Speed Calculator

[Serum]

Amen Glass.

[captain harlock]

Then, the idea is to fill up the gap between the tire and the insert, right?
I should try it very soon.

[glassdoctor]

Originally Posted by captain harlock

Then, the idea is to fill up the gap between the tire and the insert, right?
I should try it very soon.

Well not really... the ides is that the tape won't stretch. So when the tire wants to stretch and balloon out... the tape can't. If the tape is stuck good enough to the trie, it will hold the tire at it's normal diameter.

Just like if the tape was on the outside.. you can see how that would stop the tire from ballooning.... same thing if it's on the inside, assuming it's sticky enough to stay stuck. :)

Stretchy tape wouldn't work... it must be a duct or strapping type...

[BrianG]

I've heard gorilla tape works well as it is quite sticky. Just don't forget to clean the residue off the tire first.

[captain harlock]

Nice, nice, ver nice!..:)

GD, Brian, I announce both of you as Deputy Captains as of today.
Congratulations!:005:

Okay, a different question:

Is there a possibility that I can change the gears of the slipperential from 21:44 to something like 24:40 ?

I want to decrease the gear ratio to make it as low as possible. 2:2 ratio is quite high and I've noticed that the truck was somewhat undergeared.

I want to change the slipperential's own gears( of the center diff and topshaft) and not the spur or pinion.

[MetalMan]

To lower the ratio of the slipperential would require a different spur gear on the differential. To my knowledge, there are no other plastic spur gears that fit onto any center diffs that have fewer than 44 teeth, besides the one on the Revo that has 28 teeth (but that's a completely different diff).

[captain harlock]

Mike is very good in making aluminum stuff, but I don't actually know if he can make me a 40T spur for the slippy's center diff?

[BrianG]

I'm sure it's possible. The only way to know for sure is to ask the man himself! :)

[BrianG]

Due to some reported inaccuracies in the top speeds of some setups, particularly over 40mph, I want to adjust all motor KV values to unloaded values and then have the program automatically enter the motor resistance in the appropriate place. Then, the user is free to enter appropriate amperage draw, thereby making the "loaded" KV more meaningful for their application.

I know I can use the Feigao chart to get the unloaded kv values for the BK Wanderers, but what about the Neus and LMTs? I assume all LMT motors (basic, basic XLs, 19xx, etc) list the loaded KV?

[BrianG]

OK, an updated version has been uploaded.

• All motor KV values were changed to unloaded wherever I could.
• The motor dropdown lists and the data page tell you if the KV is loaded or not.
• The top speed page automatically fills in the motor resistance for each motor where known.
• Added a "calculated KV" output on the top speed page which calculates the real loaded KV value providing the raw kv value is unloaded, and you enter the motor resistance and amperage draw.

Thanks go to GriffinRU for the Excel datasheets from his Motor Evaluation program, which is where I got the unloaded kv values and motor resistance for all the non-Wanderer motors.

As usual, link is in sig...

[MetalMan]

I found one slight problem. The Rustler/Stampede transmission shows a gear ratio of 1:1.

[BrianG]

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).

[MetalMan]

Woops, my mistake :).

[BrianG]

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...

[BrianG]

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...