RE: the prefect platform for aerial photography

RE: the prefect platform for aerial photography
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RE: the prefect platform for aerial photography - 9/11/2006 5:15:14 AM

Skycam41

Posts: 516
Joined: 9/8/2003
From: Fort Macleod, AB, CANADA
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quote:

ORIGINAL: steve_molmer

This morning I finally got to test fly the lift-master.
The first flight went well the only issue was a large amount of trim to get the plane to fly strait and true.
The problem I found was that the wing had shifted during flight.
Other than that the plane flow very well.
I will post picts in a day or so.

The next flight will be with the video system up and running later this week.
If all goes well, I hope test the system out at high altitude next weekend.

This is deveolping very well and most interesting, keep us posted Steve

Mike

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Post #: 26

RE: the prefect platform for aerial photography - 9/12/2006 6:47:02 PM

steve_molmer

Posts: 132
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From: marietta, GA, USA
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dzbum:
The kits come with a wing strut setup that I am going to use.
I think the trim issue is not so mutch flex but shifting on the wing bolts. The wings and the mounting points are very well built.
The best solution is to glue the wing together.
Note: I have about 16lbs of equipment and 1gal of fuel on board.
The wing is shifting do to the addition of a camera and auto pilot in to the right wing panel.
My fault, I should have better distribute the equipment.
I have already moved it to a better location.
I found some smaller batteries that have a larger current capacity. This should shave about 2 lb off the weight.
The plane now weighs out dry at 21 lb even.
With how easy it lifts off the ground you would never know it.
here are a few picts from this weekend.

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< Message edited by steve_molmer -- 9/12/2006 6:49:21 PM >

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RE: the prefect platform for aerial photography - 9/12/2006 6:54:34 PM

Skycam41

Posts: 516
Joined: 9/8/2003
From: Fort Macleod, AB, CANADA
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Very nice Steve.... That's one big bird!!

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RE: the prefect platform for aerial photography - 9/13/2006 7:05:14 AM

JettPilot

Posts: 1151
Joined: 4/18/2005
From: Paradise, USA
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That does look like the perfect plane Steve

Had I seen that earlier I would have bought one instead of building my own

I looked all over the net, and the closest I found was the telemaster, but like you I concluded that the structure was not built strong enough. I heard to many stories of wing failure on that one

I have been flying long range video for a while, and have been watching your project with great interest. I would like to know how you get such performance out of your radio equipment ? What notch filter and Preamp are you using on your RC gear ? What did you do to modify the Lawmate equipment ? I am not familiar with that 2.4 GHZ receiver you are using, does it perform any better than the Lawmate receiver ?

If you would like to see some of my videos and stuff click on this link:

http://www.putfile.com/jetpilot

JettPilot

< Message edited by JettPilot -- 9/13/2006 7:07:35 AM >

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Post #: 29

RE: the prefect platform for aerial photography - 9/15/2006 4:47:37 PM

steve_molmer

Posts: 132
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From: marietta, GA, USA
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Skycam41

It is a big plane.
But I go by the point of if you can't see it you can't fly it...

jetpilot:

You asked how I get such performance out of my radio equipment ?

OK,
first the RC receiver has a notch filter that limits the reciver frequency to only 100 MHz above and below the selected channel.
The circuit is a tank with an adjustable ferrite coil and fixed caps across a tunnel diode.
this is easy to build but takes a spectrum analyzer and a very good scope to setup.
Unfortunately the circuit design will differ based on the type of receiver you are using.
This makes giveing out a schematic just about impossible on this.
Note: that airtronics 7 and 8 channel recivers and, the fma fortress 2000 already have fairly good filtering in place.
These receiver only require tuning of the IF and the antenna after the addition of the LNA.

LNA,
You can modify any 2 Meter preamp to work with your receiver. (mod to 72 mhz that is)
I use one made by down east microwave.
All you need to do is to inject a channel frequency you want to use in to the lna and ajust the LRC network to max gain at your channel.
I usually can get by with adding or removing a few turns in the coil of the input circuit.

The video transmitter,
note, that this one is a real pain to do.

- first you need to replace the voltage regulator with a switching type reg with appropriate filtering.
This helps keep the circuit cool and less likely to suffer from thermal diffed.

- now you need to add a pre emp circuit.
on the lawmate units look for the point on the board were the video signal is injected in to the RF section of the board.
At that point connect a 22 pf cap in line with an IN4000 diode and ground of the board. The striped end of the diode should be pointing away fro the ground connection not trodes it.
Now connect the camera you are going to use with the transmitter and connect up your equipment Rx and TX.
As you view the video adjust the trim pot on the TX board till you see 1 volt peak to peek on your scope.
Note that you may need to adjust the video gain on your receiver to achieve best video quality.

- now last but not least, get rid of the whip dipole antenna that you got with the TX.
Get an antenna from hyperlink or antennex, spherically polarized that is the key.....
using a bird or equivalent RF meter set the swr's of the antenna using the coax length, ajust it in to the 1 to 1.5 range.

The receiver,
I got tired of have so may receivers sitting around so I took a standard 2.4 ghz receiver made by cop and modified it using a controller board by 13UK.com that allows me to tune from 2.2 ghz to 2.5 ghz. This way I only need to have one receiver for almost any transmitter.
So far it seems to out perform any receiver that Ive used in the past.
I will post pics of my newest setup in a few weeks.
cheers

< Message edited by steve_molmer -- 9/18/2006 5:18:23 PM >

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Post #: 30

RE: the prefect platform for aerial photography - 9/16/2006 2:48:18 PM

JettPilot

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From: Paradise, USA
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Thanks for the very detailed Reply Steve Molmer,

I can do some of the things you recommended. I build switching regulators for all my equipment anyways filtered by large tantilum capacitors, so replacing the video regulator on the TX will be an easy task

I tried a preamp for the RC Receiver with disastourous results, but that was due to using step up switching DC to DC converter to power it, the preamp and the receiver really hated that

I am a ham and use 50 mhz so I may be able to buy a notch filter that will work.

I dont have a scope or a SWR meter that will work at 2.4 GHZ, so most of those things are out

What I could do is modify a COP receiver to tune all the frequencies if I had the schematic how to hook up a different controller for it. Do you find the COP to be much more sensitive than the Lawmate receivers ? That would be worth doing if there is a large difference between the performance of the receivers.

I look foward to your high altitude flight reports, etc. BTW, why are you using a glow engine ? Gas is MUCH more reliable, gives better endurance, does not put a castor oil mess on the plane, and works good to about 18,000 feet. Dont ask me how I know, I just do

JettPilot

< Message edited by JettPilot -- 9/16/2006 2:51:07 PM >

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Post #: 31

RE: the prefect platform for aerial photography - 9/18/2006 5:16:09 PM

steve_molmer

Posts: 132
Joined: 7/10/2002
From: marietta, GA, USA
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Jettpilot:
The receiver that cop or lawmate offer is a good unit. the key is to control the pic in the receiver.
If you look inside your receiver you will see the receiver case or tin and the conntroler board.
on the control board you will find an eprom that sets the channel I.E. the frequency that the unit operates on based on the jumper or switch settings.
If go on line to 13cm.co.UK/ and look at the Steve Drury TX/Rx controller you will get a better idea of how this works.

You asked why I do not use gas engines on my planes when I set them up as AP or UAV's.
-- gas engines vibrate way to much. ( no-mater what, you can not get all the vibration out of the equation it is a problem why add to it?)
-- a glow engine can run on JP4 with a Little adjustment at over 8 miles up. (Ref, sky scout project I worked on back in 1989)

If you need a good large glow look at RCV engines from the UK.
I use the 91 and the 120 on a few platform, they are the bench mark in reliability for long range flying.....

on a different note.
I will post picts of the video feed from the system in the morning.
cheers

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Post #: 32

RE: the prefect platform for aerial photography - 9/19/2006 9:53:57 AM

forbidden_city

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Joined: 3/27/2006
From: beijing, CHINA
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I'm very interested in the onboard power generator. Could you shoot some pics about it? How the engine drives it? Thanks!

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Post #: 33

RE: the prefect platform for aerial photography - 9/19/2006 11:23:09 AM

JettPilot

Posts: 1151
Joined: 4/18/2005
From: Paradise, USA
Status: offline

quote:

ORIGINAL: steve_molmer

-- gas engines vibrate way to much. ( no-mater what, you can not get all the vibration out of the equation it is a problem why add to it?)
-- a glow engine can run on JP4 with a Little adjustment at over 8 miles up. (Ref, sky scout project I worked on back in 1989)

If you need a good large glow look at RCV engines from the UK.
I use the 91 and the 120 on a few platform, they are the bench mark in reliability for long range flying.....

on a different note.
I will post picts of the video feed from the system in the morning.
cheers

Yes, there is a lot of vibration with gas

, I have had to mount everything in Foam to fix vibration issues. Is the JP4 conversion like a Diesel conversion ? Will glow not run 8 miles up ? I got a glow engine for High Altitude, but have never tried it up high yet, I have only done a little test flying on the airframe so far. Its a Saito 150 4 Stroke for Reliability, but I still have not tried it high up yet. Maybe it will Quit as it gets cold

Below is a picture of a Saito engine, is it possible to run this on JP4 ?

I look foward to your pictures today ! Do you have a webpage or any infomation posted about your projects, the Sky Scout Project, and current ones ? I would love to read about them

JettPilot

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Post #: 34

RE: the prefect platform for aerial photography - 9/20/2006 4:54:57 PM

steve_molmer

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From: marietta, GA, USA
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jettPilot:
For high altitude you need to stay with a two stroke or an RVC.
An engine like Saito 150 4 Stroke still has a great deal of vibration.
You will find that it will start to misfire around 5,000' to 7,000'.
I have not try-ed to run one on a kerosene based fuel as of yet.
It may take bit of modification to function on it.

For the most part the glow engines that we all use work on the same principle as a Diesel engine.
converting a conventional two stroke is only a mater of a bit of machine work and a carb swap.

jettPilot:
Foe high altitude you real need to stay with a two stroke or an RVC.
An engine like Saito 150 4 Stroke still has a great deal of vibration.
You will find that it will start to misfire around 5,000' to 7,000'.
I have not try-ed to run one on a kerosene based fuel as of yet.
It may take bit of modification to function on it.

For the most part the glow engines that we all use work on the same principle as a Diesel engine.
converting a conventional two stroke is only a mater of a bit of machine work and a carb swap.

I will post a few thing from time to time on http://www.putfile.com/docairman This site will contain picts and vid as time goes on.

Do to the issues with 911 the site for the sky scout project was taken off the public net.
I will post what has been cleared at docairman in a few days or so.

forbidden_city
You asked about the onboard generator.
It uses a pump that is operated off the vacuum of the engine to turn a sealed impeller connected to a burshless motor.
This setup then feeds AC voltage to the reg and filter boards for distribution.
This is a far cry from the original unit that I was going to use in this plane.
It only came available to me a few weeks ago.
I can not post picts of it, as it is in the patent process as we speak.
As soon as the designer tels me I can post pics I will.

more later
cheers

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Post #: 35

RE: the prefect platform for aerial photography - 9/21/2006 3:50:37 PM

JettPilot

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Joined: 4/18/2005
From: Paradise, USA
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quote:

ORIGINAL: steve_molmer

An engine like Saito 150 4 Stroke still has a great deal of vibration.
You will find that it will start to misfire around 5,000' to 7,000'.

Thats great news

Not really hahaha ! I have been dealing with the vibration already with gas, so the Saito is about the same, just make sure everything is mounted in foam. Did you see were Georgio Azza flew his 4 stroke model up to over 30 K using glow fuel and a 4 storke ??? There must be a way to do it ! I got the 4 stroke for reliability, many people say they have zero deadsticks using these 4 strokes.

I looked at your site, I had seen these videos before, but im not sure where. I look foward to seeing your recent work... You mentioned that they dont let you post all of it, do you work for Lockheed Martin ? What is your final goal with your present plane ? I am just a hobbiest and do this stuff because its a lot of fun, its a heck of a lot more fun than scale, or most things that people do with RC

JettPilot

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Post #: 36

RE: the prefect platform for aerial photography - 9/21/2006 8:36:58 PM

steve_molmer

Posts: 132
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From: marietta, GA, USA
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Jettpilot:
here is a vid of a Sig kadet with a RCV 91 and only 3 ounce tank of fuel ( http://www.rcuvideos.com/view_video.php?viewkey=b08731a97e7b91be644d&page=1&viewtype=&category=mr ) note that it runs for well over 10 minis give or take.
It is a 4 stroke by function only rcv uses a rotary vane instead of tap-it valves. This makes for grate fuel economy and very low vibration.
This was the last flight of the sig it is bing sent out to be used for a fire petrole group in CA.
You will note the video quality is not that good. this is do to the compression from 1.56 g down to windows Medea player size of near 36 m so I can post it on RC universe.
I hope to have the server back up soon so I can show some full high res video soon.

Finished a good long test flight of the lift master this morning.
All went well the wing struts and the equipment relocation worked well.
I took the plane off and turned on the autopilot. The plane fallowed the 1 mile test tlim over and around the CCRC air field like it was on rails.
I will post some video in a day or so.
I put in an authorization request with the FAA for 3 test flights:
1. 2 miles out 3 miles down
2. 5 miles out 10 miles down wind
2. 10 miles out 15 miles down wind

I hope to get the COA back from the FAA for the flights to take place on or around the end of the year after I complete the flight tests of the lift master platform some time by the end of October if all goes well.
now back to work I go.
Cheers

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Post #: 37

RE: the prefect platform for aerial photography - 9/21/2006 9:51:34 PM