Greg Covey

Hi,

I started building up my Pigi 3D from Hobby Lobby. It is a very rugged all EPP foam plane that looks like it will be a great 3D trainer.

Instead of using the PJS 1000 motor (which is often out of stock), I decided to try something different.

I am using my Mega 16/15/7 direct drive brushless motor with a 10x4.7 SF prop. The motors draws about 16amps which is much less than the PJS 1000 motor. My 3s3p Kokam 340SCD pack from Bishop Power Products weighs only 3.4oz which means my Pigi 3D plane will be about 1/2 pound (8oz) lighter than stock!

Greg Covey

Here is a close-up of my motor installation. I used the [link=http://www.hobby-lobby.com/motormt.htm](MCD400S)[/link] square laser cut mounts for Speed 400 motors from Hobby Lobby.

Greg Covey

The tail section looks very robust and my HS-55 servos fit perfectly for the supplied control rods and quick links. No bending or cutting was needed.

The supplied control horns make a solid connection to the foam surface when epoxied in place since they come with both a top and bottom cap.

My only modification here will be to add some tiny carbon rods between the horizontal and vertical stabilizers. This will keep them from warping under stress.

Greg Covey

One key area to my drastic weight reduction over the stock Pigi 3D is an amazing pack from Bishop Power Products.

It is a 3s3p Kokam 340SHC cell pack that has the equivalent voltage of a 10-cell NiCd pack and a 1020mAh capacity. The amazing part is that at only 3.4oz, it can deliver 18amps continuous and up to 30amps short burst peak!

The lower current draw of my Mega 16/15/7 will allow me to easily supply the 16-18amps needed for full throttle.

Matt Kirsch

My Feedback: (21)

Dangit Greg, I just finished my T3D!

Greg Covey

Don't worry, Matt. These planes are so different that you'll still want both...or is that the problem?

The T3D is great for no wind backyard practice flying. The Pigi 3D is much bigger, more powerful, and therefor requires a larger field. I'm curious to see how much power my Mega 16/15/7 provides it considering the weight drop from stock.

The landing gear design looks great! It is solid and well thought out. All the parts fit perfectly.

Greg Covey

The wheels were held by the supplied plastic tubing cut into 4 pieces. I then applied a drop of CA to the outside of each piece.

Greg Covey

With a little thought, the stock tailwheel can be made steerable by the rudder. This greatly improves ground tracking and allows you to taxi back to the pits.

Greg Covey

The tail definitely needs some bracing to maintain more stabile flight maneuvers. I like to glue carbon rods between the stabilizers because it is easy, light, and provides great support.

Greg Covey

Here is a close-up shot of my ESC and battery mounting scheme.

The lighter 3.4oz, 3s3p Kokam 340SHC Lithium pack needs to be up under the nose. I made a level cut-out and used Velcro to attach the pack.

Greg Covey

My finished Pigi was ready to test fly at 22.9oz. My empty plane weighed 19.5oz and my LiPo pack weighed 3.4oz with connector and wire. The APC 10x4.7 SF prop drew about 16-18amps at full throttle on my 3s LiPo pack.

Notice the antenna wire runs through a small plastic tube on top of the vertical stabilizer. A toothpick tip wedge secures the wire inside the tube.

Greg Covey

My friend and I flew the Pigi 3D today at lunchtime in 15mph winds. I wasn't sure how it would handle but my thrust tests gave me confidence that I could get out of a jam...if needed.

The Pigi flew great! Obvoiusly, the high winds had an impact on the thick, draggy airfoil, but, to our surprise, the plane was incredibly stabile!

We could hover, roll, loop, sorta-snap, and harrier to a landing. The wind made it easy to turn the Pigi 3D into a kite. It would just sit in the air like being on a shelf.

I can't wait to fly it in better conditions and I will likely move my CG back a bit knowing that it is a very stabile flyer. The aft CG will help in hovering and snap rolling.

I also used a 3-cell Kokam 1500HD pack for my second flight. It worked very well since full power was rarely used and it was taxing the cells a bit.

Perhaps an additional 4oz pack would still fly well and give me a 3000mAh duration. I plan to test it out soon.

houfek

Greg......
What kind of flight times are you getting on the 3S3P 340's ??
If I did the math correctly at 16A you are looking at just over 3 minutes at WOT ??
Thanks....

Jim

Greg Covey

Hi Jim,

Since it hovers at about 1/2 throttle, most of the flight was using partial throttle so we got about 6-8 minutes.

It was just too windy to get a real good feel for it. I'll report again after some more flight time.

Regards.

Greg Covey

I had several more flights on my Pigi 3D in much better conditions and I am indeed happy with the power system. It has enough power to hover at 1/2 to 2/3 throttle and the lighter weight (23oz) simply makes everything slow and easy.

This foamie will be a great 3D trainer that I can fly during the Winter months as well.

rmh

When I compared the 1000pjs with the mega 16/15/7 - --ON PAPER--- the comparison -by Hobby Lobby - looked to be quite lopsided.
The recommended prop size for the Mega was quite small - w/o gearbox.
I talked with the folks at Castle Creations and they felt the PJS -tho fine motors -were pretty amp hungry - as compared against the designs such as Mega -- Mayb I mis read em
anyway-- I am interested in finding out how the best outrunner designs compare with the best conventional motors --on a given amount of watts.
Obviously - the new LiPos really skew the early ideas of what combos make for the best power to weight .
This comparison would be when running at recommended input-not a peak delivery.
when I say "best combos" -I mean best power to weight .
That would be anyoutrunner or "inne" motor types motor -geared or not.

Greg Covey

Dick,

Your comparisons are valid. Often it is a personal choice as to what priority these variables fall.

The best outrunners I have seen are the Plettenberg motors with Mega right behind them. The others have less efficiency, more current draw, but a lower price.

I knew that I would be drawing less current on my Mega setup and could therefore drop almost 1/2 pound in battery weight...a significant savings. Less weight means less power needed for flying. The 3-cell, Kokam 1500HD pack works great on my setup too.

It also helped that I already had a Mega 16/15/7 to use on my Pigi 3D.

One final note, the Pigi flies so slow that the extra weight of the stock Hobby Lobby setup works just fine. Overall, this is a great unique EPP design. I guess that's why I had to have one.

Greg Covey

I wanted longer flights on my Pigi 3D and it was an easy upgrade to simply parallel two of my 3-cell Kokam 1500HD packs. I used a portion of one of the Kokam Parallel Connector Modules to plug the two packs together.

My second Kokam pack resides right on the CG line and doubles my flight time by only adding 4oz.

UCDme3D

If anybody's interested in a Pigi 3D with lipo packs i posted mine in the marketplace...

Billy Hell

My Feedback: (2)

What are your flight times?

Greg Covey

I'm getting around 10 minutes depending upon the flying. It is fun to hover practice because the plane does everything so slow and the control surfaces are responsive.

I don't have any pull-out power so although the plane performs well, it probably needs more power for good 3D moves.

madflyer

I am going to buy a Pigi (tips for building are welcome...), but I want to use an other motor than PJS 1000 , because I want to fly with a NiMh 8 cells pack , with a max current of 15-20Amps. What motor can i use , with what prop ? (and I would like to do torque-roll...)

Thanks

lynnpreston

I'm about to try a PJS800E on a Pigi. I'm doing some calculations now with various NiMH and Li-poly setups. I have a few 1800 NiMH packs that I'm going to give a shot. Weight reduction is going to be the key, though. The PJS800E generates 28.5 oz of thrust with an 11 x 4.7 prop at 17.7 amps static. Based on what Greg said his empty plane weighed, that would put the AUW at 30 oz (based on my 1800 pack). That's almost, but not quite good enough. Greg, do you have any recommendations for shaving off a couple of ounces?

Looks like the best option is to run a 3s2p pack of Kokam 1500's with a 10 x 4.7 prop. That's an expensive pack, though ($90). Ouch. A couple of people have recommended a 2s2p 1500 packs, but according to my calculations, that simply does not create enough thrust with the PJS 800.

Thoughts anyone?

madflyer

And what do you think of a mega motor , that draws less , with a smaller pack??

lynnpreston

I've got a 16/15/3 direct drive that I run in my Zagi. It's a monster, but it pulls around 30 amps with the recommended prop on 8 cells.

With a 3:1 gearbox and a 11x4.7 prop on 8 cells, it pulls around 21 Amps and genrates about 33 oz. thrust. The PJS 1000 genrates about 35 oz of thrust and pulls around 25 amps - so you're talking about a very small difference. But, if 20 amps is your ceiling, then the Mega is probably the best choice.

I also have a PJS 800E, which I have been very happy with. IMO, you can't go wrong with either a Mega or a PJS motor.