Thanks! Yeah. I definitely feel better! Started at ~310lbs, and down to 240 right now. Gained about 7lbs over the winter, but am staying pretty constant. When springtime comes around, I want to get down to 199. Still "obese" by the BMI charts, but oh well. I REALLY want to see a number that starts with "1" - I haven't seen that since I was about 13-15 years old!

That is awesome Brian. When I used to play soccer down in Florida I never got passed 150lbs and after a few injuries I finally stopped and now I'm at 185lbs. It feels like a ton though with my bad knees. Funny thing is that at 185 I'm right at the border of also becoming obese. I'll start building up muscle around my knee and maybe get the guts to fix a torn ligament on my thigh.

That's something to look out for.

It's good to take care of your body when you've got the ability to move.

As long as you don't stop eating to loose weight; you can loose weight, but it will come back sooner than you'd like.. It's simple a matter of eating as much as your body needs.. Nothing more. combine that with some cardio sports.. loose the soda's as they use massive sugar to get so addictive. You won't believe how much sugar there is in .5 litre of coke.. roughly 75g of pure sugar.. Avoid light products as well. (learned that from the swiss Punk.. (Dafni))

I guess i don't need to tell you what to do though.. It's just.. Food is addictive..

@lutach; how tall are you?

Cardio sports is the key.. (walking/biking/swimming) running isn't the best way to loose weight because it's rather easy to hurt your knees when you are high on the BMI and give your knees a high 'load', and your heart rate isn't at an ideal zone to burn fat..

Cardio sports and less Cheesy Bacon Cheeseburgers from Wendy.. (note capitals) But MAN do they taste great..

Lack of exercise during the winter is why I gained what I did. My eating habits haven't changed, but biking the trails in the winter is not pleasant because of the cold (not to mention snow and ice). My g/f has a treadmill, but that is sooooo boring! Biking lets me enjoy the changing scenery as I ride. I also work out (currently not because of a strained muscle) so I'm fairly big anyway. So, I'll never get down to what the BMI charts considers "just" overweight, but I'll be happy regardless.

The main thing I've learned about dieting is that you can't simply give up what you like because you won't stick to it. Smaller portions of what you like is better because you can stick with it. And those diet drugs are crap! They may work while you take them, but if you don't change your habits, you'll just bounce back when you stop taking them.

lol, I even tried talking to a hypnotist to see if they could make me hate the things I like that are bad for me. But they said that's not how it works. So much for a simple answer...

I'm 5'10". My diet still consists of plenty of water (I love water), fruits and vegies (All I can eat :lol:), I still love the traditional Brasilian Rice and beans w/ fish, chicken and a lean meat wee call it "Picanha" without the fat.

Getting back on topic; anyone know this?

Update to the R/C Calc site:

- Added Ohms's Law calculator page.
- Updated the look a little for aesthetics.
- Added Mod 0.4 gear data for the gear calc page (for the Tamiya on-road vehicles)
- Added differential data for the Tamiya TB Evolution

is there anyway to make teh latest version more accurate?

Its telling me that a wanderer 9xl and 5s will go 101mph on my Raze, and telling me 134mph with a 600kv outrunner on 5s///

oops disregard that last post, it was my error, i was putting in the diameter of the tire when it ballooned out, not the amount it balloons..

sorry briang, great calculator@! :D :party:

lol, the calc is pretty accurate for the most part. The user on the other hand... :wink:

Also, was working on figuring the ratios for the new emaxx (3905) tranny. It seems that the two-speed setup is a little more involved than the original; first gear has two actual ratios, while second only has one ratio. The Savage tranny kinda works the same way (somewhat), so I'm gonna do some code changes to allow multiple ratios in the tranny drop-down for these types of vehicles. Until the code is updated, here is a quick-n-dirty diagram showing the placement of the gears and the ratios:

http://scriptasylum.com/forumpics/3905_emaxx_tranny.jpg

Single speed (stock) and Two-speed second gear ratio = 1.83:1
Two-speed close-ratio first gear ratio = 2.96:1
Two-speed wide-ratio first gear ratio = 5.08:1

Update to the calc:

- Added transmission ratios for the new Emax (3905)

- Changed the code for transmission ratios to show and calculate multiple ratios. Before, any additional transmission ratios had to be entered somewhere else.

- Updated Neu motor data for 1527, 1521, 1515, 1512, and 1509 series. Also added any newly listed motors in these series.

- Added Neu 1506 series motor data.

- Fixed bug with the picture viewer where parts of the image would not display.

You should add the Mega motors as well. I know they can go up to 74000rpms, but I haven't heard of anyone going that high yet.

Added a power calculator to determine power drawn from the batteries based on pack voltage, pack capacity, and runtime. Yeah, I was bored...

Brian,

Could you please add the Muggy diff ratios in the speed calq?

What are the ring/pinion gear tooth counts?

I'll add that as well as the Mega motors tomorrow...

Voltage Question?
 

When entering voltage and battery cell size into the speed calculator do you guys put 4 cells at 3.7 volts per cell or what?

Because as we all know that's only 14.8 volts. My Polyquest 5000 mah 4s charges up to 16.8 volts fully charged.

That is a significant difference in voltage and there for RPM right? :neutral:

Ture, lipos peak at 4.2v/cell, but the voltage does not stay there very long at all when running - just take a look at any discharge graph. People generally use 3.7v/cell because that is the voltage the cell is at for the majority of the time. As a matter of fact, depending on setup, the voltage may actually fall to 3.5v/cell or lower during higher current bursts.

Also, it depends somewhat on the user.

- If you are looking for max torque specs, use a lower voltage/cell rating. High torque is generated by high current. High current causes the cell voltage to drop.

- If you are looking for max speed spec, there will be less current draw when the motor is spun out, but the cell still won't be at 4.2v because the current drawn will still pull the voltage down.

It depends on gearing and weight too. If you are geared high and/or have a heavy vehicle, expect more v drop on take-off acceleration due to the current needed. If geared low and/or have a lighter vehicle, v drop will be less.

It also depends on the battery quality and capacity/C rating. A higher quality/capacity/C rating battery will maintain a more constant voltage under load.

Brian could you add some specs for Outrunners?

I generally limit the motor choices to what Mike carries. As you can see, the motor list is getting quite long already. As a mattery of fact, I'm thinking of removing the LMT motors altogether...

Please add the Megas Acn22 series.

I will. I was waiting for the Muggy diff ratio from BlackedOutRevo...

I did some speed runs back and forth in front of my house on and off for 30 minutes or so and still had 15.4 volts on my battery this afternoon.

It was SCREEEEAAAMING!!!! The speed and acceleration is mind blowing! :surprised: I now know what "Stupid Fast" really means. :mdr:

That would be unloaded voltage though. Voltage under load is what's most important, and is one of the main differences between a good battery and a not so good battery. 15.4v does mean that the pack probably had about half is capacity left though.

Yeah, it's a 25c 5000 mah 4s Polyquest/Enerland pack.

So far I'm really happy with it. :mdr:

A simple rule is zero-crossing.
Zero crossing would be sync with every pole, so for given motor number of magnet poles and armature poles per rotation would tell you what min. RPM would be sufficient for ESC to get it going. But to get direction correct you might want to get one extra, but it can be much simpler as well. If hardware can do that, than software is your limiting factor...

I figure the balloon effect is at least 1 inch?

Differential Ratio: 3.3333333333333335
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 12
Total Voltage: 14.8
Motor KV: 3300
Tire Diameter (inches): 4.25
Tire Ballooning (inches): 1
Motor Current Draw: 125
Motor coil Ω: 0
Spur/Pinion Ratio: 3.83 : 1
Total Ratio: 12.77778 : 1
Tire Circumference (inches): 19.63 inches (498.73 mm)
Total Motor Speed: 48840 RPM
Vehicle Speed: 71.07 mph (114.16 km/h)
Effective Speed Rate: 4.8 mph/V (7.71 kmh/V)
Estimated Adjusted Speed: 64 mph (103 km/h) - 10% loss
Effective KV Value: 3300
Motor Torque: 0.27 ft-lbs
Final Torque: 3.41 ft-lbs
Final Power: 1850 watts (2.5 HP)

Griffin: So, it's not just a pure kv factor, it matters how many rotor/stator poles a given motor has as well. Hmm. I was hoping for something like "min rpm for proper ESC operation is motor kv/10", or something along those lines. I really don't feel like adding a couple more specs to each of the motors in my list.

Most of the time, manufacturers don't supply the stator and rotor pole count. Is there a way to get this information manually simply by turning the motor shaft and counting the magnetic "detents" during one full rotation? For example; a Feigao/Wanderer/Nemesis is a two-pole and has two magentic detents per shaft rotation. A Neu is a 4 pole motor, but has 12 magnetic detents per rotation.

macrow: ballooning depends a lot on the tire and the foams used inside. For a tire to balloon out, the sidewalls have to contract and good/harder foams will help limit this. 1" ballooning on a 4.25" tire is a 23.5% increase in tire size! That would make the tires look like pizza cutters and would seriously hamper handling. The calc only show theoretical speed, ot theoretical controllable speed. :wink:

You should be able to do that by turning the motor shaft by hand and measuring the back EMF. (Eagletree is sufficient to do this...)
And you need to check only one phase.
Count the number of zero crossings per one rotation and than the inverse of that will give you the minimum rpm. (1/# of zero crossings)

If I don't have the eagletree, could I still rotate by hand and simply count the magentic detents?

Not with every motor...
For Feigaos and Novaks it might work.
You can use 2LED's backtoback and count flashes :)

lol, that works. I'm sure I have LEDs hanging around in my parts bin. :smile:

Ok, so I count the flashes for the various motors and invert that number to get the minimum rpms? Example: If I count 4 flashes, that means the motor has to spin no lower than 0.25rpm for proper ESC operation? Seems kinda low...

Thanks for your assistance!

You welcome:)<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
You need to count only flashes from one LED, we are searching for zero-crossing. Otherwise you need to divide total number of flashes by 2 to get zero-crossings not peaks. Sorry for confusion, I do prefer scopes :)<o:p></o:p>
And it should be sufficient for ESC based on zero-crossing. There are ways to do the same with interpolation and curve-fitting which requires less rotation...<o:p></o:p>
And just to make sure, it is not 0.25rpm it is quarter rotation. You can convert it to RPM but to do that you need to know the minimum voltage range for ESC analog to digital convertor. BackEMF value based on RPM, but zero crossing is dependant of that. <o:p></o:p>

Bottom line if we assume that 0.25V of backEMF is sufficient for ESC than quarter of rotation would be enough for ESC logic to get going. The RPM for given motor to get 0.25V of backEMF would be driven by motor Kv. You can put this all together.

I'm running these in the road. And they do look like pizza cutters at full throttle. And handling goes out the window. From the looks of it 1 inch ballooning was a conservative guess. That would only be a half inch expansion all around. :neutral:

Sorry for the late response Brian

Drive train ratio is 14.48:1

Pinion is 11
main gear is 45

That what I found searching, so if its wrong, someone please say so, but I think its right

thanks!

@Griffin: lol, yeah, I like scopes too, but I no longer have access to one. Poo.

I don't think this is gonna work for what I wanted to do. It would have been nice to be able to display a minimum vehicle speed where ESC would work effectively, but it seems like there will be too many assumptions, not to mention all the types of motors out there to test. People are just gonna have to use common sense.

Oh well.

@macrow: the only time the ballooning figure would be nice to enter is if you are just doing straight-line top speed. I always use 0" of ballooning because I want to know the max controllable speed.

BlackedOutRevo: OK, thanks. I'll add the diff ratio. I was also working on adding all the Mega motor data so there is just one update. There are a LOT of 22 series motors! I might just add the two Mike has in his store...

I will get back to you on this,

- Added Medusa Motors

- Removed LMT motor (so few now)

- Added the number of poles and the max recommended power rating to the Data Tables page. If anyone knows the power ratings for Neu and Feigaos, let me know.

- Added dropdown box to select vehicle type. Used to make drag-adjusted speeds more accurate. However, the drag values are the same for all types right now because I don't have enough real-world samples to go on. At least the functionality is there...

Any chance of adding the Novak HV motors - not for me but was trying to demo the app and they used them. thx

I was thinking of it but I try to limit the selection to what Mike carries. It is for general purpose R/C, but I do have his logo on there. Just my way of supporting the monster without actually buying stuff. :smile:

If you supply the following data, I will do it:

- model name
- kv
- if kv is loaded/unloaded/unknown
- max rpm
- motor length
- motor diameter, weight in grams,
- flange diameter (the raised area where the shaft exits the can)
- shaft length
- shaft diameter
- motor resistance (if available)
- recommended max power (if available)
- number of poles
- roughly equate it to an existing Feigao motor with respect to power. I use a funky rating system for the motor selector.