculator and turn it into an animated GIF. I can crop out unecessary parts of the "movie" as needed...

I don't know if this will help, its from serum's website (look at the top, there are some vids)

HERE

Bye:018: