Fixed in both the regular and beta versions... Actually, the recommended rpm displayed in the warning box was wrong as well. Was simply an issue with array indexing.

I'm working on the motor selector and have some questions. I need to group all the 540 can motors by S, L, XL, and XXL size.

Would the Lehner Basics be considered S size?
Would the Lehner Basics XL be considered L size?
Would both the LMT 1940 and 1950 be considered XL size? Or is the 1940 more L size and the 1950 XL size?

Argg! LMT has too many sizes! Better question:
Where do the following motors fall in the S, L, XL (and maybe XXL) size rating?
1920 S?
1930 L?
1940 XL?
1950 XXL?

OK, no one has responded to my questions, so I guess I'll have to make some assumptions.

Anyway, I did a little more work. It's not quite done yet as I still have to factor in the weight variable (tomorrow night's project) so it picks the motor can length (S, L, XL, XXL), but I think I have the layout done. So far, it picks the motor can type (540, 380, etc) from the weight entered and picks motors whose kv value are +/- 5% of the calculated value. Then the program divides the remaining motors by motor quality. Take a look and offer feedback. BETA VERSION.

BTW: The "hard coded" values in there are just to ease my testing. Those will be stripped in the final version. Just override as necessary.

yeah... I would agree with your assumption

The 1950 is like a xl. It has almost the same deminsions. The 1930 is little shorter than l the 1940 is little longer. I think the 1920 is about an s can.

Thanks. So, the 1920 is an "S", the 1930 is an "L", and the 1940/1950 are considered "XL"?

The only reason for this rating system is so that I can choose the appropriate motor for the weight of the vehicle. Heavier ones need more torque, which requires a longer can. I guess I could get away form the S, L, XL, thing and simply go with a number rating system.

The 1940 is kind of inbetween the l and xl. So you can kind of say either.

OK, the final version is up. R/C Calculations

Sweet tool! Very good job, Brian. Thank you.

DAF

Very good!

thanks brian...I like the final version....very easy to navigate thru

Thanks all!

I still am not too sure on the motor selector. See if this sounds right to you:

For choosing the motor size (300 vs 540 can, and then S, L, XL) I am using the truck weight:

If weight < 1.5lbs, use the smaller 300/380 size can. (regular Mamba).
If weight between 1.5 and 5 lbs, use an S size
If weight between 5 and 8 lbs, use an L size
If weight between 8 and 16 lbs, use an XL size
If weight between 12 and 25 lbs, use an XXL size (LMT 1950)

I have some weight overlap for the XL and XXL size, but I wonder if there should be some overlap with the others? I know a smaller motor may work on a heavier truck, but this is for an "ideal" setup.

Then, I use the calculated requried kv value to determine the applicable motors which have a kv that falls near that value.

I wonder if there's any way to figure out how many watt/lbs we need to go a certain speed?.. that would be Freakin' awesome..... I don't know if I'm sayin' it right, but you' know what I mean....

Yeah, the trouble is getting that spec from all the different motor manufacturers. This is more generic and gained from experience and reading these forums, but probably not as accurate.

Maybe I can have a word with Mr Lehner about this. When he's in the right mood, he's very helpful ;)

But the weight/size thing looks good, Brain. From my experience it makes sense.