brandon429

Have done some updates to this ride to increase the distance it can be driven away from the home base via fpv video. the goal was to have max top speed on demand but extreme range in fpv mode with failsafes built in to ensure safety when pushing the car to its range limits. in fpv mode it is driven slow and carefully to preserve control.

the current limit is 2+ blocks non line of sight travel in a circle aound my house. In adding a 5db antenna to the video transmitter it increased to another block, what I do is run the alleys around my neighborhood pretty early in the mornings when people are not out. There is an empty lot a couple blocks away I can get to in the alleys, many times I'll make a run there to test the range of this distance drone. When it rolls, I just in my car and go get it, for a couple minutes I guess someone could steal it but they haven't yet.
There is a walkie talkie onboard so I can 'negotiate' lol if anyone ever does try and drive off with it. I keep the other walkie in my pocket. This mode is also useful because when you are doing long range FPV out on jeep trails and such, the car can become lost/disoriented very quickly. Having a walkie on hand to activate the beep alarm is a useful tool for locating a car lost in a ravine in the new mexico mountains.

using rok loks 4.0 crawler wheels was the best upgrade ever made for an emaxx. They can be ran at full speed without ballooning, yet they are soft for traction in the trails. on rokster narrow beadlock rims

the non line of sight ground control for the vehicle is now 75mhz .750mw jr custom bought online. using a collapsible antenna tube to hold the antenna 3ft straight up, it can travel farther than the video can reach through houses and interference with near perfect control. Full interference causes the vehicle to go neutral. Loss of controller power causes the car to go to neutral, there are multiple failsafes. an ofna inline on the esc is one and the mamba max esc has one.

its main design is the ability to transmit and hold signal through blocks of houses without interference, a remote drone Ive nearly got up to 4 blocks away from the home base in recent tests.


this is the street test
http://www.youtube.com/watch?v=QAf-2DxTMy0

here are a couple of the fpv tests with a new one showing the extra range coming soon
http://www.youtube.com/watch?v=kfmVWeu4w2M

brandon429

much of the work has been in separating interference between the video system and the vehicle control system. Mounting the hardware on opposite ends of the vehicle helps.

rok loks are taller than jumbo kongs and 100x more stable. rok loks can be ran at full speed with zero wobble, they have 1/3rd the rotating mass of jumbo kongs.
Upgrades do not have to be made to run rok loks, Im still on a stock transmission after a year.

When using a vehicle for FPV it lasts much longer, no major repairs compared to jumping and flipping/bashing

Sigma.40

My Feedback: (1)

Thats aewsome, I love it! But that would suck if it flips and you're 4+ blocks away .

SyCo_VeNoM

or someone decides to walk off with it
try and catch em

brandon429

I place the bet on the non rc dude dropping it when I peg 3s 30c lipox2 and mamba brushless, if it catches a shirt, whoa

brandon429

this is a rear facing view, its helpful to get the perspective of how far it can drive in what would otherwise be total signal loss for the average rc car setup
http://www.youtube.com/watch?v=I0pAQJRcH5U

378

My Feedback: (4)

Damn, they go out a ways. I wouldn't mind rigging a Baja 5B to FPV.

brandon429

yes a larger model would be more interesting and less likely to roll.


its hard to find radios that work well in between houses on the ground. 2.4 ghz gear doesn't really help much in non line of sight fpv it has to be 75 mhz unless you can custom amplify 2.4 gear but thats really technical.

in that first video going down the road it was being driven with the trim controls to lessen overcorrection

ZeroKelvin

wow, watching that thing drive thru your neighborhood going several blocks over, I was pretty impressed. So are the cameras connected to a monitor in your house then? Would be curious just how far you can eventually go with it, will take a special radio

brandon429

Im driving it off a 50" plasma in the living room lol! Its pretty sick, like being in a rally car going down the alley at scale 100mph

the camera is on a servo for pan control...ie crossing the street. it can look both ways and is HD so spotting cars or people or objects is not hard, its laser clear.

Obviously one has to be very careful running a car like this but I want to reinforce the baby steps taken before taking the model out this far away in potentially high interference neighborhoods. I didn't just hook it up and send it out to see what would happen.

The first testing, for about 8 mos, was on a losi 1/18th rock crawler. Absolutely harmless even if all controls fail and the throttle opens up. By range testing with that little guy, I was able to verify the radio actions at long distance in both high interference and total loss of signal zones. By testing for months and months all the various radio interferences that come and go were covered at both distances. It was apparent by switching off the radio and by driving the model to max range where it stopped/went neutral that all signal loss possibilities were covered, the only option for loss of control w throttle (the dreaded fail) is someone on the same channel at the same time which at this frequency I am certain will not occur in my neighborhood.

So when the gear was moved up to the emaxx it had to follow the same rules as the tiny rock crawler...it has taken two years to reach these distances, even if someone bought the same gear it would take months of tuning to make it work in a given area, tuning the receiver and antenna height/configuration for video system, its really quite unbelievable how hard it is to get a ground based fpv model to go this far. The video system takes all the work, getting the vehicle under control is as simple as switching out the stock radio system to the upgraded or customized one. Using 72mhz airplane control is easy to do for this kind of range even though that's not meant for ground vehicle use.

A low quality 72 mhz fm system will have longer range than the top 2.4 ghz systems simply due to travel of the lower frequency around and through objects (houses)
75mhz is a nice compromise and its legal for ground use, many guys online and in the forums have them for same in the right forums, I got mine that way.

comparatively, if a stock 2.4 ghz traxxas radio system was controlling the car it would have been out of range just into the first dirt alley after I went through the gate opening at the top of the block. a ~72mhz radio goes 100 times farther on the ground.

Part of the tuning it takes to make a drone have distance on the ground is:
-jittering of vehicle servos caused by video system
-having a video system battery that will last all day
-routing cabling and power wires for vehicle/video system to not interfere with each other
-antenna heights and configs (rubber duck/ vee antennas, clovers/ yagi's/patch antennas/signal filters/shock shielding for wrecks/rolls
-setting failsafes to control vehicle upon signal loss
-ground receiver station that has tons of wiring and splices to manage and rework as needed with new equipment


-changing the antenna design on all points of the design does different things on the ground, this takes the longest. There are 5 points of radio communication for the drone:
transmitter to car is two points of contact, and video transmitter on the car (rear black antenna) to the two receiver station video antennas thats three more points.

Each point of contact is altered by using tall/short antenna configs, patch antennas and yagis + the several onboard video antennas the vehicle can use, all shaped very very differently. This is a VERY expensive side of the hobby, finding an antenna config that works best for you. No one over the internet can look at your surroundings online and tell you what will make a car go the farthest, alterations in terrain and signal makeup are vastly different between locations and experimentation and tuning is the only way to do it so theres a lot of cost in buying antennas you really didn't need.

Crash engineering is extremely tough; alot of this gear has to protrude from the vehicle so stopping rolls from smashing all the delicate video gear is really hard. In time I ended up taking apart the video antennas and putting them back together with shrink tubing so they will bend/flex when the vehicle lands on its can.
I wound up having to spend about $600 for the video receiver base station alone...
this is an old pic of the base station and car, no longer is there a fishing pole sticking up off the back heh this picture was 2 antenna configurations ago

brandon429

here was the current base station, the upgrades were
-dual inline signal amps for both receivers, had to splice them into the current 12 volt system
10 amp hour 12v battery upgraded from 7 on previous ground station
-yagi antenna/patch antenna on diversity
-50 more feet of cabling added to the antennas, so they can be up to 100 feet away from the television/viewing panel. This means you can have the base station set up out front yard, run the cable back in the house to plug into the tv, and it will receive better and let the vehicle go farther. There are so many configurations that the experimentation can go on indefinately.

My goal that I will reach will be one full mile in a 360degree radius around my house, the next upgrades will be dual iphones on video link and a dragonlink ground control system that can reach a mile or better on the ground.

thehuntingterminator

that would be freaking awesome man! great job so far, and please continue! is your Maxx the BL version with the Mamba Monster? i know you've got some kinda Castle system in there i just can't tell which one...

brandon429

it does have the mamba bl aftermarket install. this was originally an emaxx 6905
one thing about that brushless, its strong even in high gearing. on the same gearing I use for high speed i can also tow a child on a razor scooter all around the park...guess its the best electric motor Ive ever owned. We have this jogging park where huge sidewalks meander for about 2 miles and its the best place to do assisted scooting. add helmet+pads+towrope+agile 10 year old on a razor scooter and you have one heck of a fun morning of FPV towing at the jogging range. 10 mph is plenty fast and has enough battery reserve for hours of pulling, these batteries on the bl are the venom 6400 mah's x2

thehuntingterminator

4s or 6s?

brandon429

its a 6s a real screamer lol

now the discharge rate is only 20c, they aren't explosive power battery packs they are for long slow range. But, in bursts they will flip the truck backwards I couldn't imagine more torque on it with these tires.

thehuntingterminator

have you ever flipped or gotten stuck when doing a long range FPV trip?

brandon429

oh yes many times. one of these is lost on top of a hill in the new mexico mountains, the video signal cut out and I had no location equipement on it. it was at night, and we spent all next morning looking for it. that was about a grand down the chute.

now I have location equipment, a pair of walkie talkies. One can be strapped to the car with a zip tie and the ringer function used to locate the truck.
In the neighborhoods I drive carefully so it won't wreck.

ThunderbirdJunkie

My Feedback: (3)

This is too cool.

Foxy

Hm...I could easily do something like this to my truggy and send it round the block for cigarettes. That would be epic, lol.

Thanks for the inspiration.

mlwgf8

My Feedback: (8)

Where did you get those tires and rims?  I looked for them but can't find them. 

brandon429

tires from stormer hobbies, when they carry them

rims from towerhobbies, the narrow beadlocks rocksters
the tires from from a store called rc4wd.com but they take weeks to fill an order, when stormer has them, they are ready to go!
try them, you'll love them. the only downside is the car will wheelie more because of higher center of gravity. but with the looks, and no high centering on curbs, its worth it!

mlwgf8

My Feedback: (8)

Thanks. Looking at your truck, you know what you're doing. It's impressive. Nice work

To anyone else who would like the tires as well here you go.

http://store.rc4wd.com/Rok-Lok-40-Se...res_p_755.html

MadManAndrew

Very, very impressive.

cummins driver

My Feedback: (31)

So you're saying you lost the whole truck, camera gear and all? [X(] I think i would have camped out in the mountains until i found that thing! haha

brandon429

A thousand dollar rig. been up there for a year now, imagine how long we looked the next day. worst thing that would have happened would be video battery (lipo) and the vehicle lipos would be ruined from full discharge but somehow the thing rolled down an embankment or something and lost video signal on top of a huge mountain, after about 3 hours of looking I just gave up and ordered another emaxx off easy pay from towerhobbies, then all new video gear and brushless sheesh and lipos, again



Thanks for stopping by! I had tons of help, if you want to see the maddest FPV thread on the web google this
"fpv car and other fun projects thread" and one from rcgroups w come up. Just a small thread with 150 pages and 200000 views l


Just made this video, its funny to see the look on the guys face who is watering his lawn. Don't mind me Mr.
Just a free roaming rc car driving down your block and behind your house then Im gone and we can pretend that didn't just happen. You can file what you just saw under things not commonly seen while gardening.

being able to circle the block that is south of my block running perpendicular is a milestone because these are directional vid receiver antennas that don't get moved during the run


http://www.youtube.com/watch?v=kSenvCPf2qs