Anyone into R/C?

Thank you for the insight. i'll do some more research on the different frequencies and their limitations. I have a pretty nice FPV setup that I fun on my Hex, so I might just take gear real quick and test it out by lowering it down a vertical run of pipe.

so if the antenna extension won't work, maybe i'll run the numbers on keeping the receiver at the end of the pipe, and extending the servo and ESC control wires. voltage drop is obviously the concern there, but it may be enough to work. that's something i can easily test out at home since it's just extending wires.

we are trying to figure out a way to self perform purely because of the amount of pipe that needs this cleanliness inspection. we have miles of pipe that needs this inspection, so hiring a third party company would quickly surpass the cost of even an ROV.

 

that's what i was talking about doing. the concern is that the transmitter/receiver simply doesn't put out the power for it.

 

Nice looking FPV setup you got going on there!

Voltage drop would for sure be an issue with that amount of extension. The good thing is since we deal with small power sources you might be able to go up to a large enough gauge to compensate the drop and still have good maneuverability. Silicon noodle wire is super flexible and can be had fairly cheap at hobbyking.

The only other viable options outside of wire extending and going to a MHz setup would be to look into helical antenna setups or some type of ground station setup. The problem with helical is the need for it to face the Tx to maintain good signal BUT I have an idea to allow that! Mount the antenna atop a servo so you can control its forward direction. If I remember correctly someone came out with a helical station that auto rotates to follow the signal, the only thing is this was all for FPV and I'm sure how well or even if it could be utilized specifically for a radio Tx but I honestly don't see why I couldn't be. My last thought is when I was beginning to shelf flying DJI was releasing a 2.4ghz ground station/data link setup that was apparently good for extending to a good range. That technology was just coming out so I don't know squat about it and have never used it but on thing I can give props to DJI for is their ability to make 2.4/5.8 ranges far better than most average out of the box equipment.

 

so extending the servo and esc control wires to have the receiver at the end of the pipe, just feet away from the transmitter may actually be feasible. it's a lot of cable to pull, but with the gearing of the crawler, it shouldn't be an issue.

Given data and assumptions:
-Receiver sends out 6V to servos
-use 20ga servo wire (24ga is standard, 22ga is HD, 20ga is extra HD)
-100' extension needed
-.5 amp load on steering servos (not using high torque servos, and there will be very little resistance on the steering)

using these numbers, you come out to a 1.02V drop, bringing your input voltage to the servos to 4.98V, so essentially 5 out of 6 volts.

i might as well try it on one servo and test it out, to see if how a servo performs under those conditions.

 

Nice figures! Lemme pose this question, once you get your 100ft run of cable setup and check your voltage coming out with 6v if your dropped down to just below 5 why not bump your input voltage up to 7v? Hell you could make a small voltage regulator and put in as much voltage as you want and then adjust it to suit the end total voltage after the drop.

 

100 feet of cable, going through multiple 90° corners, prolly won't get very far before it develops too much friction. If you have ever pulled wire through conduit, you'll know what I mean. Diameter doesn't matter as much as the corners the wire has to get around.

I'd be concerned as well about "losing it" for whatever reason, and not being able to recover it. Maybe have a plan in place for this?

FPV sounds like it may be the way to go if the signal will allow it.

 

so I just got off the phone with one of their engineers, and reviewed the limitations, and they were able to drop down the requirements to 50'-100', and no more than one turn. if it were 50 feet max, I'd be inclined to say that you could get away with just the 2.4 transmitter and not extended receiver wires.

and as with any vehicle pulling wires, it will have a tether. likely a high strength, light weight fiberglass ribbon. this is what the cables will be zip tied to, to prevent them from taking the load. it will also function as a recovery tether, should the crawler go dead.

they've got a camera that they already use to drop into pipe, that has a 150' lead, so that will be option 1. if for some reason that doesn't work, i'll break out the gopro and try out my FPV setup.

their lead engineer will be stopping by my office later today to discuss the needs further, and talk about payment. I'm not building this thing in the office, so either they are paying me to do it at home on the weekend, or I'm getting a Friday or Monday off to do it

 

I, for one, would love to see the finished product. And maybe some video of it action if that's allowed. You may be on the brink of a new career.

 

You lucky bastard!! Im jelly

I'd like to see the setup and some video of all this in action as well if it's permitted! On the LED lighting I also forgot I was going to suggest looking into the Baja LED light pods and RPM mounts. I have a set of four of them wired to plug into my receiver and they work pretty stinking good for night driving.

 

I can certainly pull a video from it.

I run those lights on my scratch built crawler. great lights, and exactly what I was planning on using for this.

 

Hell to the yeah! Nice looking crawler, is that a custom made tube chassis?! Wish I had access to the tools to make stuff like that. I always new I should of gotten into machining, my math skills are shit though. Haha

 

yep, handmade chassis. you really don't need anything special. it's just copper tube for the main chassis, and some copper flat stock for any bolted connections (shock and suspension link mounts). if you have a high end soldering iron, you can braze it together with that, otherwise a butane torch will work. I used my soldering iron.

MOA with 4 wheel steer. very light and geared very low. it'll run for 50+ minutes on a single 4500 mah 2s.

 

Look into the subsea deep water drilling industry. The blow out preventer controls used to be electric when 'shallow', then went to hydraulic as the depths increased. But with fluid you're looking at a lag time of roughly 2 seconds per 1000'...one way. Nowadays its fiber optic. Lots of info can be crammed into a single stand of fiber optic. But it may be too much to drag along. This is just subsea controls.

On the wireline logging side they have made advancements as well. With the horizontal wells they developed crawlers to drag the logging tools across. If it fails you just pull them out.

Cost effectively I would say for that short of a run a simple coax rg6-8 would suffice for all controls as well as video. You'll have to go old school analog to do it. PLC on the crawler rig likely or something like that. I've had CCTV that controlled pan, tilt, zoom, iris, a wiper, and sent the video real time all off of a coax cable. Why couldn't one of those turn some wheels.

I've driven my Axial Honcho further than 100m easily. I have a buddy in houston with FPV heat capable of 2000m with very little lag. I would say that a pipe could possibly bottle beck the signal and it go even further. Like whispering through a water line to a buddy 200' away.

Im no techie, but have been around enough of them.

 

while I love all of the new high tech stuff. I'm going to stay true to K.I.S.S. on this one. for my own sanity as well as for cost. if I can make 9 solder joints and call it done, to extend the receiver to the mouth of the pipe. I think that's as simple as it can get. as soon as I go to a coax or fiber optic, I open a whole new can of worms in the programming realm. that would increase time and cost of the project. given some of the lower cost RTRs out there, I can get this built for under $400, in only a couple of hours. assuming it works as planned, that's hard to beat with any other route.

 

Way cool! I'm about ready to sell my Slash 4x4 and make a crawler. I bought the slash to use at my cabin but the roads are too rocky and it just gets rock stuck in it all the time and breaks stuff.

 

Summit!

 

You could get a small >$100 Chinese RC that's 4wd and as small as needed. Tether it with some heavy fishing line and use a simple FPV setup. If you stay at the mouth of the pipe the signal should bottle neck directly to you.

Opening a can of worms....is any of this pipe used? Potentially hazardous? Would the RC need to be intrinsically safe?

 

probably not a cheap solution but if you're going to being doing it on a regular the cost will be absorbed.
so the solution is a remote control snake that I saw on tv. it was made to go into pipes for inspection purposes, but it also climbs trees!

http://www.nei.org/News-Media/News/News-Archives/‘Snake’-Robot-Inspector-Slithers-Through-Pipes

 

Plan is to start off with a sub $200 crawler. Not the toy grade ones, but something along the lines of a redcat or exceed.

Fortunately no need for intrinsic electronics. This is for new construction pipe. This is the final visual inspection on critical systems before blunting the ends for pneumatic testing. All being performed in areas free of fuel sources of any type at this point.
Great question though!

That thing is cool! Sounds like it is designed for smaller pipes though. After my meeting today, I was informed that 18" pipe is the smallest this thing will have to travel through, so I've got a lot of room to play with.

 

[QUOTE="colinb17,
That thing is cool! Sounds like it is designed for smaller pipes though. After my meeting today, I was informed that 18" pipe is the smallest this thing will have to travel through, so I've got a lot of room to play with.[/QUOTE]

Ah ok. Maybe consider a thin center with larger wheels so it can run upside down if it happened to roll over in the pipe.