This is what it says:

Disc Quota: 1% of 10000Mb
Bandwidth Quota: 1% of 250GB

Man I need to get some PC for dummies book. I have no idea to what the above things mean.

Basically, you have 10GB of webspace and 250GB of transfer bytes allotted. So far, you've used an itty bitty part of your allotment, so you must not get many visitors. :smile: Actually, the "1%" is probably the smallest number that it can computer without being 0% or some fractional number, so you have TONS of space and bandwidth left.

Everything I is based on e-mails and phone calls. My site is just up to give a little info in what my company does. Just let me know if you need to do the mirror thing.

FYI: I added the two new Hyperion chargers; EOS0606i and EOS0610i

Also, I would like to add some predefined tire sizes so I can have a tire dropdown list for some of the more common sizes. What I need are total diameter measurements (in inches) for the following:

• Onroad 2.2"
• Offroad 2.2"
• Onroad MT
• Offroad MT
• Onroad 40 series
• Offroad 40 series
• Buggy
• Truggy
• Anything else you can think of

I know tire sizes may deviate a little from tire to tire, but this should give a rough idea for each type. You can either PM me the sizes or post them here, doesn't matter.

Moabs are 5in tall

What category is that (MT, 2.2", tr/buggy, off/onroad, etc)? Sorry, I'm not as up on the tire brands/models as I am in electrical stuff. :smile:

Thanks though! I have a few measurements I can take of what I have and then average out the various measurements to get a decent estimate.

Ohhh ooops lol, forgot that

Those are the 2.2 moabs, for like a stampede rusty kind of truck

Brian,

You should put the NEU 1509 series motors in the calculator

Added the Neu 1509 series motor data.

Also added some notes at the bottom of the "Lipo Pack Wiring" page for the balancer Y section.

Still have to fix the bug with the picture viewer, but that'll have to wait for now...

I dont see them on there?:neutral:

There added in the speed calculator under motors? They dont show up

I just checked and they are in fact there. Look at the bottom of the Neu motor section. All the pages use the same library "database" file, so if whatever shows up in one page will show up in all pages. Try clearing your internet cache if you still can't see them.

I cleared my cache, and it works now

Thanks Brian!

I was just at my site's web stats page and found something kinda interesting. Below are all the sites that have linked back to the Speed Calc, some of which I've never heard of:

RCGroups
RC-Monster
Traxxas
RCTech
NitroKillers
WattFlyer
RCUniverse
RCDesign
RCThai
brushlessmania.forumpro.fr
HeliFreak
RadioControlZone

I was surprised to see that RCGroups had higher hits than from here. Go figure...

It's a compliment nonetheless though.

BTW, are you going to add hacker motor specs to your database?

I was thinking about adding all the motors I could find (Hacker included), but figured I would limit it to just what Mike has listed in his store. I know I don't technically "need" to, but it's a professional courtesy.

Brian... Where did the KV numbers for the Lehner 19xx series motors come from. The numbers in your calculator dont match the kv numbers on the Lehner website.

Are these possibly unloaded numbers vs the loaded kv numbers that Lehner uses? If so where did you get them?

I think one is loaded and the other is unloaded, I would assume Brian used loaded kv ratings.

I don't remember where I found the values, but the "U" and "L" after the motor kv in the drop-down lists says whether the kv listed is loaded or unloaded. I tried to use unloaded wherever possible because the loaded value depends on current draw and that is too variable for my liking.

I think Lehner's spec is somewhat loaded. I think I saw some one in another forum saying this.

All I know is I was looking up the 1950/7 on the Lehner site and its different than in the speed calc. I thought maybe there was a reason for it, but if not it looks like many of them are incorrect. Just pointing it out so you can update it if its not correct.

I do know that Lehner uses a loaded kv value.... but they dont publish what the load is so who knows what that actually means.

I will say this though. In my own calculations I use the Lehner loaded values and the nominal cell voltages (for example 14.8v for 4s) without any voltage drop and the speeds that are calulated are dang close to the real world speeds I get. When using the unloaded values from other motor you have to account for the voltage drop for the calculated speed numbers to match real world.

Brian, I didn't see novak hv 4.5 or 6.5 listed in the motors for your calculations. Do you think 4800 (4.5) and 3100 (6.5) are an accurate kv to use for calculations? Thanks.

Yeah, that's because Mike doesn't stock those systems in his store. But, yeah, you can just plug in the kv values of any motor you want. The motor dropdown is just for convenience really. If those kv values are correct, then yes, you can use those...

Man, what a smart a$$!

You crack me up Brian:rofl:

Brian, If I'm running Trakpower packs in a 3 X 2s config. with a Neu 1512 2d. What nominal cell voltage should I choose from the drop down menu? I have been choosing 3.3v.

LOL. Sorry, I didn't mean to come across that way. :oops:

@Countryhick: It depends on what you are looking for.

If you are looking for a good max speed estimate, use 3.7v and lower amperage (around 20A or so). At max speed, there isn't as much electrical load as at startup.

If you are looking for a decent max torque estimate, use higher amperage and ~3.3v. The most torque will be generated at low rpm. Also, since the highest amperage happens at low rpm at startup, that's where the biggest V drop will happen as well.

Update to the calc:

- Fixed weight value for the Neu 1512 motors. Was at 360g and should've been 290g. Thanks CountryHick!

- Added differential ratio and spur gear options for the Ofna Ultra GTP.

A planned future addition will include a new page to calculate the proper gear selection when using two speed setups. Probably next week sometime.

Added the Two-Speed Gear Mesh Calculator.

Added TrakPower Lipos to the balancer wiring section of the Lipo Wiring page (scroll to the bottom).

Regarding the Two-Speed Gear Mesh Calculator: If anyone knows the formula for calculating the amount of shaft-to-shaft distance you lose by where the teeth meet, let me know. I have most of the code done to calculate shaft-to-shaft distance, but left it commented out until I know this.

Something I've been toying with is the addition of code to estimate how much speed you lose due to wind resistance/drag. I know calculating this exactly is very difficult due to so many variables, but there's gotta be a rough estimate of speed loss.

Right now, I have a warning box that comes up if the final speed exceeds 45mph. What I was thinking is adding a reduction constant above 45mph. Basically use a formula something like:

mph_reduction = ( calc_speed - 45 ) X 0.4

So, for a top theoretical calculated speed of 60mph, the estimated actual speed would be closer to 54mph: ( 60 - 45 ) X 0.4 = 6mph loss. 60mph - 6mph = 54mph. It's just a matter of finding a constant (currently using 0.4) that is fairly close...

Whaddya think?

Well, the problem is that the drag is not constant, it's exponential.

However, I did find a neat article here that might help ya out:

http://en.allexperts.com/q/Physics-1...ce-running.htm

OK, I see that that it's not a true constant... sort of.

So, how about something like:

speed_loss = calc_speed^2 * 0.0015

For 45mph calculated speed, the actual estimated speed is ~42mph
For 60mph calculated speed, the actual estimated speed is ~53mph
For 100mph calculated speed, the actual estimated speed is ~85mph
For 140mph calculated speed, the actual estimated speed is ~111mph

Again, I want this to be just a rough estimation. Basically, I'm trying to develop a formula based on some calculated vs actual speeds from different existing setups. I know, kinda working backwards. :oops:

I would say the calculator is pretty accurate up to around 50-60MPH with the right batteries. For trucks I subtract 10% (drag/resistance/traction loss) at 70mph, 80mph I subtract 30% and 85mph and up the resistance goes higher and higher.

Added a rough estimate of speed reduction due to wind resistance, drag, etc to the top speed estimator. There is a disclaimer in the help link that says this value is very rough and many variables will affect the accuracy, but it's better than nothing IMO.

Also added power calculations (in watts and HP) to the top speed estimator.

Updates:

Added a new page to calculate the needed resistor to eliminate the spark when hooking up the battery. It has a very creative name: "No Spark" Calculator. :sarcastic:

Also grouped menu items because the list is starting to get a bit long now...

I think it's about time we send Brian some pizzas. What do you guys think?:yes:

Thanks, but no thanks. It's hard enough to lose weight over the winter months without that! 75lbs lost so far (since last June), but still have 35 to go, and not going to get there eating pizzas! :smile:

You are the man.

Cool man. I'll try the no sparky on my next setup.

What is the "rule of thumb" regarding the minimum rpm a sensorless motor has to turn for the ESC to get the proper back-EMF signals? Something like kv * 0.1?

I want to try to include this calculation in my top speed estimator to notify the user that they are geared too high for proper ESC operation...

Concrats Brian. That's serious mass you've lost!