Speed Calculator

[BrianG]

Sure. Like I said in that post; as long as he consents and provides the formulas, I'll be happy to add it.

I'll change the layout, user input error trapping, some code (mostly to use my own code library), and other small things to match the scheme of the rest of the site. But obviously B4maz will get full credit for the original idea. It all depends on him now.

[BrianG]

Criminy! That's one heck of a "to-do" list!

I'll try to answer all the points:

- Note fields would be handy for screencaptures I guess, but might confuse the user. Most would be asking "If that has to calculation purpose, why is it there?". Usually, people post the setup in a forum post and then add more details in the post.

- Motor pole count. Actually, I do have that information already in there. But since it's not used for any calculations, it's just visible on the "Data Tables" page just for informational purposes.

- Yeah, I can add more motors, but as you can see, the list is quite lengthy already. I try to stick to the more common motors out there and/or the ones that Mike sells. If others chime in saying those would be good additions, I'll add them.

- Motor current draw: What type of additional help is needed? There are SOOOO many variables that influence this that the only two usably values IMO are 0A and whatever you think the max would be. Everything else is pure speculation.

- The 1:1 rollout was something recently added by request. I'm not really sure what benefits it has other than as a starting point for gearing. So, that's what I put.

- Adding metric units should be fairly easy to do. I'll check into that.

- Adding tires, tranny, spurs, and chargers should also be easy to do. Check for them in the next update.

- System wiring page. Adding specific ESCs is kinda redundant. I would prefer maybe "classes" of ESCs; something like Opto-ESCs, ESCs with linear BECs, ESCs with switching BECs, etc. Something for me to think about.

- BL Parameter Comparison page. This was just a little project of mine trying to find an easy way to graphically show the relative impact of gearing, voltage, and motor kv. I specifically wanted to keep it simple for the newbies. Once they understand that higher kv is not always the best, then they can go into the other pages for detailed calculations.

- Lipo wiring page. I tried to include the 3 major lipo hookups; Trakpower for its unusual wiring arrangement, Hyperion for its odd wire sequence skipping, and everything else. "Everything else" has the wires in sequential order with no skipped spaces, so that covers pretty much anything out there. And, actually, you CAN wire it up like in your "wrong" picture, but you have to be SURE you have the plugs in the right order. My personal Y adaptor does have that common wire still hooked up, but I know what I'm doing.

And the type of connector is pretty much irrelevant IMO. I just chose Deans because that's what I have and it looked ok. Besides, people have different ways to use bullets (ie: two females on the pack, vs one male and one famale for "polarization").

- Electrically speaking, it makes no difference which order the wires are attached. The only time it matters is if your specific charger/balancer specifically says to connect things in a certain order.

- Memory slots. Yeah, that can be done, but really complicates things. Since I'm using a static site (no active server content), I'd have to rely on cookies. And I hate dealing with cookies. They don't work well when I'm developing on my computer, so I'd have to upload test code at my site each time to see if it works. I would really rather not go that route. But TBH, there was times where I wish I could have saved a setup because I had to go to another page briefly, but didn't think it was worth the bother to implement.

-Lipo voltage. Yeah, 4.2v/cell is not a practical voltage value in a setup, but I do have the 3.7v value highlighted to implicity tell the user to use that one.

- Gearing pages. Since there are a ton of different things a user could be looking for, I just provide the basic tools and let them figure whatever they want to figure out. For example, if they want to switch between Mod1 and 32P but keep the same shaft-to-shaft distance, they would use one page to get their current shaft to shaft distance, and then another page to figure out the gear diameters to match that for a different pitch.

Whew! I hope you don't think I'm trying to get out of doing more work. I don't mind adding features as long as 1) it would be useful for others, 2) doesn't complicate things uneccessarily, and 3) I feel like it.

Welcome to the forums BTW!

uhh... Brian... you probably gonna hate me after this, but anyways...

http://www.outcastrc.com/features/scales/scales.htm

Exactly! You've got more work to do! The height is actually the diameter of the tyres. Good luck

[Aero]

Thanks! It's not really a to-do list, thought this cool calculator author need feedback as thanks, do not think that i know all im talking about :) It's nuthing but ideas and such. So you judge whats worth a second thought. No hurry, promises and all that..some of the suggestions are old, but finally vented them. then if other like them, i hope they would mention it or something, to reflect its not only ONE person who like to see some particular 'udate' (or a dozen, sorry they came in a bunch..).

Note field: confuse users..ok then. I suppose by not filling the field out its not confusing ? Too bad, I liked that idea In fact all captured calculator images look alike, but i guess one can always photo edit it, or title them..

Motor pole count: too long list? i respect your implementation-wise arguments, i cant speak much for that. whatever works now is nice, and a longer list dont sound like a bad thing..dunno maybe its good to have the pole count on motors in the drop down curtain..maybe not? all these things in general with stating/posting data would especially help if LOOKING for some data, or be sure what to pick. it may maybe be too idiot-proof.. If all the motor data, like pole count is in the data table, cant the drop down curtain somehow be linked to that, if that make sense?

and YES ammo motors are popular, i have 3 of them. They are very common to me. In that case, Mike should sell them

Motor current draw: some guidance would be nice, like a drop down curtain with some numbers. I doubt newbies understand this calculator much, but i recall myself! say, I got some number from part specs and dunno where to put it. I punch in 12000Amp. fx. in the ?-sign or in drop down curtain some where-about numbers could be picked or referred/related to. You could also excess the use of likely words. Fx. 'average' and 'burst' and 'max', so to the user wont be in doubt where to put some number. liek a motor come with 2-3 specs. or say, some lehner motor, like a 1940/7. is that 1940kv..7 pole..no. Bad example. cant explain it better tho..my bad english..

1:1 rollout: isnt that rollout thing the result of acceleration+torque relationship ? why is it goo to know that the truck move one inch for a single motor rpm. i dont believe in that 1:1 'rule', its some small scale torqueless buggy thing no? and I suppose rollout ideal, would have something to do with KV and length of a motor(a motor model)..and weight if vehicle etc..? but me dunno - maybe ill get it later..

BL Parameter Comparison page: it does look interesting. Perhaps some check-mark boxes, with influental components could be cool to have and see what happens/changes..but i suppose ur in developing something already ;)

Lipo wiring page and connecting sequence: Can you please re-check the 'wrong' picture in detail Brian ? hehe, i also know what im doing (well once in a while!) and once i had an incident.

Deans/bullets: just cosmetic rambling as you can see i edited your picture to show E-flite connectors i know its irrelevant..

Memory slots: oh ok. what about making a 'get picture' buttom for this and that/here and there, so the picture could pop up in a new window, or one could save it as a file. or about file, ability to save the seup and load it (like import-export)

Gearing page: maybe it could be nice to have a 3rd sub-calc there, like type(select) in gearing/~ratio, and either spur or pinion, select pitch, and get result, change pitch and have one gear value fixed, get result ?

Originally Posted by BrianG

Whew! I hope you don't think I'm trying to get out of doing more work. I don't mind adding features as long as 1) it would be useful for others, 2) doesn't complicate things uneccessarily, and 3) I feel like it.

Welcome to the forums BTW!

Yes, its only humble requests..and not all too clever. i did read that you have asked feedback often ;) yes i read all 51 pages first

Originally Posted by Aero

.................
Yes, its only humble requests..and not all too clever. i did read that you have asked feedback often ;) yes i read all 51 pages first

uhh.. wow.

[BrianG]

Originally Posted by Aero

...Motor current draw: some guidance would be nice, like a drop down curtain with some numbers. I doubt newbies understand this calculator much, but i recall myself! say, I got some number from part specs and dunno where to put it. I punch in 12000Amp. fx. in the ?-sign or in drop down curtain some where-about numbers could be picked or referred/related to. You could also excess the use of likely words. Fx. 'average' and 'burst' and 'max', so to the user wont be in doubt where to put some number. liek a motor come with 2-3 specs. or say, some lehner motor, like a 1940/7. is that 1940kv..7 pole..no. Bad example. cant explain it better tho..my bad english...

First of all, what is "fx"? Is that like "ie", "eg", or "example"? I guess I could maybe offer some very basic guidelines as to what current numbers to use. 12,000A is not very realistic unless you have a 500Ah 24C battery.

Originally Posted by Aero

...1:1 rollout: isnt that rollout thing the result of acceleration+torque relationship ? why is it goo to know that the truck move one inch for a single motor rpm. i dont believe in that 1:1 'rule', its some small scale torqueless buggy thing no? and I suppose rollout ideal, would have something to do with KV and length of a motor(a motor model)..and weight if vehicle etc..? but me dunno - maybe ill get it later...

Like I said, it was something that someone requested. It's a good starting point for a very safe gearing for someone with no experience with how BL setups act. From various test calculations on different setups, it tends to be very conservative for gearing. Of course, top speed would suffer, but the chances of pushing the components too hard are pretty slim if you follow that rule.

Originally Posted by Aero

BL Parameter Comparison page: it does look interesting. Perhaps some check-mark boxes, with influental components could be cool to have and see what happens/changes..but i suppose ur in developing something already ;)

Like I said, it was just to give newbies a basic idea of how things work. Since it doesn't have absolute numbers, it just shows relative changes. Definitely not definitive (lol, that was a conflicting statement ).

Originally Posted by Aero

Lipo wiring page and connecting sequence: Can you please re-check the 'wrong' picture in detail Brian ? hehe, i also know what im doing (well once in a while!) and once i had an incident.

lol, now I see! Yeah, that would be bad. I had to really look to see what you meant. I think for the sake of simplicity, I would add some kind of note or indicator showing which balance plug goes with which main harness wire.

Originally Posted by Aero

Deans/bullets: just cosmetic rambling as you can see i edited your picture to show E-flite connectors i know its irrelevant..

To be honest, I just don't feel like creating graphics for every combination. I can just imagine if I add E-Flite connectors, someone will say "where are the traxxas plugs", or "where are the bullet plugs". I think people are smart enough to realize they can use whatever connector that floats their boat.

Originally Posted by Aero

Memory slots: oh ok. what about making a 'get picture' buttom for this and that/here and there, so the picture could pop up in a new window, or one could save it as a file. or about file, ability to save the seup and load it (like import-export)

The import feature would be the easiest way to implement this I think. The current export feature is "blind"; meaning, it simply looks through the page and gets the field title and value for any field with a custom element attribute. I'd have to design the import/export system such that it is backward compatible with any future upgrades (like if I add a new field, or remove one). I'll have to give it a little thought.

Originally Posted by Aero

Gearing page: maybe it could be nice to have a 3rd sub-calc there, like type(select) in gearing/~ratio, and either spur or pinion, select pitch, and get result, change pitch and have one gear value fixed, get result ?

This was actually requested a while back. But due to complexity, I compromised by creating a table with alternate pinions which show the resulting speeds (click the little gears icon in the results section - in the top speed estimator only).

Originally Posted by Aero

...yes i read all 51 pages first

You have WAYYYY too much time on your hands!

[Aero]

yes, fx. = for example

If i had too much time on my hands, i wouldnt have bothered you in first place. I actually meant to email you instead, but anyways you can delete the post/data when you dont need it anymore.

I took, that it was making common sense to have read the whole thing, before making suggestions, then read that you often welcomed thoughts and opinions..didn't really know you were still developing the calculator, before once I saw some minor changes (thanks to kopfpilot) here and there.. It's by far the ruling rc calculator I know of yet. Well it was interesting to read the history of it. Not much to read, but it not my native language..

pinkpanda> Very helpful..Doesn't matter. We both had a say.

good luck with the calculator. I owe you a high class pizza, but if your BMI prefer I might paypal you instead, so much easier over long distance

besides you deserve it!

[BrianG]

lol, I'm all over it. (not).

[pinkpanda3310]

You do to much Brian but thats why we love your calculator

I would have done like you said and stopped what's available in RCM.

[BrianG]

In case no one has noticed, I made several changes the last few days. The following list is taken from the release notes file:

- Added form import feature. This allows the user to save prior setups into a file and reload them at a later date.

- Changed the method used to export field values for forum posting to prepare for a possible new feature.

- Added more detailed "help" explanation for motor current value in the top speed estimator page. Also, added a warning when the motor current value exceeds 250A.

- Added more details for lipo Y adaptors to help reduce the chance of mis-wiring.

- Added e-Savage metal tranny ratios, and spur gears.

- Added HPI Baja, HPI Dirt Bonz, Trx Response, and Trx SportTraxx tires.

- Added Great Planes Ammo 36-56-2600, 36-56-1800, 36-56-1200, 36-88-1280 motors.

- Added Imax B5, Imax B6, Imax B6AC, Imax B8, E-Station BC8DP chargers.

I probably need to explain the new import feature a little more. There is a new button on the "top speed estimator" and "parameter solver" pages that says "Import Values". This lets you import values from previously exported data. You would save the exported data to a file (or post into a thread), and then at a later time/date, copy the text to your clipboard, and then re-import the data using this button. The form fields will be repopulated with the data so you don't have to manually type in all the data again.

[Kcaz25]

Thanx Brian! Really love the import/export feature!!

Didn't know Great Planes had a 88mm!

Brian, how does the speedcalc calculate torque?
If I enter a higher amp draw the torque outcome increases. But isn't it so that a higher torque motor will draw less amps? (comparing two motors of the same series: a higher kv vs a lower kv, both geared for the same speed@the same voltage)

[BrianG]

Torque=(1352/kv)*amps

So, lower kv and/or higher current equals higher torque. And then, the lower the gearing, the higher the torque as well.

Thanks. What I'm trying to understand is this:

Originally Posted by lutach

From what I've seen in my set ups, all the higher Kv motors geared for the same speed have always asked for more AMPs then with a lower Kv ones. It might have to do with the winding resistance (Rt) and the fact that most higher Kv motor have higher Io (No Load Current). For example: A Aveox 1415/2Y has a Rt of 0.022 Ohms and a Io of 1.8, now a 1415/1.5Y has a Rt of 0.010 Ohms and a Io of 2.5. I have tried the 2 motors above with 6S both geared for the same speed and the 1.5Y was always warmer and pulled more AMPs then the 2Y.

You can get two motors from the same series (neu 1515) and run them both on 6s. The lower kv motor would need higher gearing and the higher kv motor will need lower gearing to achieve the same speed. Why will one motor run cooler and longer than the other?

My assumption was that both motors would produce the same amount of watts and therefore the same amount of amps. But if the runtime on both motors is different, one will actually pull more amps&watts...

[Aero]

Cheers BrianG!

Where can I find the Keda Model 1900kv motor ? When picking motor, I thought it would put in the resistance as well but it doesnt. also about that 'enter current draw' should i put in 3.9A or 55A? under the ?-sign is says 'motor current draw'. even my medusa motor wouldnt draw 200a ? it continue about weight of truck.. i dont understand this.

i was hoping it put in the right specs of motors in the right field(s).

Section two, in 'gear diameter calculator' would be nice to have 2 or 3 of that next to eachother(sidebyside) so one can compare different gear sets.

brilliant work again!