Are you sure you don't mean the differential? I show a ratio of ~2.72:1 for the tranny, but a ratio of 1:1 for the diff (since there is no pinion and ring gear and the diff is really part of the tranny - much like the Jato).

Woops, my mistake :).

LOL. It happens to the best of us. :)

How do you like the switch to unloaded kv values? Makes calculating loaded kv much easier. Also, there are still a bunch of unknown motor resistances. If you know where I can get the rest of the data, I'd really appreciate it. You can see which motors I'm missing in the data page...

New version:

• Added a new page to calculate various Lithium battery charger figures and shows the max charge current and what the charger is limited by at various cell counts. Since most chargers require a 12vDC input, a power supply calculator is included to help the user pick the appropriately sized power supply.
  
• Added a charger information table to the "data" page.
  
• Added pre-defined spur gear drop-down list.

If anyone has the specs for more chargers handy, I will be happy to add them...

brian your specs on the duratrax ice are backwards. it should be 4s and up to 8amps.

LOL. ok, I can fix that. All the settings are in arrays, so it's fairly easy to mix something up. :)

I was just thinking how great your little tool is, and what it became over the last couple months. Great, man. Thank you very much! It's one of the most clicked bookmarks on my desktop. I'll make sure to pass on any new numbers I come across.

It's growing so much, maybe you should put up a "NEWS" section on the start page!? :)

It is.. It is AWESOME Brian.

One powerfull tool indeed.

Thanks guys! It HAS grown quite a bit from "v1", lol. I just keep adding things and adding things, and now it's almost a complete site in itself! I thought about creating a subdomain for it, but then I'd have to change the link.

The trouble is that it is getting to the point where it's almost getting too complex to use. The code for the help system is getting quite large - the array that holds the data has 76 entries! And the main code library alone is over 40k bytes! The original intent was to make a simple, inuitive tool that newbies could use, but now I wonder if it's too much?

As to adding a "news" page; I thought about it, but I'd rather people read about the news here and then navigate to it from here. The original intent was to supplement the RCM site, not to be so "stand-alone". If anything, I might simplify the release notes and put that on the home page.

Again, if anyone has more data (motors, transmissions, diffs, charger, etc) I would be more than happy to add it...

Brian - Thanks for keeping up the hard work on this. Very useful information all the way.

Fixed the ICE charger issue and also fixed a couple other small things with the charger info.

In the Lipo charger section, the ICE doesn't have a power output limit shown - it is 120watts. The TP-1010C can put out 210watts maximum. The Hyperion EOS 5i series can put out 50watts max. If you want to add the Astroflight 109, it can to up to 9s Lipo and 8amps, with a max. power output of 170watts. There is also an A123 version of the Astroflight 109, which can do 10s A123, 8amps, and 170watts max.

Sorry for the extra info., but I figure it might be useful for some others out there :).

Thanks MM! Where I didn't know the power rating, I put 0. And the TP charger power rating is an "oops" - I thought it was 300w.

And the extra information is perfect! Also, if there are any other noteworthy features (for the data table page), I can add that as well. Like if the charger can do other battery types, if it has an adjustable CC/CV threshold, etc.

Truly awesome work Brian. I have used this site so many times, and it has helped many times to decide on gearing, etc.

Big thanks!!!

It would be great if you could find the info for the Superbrain 989 otherwise I'll be asking lots of questions later on, lol. :005:

You're welcome.

Supply the info for the 989 (and any others) and I'll put it in. :)

I figure I do the hard part of coding it all, you could at least get some data for me. ;)

Yah, I know, I'm lazy, lol. I'll need to find someone on the forums with a 989 to give you the info.

what cha need? i have a 989 i can help u!

pm me with what u need for it!:018:

- max cell count
- max current
- power limit
- if it runs on 12v
- if it runs on 120v AC
- whether you can adjust the CC/CV threshold
- efficiency
- any other noteworthy features.

It's OK if you don't know the efficiency (the code assumes 80% as a ballpark figure if it isn't known). This value is not something commonly given, I just happened to measure it on my EOS 7i a while back.

Thanks in advance! You'll be contributing to a good cause. :)

ok i will help as far as i can, i mite ask ???'s to how i figure out the stuff lol... but tomrow, everyone here is sleeping, and i and going to bed soon lol

but from what i know

the ps it comes with is 15.8 volts i THINK i need to double cheack

it says on the box 10 amp ac/dc charger, so idk.. cant say if it runs on 12 volts as i dont have anything to run it with other then the ps it comes with... 120 ac, idk, what ever voltage in the us is is what its going to always be at... need to have her on and look around for the others... and idk what or how to cheack alot of this as i never cared lol, so if u could help when i need to then that id be great!

That's OK. I just went to the MRC website and got the data. They didn't list the power limit, but since the included power supply delivers 10A at 15v (150w), I assumed a 120w power limit since they probably figured in a 25% margin, not to mention charger efficiency. If this is incorrect, someone can let me know...

k good lol now i cant screw up sumthin LOL

Much better! However, the regular AF109 can only do 9s Lipo.

Fixed...

Great. Thanks Brian for adding the 989. Really appreciate it.

I was working on something like this minus all the extra features. Now I'm thinking I might have the basic calculations and then add extra stuff to find roll center and all that dealing with the car setup.

Heres the project page. http://sourceforge.net/projects/rc-gear

Hi Brian, great work BTW. One small request, could you please add the 51T spur to the drop down menu? It has all the revo spurs, and this would be convient when comparing between the Emaxx/strobe tranny and the stock Revo. Thanks!

***RC***: No problem. :)

I think I've seen that before - nice job!

If you want to borrow any data from my web version, feel free. Most of the data and common functions are in the "library.js" file, which is called in all the pages. I'm sure you know how to get the file, but I can also send it to you. Each data array has comments to describe what the various values are.

Done! Also added the pitch in the spur list and fixed a small bug (does not affect calculated output - just a user-interface thing).

Last weekend I made a drag race with my SuperMaxx( 1950/10, 149.18 controller, 6s Ev020 packs and 20 pinion: 36 spur in a Slipperential) against an electric powered 1/10 touring car with a very fast LRP brushless system with only 6 sub-c cells and I was very close behind it and never were able to pass it?!!!!

I used your speed estimator, Brian, and it gave me a 46-47mph speedrun while I was hoping for 50-55mph.

I think the Slipperential's gear ratio is a bit high.

What do you think? should I get a centerdiff?

u arent going to beat that touring car man, there whicked fast with bl no matter what bl is in it and batts.............but cd, u already got one in the slippy dont u? or whats would be different? sorry, idk so dont be harsh

From what I've seen, the slipperential tends to create a low gear ratio. To get more speed, try using smaller spur, larger pinion, higher voltage, higher kv motor, and/or bigger tires.

And don't forget, once the calculator gets past ~45mph, wind resistance plays a BIG role in actual speed (depending on vehicle).

The slipperential has a centerdiff, indeed, but it's not directly connected to the pinion. I want to make a direct connection between the pinion and the centerdiff to increase speed a bit.

Your suggestion is a bit hard to make since it'll cost money.

I believe a direct drive ( cd-pinion) would help alot.

Promod once ran a Lehner XL1600 with 6s lipos in his truck with a centerdiff and it made a nice 50mph for him.

I'm 100% sure the problem is with the slipperential( it's for racing).

ultimately i think your fighting a loosing battle because his car has more top speed potential than yours... but if you want to try... i think i saw a 24t pinion in the rc-monster store... theoretically that will give you a 20% increase in top speed and its quite cheap compared to getting a whole new motor... if you still have your emax tranny, you can slap that back in there for the race as well, that should theoretically give you another 20%

New addition to the calculator. This might be hard to explain, but I'll try.

On several pages, there are images that change depending on the options listed. These images are made up of smaller images put together like a puzzle. As such, you can't simply post a direct link to any image since it would only be one piece of the puzzle.

So, each page that has images like this, there is a new button called "Get Picture". When clicked, a help window will pop up with a link that you can post in the forum so other can see it.

For example, on the "Lipo Wiring" page, the first section shows how a pack is built, but defaults to a 1s1p pack. If someone wanted to post a picture of what a 4s2p pack looks like, they just click the "Get Picture" button, and then copy the section in blue into a link on this page. Like this:

Link to see a 4s2p pack.

Hopefully this will be useful. :)

Added differential ratio for HPI Hellfire...

somehow I saw this coming.. :)

Actually, I did it for you and Mike since you said you both got one. :)

Seriously, it's kind of an odd ratio. A 42T ring gear? But I actually counted the teeth and verified it. Figured it was oddball enough to add it.

BrianG, thanks for making the speed calculator. I use it all the time. Half the time I'm on rcmonster I have the calculator open as well, so when people say they X motor on X voltage with X gearing in X vehicle, I can quickly put that into the speed calculator to get an idea of what speeds where talking about.
I also use it to quickly check what kv all the different motors are, since I can't remember all of them. It's a lot quicker than looking for specs on a manufacturers website. If it's not too much of a pain would you please be able to add a few more of the neu 15 series motors, mainly the lower kv ones, since neu are the hardest for me to remember and theres the less of the neu's on there than most other brands.
If it takes too long don't worry, but if you do then, thanks.

Cool! I'm glad you found it useful!

I guess I could add the other 15xx motors. :) I just have the ones I did simply because those are the ones Mike stocks.

EDIT: Added all the 1512 and 1515 data...

Oh, he can special order the other ones as well though can't he?