trash
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Holy **** people !
I been away for a while and you people have been busy.Some awesome stuff their kiddies ! I moved house and I had a whole box full of A40 bits that one of my cats had got into and chewed. Smack that kitty !
Hundreds of propellers and motors and well, half chewed wings which I thought were now useless. I put them all in a big box and took them to my local ham radio boot sale.
I can hear the screams now !
Ah, but fear not fliers ! I do remember who I sold them to (I think) and I’m sure this fella will be more than happy to exchange parts for some help with modifying his A40 to something cool.
I will try an introduce him to this thread.
looks like I have another project to play with.
I’ve been doing some modifcation to the hotwheels radar gun lately.
This critter will make for some interesting modifications.It would also be easy to rip it out and build it into another car like a mini-Z.
Yeah, I’m still out here too. Don’t get to log in as much as I’m working away from home a lot trying to pay the bills and not much time or money for new toys, and the old toys are starting to rust.
I haven’t heard too many truckies on ch8 here in Australia for a while.
They all moved to ch40 UHF.27MHz is rather quite these days. Most of your interference will come from industrial diathermy machine on 27.145MHz which just happens to be where a lot of low power RC cheapy 1980’s toys used to be.
Chances of interference from 27MHz CB are small these days.
Above 29.7MHz it is quite so there is even less chance there.What about the good old rollerskate bearing oil ? It was really fine and designed for speed.
I’m not sure how much Jaycar is peddling it for, but you can also find the same stuff at a gun shop. There are several brands, it’s cheap and has that nice “just shot up a post office” kinda smell. Actually, a bit like bubblegum ?
Basically betty, it isn’t really that hard to do.
In your case crunching numbers isn’t going to help a lot, but trial and error will work well for you.Loaded antennas come in a couple of forms, bottom, top and center loaded.
I’ll skip the complex and boring information on each type.A good place to start is with an old CB antenna. Obviously they are tuned to 27MHz and are usually top loaded. Unwind the wire, cut the antenna short and rewind the wire on in the new position basically trying to mimmic what you started with on a smaller scale.
I wrote a nice tutorial on testing transmission lines and antennas.
http://www.austech.info/showthread.php?p=1047955#post1047955
the bottom half deals with antennas.Ideally you’d use a 27MHz SWR (it’ll work for 35MHz) and a 35MHz oscillator or transmitter with enough power to drive the SWR to be able to test the antenna. I fear your RC transmitter will only be a couple of hundred milliwatts and not really enough to drive the meter fully.
If you’re talking about an RX antenna for the chopper. Don’t bother… the piece of wire currently in use will suffice.
Seeing that you’re taking an interest in electronics and radio. Might I suggest that you or anybody else interested in radio and electronics consider the new ham radio foundation licence. http://www.wia.org.au It’s very easy to get these days. No morse code and the test is 20 questions easy multiple guess. Easier than getting your L’s for a car.
Crystals don’t blow. The best way I can describe them is they are a rock with a wire connected to each end. Actually, that’s exactly what they are.
If you were to pick up a rock off the side of the road and measure it with a multimeter, you could expect the same results.
Xtals are high impedence devices, so they are very difficult to damage.
It is possible to break them physically by hitting them with a hammer etc or dropping them, but even that’s hard to manage.Xtals do actually require to be tuned. In most hobbiest cases, your transmitter/receiver is tuned wide enough to accept a range of frequencies at the expense of efficency and stability. Generally compare your new frequency to the old one.
If it is 27.095 and the new frequency is 27.145 then they should without any fuss. If however the new frequency is something like 27.850, then this might be a little too far off, but should still work in most cases.If however you’re trying to use 29.550 or 36.300MHz these are too far off frequency or in a different band all together. On top of that, there are different xtal types and cuts. But most RC xtals are all cut to the same way.
There are some simple xtal testers that you can make that just have a simple LED to show they are working. If you have a CRO, you can see your transmitter’s carrier… you won’t see the actual sine waveform, but you will be able to see the carrier power. If you have a frequency counter or spectrum analyser, then you’re a god.
A simple xtal tester should cost about $10 or less to build.
A CRO (Cathode Ray Oscilloscope) can cost anywhere from $30 – $1000
A frequency counter $10-$500
A spectrum Analyser $300-$2000A CRO you can buy from Jaycar or Dick Smith new, but second hand ones are easy to come by. I often see them sold for ~$50.
Frequency counters are also easy to come by. You can get cheap hobbiest ones that work up to 50MHz for less than $20 at flea markets, but if you have the cash, you can buy some really nice 3GHz units for about $100 like the star-tek or optronics of ebay.
Spectrum Analysers are usually expensive, a new one can cost about $30000, and most serious ham radio hobbiests will spend $3000. But there is a lot of older spec-an’s that do not cover over 1GHz and therefore are only of limited used. You can pick them up for as cheap as $300. Ebay is a good place to find them, but you have to consider shipping costs.
You can also make a spectrum analyser out of an old CB radio.
I’ll try and find the URL for the planes.http://www.vkham.com classifieds is another good local place to look for gear.
.edited….
$240 !!! ouch !!!
There was a new micro plane that I saw in honkers for $20 that looks very similar to the one kerosene has posted, but it is a biplane, with 2 motors and slightly shorter wingspan. They are indestructable… I saw the demo bounce off the ground and keep flying.
I’m here, I have heaps of parts and If I don’t have them, I can get them or tell you somebody who does have them.
There are lots of things you can set on them for different performance. trading off one characteristic for another. Like pitch stability for manouvability.
I got one a few weeks ago in hong kong for $15.
They fly ok for what they are. They are as simple as the single channel choppers to fly… hovering doesn’t take much effort, but after a short period of time it starts to gyroscopically wobble. The tail rotor doesn’t do much but give it a gentle nudge forward .
They’re ok to play with but they are nothing like a serious 4/5/6channel chopper.Turned up to the 1/10th track night at the showground and it wasn’t too hard to find somebody who’d help me out next door.
yep, I’m still flying. don’t let the cost put you off. A cheap hang glider can cost less than an mid priced RC plane ! You can pick up a cheap hang glider for $300. It won’t fly like a dream, but it’ll make you a much better pilot.
A good midrange hang glider costs about $1000 second hand. This is about what I would get for my glider if I sold it now. It’s more than capable of flying cross country. I’ve flown it from Stanwell Park to Wollongong and back on several occasions. The longest flight I’ve done with it was 6 hours.
Paragliders are slightly more expensive, and they wear out after about 300 hours of use. I do about 20 hours a year on mine.
Looking at ebay, there are a lot of cheap paragliders on there. Most of them look good but you’d want somebody who’s been flying for a few years to be able to tell you if they are ok.If you’re in the Albury area, go up and check out Bright. There are plenty of paragliding and hang gliding instructors in the area, an if you do one lesson every weekend costsing $100 or so, you can flind yourself flying free in a few months without missing too many dollars. Most instructors also hire out equipment, especially if it is one of there own students.
was thinking of some other things for undercarriage an wingtip damage.
If you find yourself rolling into landing so that a wingtip touches and turns your nice controlled landing into a flat spinning nightmare. Well a little tiny amount of trim normally does the trick. Short of that you can get sneaky and put some landing gear on the wingtips. I’ve not done this, so I’m not sure how well it would work. But a small light piece of stuff wire bent back underneath the wing so that it would act like wing tip wheels (think harrier jump jet type wingtips, just without the wheels). It’ll stop the wing dragging on the ground and reduce the drag enough to allow the fuselage to grab the ground before the wing does.
Ideally, you want to try get the tail to touch the ground first. this is the trick to flying into and landing in ground effect.
I’m about, I only get to log in occasionally these days. I work away from home lot. Just got back from HK, checked out the latest in toys while I was there. RC helicoptersare all the rage. They range from dirt cheap $5 single channel models, through to the the big autogro electrics for about $350.
A whole range of micro planes for $20-$40, some realy nice models with all kinds of combinations. Picked up a micro outboard motor boat for $8. It’s not fast, or proportional steering, but it won’t be long before somebody soops up the little bit motor on them. I even saw a very cool WIG/ekranoplane. But it was too big for me to carry back and I didn’t have enough time to post it.It’s been a while since I read this thread. I’ve been teaching a few friends to fly A40’s. One had a lot of trouble at first, one of the engines was slightly lower speed causing the plane to bank and dive.
Once that was sorted, we got to the business of flying straight.
It still amuses me that all my friends were just so stunned with being able to fly a plane first go, that they had no idea where they were flying.
Cricket pitch keeps them focused on the task at hand.
Fly straight and get that plane onto the deck. You miss, then it’s power off and into the grass… your punishment for failure is walk over and pick your plane up and walk back and do it again.Next was a 90 degree turn and landing… fly across the park and land
Then a 180 degree turn and land. Finally they could do a full lap of the park and put the plane down on the pitch without much effort.After about an hour of practise they were flying in control, with no planes in trees or nose diving into the ground. Flying combat is a hell of a lot of fun.
I feel like the red baron chasing friends trying to bring them down, while they try to avoid me and stay in the air. The learning curve becomes expotential. They quickly learnt how not to over react and how to recover from trouble even at low altitudes.I wish I had a video of a lucky attack. I dived and swooped in from above my friend’s plane. He didn’t try to avoid me because it looked like I was going to fly underneath him. But I pulled the plane up into a loop rolling towards him and flew straight through his right wing from the underside and stalled out of it into almost level flight, while his plane ended upside down and spiral diving into the ground. I can still hear the “awwgh !” from those watching.
Normally this is the kind of thing you would expect with multipath problems and higher frequencies. But RC cars all opperate bellow 100MHz, so multipath only occurs over large distances, generally not inside a shed.
A good example of multipath is if you’re listening to an FM radio station that is weak or you have a crook antenna, as you pull up at a set of traffic lights the signal seems to fade in and out as you move forward about every 1.5 metres. This is because the signal is coming from two directions (because of reflections etc) and when they both arrive at your antenna out of phase, they cancel out. Thought I do not think this is your problem.
What it does sound like is the metalic wall is in the near field of the antenna of the car. It is either de-tuning it or decoupling it. Hence touching the wall with the TX antenna uses the wall as the TX antenna.The way to make sure that at least the receive antenna isn’t being detuned is to place a 10pf capacitor in series with it, if there isn’t already one there.
If it is 100pf or so, then reduce it. 47,33,22,10pf are a good choice. The smaller the capactiance, the greater the decoupling but at the risk of attenuating more signal.ALL OF THEM !!
There is a cluster of about 30 shops there… there are also a few scattered in a neighbouring street, look for the adverts in Mong Kok station.
Ask some of the Mini-Z sellers where the nearest indoor track is. It’s in a building opposite the hospital… I can’t remember what floor, but you’ll be most welcome there.
Also get you bum up to Sham Shui Po, Aplui St before you make any major purchases. You’ll have to look hard for some of the more interesting stuff. It’s mostly electronics up there but still some RC gear and it’s cheaper than Temple St.
Learn some Chinese… or learn to bargain hard in the street markets. 🙂
hehe … been a while since I played with mine. I used to have a lot of fun scareing neighbours in a block of flats next door. Fly it up to their balcony, and turn it off when they cam out to look.
But now I have got to get me a directionally contoled one !
oh hangon … it’s one of those 4 prop units. Nar…. I was thinking of a single prop with a kicker.
Gyroscopic forces react at 90 degrees to their inputs. Pitching the prop in relation to the earth’s magnetic field is another way of steering them. I think a larger version would make an excellemt military serveilence aircraft.
Edited by – trash on 18 August 2005 20:04:35
I was in frontline hobbies in newcastle yesterday… wow.
I was looking at… well everything.. but the aircraft of course had me giggling. The most amazing one was a witch. Yes, pointed hat and flying a broomstick !!!
yeah, let me know the details merc … I’m not as cashed up these days, but I could spare a couple of dollars for crash testing.
I got a fat !
I really got to be me a hybrid N2O hydrocarbon rocket motor.
Looking at the fuel in SS1 … it burnsRubber !!! What an awesome rocket fuel 🙂
I even saw an esters model of it in a shop yesterday… coool.
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