bberan

My Feedback: (8)

My father John and I have embarked on building the AMR 402-B 22% kit. Our plans are to install the Wren 44 Turboprop engine. AMR has performed some preliminary sizing modeling and it appears the Wrenn 44 will fit quite well with very minor modification (You can see it the printout in top of box). The kit arrived a few weeks ago. Two boxes. One box contains a very nice 2-piece cowl and the second, larger box contains a very large amount of wood. There is quite a bit of laser cut wood, both balsa and plywood. I am currenlty working on the vertical stab. I will post to this forum as building progress dictates. We will hold off on Turboprop purchase until fuselage nears completion so as not to start the engine warranty too pre-maturely.

dragonbuilder

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Hi there.AMR? Where can I find this kit?

Revy

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Aircraft Modelers Research, awesome guys to deal with!

bberan

My Feedback: (8)

www.amr-rc.com They are located in Canada.

Bob

bberan

My Feedback: (8)

Vertical Stab and Rudder complete. Hinging will wait until fuselage fit is verified. Both the vertical stab and rudder turned out very strong. Have now started on horizontal stab and elevator. The kit includes a nice jig that holds all the ribs so that the sheeting can be applied in a simple fashion. The one photo on the stab shows my method of ensuring that the sheeting stayed pulled down firmly to the ribs while the glue dried. Weight at the rear of the sheeting and wide masking tape at the front eliminated the needs for pins which may not have held the sheeting as well near the front where the curviture is greatest. My father John is working on the fuselage and we will post some pictures of that as well. Hoping to purchase the Wrenn 44 Turbo-prop before years end as I suspect we will be ready to finalize installation design with the help of AMR. I have also been researching 3-bladed propellor size and availability for the engine/aircraft combination. Xoar looks to have the right selection of wood props (Recommended by Wren) in the range I am considering. The Wren manual indicates a 22-12 as a choice, but I would like to go to a lower pitch (10 or 8) as I suspect the Air Tractor will be a fairly slow flying airplane. Ground clearance will likely dictate whether I use a 23-10 or possible a 24-8 (Which seems kinda big to me). I am working with the USA Wren distributor on propeller selection.

bberan

My Feedback: (8)

I have been working on the horizontal stab/elevator. The stab and elevator are built on a jig and cut apart later. In the photos, I have yet to cut them apart. I made a few minor changes that are personal preference only. One of those changes involves the elevator horn attachement. I chose to use a slightly different Dubro product than supplied in the kit. The one I used has two pieces than can tilt relative to one another for installing a horn on an angled surface. The other change I made was to glue in the tubes for the aluminum spars prior to sheeting the bottom of the horizontal stab. Normally this step is performed much later as part of the fuselage contruction. I did this because I wanted to ensure the tube/rib joints actually got glue on them. Also, I thought it would be easier to ensure that both stabs matched one another (No twist between them) if the tubes were glued in while both stabs where lying on the same flat surface. I also took advantage of the jig interface cutouts in the ribs. I bought a 1/4" square piece of steel from a hardware store ($5.00) and placed it in the rib cutouts to help reinforce straightness while the expoy for the tubes was drying. I also installed an additional piece of hardwood that interfaces with the aft aluminum spar tube for the purpose of locking the aluminum spar with a screw. My dad is working on the fuselage, which has made progress, I just need to get some photos.

bberan

My Feedback: (8)

Here are some more photo's of completed stab/elevator. I did a few things a little different. I used a thin sheet of fiberglass for the servo cover instead of the supplied plywood piece. Nothing wrong with the plywood, just personnel preference. Also, for the elevator/stab gap filling strips, I used a piece of 1/16" basswood instead of the suggested 3/32" balsa. I was concerned the edge of the balsa might get beat up. Also, because I used basswood, I was able to sand a bevel in the aft edge for a thinner gap. I also beefed up the joint with some small triangular stock. I also drilled tiny holes directly above each hinge set screw so I can seperate the elevator from the stab if neccessary. I have also included a photo of the Wren 44 Turboprop. The propellor is Xoar 22 X 8, 3 bladed. I am keeping the pitch low as the Air Tractor is not a hot rod.

bberan

My Feedback: (8)

Work on th airplane continues. Here are a few photo's of the fuselage and wings. I am using two servos for rudder and tail wheel. I prefer this as it allows me to use mixing. I can have one servo behavior for the rudder and a different servo behavior fot the tailwheel. It is nice because the tailwheel will only move when the rudder moves based on a rudder stick input. The tailwheel will not move as a function of rudder/aileron mixing (Which is what I want). In addition, I can have the tailwheel movement stop altogether as a function of throttle. I usually set this feature to somewhere above half throttle so that for flying around, the tailwheel doesn't move at all. We have now run the Wren 44 Turbo prop several times. The engine runs very well and seems as though it will have plenty of power. I have located a place http://www.sacmidwest.com/index.php that makes scale instrument panels. I am having them make a scale panel from a photo I received from Air Tractor of the 402's instrument panel. Will post a photo when it arrives.

bberan

My Feedback: (8)

I have started to fit the turboprop engine. here are a few photos.

bberan

My Feedback: (8)

I received the new instrument panel for my Air Tractor. The instrument panel was made by http://www.sacmidwest.com/index.php. I had them work off of a photo I received from the Air Tractor company. It turned out pretty nice.

brenthampton79

Cool wish I could turn loose the money to build one with a turbine

Super08

My Feedback: (2)

Very nice!

DENTO

ADD TO THAT
REGARDS

c114

I just bought one of of these kits, should be here next week. I do believe I'm going to go the turbo prop road as well. Am really looking forward to how it flies, hope there is vidio.

Rolly

bberan

My Feedback: (8)

I will definitely provide video of model when complete and flying.

Bob

bberan

My Feedback: (8)

Here are a few photos of the wing tube installation. As you can see, alot of space is required. Fuselage was set at 0 degrees both foward and aft and side to side. The wings were installed and only minor adjustment was required to get the same dihedral on both wings. Wing incendence was also checked to make sure it was equal on both sides. The design appears to be set for 4 degrees positive incidence. Both wings were right at 4 degrees without any adjustment. The phenolic tubes were taked in placed and then everything removed for a thorough gluing. Wing sheeting will be next.

t6racer

Hi Bob
I have a wren turbo prop in a PC6 120 inch wingspan weight 28lbs 20x12 3 blade prop.
I have also this kit to build for the turbo prop, the porter is balistic on full throttle the skytractor should come in around 28 to 30 lbs I think. I fly the porter on below half throttle to half throttle it will will pull up at at 80 deg at full throttle & hit the moon if I don't get off the throttle, this motor is equal to a 100cc gas motor.
Great motor you will have a ball.

bberan

My Feedback: (8)

Here are some photos of preliminary engine and cowl installation. More trimming is needed around exhaust to avoid burning the fiberglass. There are two additional pieces being used in addition to the modified firewall. There is a 3/4" spacer and a 3/16" spacer. This gets me to the right distance for the spinner to cowl interface. AMR provided me the modified firewall and the 3/4" spacer. They also provided me with a template for the 3/16" spacer. This spacer will serve two purposes. 1) it's a spacer and 2) a bulkhead of sorts that I using to better isolate the hot section from the intake. You need to avoid hot air from getting back to the intake as it will raise the overall engine operating temperature.

bberan

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Here are some more photos. They all wouldn't fit in one post

bberan

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Here are a few photos of the inlet which is mounted to bottom of cowl. It is held on with 6 #2 sheet metal screws from the inside. Because of the turboprop, the inlet will be functional and provide a source of cool air to the engine, well away from the hot exhuast.

bberan

My Feedback: (8)

Here are a few more photos after the exhaust have been permently installed and the cutouts enlarged to proper clearance.

redbiscuits

My Feedback: (6)

Very Nice!

Avistarpilot

Wow! What an awesome project. I've got the chance to work on these things in real life and seeing a model of it, and how everything is exact to the real thing to the last detail is just awesome! Love the turbo prop exhaust ducts. You don't realize how big these things are until your up close and personal to them. The Air Tractor 802's are insane!

Can't wait to see the finished project. Hopefully the wings don't crack like the full scale birds do!

daveopam

My Feedback: (9)

Fantastic work! Wish I had your patience.


david

bberan

My Feedback: (8)

Starting the finishing process. It will take awhile. Horizontal stab/Elevator is complete. Laying out lines on fuselage with paper templates. Photo on computer screen is the scheme I am going for.