lots.... and LOTS of questions about my Gorgon

[CertifiedMike]

Oh! @JustnWynn , do not leave that servo plugged in while not in use. It will suck that battery dry, like an ex-wife.

Good point!!!

 

[WickedFog]

But wait. You're not done. You absolutely have to set your servo endpoints.

Radio steering trim at zero. Go into your EPA setting for channel 1. Turn the setting for both left and right turn of the steering down to like 20% or so.

Now, crank the steering all the way right and hold. Adjust that endpoint up and you will see the steering start to turn. Keep going up until you see the steering does not move any more because you have reached the mechanical limit of the steering linkage. Now back off the endpoint off one click at time until you see the steering loosen up as it starts returning. That is your endpoint.

Do the same holding left on the steering.

That will keep you from burning up your servo prematurely due to the servo trying to travel too far and binding the servo.

Double check this by cranking your steering all the wsy left and right. You should feel a bit of play in the linkage. If it's tight, you are still trying to turn too far.

Always do this on EVERY new servo setup on your RC's. Even RTR RC's, because they are never right.

 

[JustnWynn]

good morning everyone! wanted to say thank you again for everything... I'm at a good stopping point for now i think. gotta try to keep it fun. yesterday was... trying on my patience. lol
gonna move on to my other project. the toy grade to halfway hobby grade. the wifey and i are doing some painting today for that one.
but i wanted to show off my big tires in case anyone was curious as to why i got that big servo

then this is the shell that i'm gonna try make work with it.

thats it for now.
opinions are always welcome!

cheers, fellas

 

[WickedFog]

You have to take those big tires into consideration with regards to your gearing. As cool as it looks, it is going to put a monsterous load on your motor, and ESC. You have to adjust your pinion/spur accordingly. You do that by calculating your final drive ratio now, compared to the typical ratio with stock gearing, tires, and motor. Use the pinion and spur to get back close to your original final drive ratio. Or if you upgrade the electronics to handle more load, you adjust for those electronics. With those tires, you are very likely going to burn things up very quickly if the motor/ESC can't handle it.

Looks great though! So get out your calculator and make them work

 

[332_RC]

What's the OD diameter of the tires?

 

[JustnWynn]

you got it, obi-wan.

 

[JustnWynn]

You have to take those big tires into consideration with regards to your gearing. As cool as it looks, it is going to put a monsterous load on your motor, and ESC. You have to adjust your pinion/spur accordingly. You do that by calculating your final drive ratio now, compared to the typical ratio with stock gearing, tires, and motor. Use the pinion and spur to get back close to your original final drive ratio. Or if you upgrade the electronics to handle more load, you adjust for those electronics. With those tires, you are very likely going to burn things up very quickly if the motor/ESC can't handle it.

Looks great though! So get out your calculator and make them work

What's the OD diameter of the tires?

they are 6.5 inches, sir

 

[WickedFog]

If you need help, here is a post I did for another guy.
Post in thread 'A possible alternative Crawler motor for Large scale rig ....' https://www.rctalk.com/forum/thread...motor-for-large-scale-rig.144284/post-1493316

 

[WickedFog]

If you scroll up in that thread, you will see where Big Kid calculated his final drive ratio.

 

[332_RC]

they are 6.5 inches, sir

My Gorgon tractor tires are 5-1/2" tall. I didn't change the stock spur or pinion but it's brushless 3500 & 100a so it gets on pretty good. The 3660 has some torque. I'd imagine there are smaller pinions for your build, but don't know how much smaller. IIRC 13t is stock, 11t may be the smallest but idk what motor shaft you have. It may amp out & get too hot.

 

[JustnWynn]

ok.. here we go
6.5in tires
61t spur
16t pinion
2 spur rotations for every tire rotation

stock final ratio is 17.92

 

[WickedFog]

Gear ratio is 61 ÷ 16 = 3.8125
So 2 spur rotations to one tire rotation is 2÷1 = 2 for your transmission gear ratio of 2:1. Is that right? I am seeing it is supposed to be 2.85:1 after a little googling.

 

[JustnWynn]

ill be honest.. its a rough guess on the rotations.. can only the spur to move 2/3 way around for every between 1/3 and half of tire rotation

 

[WickedFog]

Well, after looking at the transmission gears, I am actually calculating it at 3.55:1. So we gotta get this sorted. 3.55:1 sounds much more typical.

Mark a tooth that you can time with a mark next to the spur, and put a dot on your tire aligned with something on the chassis, or setup a stick taped to the chassis to line up with the mark. Rotate the spur til you get one full tire rotation. Make sure to count the full spur rotations. Once the tire rotates fully, count how many teeth the spur rotated past your timing mark on it's last rotation and let me know the full rotations, plus the extra teeth that went past it.

I am hoping you see 3.55:1.

 

[JustnWynn]

Well, after looking at the transmission gears, I am actually calculating it at 3.55:1. So we gotta get this sorted. 3.55:1 sounds much more typical.

Mark a tooth that you can time with a mark next to the spur, and put a dot on your tire aligned with something on the chassis, or setup a stick taped to the chassis to line up with the mark. Rotate the spur til you get one full tire rotation. Make sure to count the full spur rotations. Once the tire rotates fully, count how many teeth the spur rotated past your timing mark on it's last rotation and let me know the full rotations, plus the extra teeth that went past it.

I am hoping you see 3.55:1.

ok.. on it. one moment

 

[JustnWynn]

ok... 33 teeth past one roation per tire rotation

i feel like i should mention. there were gaps where the tire turned without the spur or any gear turning. is that normal?

 

[WickedFog]

Little slop in the mesh of all the gears. That is normal.

 

[WickedFog]

I sent you my phone number. Give me a call.

 

[CertifiedMike]

good morning everyone! wanted to say thank you again for everything... I'm at a good stopping point for now i think. gotta try to keep it fun. yesterday was... trying on my patience. lol
gonna move on to my other project. the toy grade to halfway hobby grade. the wifey and i are doing some painting today for that one.
but i wanted to show off my big tires in case anyone was curious as to why i got that big servo
View attachment 215019
View attachment 215020

View attachment 215021

then this is the shell that i'm gonna try make work with it.

View attachment 215022

thats it for now.
opinions are always welcome!

cheers, fellas

My opinion, since you asked, is that all the work and nonsense and double back tracking and refiguring was ALL worth it!!!
That thing looks CRAZY and I can't wait to see it roll!!!

 

[JustnWynn]

thanks! .just did my first pass.... its wicked!! still working bugs out of the transmitter with no instructions (thank you @WickedFog )

but it seems stubby bob was a good analogy.. it rides wheelies in 6 in grass!!

rear suspension in MUCH too soft. now that i have all these metal gears.. i'm gonna try the harder helper springs.. but i dont know.. its very much more heavy than it was. but those proline shocks werent cheap so we're gonna make it work. ha