Thread Tools
This thread is privately moderated by Eddie P, who may elect to delete unwanted replies.
Aug 25, 2007, 08:32 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
Discussion

British Aerospace BAe-146 (4 engine EDF), in 1986 PSA Airlines Colors


Edit: Eighteen (18) Seasons of Radio Controlled EDF airliner flight for 2017 on this project!!
Well, OK, I admit, the last few seasons have been "bye" seasons as I've been trying to source my fifth set of replacement brushed motors. This culminated with a complete brushless renovation, as I think I might have gone through all the remaining stock of Robbe 410-12 motors left in seller's hands

This was my first electric model after making the conversion from large glow powered warbirds in 1999. I was told: 1) Electrics don't fly. 2) Electric Ducted Fans don't work and they sure don't fly or even taxi well 3) Multi-engine models are a crash waiting to happen in general 4) This project is way too ambitious for an electric noob to try, don't ya think big guy? 5) You are going to glass it? Sure, right, you'll never finish and if you do it will not fly even with glow powered props 6) Robbe has discontinued it, so you can't get it 7) What flaps? It doesn't have flaps.

Well, needless to say my modified Robbe BAe-146 electric powered airliner is still flying strong today. So take sage advise into consideration but don't let someone's remarks keep you from building what you know will at least be worth the experience. Nothing risked, nothing gained, right?

I covered the foam, 6+ foot long wing and "basket ball" wide fuselage, empennage and long swept wings in glass (the whole thing is glassed). Then I painted the finished product and also fit the wing with scale Fowler type flaps for shorter, steeper approaches.

When it was brushed power I went though 4 sets of motors as brushed motors have a definite lie span (used 16 motors in all). The12 volt can motors and Robbe Rojet 74mm EDF power plants were good for 800 watts in at about 55 percent efficiency. She was no speed demon but flew well as long as you wanted to fly scale.

I began using a 8200 mah 5S Lipoly pack in it starting in 2003, a vast improvement over the original 16 cell 2400mah NiCd pack. The capacity was huge but it was necessary as the Lipoly cells were only 5 to 8C rated back then (!!!) I was pushing it with 50 amps. Then I reduced weight considerably with a 5s 5000mah, 30C pack in 2008. It's a 1000 watt airplane weighing approximately 8 pounds. It's not a rocket ship but it does fly like a heavily loaded regional airliner on a hot day (with an engine failure ) Very scale like in some regards, but it could use a little more power for some of the mods I have in mind.

These pictures were taken at the California Jets rally in 2006 by Uncle Joe. I didn't realize it at the time, but the BAe-146 came in second to a $20K F-18 for "Most Realistic Flight" award. I was hot dogging it through the middle of the flight routine with fast fly pasts and steep banks, taking advantage of all that 8200mah capacity of the main flight pack. If I had known my electric airliner made such an impression with the judges I would have toned it down a bit and gone completely scale.

This model has won "Peoples Choice 2002 Bay Area Duo", "Best of Show" and "Civilian, Scale" at a couple other RC eventst.

Kingdon Jet Rally October 2011

The BAe-146 was honored to win "Best EDF Jet" at the "Kingdon Jet Rally Over the Valley" October 2011. The old gal still has got a little left in her!

Short video clip of the -146 and the CV-580 turboprop several years back at an E-rally-
https://www.rcgroups.com/articles/ez...nov/bad/EP.wmv

- heavy crosswind by the way in case you didn't know by the video - but it was steady at least

Summer 2017

The model now has two brushless HET 5W, 1800kv motors in CS-70 12 blade fans and is running off 4 cell packs (4600mah) for each fan. The whole input wattage is just about 700 watts and the 88 percent efficiency gives me about 30 percent more power to the fans than I had at 800 watts and 55 percent efficiency. The fans are extremely quiet so the model also got a sound system. See page 27 an onward for the 2017 renovation to brushless power and sound. I have the timer set to 9 minutes but frankly the model can fly a lot longer.

Robbe BAe-146 Sound Module Installation (5 min 14 sec)


AND in FLIGHT...

Electric Airliner with Sound! (7 min 54 sec)
Last edited by Eddie P; Jan 03, 2018 at 06:40 PM.
Sign up now
to remove ads between posts
Nov 11, 2008, 04:38 PM
Always around.......
FresnoJay's Avatar
Gorgeous bird. I just recieved some info on this bird for 70mm fans. Its gonna be a scratch project that I am going to try to get done sometime in the next year. Again Sweet looking plane.

Jason
Nov 17, 2008, 01:27 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
Thanks Jason; when you get going on yours, let me know. We'll have to fly them together at the Willow or one of the other many events in CA.
Aug 21, 2011, 01:45 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
Here is some insight as to what I mentioned regarding the new modifications forthcoming for the BAe-146:

https://www.rcgroups.com/forums/show....php?t=1390466
Sep 13, 2011, 09:26 PM
Up-Out-&-Gone
demondriver's Avatar
Beautiful work Eddie! the 146 is a real british classic! I never saw one one the east coast only in Dallas and California in the 90's I think it was United or USair, PLEASE take plenty of video.
Latest blog entry: RC 737 Max 7 Maiden flight!
Sep 13, 2011, 10:28 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
You know, you are right. I'm going to make more of a concerted effort to get some decent HD video of the -146. I've flown it so much over the years, it wold be nice to have a little bit of it on HD video too. It's a fun airplane to fly for sure.

This second set of brushed motors that I'm on won't last many more seasons. (these went on the wing in 2006 to replace the originals from 2000). I've been trying to finalize my fan and motor choices for the re-motor. The 75mm fans are an odd ball size. I might have to cut down some of the new 80mm Eflite V32 rotors. Problem with those is they are set up for 5mm shafts. How many 400 amp motors have 5mm shafts? Not many I know of, most motors of that size and 4mm shafts. I will also have to cut into the wing a little to get at the wire harness. The original setup was for series connection on the can motors. Brushless ESC's will not do series wiring.
Sep 19, 2011, 11:47 AM
Up-Out-&-Gone
demondriver's Avatar
Eddie I thought you'd get a kick outta this. . . . . . I know I did!

Various BAe-146's In Action (2 min 12 sec)
Latest blog entry: RC 737 Max 7 Maiden flight!
Sep 19, 2011, 03:28 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
That was awesome. A rare time capsule look at both PSA and Air Cal after they were both bought by USAir and American, respectively. Around the same time Western was bought by Delta. All sorts of changes.

Just another time capsule memory from my own head. I used to love getting on jets as a kid at San Jose via the stairways where you walked outside on the ramp before getting on DC-10's, DC-8's, etc. Only then, did you get a good feeling how big those marvelous machines were, and you got to hear and smell the action without barriers for a moment. I have to admit I got a huge kick out of finally making it to a pilot job where I got to park out on the ramps at San Jose flying big Douglas and Boeing aircraft (at different times) at the same gates that I used to walk out to those jets in awe as a kid. Now it's all paved over and new terminals are built with jetways where the act of flying is attempted to be covered over with as much thick non-aviation varnish as possible. While some great opportunities still exist to see real aviation in airline operations, a lot of it, by design, has become something that doesn't resemble flying anymore for passengers, like it used to. Both in service and in raw aviation experience alike.

Thanks for posting the video, I like it.

Here's an "interesting" video with some good in flight footage. It's a bit, well, reminiscent of an old Soviet propaganda piece but a few of the in flight shots are very unique and nice to watch. Even though there is an annoying bit of splicing during the landing scene where a maintenance run demo is spliced in. This goes back and forth in the landing scene, to suggest that it is in flight footage in the cockpit. Well it's not but I appreciate the enthusiasm But it has some good parts to it among the goof ball parts toward the end.

Aerolineas Star Peru BAe 146-100 (2 min 17 sec)


And for detail guys... I'm not typically a big gamer of flight simmer, but those guys do their homework. Here is a sim video showing the gear, flap, and speed brake ops of the -146. Makes me really want to get the gear mod going but I'm not ready for that yet and

QualityWings Simulations: The Ultimate BAe146 / Avro RJ Collection (1 min 12 sec)
Last edited by Eddie P; Sep 24, 2011 at 01:45 PM.
Sep 27, 2011, 01:25 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
As a sneak peak, I'll let any airliner fans out there know what I'm working on, so far, in my next project. (By definition, if you are looking here, you must be at least a little into airliners?) I've only put in about 20 hours of work into it so far, in terms of sanding, cutting and building. But there has been a lot of design thought that probably counts a heck of a lot higher over the last many years.

I'm building a 1/16 scale Douglas DC-8-61. The model will be about 12 feet long (3600+mm) and have a wing span of about 9 plus feet (nearly 2800mm). I'm estimating an all up weight of approximately 30 pounds, or 13.5 Kilos. The model propulsion with be 4 EDF powerplants, 70mm sized at approximately 5 pounds of installed thrust each (20 pounds of thrust total) and approximately 6500watts total. Of course, it will be as scale as I can reasonably and reliably get it including all the basic controls you'd expect. Plus I'm adding a scale sound system to replicate engine startup, taxi, reverse thrust, touchdown sounds, and it will augment the takeoff and in flight sounds of the fans but the fans will surely dominate the in flight sounds, especially as the model approaches the observer.

The full size has the P&W TJ-3D engines, these are not the big fan jets of modern times, they are the smaller, low bypass turbojet fan engines of the early days just after the first generation pure jets were improved upon. The design and build challenge is to fit powerful enough fans in such a small inlet and nacelle to power the large aircraft. It is now finally possible to do well with the most recent motors, fans, controllers and batteries. I've been waiting for this opportunity, I always really wanted to make the "classic" small inlet engines work to build a jet that is as much a historical period piece as it is a technical accomplishment.

Trivia. The DC-8-61 was the first airliner to be called a "Jumbo Jet". It wasn't the 747, even though the 747 later inherited the nickname as an adopted brand name for the mammoth size and unique two story/level layout. The DC-8-61 was in fact longer than the later "Jumbo" size DC-10 wide body. The DC-8-61 was so large and heavy that the FAA decided to make a new classification for it as a "Heavy" jet for distance and time separation decisions for ATC and other aircraft to adhere to for safety due to wake turbulence.

The earlier, shorter DC-8 was the first airliner to break the sound barrier. During official flight testing the Douglas engineers took the aircraft to a planned Mach 1 plus at high altitude. The DC-8 was the first airliner to be built with a fully trimmable stabilizer, not just an elevator, so the supersonic shock wave that normally blanks out the flight controls was able to be overcome with a fully flyable geometry tail surface. That was over 51 years ago. http://www.dc-8jet.com/0-dc8-sst-flight.htm
Last edited by Eddie P; Nov 16, 2011 at 12:42 PM.
Nov 27, 2011, 07:10 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
UPDATE:

I'd like to thank "Union Models" here on RCG for providing me with the wiring diagram for this model. I build this one a long time ago and somehow got it in my head that the wiring buried in the wing was series-parallel for the motors. I've lost the plans and wiring diagram but UM sent me his via PDF file the other day.

It turns out, since I build the model per plans on the power, that this is a STRICTLY PARALLEL motor wiring system. This is great news. This means I will not have to do any wire surgery on the model, outside of the insignificant task of routing a small a channel in the wing to run the brushless speed controller wires from each nacelle to the wing root.

So - The Brushless Upgrade to this 12+ year old Robbe BAe-146 will go back on track this winter with some degree of haste. I'd like it flying again before March. Since it will take me a month to gather the new parts together and test what fan rotor I'll be using and settle on a motor with the proper KV for the fan and cell count, the minor task here is just getting it done when I have the parts settled on.

As far as why I thought it was series-parallel, it goes back to a few old magazine articles that quoted that. I suspect they were referring to "series" being the battery pack, and "parallel" being the motor wiring. I just call this type of motor wire harness a "parallel" harness since all the + leads on the motors/ESC go to a + lead on the battery and all the - leads on the motors/ESC go to a - lead on the battery.

Since I originally had the Mega 16/25/3 in mind I've traded my motors out for other things and now I'll start on a clean slate. I imagine I'd like to spin either the Kyosho fans or the 7 blade Kyosho rotor replacements fans HK sells or the 10 blade CS fan (even though it's 70mm I'll try it anyway) at any speed it takes to get appx. 300 watts. I suspect I might settle on a HET or similar motor at a sub 2000KV level for a 5s pack or possibly 4s if I can't make 5s work for the available KV.s

More to come soon.
Jan 23, 2012, 08:11 PM
Official Boat Bum
Eddie P's Avatar
Thread OP

Fan testing


For starters, I used a spare BAe-146 foam nacelle that made testing fairly accurate. With the exception of the CS-70 fan (where I used the inlet ring only), I used the nacelle to give decent "installed" testing conditions. I did not measure thrust. I'll measure thrutst once the motors are installed in the aircraft as a group, then I'll have an accurate measurement of total thrust.

For now I measured the conditions of my nearly 100 percent chosen motor, the HET 5W motor on 4 cells. It's got a KV of 1800 and it is good for 450 watts, though I plan on only having it run to 250-350 watts per motor.

*Kyosho 5 blade, 75mm Rotor, in Kyosho 75mm shroud installed in BAe-146 nacelle: 14.8Amps, 15.6Volts, 230 Watts per unit. Sound - Typical fan, sorta gravely and loud.

*CS-70, 10 blade 70mm rotor in Kyosho 75mm shroud, installed in BAe-146 nacelle: 18.5Amps, 15.2 Volts, 281 Watts per unit. Sound - more air noise, less fan shriek.

*CS-70, 10 blade 70mm rotor in CS70 Shroud with inlet ring only: 19.0Amps, 14.9Volts, 283 Watts per unit. Sound, very similar to 75mm housing, slightly less motor noise and more air noise. I suspect the improved stators in the CS housing and 2.5mm less blade gap per side account for more efficiency and better sound.

*HK 76mm, 7 blade fan cut down to 75mm in Kyosho 75mm housing, installed in BAe-146 nacelle: 20.3Amps, 14.8 Volts, 301 watts. Sound - Much more of a typical, EDF shriek for the fan sound. Lots of pull, but I think I'll pass on this rotor simply because I don;t believe I need the thrust and the sound is fairly harsh in the 4 stator housing I'll likely continue to use.

So far I believe the 75mm Kyosho fans would be an easy swap to use with the new brushless motors. I also believe the CS-70, 10 blade rotors might work as is for a quiet option even with a large blade gap. Though, I'm curious about thrust, which I will measure installed in all 4 nacelles. Another consideration is to carve 4 new nacelles for the CS-70 fan. The inlets will be smaller and more scale -this is good. And the sound will be an improvement. I may keep that "upgrade" for next season after I successfully fly the model on brushless power in the old nacelles, first.

I'm sold on the 5W HET motors on 4s. Now I have to settle on a decent set of speed controllers that can offer a programmable soft start and have smooth throttle response. I'm considering everything from Turnigy 30 amp ESC's to Castle Creation units. I believe 30 amps will be sufficient for some "head room" and also small and light enough to be a good choice.

My efficiency will go from appx. 50 percent on the old brushed motors to appx. 80 percent at least for the brushless upgrade. This means even for a 230 watt per motor setup, I'll have an 84 percent increase in thrust and with 300 watts per nacelle I'm looking at 240 percent increase in thrust.
Last edited by Eddie P; Feb 24, 2012 at 11:17 AM.
Feb 08, 2012, 06:01 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
I've got the extra HET 5W motors coming (1800kv). These will power the Kyosho rotors in the stock nacelles initially.

I'm using Turnigy 35amp ESC's and handling the voltage spikes in the lines by adding 470uf 35V capacitors, two in parallel at the inboard motor stations and 3 in parallel at the outboard motor stations. This is to account for the extra long wire runs in the wings. We are talking 30 inches of wire run in the outer pylons where 8 inches is considered long. Considering some advice on adding 220uf capacitirs for each 4 inches of extra wire run beyond 8" that means I'm slightly conservative in my capacitor use at these stations.

Near term plans are to fly the model stock again and have a friend document the sound and flight qualities with a good video camera. I'd like to get some sound files too. Also I'd like to take some sort of thrust reading. Then once that's done I'll plan a day or two of heavy work to do the motor, ESC, capacitor and rotor conversion. Then to fly the model and do the same with sound and video files.

I'll probably fly the model with the Kyosho fans for a season but in the next phase I'm going to work on 4 new nacelles custom fit for using 4X CS 70mm 10 blade fans. This will actually be a scale upgrade since the real BAe-146 engine inlets are smaller in relative size than the model. I'm also expecting a sound upgrade in that the 70mm fans are pretty nice sounding. I've tested them in a few different setups using nacelle ducting and I'm impressed with them in the 275 watt region.

Should have the motors and ESC's in a week or two, then the upgrades.
Mar 03, 2012, 02:43 PM
Official Boat Bum
Eddie P's Avatar
Thread OP
Looking at the cable runs in this wing, there will be a need to add capacitors as mentioned earlier.

Just in case anyone else is wondering about cable runs, here is what I've learned over the years. Basic + and - cables for most "quality" ESC's, from the battery to the ESC, should be about 8" or shorter. Obviously shorter is better as it saves weight! However, if you need to lengthen them, you can, but follow some guidance based on electrical engineering rules of thumb.

For every 4" extra in DC cable length, a capacitor of at least 220muf (micro servants) in capacity and voltage of appx. twice the planned pack voltage should be soldered in parallel just before the ESC. That means the + lead to the capacitor to the positive cable and the - lead of the capacitor to the negative cable.

The added capacitor(s) serves to absorb and smooth out voltage variations that occur in long wire leads. This is a layman's explanation, EE's out there please forgive my simple explanation this is for the "rest of us". Since the demands of the ESC vary, electrons from the battery will surge in the cables to fill the need. Over longer distances and wire resistance, voltage spikes are seen at the ESC unless we offer some sort of voltage reservoir to absorb the ebbs and flows from the battery and the wires. The reservoir is the capacitor. While the ESC has capacitors in the system to deal with this, the built in capacitors are designed for 8 inch cables. so if you up the cable run, help the ESC with additional capacitors. If you have 12" cables, solder an extra capacitor into the wire runs just ahead of the ESC. If you have 16 inch cables, put two capacitors in parallel (sitting right next to each other, plus to plus, minus to minus). Set them up so they are rigid and will not short out. I add some small amount of 1/64" ply strip between the bare cap leads so they won't be able to touch if deformed for some reason and then electrical tape the area up nicely.

When adding cable length don't just add one large cap to deal with the extra capacitance required. Two caps in parallel work better than one large cap if you want to compare working capacitance due to how electrons behave. I won't go into technicalities, and of course there is some variance here to this rule of thumb. But when making long motor leads and in doubt use more of the smaller capacitor variety rather than one huge capacitor. In one jet I have three caps in parallel due to where the motor and ESC are and where the batteries must be.

The three AC motor leads: If you lengthen the three motor wires too much you actually change the motor KV measurably and also interfere with the ability of the ESC to effectively communicate with the motor. So IMHO based on experience and according to my father who is an electrical engineer, if you have to lengthen a set of wires "significantly", it's actually better to lengthen the positive and negative wires with added capacitors than to lengthen the three AC motor wires. Again, this is my opinion.

Capacitors come in all shapes and sizes. For our needs, we should be using Low ESR capacitors when possible. You can buy these from these types of sources (don't just go to Radio Shack if you can help it, buy quality Low ESR capacitors). You'll see names like Rubycon, etc. as I believe many high end ESC's use these types.
http://www.capacitorlab.com/where-to...tors/index.htm
http://www.badcaps.net/pages.php?vid=22
Example, 4s systems:
http://www.thecapking.com/35zl220.html
http://www.badcaps.net/store/product...roducts_id=166

Lengthening plus and minus cable leads are fine if you use the above technique based on the mathematical rules of thumb. I've found it works great and frees you up to set your aircraft up soundly even in tricky situations where you can't always have your battery right next to the ESC. Multi-engine models are one of these places where it's not always possible to set up short cables.

As an aside, if you have high voltage systems and a lot of capacitors, you should also consider an anti-spark lead. I use anti spark leads for anything above 8s. As an experiment on this 4s system with long leads and 4 motors, I'll be using an anti spark system in this aircraft due to the long leads and extra capacitance. The anti-spark lead charges the caps slowly and reduces the spark to zero on hookup, not to mention treating the caps much more kindly (much of the wear and tear on otherwise un-abused electronics is on power up). https://www.rcgroups.com/forums/show....php?t=1229558
Video from Ron101:
(9 min 45 sec)
Last edited by Eddie P; Mar 10, 2012 at 03:37 PM.


Quick Reply
Message:
Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
micro electric semi-scale project? rodair Scratchbuilt Indoor and Micro Models 2 Apr 24, 2006 12:25 PM
Ben Howard's "IKE" 1/4 scale project Dave Grife Scale Kit/Scratch Built 184 May 26, 2003 08:13 PM
Any advice on components for small scale project? Patrick_sween Scratchbuilt Indoor and Micro Models 13 May 13, 2002 07:03 PM
Awesome Scale Project!! mt_100 Electric Plane Talk 1 Feb 06, 2002 04:00 AM
When should I attempt my first scale project? totalboss Scale Kit/Scratch Built 3 Nov 14, 2001 03:34 PM