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View Full Version : Conversion of a 2M pattern/artistic aerobat


Mike Parsons
07-14-2006, 01:01 AM
Well, I am far enough along that I can post some progress. This is a 2M Artistic Aerobat from Extremeflightrc.com. Chris is not producing these as of yet but could in the future. He has many other projects going on for the RC community that this has been shelved.

I watched him fly his IC version at a funfly a couple of years ago and fell in love with it ever since. He had a second prototype and knew of my interest, so here we are.

Here is the motor and setup:
Hacker A60 18m
19X12 wide APC
Prototype Torque 90a ESC
4- JR 8411's (dual elevator and ailerons)
1- JR 8611 for the rudder (overkill)
6v UBEC


This plane is a 2M all built up model in usual EFRC quality. The wings have a CF wingtube and the elevators use an aluminum one. The usual hardware came with the kit (CF control horns, balllinks, titanium control rods etc).

Chris even provided an extended swept back gear for electric conversion! The gear holds up fine, but any bow in it and my 19" prop gets a bit too close for comfort. I have reinforced the gear with 1/8th steel rod just to be sure it doesnt bow out.

I have no idea what this power system will do on a 19X12 yet as I have not run it up. An A50 would have been plenty at 1500 watts I am sure, but I am looking closer to 1900-2000 watts if I want to try and compete with it.

Here are some photos:

Jeff Boyd 2
07-14-2006, 03:32 PM
WOW . . very nice Mike. Looks like a very light frame too. What is the flying weight?

Jeff

Mike Parsons
07-14-2006, 05:29 PM
Thanks Jeff. I am shooting for 10 lbs. I am going to weigh it tonight now that I have everything in it. I will post back with the weight. Fingers crossed.

Rugar
07-14-2006, 07:11 PM
That's nice Mike. How mush hassle is getting the packs in and out going to be? Does the Canopy/Hatch attach with screws, or can it be quickly removed?

Mike Parsons
07-15-2006, 03:42 AM
Thanks Gerald. The packs are actually quite easy to get in and out. They sit in the fuse and then merely slide up to the motor box. I use two velcro straps to hold them in place using the existing fuel tank floor.

The canopy is held on with ply tabs in the front (by design) and a spring loaded hatch latch on the rear (aftermarket). Quick and painless :)

Here are a few more photos as I have finished up.

Looks like I hit 11.5 pounds. Still plenty light for this size plane, but it is 1/2 pound too heavy for competition. I am going to fly it as is and look for ways to get some weight off of it later.

-Mike

Mike Parsons
07-17-2006, 05:22 PM
I was able to run it up last night. With the 19X12 APC wide, I am getting close to 2k watts. I could push it harder if I had room to swing a 20 or 21" prop. I am looking into getting some Bolly replacement gear to see if it will give me that ability. Hopefully I can test it this weekend!

Jeff Boyd 2
07-17-2006, 11:26 PM
Nice . . that should feel great in the air . . plenty of vertical.

PS. Bolly gear is manufactured about 10 minutes from my house. Les Bollinhagen (owner) is a founding member of my club . . He does REALLY nice work. I think it's all about passion ! ! ;-)

Mike Parsons
07-18-2006, 01:38 AM
Thanks Jeff. I am really happy with the setup so far.

Bolly gear is nice stuff. I have to measure for the new gear tonight, but as long as it gives me more clearance, I will be placing an order. It has to be the passion!! :)

Mike Parsons
07-20-2006, 09:38 PM
Yep...that ought to do it.

Milton
07-21-2006, 01:46 AM
[quote=Looks like I hit 11.5 pounds. Still plenty light for this size plane, but it is 1/2 pound too heavy for competition. I am going to fly it as is and look for ways to get some weight off of it later.

-Mike[/quote]

The sad part about the weight is that the glow planes are weighed with no fuel and electric's have to be weighed with fuel.

Mike Parsons
07-21-2006, 02:05 AM
I know. I wish they would change that. There is no advantage that I can think of for having that rule or keeping it.

Jeff Boyd 2
07-21-2006, 02:18 PM
LOVE your meter reading . . I'm saving up for a meter reading like that of my own ! ! ;) :D

Mike Parsons
07-25-2006, 12:31 AM
Well the maiden went off without a hitch. The first flight was trimming the plane out and tried a top loop with a 1 1/2 snap at the top. It was beautiful. Even on low rates the ailerons were a bit too much, so I landed and cut the low rates down to 35% and expo @ +50. Upon throttle up, the motor wouldnt spool up past 30%. At first we thought LVC was kicking in as I have it set to soft cut-off. We checked the battery voltage under a wattmeter and it was fine. We tweaked with what we could and decided not to risk the airframe. Wouldnt you know it though, I got home and the darn thing worked fine. I am going to check the software on the ESC tonight and update where necessary and plan for another outing this weekend.

First impression is that the CG is dead one (need more tests before I can confirm) and it fly's very true. RPM was 6800 at 2490 watts. It has insane vertical performance and the top end speed is quite nice. The motor is quiet in the air and all I could hear was the prop ripping for air. More updates to come!

Mike Parsons
08-14-2006, 04:17 PM
I got two very good flights yesterday. I had some heating issues from last weekend. For this reason, I opened up more cooling and created some baffles to direct air from the cowl that will land directly over the motor.

I am still concerned a bit by the heat as it was an 80 degree day yesterday and the motor was 125 F after a 6 minute flight. I wont know more until I can get a normal day (90-100 F) and see what the temps are. I have an inkling to try an AXI 5330 or Cylcon F3A up front.

Regardless, the plane fly's great and I am impressed (but not suprised) at how true it fly's.

-Mike

Electrick
08-29-2006, 01:54 AM
The sad part about the weight is that the glow planes are weighed with no fuel and electric's have to be weighed with fuel.

The battery pack is the fuel tank; it is not the fuel itself. The fuel (electrons) weighs nothing, since the pack weighs the same charged or discharged.

The pattern guys have already argued this one to death, and that's how it ended up in the rules.

Rick

Jeff Boyd 2
08-29-2006, 02:02 PM
I know. I wish they would change that. There is no advantage that I can think of for having that rule or keeping it.

Mike, what IS the actual rule regarding batteries and weighing ??

What if you actually put a fuel tank in it and just took it along for the ride??? . . could you actually get the model weighed with your empty fuel tank (like all the others) MINUS your batteries (the fuel)???? . . just thinking . .

Jeff

Mike Parsons
08-29-2006, 02:36 PM
Jeff,
That would be a sneaky loop hole wouldnt it :). I have the exact verbage around here somewhere. Ill see what I can find.

davidsons
09-08-2006, 01:18 PM
The battery pack is the fuel tank; it is not the fuel itself. The fuel (electrons) weighs nothing, since the pack weighs the same charged or discharged.

The pattern guys have already argued this one to death, and that's how it ended up in the rules.

Rick

Sounds like Electric Discrimination to me. I'm sure there is an attorney somewhere that would take this case. :rolleyes::D

Electrick
09-08-2006, 02:41 PM
While I don't necessarily like it, it makes perfect sense to me. The fuel guys shouldn't have to endure what would amount to a disadvantage because the electric guys chose heavier fuel tanks for their planes.

I would probably be in favor of some sort of compromise, but as things are, most of the veteran pattern guys who go electric have no real trouble making weight if they plan ahead--and things are only getting lighter/better with respect to LiPos.

With the current rules in place, it has already been demonstrated that electrics are absolutely competitive with glow, so I don't believe they need any added advantage that would be provided from allowing the airframe to be weighed minus batteries. That would only drive an argument to allow electric airframe size to become larger than 2mX2m, creating what could easily be argued as a disadvantage to the glow guys.

Rick

Jeff Boyd 2
09-09-2006, 01:56 AM
Hmmmmmmm? . .

While I currently fly Glo Pattern (with a CA Models Epsilon 120) . . I think the Electric guys are disadvantaged. The Glo guys get to weigh their models WITHOUT fuel, and then fuel their model finishing with a model that are mostly overweight when ready to fly. Sometimes significantly, I might add. While the Electric guys have to weigh their models complete with "fuel" to make the weight.

The disadvantage is in the choosing and building of the airframe, as many ARF's and Composite models will not make the weight if built as an Electric.

The advantage (and yes there is one) is that when you do build an electric to make the weight, it should be a nicer flying model than many (most?) equivalent Glo models at FLYING weight.

I don't think there would be much argument over the size of the airframe. 2 x 2 is the rules for the frame, and while many top class models were using the full 2 x 2 dimensions, the more recent models have reduced the size, particularly in the wingspan. I am not sure, but I have heard that this helps with the increase in integrated rolling maneuvers and snaps in the latest schedules . . while leaving the fuse closer to 2M keeps the smoothness with line changes. Again, I am not sure about this as I am not flying at the top level, or compared models.

I would love to build an electric F3A and turn up with a 'special' fuel tank, and weigh minus batteries, THEN fit the batteries into the 'fuel tank' when getting flight ready . . Wow, I'm a stirrer . . hahahaha