Speed Calculator

[BrianG]

lol, yeah, the ratio is messed up. It should be ~2.4. I swapped the input and output gears around.

Just take the reciprocal of the current ratio of 0.4167, which gives you the correct ratio of 2.3998080153587712982961363090953. Yeah, you can round that to 2.39981 if you want.

And if the ratio is different for the B vs the T, let me know. I add what people tell me and I assume they are correct.

[Unsullied_Spy]

Originally Posted by BrianG

And if the ratio is different for the B vs the T, let me know. I add what people tell me and I assume they are correct.

It is different. I posted the gear sizes for both a few pages back. IIRC the top gear on the B is 20T and the T is 19T. I checked HPI's website to be sure.

[BrianG]

Uploaded update.

Fixed error with HPI Baja 5T/B tranny ratios.

Added Baja 5B/T tire sizes.

Added nitro 4-tec tranny and diff ratios.

[BrianG]

Something interesting... or at least I think so.

http://www.offshoreelectrics.com/inf...s_Tips_&_Info_

(top two)

And yes, they asked permission.

[George16]

Good job Brian. Congrats.

[BrianG]

Thanks!

Originally Posted by Gee

...Maybe add an option to say your parameter solver or speed calculator that would pump out a table of what the est speed would be for say 10 different size pinions in increments of 1.

Don't know if I saying it correctly.

For example you would put all the info in for your RC on the est speed calc. Then instead of needing to go back and changing the pinion size from 10, 11, 12, etc. to see the different speed you would get. You could hit a button and it could display a table or something with the different speed you'd get for say a 10T - 20T pinion. It be cool then to go back and change the spur gear and see what the table would put out using the same pinions. Even on the reverse side say it would pump out the size pinion for estimated speeds of 30, 35, 45, 50, etc.

What do you think?

For some reason, I was downstairs thinking about how I was gonna make LST2 shocks fit my XT8 and the solution to this request hit me. I wasn't even thinking of anything close to this, but all of a sudden I remembered this request and an easy way to implement it. Weird.

Anyway, I added "speed vs pinion" feature to the top speed estimator page. After calculating the top speed, a gear icon will appear next to the estimated speed field. Clicking that will open a help window showing the speeds for different pinions.

[What's_nitro?]

Great idea. Congrats on your "exposure"! Now how do you make money from that???

[Finnster]

Originally Posted by BrianG

Thanks!



For some reason, I was downstairs thinking about how I was gonna make LST2 shocks fit my XT8 and the solution to this request hit me. I wasn't even thinking of anything close to this, but all of a sudden I remembered this request and an easy way to implement it. Weird.

Anyway, I added "speed vs pinion" feature to the top speed estimator page. After calculating the top speed, a gear icon will appear next to the estimated speed field. Clicking that will open a help window showing the speeds for different pinions.

Hey Brian,
Any chance you could update the Flux tranny ratios in the calc? Here is JThiessen's scan of the manual w/ the new gears

Great idea on the on the spd vs pinion. Its really nice to just look at the ranges instead of having to re-select the pinion. One thing tho, perhaps could the list read down the column instead of L->R? Just makes it a bit tougher to read. No biggie.

Also, couple other little things. The Sav XL spur, 52T iirc, Flux is 44. Lastly, regarding the Cen diffs. The genesis/nemesis and matrix all use the same diff. People may or may not know that. Don't need to update the name, but eh, some of the others are multiply named.
good job as always!

[BrianG]

OK, I changed the order in the speed vs pinion table. Critics!

I'll take a look at the Flux tranny diagrams sometime soon.

As far as the other diffs, etc is concerned: To be totally clear, post the model and the tooth counts of the diffs and I'll add them.

[BrianG]

Ok, I added the diff for the HPI Flux, but am having a little trouble deciphering the tranny. I've attached the PDF excerpt from the manual showing the tranny.

86087 looks like the input gear, but there are two which is common for two-speed trans. Then I see the output shaft with one gear (86098), simple enough. But then I see what I think is the idler shaft with only two gears on it (100905 & 86084). If this is two speed tranny, where is the intermediate gear on the idler shaft (the one that contacts the output gear)? If this is a single speed tranny, where is there a dual input gear and two output gears? It looks like maybe this is a single speed tranny that is set up for future dual speed use. So, until this is cleared up, I'm not going to include the Flux tranny.

[Jabe]

I got idea, for your site, make "battery finder", so you can find perfect batterys for your car.
So you shoud have these filtering options, widht, height, lenght, weight, battery capacity in mAh, constant current, brust current, voltage, saddlepack or not.

[BrianG]

Thanks for the suggestion! I had thought about that a while back while using a similar tool at another site, but it was not implemented well. I'm sure I could do a much better job.

[lincpimp]

Hey Brian, here is the info on the flux...

http://www.rc-monster.com/forum/show...d=1#post263911

[lincpimp]

Hey Brian, you have the incorrect ratio listed for the savage trans...

Well it is not correct for the X model...

The output gear is 29t, p/n 86098

And the gear that drives the output gear, on the center shaft is 32t, p/n 86084

So that ratio is 32/29, so 0.90625

You have 30/31 listed for the secondary reduction (which is actually not a reduction in the x tranny)

Now the 1st and 2nd ratios look to be correct, but I checked anyways.

Input gear cluster, p/n 86097, is listed as 18-23t. The 1st and 2nd gear "spurs", p/n 76914 & 76924, are 44t and 39t repectively. So that looks good.

So 1st is 18/44 and 32/29 so 2.444 x .906 = 2.214
2nd is 23/39 and 32/29 so 1.695 x .906 = 1.535

Those figures are rounded, and I know your program does not round the same. But you get the idea.

Are the figures you listed for the original savage 25 tranny? I will have to pull up a manual to see...

Just checked the savage 21 manual and it is identical, save for a different number for the 39t gear... Same ratios though

[BrianG]

Since I rely on submitted data for much of the ratios listed, I ptobably got the incrorrect info from someone, or just made bad assumption(s). Sometime soon, I will sit down and compile a list of changes for the next update.