FAQ: Frequently
Asked Questions
Q.
The project files you provide are corrupt. That is to say, my zip
program cannot open them; It complains that they are not valid
archive files. Would you please fix your zipped files!
A. You must
be using Internet Explorer. It has a HTTP 1.1 protocol bug that can
cause compatibility problems on some web sites. To fix this please open
IE's Internet Options menu, click the Advanced tab, and uncheck the two
HTTP 1.1 settings (they are under the "USE HTTP 1.1 settings"
category). Then clear your browser cache (delete Temporary Internet Files) and restart Internet Explorer.
Q. I have
a question about an RC-CAM project or other technical issue. May I contact
you directly?
A. Please do
NOT write us for personal help. Instead, post your questions in the User-to-User
Forum. You will receive great advice from the members. Just join the Forum
by clicking the Forums link.
Everyone deserves to
learn from the comments that are shared on the Forum. So send your questions
there and not to us. Your cooperation is appreciated.
Q. Is there
a membership fee to join the RC-CAM forum?
A. None at all.
We freely offer the technical information to help assist you in building
your own camera system. All we ask in return is that you share your improvements
with all the RC-CAM project members. Please post your ideas in the RC-CAM
User-to-User Forum.
This is NOT a commercial
web site. There are no gimmicks and we do NOT have any evil intentions. We
make every effort to make our site a safe place to visit. We do not use banner
advertisements, popups, or request that you make donations. We do not make
a penny from your participation. The site's expenses are paid by generous
private donors who enjoy expanding the DiY R/C hobby.
Q. How do I buy a wireless
video system or project parts from you?
A. We do not
offer anything for sale. If you need a part then please consult the sources
shown in the project.
We do not work for,
nor represent, ANY supplier of the parts used in the RC-CAM projects. Any
reference to a vendor is for your convenience and we do not endorse or profit
from any purchase that you make. You are free to use any parts source that
you wish.
Q. How
much do you charge for aerial photography?
A. We do not
offer this service. We never have. Besides not having the time, obtaining
decent liability insurance and other legitimate business expenses, all help
to make this financially unattractive to us. Another issues is that our camera
equipment operates on the Amateur Radio (ham) frequencies. In the USA, it
is unlawful to use these frequencies for the gainful benefit of your
firm/employer.
There are aerial
photography firms that are for hire, so try a web search.
However, if you are
a big budget Hollywood studio then maybe we should talk. Of course we will
need a private trailer, a few of those chairs with our names on the back,
big catered lunches, and tall beverages with fancy umbrellas in them. If
your package includes these amenities, then let's do lunch.
Q. I really like
your projects and want to build one of them. But, I need some advice before
I do anything. Who do I contact to get my questions answered?
A. Please post
all of your questions in the User-to-User Forum. You will receive great advice
from the members. Just join the Forum by clicking the
Forums link.
Please don't send private
e-mails asking for personal advice. Instead, send your comments to the forum
and get help from other folks that have built the projects. Besides, everyone
deserves to learn from the comments that are shared on the Forum.
However, if you must
privately write us then please visit our Contact
page. If your question is technical then please do not be surprised if we
direct you to the forum.
Q. I can solder and
I have built a few electronic kits. But after reading your web site information,
I find that some things are unclear to me. I also do not fully understand
the schematics. Do you think I can build your projects?
A. You will
need moderate electronic assembly experience to build our projects. If you
are an entry-level electronic hobbyist then some of the information will
be beyond your abilities. If this is the case then find someone with the
tools and experience to help you out.
The last thing you
want to do is to guess at the circuit's construction. Unless you have lots
of free time, an unlimited budget, and a good fire extinguisher, we suggest
you buddy up with a more experienced electronics technician. Or perhaps a
commercially made solution is better suited for you.
Q. I
see that some of your Special
Projects use PIC microcontrollers. I have never used one of these interesting
IC's and I am not sure what is needed to program them ("burn" the
code).
A. Our PIC based
projects are not a good choice for beginners, despite their simple looking
nature. However, if you have successfully built several electronic projects,
and wish to try one that uses a microcontroller, then the RC-CAM projects
are a perfect choice. Programming the PIC chip is simple. You need the PIC
chip, a suitable programmer, and a PC.
Q.
So, to build one of your PIC chip based projects I need a "PIC Programmer?"
A manufacturers list would be GREATLY appreciated. I'm sure others
would benefit from it as well if equipment sources were shown on your
website.
A. We go out
of our way to not specify equipment. If we were to list equipment like this
then we would feel compelled to buy it and try it first. Given that our pockets
are not THAT deep, we are not able to do so. The equipment we specifically
use is commercial quality and cost several hundred dollars -- not a good
choice for a hobbyist!
Also, many of the web
sites that have plans for building a low cost programmer do NOT offer support.
If we mention their links then we will end up being their technical support
when things go wrong. Again, not something that we are prepared to
do.
There are several
hobby-grade PIC programmer kits out there that are low cost. The
www.picallw.com site
has links to some programmers for under $35.
The
www.ic-prog.com site
offers free software and provides several schematics to build your own $10
programmer using common parts. The
EPIC-Plus
programmer is more expensive than most but reportedly works well too.
Please note that we have NOT tried any of these programmers!
For additional
recommendations please post your PIC programmer question on the Forum. Others
have been in your shoes and have found something that worked for them. In
fact, this has been discussed before -- the messages can be found in the
forum archives.
Q.
My PIC programmer reports that the PIC12C508's data is bad. The error
message claims that data at an address is incorrect and it aborts the verify
cycle. I have burnt several chips and they all say the same thing. I think
your hex files are defective!
A. The PIC12C508/509
hex files are fine and so are your chips. With most of our hex files it is
not possible to verify the chip after the programmer has finished its auto
programming cycle. The programmer (1) burns the data, (2)
verifies the data, then (3) sets the configuration fuses. In
that order. At this point data verification is not possible and the chip
will fail to compare if you attempt to manually verify the data. If the chip
was defective the programmer would have reported this to you during the initial
chip burning cycle.
Whatever you do, do
NOT program the PIC chip twice! That will ruin it. If you tried doing this
then toss the PIC in the trash and try again. Do not attempt a "Verify" cycle
after programming is done. We cannot stress this enough: If
an error was not reported during programming then just trust that all is
well and install the chip.
Q.
I tried to manually verify my PIC12C508/509 chip and it fails at address
40h. There is no data after that address! Your hex files are
defective!
A. The PIC hex
files are fine and so are your chips. You cannot manually verify Code
Protected PIC chips. Please read the previous
FAQ post.
Q.
I am very frustrated. I have programmed several PIC chips with your
hex files. They do not work! I know my programmer is good because I have
used it on other projects. Your software must be bad!
A. Sounds like
you are allowing the programmer to alter the chip's factory installed OSCAL
value. DO NOT ALLOW THIS! Every PIC programming system is different on how
this is handled. For example, the popular freeware
IC-Prog application
presents a dialog box that looks like this:
You
must answer NO to this prompt (do not use value from file). If
you answer YES, the OSCAL value will be altered and the chip will ruined.
Consider yourself warned.
It is a good idea to
read your blank PIC before you program it. Record the data at the
last two address locations (at the end of the hex display). Then read the
RC-CAM hex file and program the chip. Finally, read the PIC again and look
to see if the last two addresses still match what you recorded. If the two
data bytes do not match, the PIC will not operate correctly.
Q.
I am trying to program one of the PIC12C508/509 based projects. When
I load the hex file my programmer reports that the file is invalid. What
is going on?
A. Try this.
Use a text editor such as Notepad and open the hex file. Go to the end of
it. The very last line says ";PIC12C508A". Delete that last line and
then save the file under a new name. The new hex file may fix your
problem.
Q. I would like
the source code to one of your PIC microcontroller projects. Why can't I
find it on your web site?
A. Every one
of our published PIC projects includes the compiled hex file, which is all
you need to program the microcontroller chip. Beyond that, source code files
(and code snippets) are not public. Request for it will be denied, so please
don't contact us for it.
Q. How come
there are several different RC-CAM systems mentioned on the web site? Which
one should I build?
A. It sounds
like you have not read the web site yet. The RC-CAM project spans four
generations of video systems. Each system was improved upon by the following
generation. Nearly all are based on a low cost consumer video surveillance
system. The current RC-CAM system is called
RC-CAM4. To learn more you will need to visit the
site. Please start by reading the Home Page.
Please keep in mind
that RC-CAM's XCam based camera projects were developed a few years ago.
Since then, commercially produced miniature video systems have appeared on
the market. The prices on some of them are now low enough that it is no longer
necessary to hack your own. But, if you have an old XCam collecting dust
and would like to use it on your R/C model, then our RC-CAM projects will
surely help you out.
If you are interested
in knowing more about the commercially sold wireless video systems then do
NOT ask us via a private email. Instead, please take the time to review the
RC-CAM forum discussions. That is a great place to ask your R/C wireless
video questions too.
Q. What should
I use to monitor or record my videos at the field?
A. Watching
and recording your videos at the field can be done in a number of ways. Here
are some ideas for you to consider:
The simplest method
is to use a camcorder. Your RC-CAM video and audio cords would plug into
its external A/V jacks. Not only will it record your model's videos, but
its viewfinder also doubles as a real time monitor. The nice thing about
this solution is that it is fully self contained and very portable.
If you do not wish
to use a camcorder then a small AC/DC TV can be used. You can also use them
with your camcorder to allow others to see what you're doing. These portable
sets can operate on automotive power or regular AC current. Some have provisions
for internal batteries. Be sure to obtain one that has external A/V jacks.
Screen sizes can be as small as three inches (LCD models), but a nine inch
high-contrast CRT color screen is ideal. For best viewing on a video monitor,
a heavy cloth or cardboard shield may be needed to improve video contrast
in sunlight.
Within the custom
automotive market, there are several very compact color LCD monitors. These
are designed to be built into the headrest of minivans and custom cars to
allow passengers to watch entertainment videos. They all accept standard
video and operate directly from 12VDC. Some have very high contrast screens
and offer good visibility in soft sunlight.
You can also use video
glasses. Depending on the model, these units are worn as glasses, goggles,
visor, or face mask. They all have tiny video screens in them and a earphone
provides audio. Some are designed to fool your eyes and can project images
that look as big as a large screen TV. Most offer good video contrast on
sunny days and are quite fun to use.
Another popular method
is to use a portable TV/VCR combo system. These compact units have a TV set
that is integrated with a record/play VCR. Your RC-CAM video and audio cords
would plug into its external A/V jacks. They come in various screen sizes,
but nine to thirteen inches is typical. They are designed for use while traveling
and can operate on household AC or 12VDC power. Most come with adapters that
allow them to plug directly into an automotive power jack (cigarette lighter
outlet).
If your budget is limited,
you can use your household VCR and TV. For AC voltage, a "Power Inverter"
can be used. The power inverter is a brick sized unit that converts 12VDC
Automotive power (or a hefty 12V Gel Cell) to 120VAC 60Hz power. They are
also available in formats that offer the "mains" voltage used in other countries.
Be sure to observe the combined wattage of your TV and VCR. Always
use an inverter that has at least 25% more wattage than is indicated on your
electronic appliances. A typical 150W unit will cost about $60.
For more ideas please
see
http://www.rc-cam.com/fldequip.htm.
Q. I live in the USA
and I am concerned about legally operating the RC-CAM transmitter. Is it
FCC legal?
A. That depends.
RC-CAM uses the "XCam" camera systems. These low cost units are consumer
products that are designed for license free use. They operate under FCC Part
15 rules.
However, if you make any changes to its RF circuitry
or antenna then it is expected that you hold a valid Amateur Radio (ham)
License. Details to obtaining a ham license can be found at the
ARRL web site. This government issued license is for
non-commercial (hobby) use only. In the USA, it is unlawful to use
the ham frequencies for the gainful benefit of your firm/employer.
Q. How much does
RC-CAM4 weigh?
A. The airborne
weight is about six ounces. That includes the battery pack. With some effort
(and luck), the weight could be reduced to less than three ounces. Obviously
a lower weight would require a lighter battery and the elimination of the
plastic enclosures.
Q. What is the range
of RC-CAM4?
A. Using the
custom collinear antenna on the XCam2 transmitter, you should obtain 300
to 400 feet of range. It would be possible to extend this range to about
600 feet with improvements to the antennas. A 50mW or higher
RF amplifier on the Tx would help too. The details to user
submitted improvements can be found in the RC-CAM Forum archives.
By the way, the PEP
radiated power from the XCam2's patch antenna is 25mV/meter (measured
at 3 meters). This equates to less than 1mW (<0dBm). This meager power
is typical of all FCC Part 15 approved 2400Mhz wireless systems. However,
XCam2's actual RF drive power is about 5mW (into an ideal 50 ohm load). So,
a Tx antenna upgrade should offer better performance with your R/C model
application.
Q. I have seen
advertisements for wireless spy cameras that can broadcast for several hundred
feet. Some claim 2 miles! Why is the range of RC-CAM4 so limited?
A. Before we
get into the details, let us first warn you that many vendors of wireless
camera transmitters tend to offer VERY optimistic range claims. Their data
is obtained in an ideal environment using a fixed line-of-sight target.
In our R/C application, with its moving models, the conditions are quite
different. To get a better idea of the practical range you will experience
with their wireless systems, we suggest that you divide their distance claims
by at least four. If their transmitter uses a directional antenna
then your results will be even worse (divide by about eight).
There are limits to
what you should expect with any small wireless camera system. If you need
to transmit your R/C model's high resolution video beyond visual range then
you will be hard pressed to find a license-free system that will satisfy
you. The difficulty is that in the USA, "legal" FCC approved video systems
are very low power.
Higher powered systems
are available. These require you to be licensed to operate them. Just keep
in mind that the low cost, low frequency AM systems (400-450Mhz range), often
have inadequate bandwidth for good color reproduction. The higher frequency
systems (900-2400 Mhz) can suffer from RF propagation issues that limit their
effective range in RF reflective environments.
What is ideal for distances
over 1000 feet? For R/C ground vehicles, that is a tough distance to achieve.
Besides luck, we suggest a 900MHz transmitter with at least one watt of RF
power. For model aircraft, a 900MHz to 2400MHz system with at least 100mW
of Tx power is a minimum. For longer range, plan on substantially more Tx
power. Generally speaking, to double your range you must quadruple the RF
power.
You may also need
to use a high gain Yagi or Patch antenna on the receiver and manually aim
it at your aircraft as you fly around. Yes, that will require a second person
or an odd looking hat mounted antenna. The hat antenna might not win any
fashion awards, but it is simple and works well.
You will often hear
a good amateur radio operator comment that spending a dime on the antenna
is more valuable than spending a dollar on raw RF power. That claim couldn't
be more true, so do NOT ignore the antenna side of the equation. |

Photo courtesy
of la9ex,
Norway |
So, if your R/C model
application requires a video range of several hundred feet then you will
need to purchase a high powered system at a cost of several hundred dollars.
These are NOT license free and for USA based hobby (personal) use they will
require that you hold a valid
Amateur Radio (ham) license. If your application is for
business, commercial, or scientific use, then you will need to obtain a
commercial license.
Sorry, but we do not
offer purchase advice on any of these commercial video systems. Contact your
local "Spy" shop or search the web. You can also try posting your purchase
questions on the User-to-User Forum to see if anyone
else has some good recommendations
Q. I understand
that I can increase my system's RF range if I build a better antenna. I would
like to design one. But I am confused about it all. What is a dipole, Yagi,
half-wave whip, and so forth? How do I do make one? What is best?
A. There are
no easy answers to this one. We suggest that you visit the library or a large
book store. The ARRL web site's
book store has several antenna books that you can purchase
and most offer sufficient information to allow you to build your own. Be
prepared for some VERY serious reading.
Some of you may have
noticed that the RC-CAM project represents a small faction of the ham radio
hobby, called Amateur TV (ATV). If you know of any ham operators then perhaps
they can offer some antenna advice. We also recommend that you read this
short FAQ on ATV range:
ATV
Range.
Lastly, there are a
some antenna projects on the RC-CAM
Special Projects
Page. The "GPP" 2.4Ghz Patch antenna is easy to build and works
great.
Q. I heard that
I can increase my XCam2's range if I add a RF power amplifier. How do I do
this?
A. There are
several ways to do it. Some wireless video vendors sell broadband RF amp
modules that require simple connections to your battery and antenna coax.
Pricing ranges from $75 to $300. Check with your wireless video equipment
supplier to see what is available.
However, most hams
will prefer to roll their own. There are IC's that ease the pain of doing
this. For example, the popular
Linx BBA-519-A is a tiny module that will boost the power
to nearly 50mW. This will triple the XCam2's range. It is small enough to
fit inside the XCam2's case. It is very low cost -- about $15 at
http://www.digikey.com/. The RC-CAM Forum has had several
discussions on using this part, so check the archives.
Regardless of the way
you incorporate one, hobby use of an RF Amp in the USA will require that
you obtain a ham radio license. Adding a high powered RF amp is not to be
taken lightly, so do it safely and legally please.
Q. While performing
some XCam testing at my house, I was getting terrible interference on my
XCam. It was constant and was not dependent on antenna position. Thankfully
I found that it worked fine at the flying field. I am curious -- where is
the household interference coming from?
A. There are
several sources of interference, some of which are due to other consumer
devices that operate near 2.4GHz. We suggest that you start by removing power
from your cordless phone, wireless lan, and anything else that communicates
using RF energy. Such devices at a next door neighbor's house can affect
you as well. Finally, a microwave oven that is cooking something will totally
cripple your XCam reception.
If the interference
is intermittent and antenna position sensitive, then it sounds like you
are experiencing "multipath" interference. This is a phenomenon where
the RF signals bounce off nearby metal surfaces and corrupt the main signal.
It often appears as quick flashes of black or jumbled video. This is very
common if you are near any structures, especially large metal ones. This
issue will not bother you when you get into open space. Expect to see it
around your house, roadways, or industrial buildings.
Q. I cannot afford
the Panasonic CCD camera you recommend. Why don't you just use the color
camera that is supplied with the XCam2 transmitter?
A. The XCam2's
CMOS color camera is fine for fixed installations. But it has a very slow
iris. On your moving model, this issue will cause the video signal to saturate
and you will get lousy images. Yes, it will drive you nuts.
There are other issues
too. It does not have backlight compensation, so highly contrasted video
will look terrible. The focus is poor too. On the other hand, it does make
an interesting paperweight.
You really need a good
camera that offers DSP (digital signal processing) video correction. There
are many to choose from, but nearly all are CCD types with prices starting
at about $90 USD. If you find a low cost high performance CMOS based camera
then please let us know.
Q. I am looking
at buying a wireless video system. I have seen systems that use 434Mhz, 900Mhz,
1.2Ghz, and 2.4Ghz. Which is best?
A.The nice thing
about the 2.4Ghz systems is that they represent the latest technology. The
high quality systems will offer very good Rx sensitivity and tiny Tx's. Power
requirements are convenient too (often 5V). Lastly, the antenna sizes are
1/5 of a 434Mhz system and 1/3 of a 900mhz. So, mounting the aerial on a
model is easier and allows more flexibility to ensure an effective position.
The 900Mhz systems
represent slightly earlier wireless video designs and so they seem to be
lagging in technology. But, a high quality system will theoretically outperform
a 2.4Ghz system, especially in a RF reflective environment. Most of the 900Mhz
models are stuck in the 12V realm (I prefer the 5V systems since they tend
to be more efficient at power consumption).
Of all the wireless
video RF bands, the 434Mhz (420-450 Mhz) UHF transmitters suffer the most
color degradation due to their AM operation. They are also prone to cause
interference when installed near 72Mhz and 75Mhz R/C receivers. And lastly,
the 434Mhz video transmitters often require that you use a UHF television
to receive the video signal. Although this may sound like an advantage,
television tuners usually have very low sensitivity and can cause reduced
range. Ham ATV'ers get around this by using a UHF to VHF down-convertor,
but that expense just makes these systems less attractive. Frankly, for our
R/C aerial application it is best to skip the 434Mhz wireless video
products.
I cannot recommend
the "1.2Ghz" systems, at least not in the USA. Most of these are sold on
eBay and are imported from China. My concern is that they are not transmitting
on legal USA frequencies (even off-limits to hams). They often use 1.0Ghz
to 1.24Ghz, which is reserved for USA aviation navigation and government
applications. The sellers rarely understand this (or do not care that the
buyer will be in violation of US laws). If in doubt, ask for specific technical
data and investigate to see if your ham license allows for legal
operation.
You will need a ham
license to operate any of these systems, as well as verify they use a legal
frequency. If the seller says they are license-free, then request the FCC
ID/Registration number, which is printed on the ID label affixed to the
transmitter. Then look up the number on the
FCC database to see if it is legitimate.
Q. I need to connect
two or more displays to the video signal. I tried to patch my video goggles
and portable monitor to the single output of the XCam video receiver, but
it looks terrible when both are sharing the signal. What is the correct way
to do this?
A. If you connect
all your display devices to a single video source then you will usually
experience poor brightness and contrast. Fortunately, the buffered video
output of a camcorder or VCR allows you to drive an additional video device.
Trouble arises when you connect devices that do provide "loop-thru" buffered
video.
If each of your video
displays have 75 ohm/Hi-Z switches, then you can set them all to "Hi-Z" except
for the last display. Set the last video device's termination switch to 75
ohms. To work correctly, all displays must be cabled in a daisy-chain (loop-thru)
fashion. This method works well if the cable lengths are reasonable and you
correctly terminate the last device in the chain. Note: Most consumer displays
do NOT have the necessary switches.
As mentioned, some
consumer monitors have a buffered video-out on them. If so, you do not need
to play with Hi-Z switches. You can merely connect each buffered output to
the next display.
Otherwise, you will
need a video buffer box (distribution amp). These are available from well
stocked A/V retailers or online sources. Here are examples of such
products:
MCM #82-9355, 1 X 2 Video Buffer (12 VDC)
MCM #33-6875, 1 X 4 A/V Buffer (15 VDC)
MCM #33-6880, 1 X 7 A/V Buffer (15 VDC)
TRS #15-1172, 1 X 4 A/V Buffer (115 VAC)
Note: We have not
tried these product examples, so use at your own risk.
Q. I live outside the
USA. Where can I get a PAL video based XCam2 unit?
A. XCam2 systems
that are sold in North America can support PAL video. All you have to do
is install a PAL video type camera. The transmitted signal will then broadcast
in the PAL format. Please be aware that the USA type AC wall adapters
(transformer power supply) will not work in European countries. This is
not an issue since you wont need them.
However, a PAL configured
XCam is available from X10
Europe. From what we can see, they sell only the older model called the
XCam
Anywhere. This camera system is similar to the one used with RC-CAM2
and RC-CAM3. It is much larger than the XCam2 product.
If you cannot obtain
a X10 video camera system in your country, then why not consider hacking
something else? There are several sources to these kinds of products and
many are sold worldwide. The modifications used by the RC-CAM projects can
be applied to most any 2.4GHz wireless camera system.
Q. I think that your
site's information has errors. I just built the camera project and it does
not work! Since I feel that you are to blame, how do I get you to replace
my damaged parts?
A. Every little
detail on the RC-CAM site is offered AS-IS, with no implied warranty. Regardless
of why your project fails, you (and only you) are solely responsible. In
our efforts to help project builders with non-working systems, we have found
that in every case they made an error during the course of soldering their
parts.
However, given the
constantly changing XCam camera designs and the fact that error prone humans
have created this site's information, it is only a matter of time before
a mistake is published. So, if you see a web site error please report it
immediately! Visit our Contact page for email
details.
Thankfully, no one
has asked this question. We only post it to make it clear that we are not
responsible for making your project work. If you have technical troubles,
please post your questions in the User-to-User
Forum.
Q. I am very interested
in purchasing an R/C model helicopter. What do you recommend? What is the
best radio control brand?
A. This is like
asking "what is the best car to buy?" There is no single correct answer.
We suggest that you post such questions at the sites mentioned at the bottom
of the main page. Be prepared for a flood
of responses.
Q. I cannot get
my model helicopter videos to stop shaking. Why are yours so
steady?
A. You must
balance your helicopter. This includes the main blades, clutch, fan, tail
drive, and more. For help on how to do this, just ask your hobby store to
order the book called "Ray's Complete Helicopter Manual" published by R/C
Modeler Corp. Or call them directly at 818-355-1476 (USA).
You also need to experiment
with your camera mounting technique and location. In our attempts we have
experimented with iso-grommets and rubber foam to damp the high frequency
engine vibrations, different mounting locations to curb the lower frequency
rotor induced issues, and occasionally we succumb to witchcraft. From what
we have seen, there is no single solution that will work for everyone.
Despite the typical
recommendations to use "soft" mounting techniques, we have found that
a well balanced heli can offer fair results using a firm mount to a "beefy"
part of the heli frame, with as little mass as possible in the camera housing.
If this does not work, then you will need to revert to an elastic suspension
system. Such a system can be base on taught rubber bands, resilient foam
pads, commercial iso-damp grommets, or other techniques. Adding mass to the
camera may help too.
There are commercially
built R/C Camera carriages for model helicopters. They have implemented measures
to reduce vibration. The bad news is that they cost $400 and up.
Q. How much weight
can a R/C model helicopter lift? Will the camera's weight cause
trouble?
A. This is a
very subjective question. It really depends on the specific model and
YOUR flying skills. Our rule of thumb is to keep the payload weight
of a typical .30 size model heli under three pounds. It could lift more,
but it may be a handful to fly for most folks (and perhaps dangerous too).
Even the lower payload weights will affect flight behavior, so always fly
with extreme care.
Larger model heli's,
such as .60 size and gassers, can take on much bigger payloads. We have heard
from folks that are carrying twelve pounds of video gear. However, less would
be better, especially if you expect to do more than simple forward
flight.
If you wish to determine
how your model will fly with the extra weight, just attach a plastic container
and fill it with different amounts of water or sand. Be sure to observe your
model's center of gravity!
Q. I want to add
pan and tilt to my R/C helicopter's camera. Any ideas?
A.
Well, if you really insist on doing so, then a pair of R/C servos could be
used. Refer to the figure on the right for an example of a VERY simple pan
& tilt mock up.
One side of servo "A"
is mounted to a platform on your model. Its output wheel is directly
connected to the side of servo "B." The camera is mounted to the output
wheel of servo B. Using double sided tape, you can prototype a simple
system in a few minutes. However, your working version should involve more
permanent means.
Standard
R/C servos offer about 120°
of wheel rotation,
which should be fine for your pan & tilt system. Need more movement?
Airtronics and Multiplex offer special proportional retract servos that can
give a full
180°, but
they are more expensive than a standard servo.
However, you can hack
your cheap servos for more rotational movement. Just add a 1.5K ohm resistor
in series with each outside leg of the servo's feedback pot.
With a little resistor tweaking, 160°
degrees is possible.
Be careful though -- some servos will stall if you allow them to rotate too
far.
You should be aware
that operating a pan & tilt feature while you are safely piloting
your model will require a dedicated camera man. Usually a second R/C transmitter
is used to control the camera.
A precision Pan &
Tilt servo controller is discussed on the "Projects" page:
PanCam.
Please keep in mind
that your R/C model helicopter is already an ideal pan and tilt machine.
An experienced pilot can perform amazingly agile maneuvers that can aim the
camera in almost any direction. As such, try a rigid camera mount before
tackling something more complex.
Q. I
downloaded your video files, but they do not play correctly. What is wrong
with them?
A. If you are
a PC user then you will need the latest version of the Microsoft Media Player
(at least version 6.4). The Movie Catalog page
has a link to this free program.
If you attempt to play
the video and are prompted to download any additional codec filters, then
please do so. If you are still having troubles then try saving the video
files to your hard drive before playing them. Just right click on the movie
download icon and choose the "Save Target As" feature.
If you are using a
Mac PC, then download the latest Intel Indeo codec filters from your media
player's web site.
Q. Can I link
to your site?
A. Your web
site is free to include a link to our site's home page
(http://www.rc-cam.com/) as long as you are using us to promote the hobby
in a positive way. You are not allowed to add links to any of our other pages,
photos, or video files.
If your site includes
a link to us, please send us an email notification.
Q. Who is "Mr.
RC-CAM?"
A. He is a guy
in the USA that appears to have way too much time on his hands. However,
this is hardly true and in fact his desire to fly his R/C models is often
curtailed by his work schedule. To pay for his hobby activities, he designs
and supports electronic products for medical, industrial, and consumer
applications.
** USE THIS SITE'S INFORMATION AT YOUR OWN RISK! **
R/C
model aircraft are not toys and should be flown under the supervision of
an experienced adult pilot. Our web space sponsors are not responsible for
the content of this site and do not endorse radio controlled model helicopters
or the use of video camera equipment on them. Our sponsors and/or the web
site's authors are NOT responsible for any personal injury, property damage,
or financial loss resulting from using the published information. |