Week 5 of the RCBits 10/10/10 Sale!

We've entered our fifth week of our 10/10/10 Sale. This week we've got 10% off all Beam E4 and Beam AvantGarde parts.

More Beam parts will be coming to us in the near future, there's a revision to the E4 as well as the AvantGarde so now is the ideal time to stock up on some spare parts for your current model so you can get through the flying season with minimal downtime. Hooray!

Gaui NX4 and X5 Pre-Christmas Specials

As a lead up to Christmas we've got a couple of great deals with the NX4 and X5 Gaui kits on offer right now.

The NX4 Combo includes an Engine, Pipe and Gryphon Push-button glow device for a smooth $675.

The Gaui X5 combo A (airframe + Mini V-bar) now comes with a FREE set of Edge 523mm FBL blades.

We've only got a couple of each available, so its first in best dressed on these sweet deals.

3DX China 2012 - Pictures and Videos

Well last weekend I happened to be in the neighbourhood in China and decided to pop by the 3DX China event to give some moral support to Marco and Vas.

Whilst I was there, I took a bunch of photos and videos of the event and have just finished getting them online.

You can see all the youtube videos here.

And for the photos - check out our facebook page, or if you want to view the 3DX China album itself, click here.

Just as a sampler, here's my favourite photo from the event. Let me introduce to you, Tony Tseung the wifi hotspot.

Gaui NX4 Kits are here!

We've got our kits this morning and we're prepping them to be sent out to all customers this week, the plan is to get them in your hands pretty much on the exact release date (which is next Monday by the way). We have a few of each kit left in stock, so if you're keen to be one of the first with this screaming little machine at your field, now is the chance to get one from the first batch.

We've got the accompanying engines, pipes, governors and other bits to go with it - just pick yourself a FBL system and some servos that suit your fancy and get into it!

Gaui Field Reps

Just thought I should make a public announcement to introduce to you the Gaui Field reps we have on board for the coming year. Some of them you might know already! they join our existing team of field reps and team pilots

So, without further ado may I introduce to you (in alphabetical order of surname)

Charlie (Chucka) Lewis

Chucka is an existing RCBits field rep but has stepped up to become one of our Gaui field reps after falling in love with his X7. Chucka was a frequent attendee at most funflies this year, but has spent the last couple of months working away in the mines so he can take most of next year off to continue doing what he loves - flying choppers!

Jimmy Searl

Hailing from Nowra NSW, this young bloke has been popping up at a few events in NSW and the ACT and has been flying the socks off his lil 450 and 700 (which mind you, is now retired for a Gaui X7). We look forwarding to seeing much more from this chap next year. Watchout!

Vas Serovski

Most of you should all know our good mate Vasko. I like to call him the Gaui tech-man - if there's a new upgrade part for any Gaui helicopter, he knows about it. If there's a build issue that old mate is having, Vas has already spoken to him an fixed it. Vas knows his Gaui stuff inside and out, and it is a big pleasure to have him on board as one of our field reps. He's a member of the famous SSSFA club in south Sydney, so catching up with him for a chin wag is always easy for us.

Well, that's the new additions, please give them all a warm welcome. We're all looking forward to seeing what these boys get up to at the local field and on the forums throughout this coming flying season.

How to "run in" an OS50/OS55 Engine

New engines are not ready to be thrashed in Idle Up or Stunt mode
(Also applies to old engines with a new ring/piston/liner)
A new engine needs to be put through a short and simple "run in" procedure
(The American's call this procedure "Break In" but I dislike the term "Break")
The "run in" procedure introduces new metal engine parts to each other and allows them to "mate" nicely
OS engines require minimal "run in" time - you can complete the process in 3 flights

Generally new engines come with oil over the engine internals
If your engine has been sitting unused for a long period of time and is rather "dry"
a nice thing to do is put a few drops of fuel into the engine via the glow plug or exhaust.
This provides lubrication during cranking and starting...

The OS55 has two needles and a screw
The needle above the fuel inlet hose is the main needle (also called the high speed needle)
The other needle is the mid range neddle

The idle mixture is a screw (which drives an elipical cam)
The idle mixture should almost always be left at the stock setting
which is the slot in the screw is in line with the bolt holding the brass plate
(There are times when it's advantageous to have the idle mixture a tad rich)

The main needle controls total fuel flow into the carburator
You mainly tune this needle based on the engine needs and performance in idle up (stunt mode)
This is why it's also called the high speed needle
At lower engine rpm/speed the fuel mixture is better controlled by the mid/idle settings
But you have to get the main needle right first
Changing the main needle setting alters the fuel delivered to the mid & idle circuits
If you don't follow a process you can end up changing needles forever and getting frustrated
Get the main right, then fine tune the mid - seldom need to mess with the idle

The carburator settings for initial run in are the default settings in the manual
For the OS55 this is 2 turns out from fully screwed in - on both the mid and high needles
(This is likely to be excessively rich - 1.5 turns on the mid may be better)

Gently screw the needles in by hand until they are closed
Do not use force, that will damage the needle tip and alter tuning and performance
Then rotate the outer keeper until it's in line with the slot in the needle
This is used as your tuning reference point
Now turn the needles out, with every half turn, the needle slot will align with the keeper
This makes it easy to spot 1/4 and 1/2 turn needle positions

When running in an engine you do not want the engine to be "slobbering rich" (like Bill Gates)
This will prevent the engine of getting up to a useful operating temperature
and make operating the engine/model very difficult
The general rule of thumb is to run the main needle either 1/4 or 1/2 turn richer than normal

Running in an engine requires the engine operating at a nice temperature
This temperature will be lower than normal but not excessively cool
The lower temperature is achieved via slower RPM and lower workload
Running in an engine requires a mild and varying workload (varying RPM also helps)
Making the engine do work puts pressure on the ring against the bore
This encourages the new metal parts to mate and get used to doing useful work
We do not want to subject the engine to full throttle during run in
We do not want to run the engine at excessive RPM (stay under 2000 rpm headspeed)

The run in process is also about putting the engine through heat cycles
Don't immediately refuel and fly again, let the engine cool down

I like to do the very first flight on a TX throttle curve rather than a governor
This enables more RPM variation to be used (the governor will run a constant RPM)
When running in an OS50 or OS55 I tend to use the following throttle curve: 0 28 38 48 100
After the run in process when you've leaned the engine out this should be reduced to 0 25 35 45 100

So, you're ready to start your new or rebuilt engine
(Make sure you have a new OS8 or Enya3 glow plug)
If you have a pumped or regulated engine it may be helpful to
use full throttle with the glow plug OFF and crank the engine over
This will build up pressure in the tank and bring the fuel up to the carb
(This is where we need that internal lubrication!)
Then close the throttle, turn the glow plug on, crank and start the engine

Most likely the engine will start and then die immediately
due to being new and rich and the idle trim not being right
Increase the idle trim and restart the engine

The next most likely problem
is the engine dying as soon as the glow plug power turns off
That's due to the engine being very rich and snuffing out the glow plug
Increasing the idle trim should help
alternatively close the main needle by 1/8 or 1/4 of a turn

Your next problem is spooling up
With a rich setting this adversely effects the low speed performance
and makes spooling up difficult, the engine may cut
Just restart and spool up slowly,
once you get past the ~20% stick position it should spoolup fine

Take off into a hover and let the engine and carb warm up for 20 to 30 seconds
If the heli is wobbling or nodding that means the headspeed is too low
Raise your throttle curve a little to address this
There should be plenty of exhaust smoke
(unless you are using thick oil like CoolPower Green)

Next go into forward flight and do simple figure 8 circuits
You can gently build up quick forward speed and use a significant banking angle
Don't use full collective however, ~80% should be your maximum
Mild stall turns are also useful for putting pressure on the ring
Mild climbouts are also useful (do not bog the engine)
Just fly around putting mild and varying load on the engine

At the end of the first flight let the engine cool down
If your fuel tank is exhaust pressurised always refuel immediately
This pushes the hot and toxic exhaust gas out of the tank and makes the clunk line last longer

When you start the engine for the 2nd time you will notice that it starts easier and is more willing to idle
This is a clear indication that the run in procedure is working correctly
You will notice a further improvement in flight 3

In the 2nd flight you do more of the same, perhaps applying a little more load this time
Again, after the flight, let the engine cool down.

In the 3rd flight you can go into a idle 1 (stunt 1) with a reduced headspeed setting
Something in the 1800 rpm to 1900 rpm range would be good
Again, fly around making the engine do useful work with a varying workload
At this stage you can certainly do extended climb outs (longer/higher)
but don't use full collective (perhaps ~90% now)
Again, after the flight, let the engine cool down.

Once these three flights have been completed you can return to normal operations
You will re-tune the engine for normal operations (see how to tune article - coming)
You will lower your normal mode throttle curve
(because the engine will rev harder when you lean out)
You can use idle up (stunt mode) and go 3D


Gaui Day 2012

So, Kristy and myself headed over to Taiwan almost two weeks ago to attend the Gaui Day event held in Taipei on the 13th of October. Having not ever been to Taiwan before was very exciting us. Upon arriving at the airport, we were collected by a driver and taken to dinner with the other guests and Gaui crew. There we met with Anny (Mrs. Gaui), Alex and his wife, Howard, Tony, Chance, and all the international guests and pilots who were over for the event and had a delicious meal. Apparently one of the dishes we had contained frog - and it was actually pretty tasty!

We spent the Thursday getting a bit of a tour of Taipei, checked out some markets, ate stinky tofu, caught the MRT, ate some ice cream, checked out Taipei 101 and all the fancy shops in the mall there. Then we went to dinner at a place where we fish for shrimp, then tear off their arms, salt them and BBQ them whilst alive. For those with a sensitive nature to marine life, this was definitely not the place for you. They were very delicious though!

On Friday I went with all the pilots to the field and watched them practise their routines, tune their helis and so on. There was some wicked flying action going on and a little bit of carnage. The broken helicopters were brought over to the bench where Eitan's and Mitch's dad would promptly start repairing them - super quick! I took some photos and just slapped them on the RCBits facebook page. At about 2:30pm I jumped on a bus and was taken to the Gaui factory for a bit of a tour with the other distributors. The R&D blokes demo'd the new MRT Core GPS / Flight system for the quads and showed us all the new cool features to expect, my initial impression of it is that it looks quite good - I'm eagerly awaiting to see what the street price will be for it, and more importantly ... when it'll be ready! Hassled Bobby a bit while I was there about the new Gaui NX4, the Gaui Mini V-bar and the new Governor that's coming out, it all looks pretty darn impressive. As the sun set we all piled back onto the bus and headed over to a buffet restaurant for dinner. We all ate lots of yummy food. Turns out it was Mitch's birthday on the Saturday, so Gaui surprised him with a birthday cake, we sung Happy Birthday, then there was a bit of a food fight between the youngsters, good times. After dinner, Kristy and myself went with Tony and one of his 50 goddaughters Isabella to the night markets, there was so much awesome cheap stuff going there, mostly clothes, shoes trendy accessories, but also lots of crazy food like beetles, snails, indescribable meats, vegetables and foods. You'd walk through the food section and every 2 meters you'd be hit with a variety of pleasant and unpleasant smells. Truly an experience, and one that I would highly recommend for any visitor to Taipei.

Saturday, the actual Gaui day event, was a massive day. We got to the field at about 8am (this was the late bus, the others were there from about 6am) and the whole field was setup beautifully with lots of tents, banners, flags, a huge blow-up castle like entrance thingy, food stalls and all sorts of things going on. There was a traditional Lion dance which showed off some pretty excellent acrobatics, there were Gaui promo girls, Gaui dancing girls, heaps of demo flights (synchro, flights to music, freestyle etc) and a 3D competition for local pilots as well. There was a huge spectator crowd that was in absolute awe for all of the demo flights. Highlight flights for me was Asaf and Eitan's synchro flight, Mitch's freestyle flights, Bobby's NX4 flight to music, Poom's freestyle and Bobby's night flight. All the other pilots flew excellently, the Bosso's put on a good show and CD and Kan flew amazingly as well. There was so much blade scraping going on. Poom and Mitch have some obsession with ruining their tail blades almost every flight (they're sending Matt Botos broke I'm sure). The night setup was really good, two small scaffolds held up the PA system as well as some disco lights. The DJ was cranking tunes all day, but sweet jesus - we must have heard Gungnam style like 30 times. I'm also well and truly sick of that "Moves like Jagger" song as well. No biggy. The evening wrapped up at probably 9:00pm or so, we headed back to to the hotel via the office, and got back to the hotel at about 10pm and literally went straight to bed, I was a tuckered out little boy.

Sunday was wrapped up by going market shopping with Tony until about 2:30pm when we had to get back to the hotel to catch our ride back to the airport. Tony was our expert tour guide (and I mean that in a serious way), he is multi-lingual, seemed to know almost everyone we bumped into (did I mention the 50 goddaughters already?), was a mobile wifi hotspot and a true gentleman, you really couldn't ask for more. Kristy shopped for more shoes, and some gifts for friends back home. We had a nice quick lunch of Tonkatsu-something-something and then wrapped up our market shopping by watching him buy duck tongue and other sorts of animal entrails I'd never imagine eating. We finished the shopping up, caught a cab back to the hotel and grabbed our bags, said our goodbyes and headed off to the airport for the flight back home via Singapore. Totally smooth sailing all the way through, a seriously great holiday, and a magnificent funfly. I could not recommend it more to anyone, definitely slap it on your funfly "bucket list".

If you'd like to check some photos out of the Gaui Day, I suggest having a look at the album on our facebook page. For photos of the food, well, that's Kristy's department - stories on her food blog should start making it up in the next couple of weeks. You can see all that kind of thing at www.talesofaconfectionist.com.

NOW STOCKING: SAB Goblin 630 and 700.

Hello again.

Some of you may have noticed the other day that a SAB Goblin 630 and Goblin 700 parts starting appearing on RCBits. What does this mean? exactly what you think it means buddy! We are now stocking kits and parts for the Goblin 630 and 700 helicopters.

At this exact point in time, I'm almost half way getting all of the parts online. We have a couple of Goblin 630 kits available as well. I *might* have the rest of the parts online by late this evening (there's about 70-80 to go), but the more realistic time frame would be tomorrow evening.

Our shipment has already arrived straight from the factory - there's no middle men in this arrangement. The gear is physically sitting there ready to ship in your orders. Buy with confidence, have your stuff shipped without delays. We won't make excuses ;)

Canberra Chopfest 2012

Well so ends another Canberra Chopfest, this year saw more pilots than the previous two years. We had just short of 50 registered pilots this time which I think is pretty good.

Blokes drove in from Melbourne, Seymour, Griffith, Wagga, Sydney, Gosford, Newcastle and some even as far as Brisbane to make it down for the event.

Friday started off as not much of a flying day, it poured almost the entire time so that put a bit of a damper on the last minute Friday night flying plans. We all met up for an informal feed at the Burns club in Canberra and got acquainted with each other.

Saturday saw some flying happening, but with a few showers and some sleet falling from the sky, most of those in attendance who are used to a warmer climate felt a little cold.

Saturday night saw some calmer weather, allowing us to meet up for an informal night fly near where we had dinner in Kingston. The police rocked up soon after we occupied the designated space - thinking we were some local car club wanting to do some burn outs. They left after the first couple of us went for a fly, as they had a pretty good idea that we weren't the mischievous crowd they thought we were. Saturday ended on a pretty good note with some excitement for better weather on Sunday.

Sunday turned out to be a much nicer day, the wind was a lot calmer and the sun warmed us up and most everyone went up with their helicopters and enjoyed themselves. It was good times.

The club members put in a great effort in keeping everybody fed and hydrated at the field, big props to Peter, Terry and John for their efforts in keeping all basic human needs met.

By the end of the afternoon, most people were quite satisfied with how the weekend panned out. Some won some prizes from the pilots draw and everyone seemed to go home quite content with the event. All in all, I'd say it was quite a good weekend.

I snapped this photo just before I left the field at about 5pm on Sunday, you could not tell a funfly was here just hours before. It was like... it never even happened.

Hope to catch you all again next year!

Tony tests out the Gryphon Quasar HV BEC

A couple weeks ago at the field, Timmy and I had a short discussion about BECs. He decided to send me a Gryphon Quasar HV BEC for testing.

There have been a few reports in the past were the original Quasar users have claimed the BEC failed, and damaged their electronics. The manufacturer, Gryphon RC, revised the BEC, making it more robust. The revised unit is more tolerant to high frequency input ripples (caused by the ESC during PWM switching), and high frequency and high current load transients (high power brushless servos etc).

The unit Timmy sent me was the v2, revised unit. It can be seen below.

Anyways... The specs for the unit are:
Input Voltage Range : 11V ~ 75.6V (3~18 Cells)
Output voltage Range : 5.2V, 6.0V, 6.8V, 7.4V, 8.4V Selectable
Voltage ADJ : 4.8V~7.7V ADJ (Potentiometer)
Output current(Peak) : 20A
Output current(Cont) : 10A
Low voltage alarm setup : 10V~75V (Available GDB-1010 or GDB-1030)
Size : 12mm(H) x 31mm(W) x 52mm(L)
Weight : 20g (Excluding Cables)

The first thing i did was pop it open to have a sneak peak inside.

The PCB layout looks nice and neat, and the unit looks well assembled. The PCB has a nice gold finish, which not only prevents corrosion, but looks cool too .

The PWM controller IC is an LM5088, from National Semiconductor. I know a few guys on the electronics forums that have used it successfully in multiple circuit designs. The only downfall of this IC is its a non-synchronous controller, so at higher input voltages we will have more power lost (heat) across our free-wheeling diode in the converter. Synchronous designs use two FETs as opposed to one FET and one Diode in the converter. The non-Synchronous design, however, has the advantage that it wont blow up if you accidentally plug a receiver pack in conjunction with the BEC, and it wont adsorb reverse voltages. So we can say its a more idiot proof design.

After analysing the circuit, i thought 10Amp continuous load current at 75V input is a bit too optimistic. Especially with only that tiny red heatsink. So the testing begins...

I wanted to test a few things:
1) Output noise at 10Amp load with 50V input (12S Lipo)
2) Temp rise at 10Amp load with 50V input after 1 min. (lets face it, our servos are never going to draw more than 10Amps for more than a minute straight)
3) Response to input voltage transients.
4) Response to Output Load transients.
5) Voltage regulation at Peak Current (20 Amps).
6) Short Circuit Situation

Testing Methods:
1) Applied a 10Amp load (using my Variable load - Based on my MOSFET design, as can be seen in the pic), and measured the noise using my oscilloscope.
2) Applied a 10Amp load and measured the temp rise after 1 min.
3) I used my current limited power supply to power the BEC, Connected a FET across the input terminals of the BEC, and used my function generator to apply 0->5V noise at the FET gate, causing voltage ripples on the supply.
4) I actually tested the unit on a set of outrage torq servos, and quickly pulsed the cyclic with the servos under load, and used my oscilloscope to monitor the output voltage. I also loaded the BEC with some halogen down-lights.
5) Monitored the voltage during 20Amp peaks using my oscilloscope.
6) Just shorted the output leads.

1) Only 40mV low frequency ripple, and a 350mV high frequency ripple. This is pretty good. The high frequency noise will be filtered away by the ceramic caps in your Rx and Servos, so they will only see the low freq ripple of 40mV. And remember this is at 10Amp load. The Voltage was rock solid at 7.4Volts (+/- 0.02volts).

2) Only 34°C rise after 1 min @ 10Amp load with a 50V supply. I quickly gained confidence that the unit will easily handle the current at the rated 75 volts. Looks like the diode used is a later generation schottky diode, with low forward voltage drop. Not bad at all..

3) With input voltage ripples, High and Low freq, the output remained solid at 7.4V. The picture below shows the dual tracking powersupply in series mode, giving us ~50V to supply the BEC.

4) My servos wouldnt draw more than 6.5 Amps from the BEC, even under stall. The voltage was rock solid.

So i connected some downlights to the BEC. The voltage dipped slightly... then quickly rose. This dip is probably because down-lights are basically a short circuit when cold.

5) At 20Amps the voltage at the BEC terminals was 7.39Volts. The voltage on the end of the wire was 7.32Volts. The unit has a Dual feed going to Rx. This minimises the droop and also provides redundancy.

6) The ULTIMATE TEST... The unit survived a direct short for 20 seconds. I directly shorted the outputs and measured the peak current. My Clamp meter outputs 1mV per 1Amp, and the Fluke registered 27.75Amps peak under short circuit. The BEC limited the output current by dropping the voltage, and saved itself.

Basically, this unit is very efficient, regulates perfectly, and is very robust too. I never had a chance to see or test version 1 of this BEC, so i cant comment on it. However, after a combination of efficient and robust operation during testing, i have gained confidence in the unit and it has earned a place in my Goblin. Nice one.