MAYTECH CF PROPS FOR H

[Ralphy]

Yeah but 4k is too much. Thinking about making it as a $400 product.

Wow... interesting the site took 23 orders between us too. Busier than I expected.

You’ve been playing with them for awhile, this is exciting to me. Particularly how receptive & quick Ralphy is to listening to new suggestions and put them to tooling. I thought it was a good idea, but just wasn’t certain on eng brake... we chatted and Ralphy introduced ver3. Very Cool!

Glad to help you guys. Only 2 orders were sold according to my records. Let's keep up the collaborative efforts to make the H awesome.

Those little factory props won't hold up when we start flying tethered for 6-7hrs.

 

[Ralphy]

I have two H’s, one a year and a half old the other a year. In all that time I’ve never taken the props off of one, but replaced a set after an encounter with a tree with the other H. Same applied to the Chroma, they remained on the aircraft until it was boxed back up for transfer to the new owner.

Not one ever separated by itself.

Well yes always take them off and that caused wiggle on the plastic factory props. That's part of why I made this invention. I take off props and landing gear and stick the H in a little 10" Dewalt bag. Very low key I look like a regular construction worker until I open the bag.

 

[Ralphy]

To avoid the problems of needing a higher gauge wire for the current, send it up as higher voltage (smaller gauge) and step it down on board. Would also want a battery on board the H that would allow enough juice to land in the event of a systems failure. You'd have to pack all that into a space that fits into the battery compartment. Not hard, just keep in mind.

On the ground, you'd need the power supply, a spool of cable (preferably at least 4-conductor - 2 for power, 2 for status) - and you'd not want that cable to be heavier than phone cord. You also need a means to auto-payout/retrieve that cable, but not pull on the aircraft more than gravity is going to make it. Various monitoring would be good too. You'd want to be able to suck the power from a car battery as well as from a socket, and it would have to be *certain* and *stable* - that means redundancy in your base station..

I'd be wary of motor temps, too.

The H has a max draw of 45 amps until full throttle loaded with a battery. When we pull the battery out and replace it with something like a 1500 mah 4s the power draw must drop to about 10 amps. I think I'll make it so it feeds off a 12v with clamps for the first version. Is there anything out there that is a spool adapter to run current down the center? I don't want to twist the supply cable going into the spool.

 

[Dougcjohn]

That would need a form of brush contact... thinking of garage ceiling power cord reels, vacuum self winding reel, etc.

Looking more at the light weight spool, not gauge... something along these lines.
https://www.google.com/search?sourc...c#imgdii=t0qTWU7umUXyuM:&imgrc=1BPymRp4actUOM:

https://www.google.com/search?sourc...c#imgdii=14GHT2AOJXsUuM:&imgrc=1BPymRp4actUOM:

 

[Dougcjohn]

A design manufacturer of power reels... might be worth a chat for you.
Our Brands - Reel Power International

 

[Ralphy]

I think the power reel is to heavy duty. I found a patent for the telephone 360 connector and I thought that can be used to develop something with similar characteristics but a higher ability to handle mechanical stress and electrical current draw.

 

[Dougcjohn]

That one looks pretty good on paper!

Power Reel: Agreed, power reel example way to heavy, the plastic reel & contact center spool were inline to your idea; with design towards a lighter package.

The other variable is the retraction spring and tension. Needs to be able to provide long distance with tension light enough to not require bird to work against it. A clutch to prevent retraction until desired might work into design too. Alt option is no retraction spring, use a adj tension plate / clutch to extend and engage a small power winder when needing to retract.

 

[Dougcjohn]

Not to copy, but to enhance ideas of a better / lower cost product... have you considered purchasing one to examine their working design?

 

[Ralphy]

Not to copy, but to enhance ideas of a better / lower cost product... have you considered purchasing one to examine their working design?

No I dont need to see theirs to make a lower cost one. Its a simple setup im not sure were the 4k price comes from.

Its an AC 120v power supply the thinnest cable you can find to minimize weight run 120v AC up the wire and a tray with stepdown circuit tranformer with a rectifier an constant voltage output to give the H 16.3v DC.

House everything in a case with a plastic reel and 360 swivel connector to prevent wire tangles.

Simple enough

 

[FePhoenix]

Each of the static to rotating mechanisms ("rotary joint") posted so far are is multiconductor. Why? You need just 1 conductor, the "hot" side of power (ground is a given). A lightweight cable is needed. I'd look at the RG-179. It's a thin coaxial cable that can handle 900V AC and weighs a mere 5lbs for 500', Send the power up the line as AC. 120VAC at 2A converts to 16VDC at 16A. Rough numbers, and does not take transmission line loss or conversion loss into account.

You want to send it up as AC because it's more efficient. You want to use a coax cable to shield the H from AC bleedover (could affect compass, GPS if unshielded).

Depending on what you use tethering for, take-up reel tension can be made into a moot point. IF SAFE TO DO SO, just disconnect at end of mission and land the H on a small battery that is incorporated into the battery-socket converter - and reel in thee dropped cable at leisure.

Ralphy, don't forget that the "onboard" portion of this system MUST incorporate a battery with enough power to land the aircraft safely with no power coming in.

 

[Ralphy]

Each of the static to rotating mechanisms ("rotary joint") posted so far are is multiconductor. Why? You need just 1 conductor, the "hot" side of power (ground is a given). A lightweight cable is needed. I'd look at the RG-179. It's a thin coaxial cable that can handle 900V AC and weighs a mere 5lbs for 500', Send the power up the line as AC. 120VAC at 2A converts to 16VDC at 16A. Rough numbers, and does not take transmission line loss or conversion loss into account.

You want to send it up as AC because it's more efficient. You want to use a coax cable to shield the H from AC bleedover (could affect compass, GPS if unshielded).

Depending on what you use tethering for, take-up reel tension can be made into a moot point. IF SAFE TO DO SO, just disconnect at end of mission and land the H on a small battery that is incorporated into the battery-socket converter - and reel in thee dropped cable at leisure.

Ralphy, don't forget that the "onboard" portion of this system MUST incorporate a battery with enough power to land the aircraft safely with no power coming in.

Cool thanks man. Yeah the small battery is essential because of safety and its also the cushion that can provide a momentary surge of power that the H can draw during rapid manuever.

You need more than one conductor, are you planning on using the shield as a ground? That defeats the purpose of the shield.

I have to design the rotary joint.

 

[FePhoenix]

Cool thanks man. Yeah the small battery is essential because of safety and its also the cushion that can provide a momentary surge of power that the H can draw during rapid manuever.

You need more than one conductor, are you planning on using the shield as a ground? That defeats the purpose of the shield.

I have to design the rotary joint.

Shield as ground is legit, as long as it's grounded at the ground station, and in the aircraft (battery negative), bringing the entire system into a common ground. Grounding the shield at both ends preserves its function as a shield while still allowing it to carry power (or, more accurately, the power return). Note the 3-prong power socket in your wall. The ground and "neutral" lines can be combined (and often are in various electronics).

 

[Ralphy]

Shield as ground is legit, as long as it's grounded at the ground station, and in the aircraft (battery negative), bringing the entire system into a common ground. Grounding the shield at both ends preserves its function as a shield while still allowing it to carry power (or, more accurately, the power return). Note the 3-prong power socket in your wall. The ground and "neutral" lines can be combined (and often are in various electronics).

This can be an issue when inspecting high voltage towers at close range. Some idiot will fly too close and get zapped with 69kv volts

 

[FePhoenix]

This can be an issue when inspecting high voltage towers at close range. Some idiot will fly too close and get zapped with 69kv volts

So put a disclaimer with it that it's not to be used in areas that offer this sort of hazard...

 

[Ralphy]

So put a disclaimer with it that it's not to be used in areas that offer this sort of hazard...

That may work but I now there might be curious folks who dont read before they fly.

 

[Dougcjohn]

No I dont need to see theirs to make a lower cost one. Its a simple setup im not sure were the 4k price comes from.
Its an AC 120v power supply the thinnest cable you can find to minimize weight run 120v AC up the wire and a tray with stepdown circuit tranformer with a rectifier an constant voltage output to give the H 16.3v DC.
House everything in a case with a plastic reel and 360 swivel connector to prevent wire tangles.
Simple enough

Yep, I'd agree AC voltage, transformer, rectifier and sm gauge wire is the simple part... many options for all these components exist. I was meaning the cable mgmt component. Not as simple as it sounds. Keep in mind the H has about 1500g payload maybe little more if removed LiPo battery weighs more than the installed AC pak: transformer, rectifier, backup battery. In the 1500g, I believe the camera asmb is part of the 1500g.

As Kris indicated, the sm wire is in the range of 5lb for 500feet adding to the payload and if the reel creates sufficient drag, that adds to payload too. The payload isn't much to begin with on the H, if max'ed it'll stress the motors.

I'd ballpark estimate you have less than 2lb payload if carrying the camera.

The cable mgmt would require very small wire cable and the tension spool creates near zero drag/resistance.
How much cable is visualized, all work vertical or horizontal such as bridge inspections. If horizontal, adds the need of the cable tension to prevent gravity unwinding as you move toward center of bridge or horizontal object.

 

[Ralphy]

Yep, I'd agree AC voltage, transformer, rectifier and sm gauge wire is the simple part... many options for all these components exist. I was meaning the cable mgmt component. Not as simple as it sounds. Keep in mind the H has about 1500g payload maybe little more if removed LiPo battery weighs more than the installed AC pak: transformer, rectifier, backup battery. In the 1500g, I believe the camera asmb is part of the 1500g.

As Kris indicated, the sm wire is in the range of 5lb for 500feet adding to the payload and if the reel creates sufficient drag, that adds to payload too. The payload isn't much to begin with on the H, if max'ed it'll stress the motors.

I'd ballpark estimate you have less than 2lb payload if carrying the camera.

The cable mgmt would require very small wire cable and the tension spool creates near zero drag/resistance.
How much cable is visualized, all work vertical or horizontal such as bridge inspections. If horizontal, adds the need of the cable tension to prevent gravity unwinding as you move toward center of bridge or horizontal object.

Very good points. In the order of priority I will start with taking my existing tray...The top secret V2.0 that no one has seen and get a circuit in there that takes 120v and steps it down rectifies it and stabilizes the voltage output and current.

The second step will be integrating the cable and backup battery followed lastly by the box and reel mechanism.

Time to get the electrical engineers to figure out power solutions.

This is so much fun!

 

[Dougcjohn]

How cool... you have a prototype v2 already! Oh that sweet! Hope this develops great for ya... and I'm very interested in market price when released. As indicated above, if you can get even close to your desired $400, you'll knock the competition out the door for all but the most demanding or govt contracts that require various cost inducing factors.

 

[Ralphy]

How cool... you have a prototype v2 already! Oh that sweet! Hope this develops great for ya... and I'm very interested in market price when released. As indicated above, if you can get even close to your desired $400, you'll knock the competition out the door for all but the most demanding or govt contracts that require various cost inducing factors.

Yeah V2.0 was out for a while it balanced the craft perfectly with a 8000mah battery.

Given the history of v1.0 tray and the charge adapter getting copied I'd figured I keep the design safely to myself.

To this day no one has made a v2.0 tray....ja ja ja ja

OK so here goes power supply needed in the tray should exceed the average consumption of hoover at 14,000 mah 16v.

I'm thinking a driver that can take 120v Ac rectify get it to 16v dc 20,000 mah

Momentary power demand of up to 40a can be supplied by a 1200mah 4s lip rated at 30c -40c.

Thoughts ?

 

[Ralphy]

Let's play a game which is the knock off that throws it outta balance and which one is the innovative one?

Don't look at the legs cause that's cheating.