samparfitt

My Feedback: (43)

A suggestion was made to start a construction thread so here it is.
This is OUR thread so ALL may contribute to it.
(besides, I'm working on 5 planes at once so I'm spread pretty thin).
I'm copying the last few pictures I had on the other thread.

This is the first of two boxes:

First picture:
As it arrived in box one.

Second picture:
Everything out of the box.
The fuse is fiberglass.

Third picture:
Hard foam wheels.
In case you want to get replacements, they measure 2 7/8" and 3 3/4".
Usual hardware stuff. The control horns are colored: nice so they match the plane.
The tanks are 8 oz (maybe 10). No label so I'm guessing.

Fourth picture:
Cowls with an OS FX .91 next to it for comparison.
The head will be sticking out the bottom but not by too much.

samparfitt

My Feedback: (43)

First picture:
Retracts appear sturdy and no slop noticed.
Looks like 3/16" diameter.
Will have to buy struts unless they're in the other box.
I plan on putting at least a medium robart air tank in, or if not enough room, 2 or 3 small ones.

Second picture:
Six canopies.
Already painted.

Third picture:
Nose retract area.

Fourth picture:
Nose retract with cover removed.

samparfitt

My Feedback: (43)

first picture:
Where wing connects to the fuse.
No manual in this box.
Without the other box, that's it for now.

samparfitt

My Feedback: (43)

The second box arrived today:

First picture:
As is, with the cover off.

Second picture:
The horizontal stab is the first item out.
It is built up wood, fabric covered and painted so all parts match.

Third picture:
Left wing.
Built up wood with fiberglass nacelles.
The wings are partially sheeted so the ribs show through the fabric covering.
Don't know if the real had this but it wood seem that
the entire wing would have been aluminum covered.
This wasn't real noticable (at least in the basement) and it would save on weight.

samparfitt

My Feedback: (43)

First picture:
Bottom of nacelles.
You can see the faint outline of the piece of fiberglass that is removable.

Second picture:
With piece of fiberglass removed.
That white line is the guide for optional wire controls of all 4 flaps by one LARGE servo.
There is not much room in there for larger tanks.
I bought 16 oz sullivan's flexible tanks and I'm not sure if I'll be able to get them in there.
There's a servo mount on both sides which I'm assuming for upright or inverted engines.
I may be able to carve some ply away and have the tank shifted to one side.
I don't thing this will affect fuel flow.
I may have to go to 12 oz flexible tanks.
The manual says 15 lbs.
With the one servo, versus four, controlling the flaps and one also for the rudder,
this may be possible.
I didn't see any instructions for elevator servos but I only looked through the manual quickly.
With this light of a twin, and using OS FX .91'x, I will be able to fly at 1/2 to 3/4 throttle
and save a lot on fuel consumption.
All the parts are very light so she may come in at 15 lbs.

Third picture:
Vertical tail and rudders.
Built up wood and fabric.
The manual also shows optional wire control with one servo of the rudders.

Fourth picture:
Loose assembly of the plane.
83" wingspan.
Seems like it would have been easier and stronger to make the top removable for
putting the wing on (but time will tell) instead of having the bottom removable.
The plane would also stay upright that way when putting her together at the field.
Four bolts instead of 2 dowels and 2 bolts are used to hold the wing to the fuse.
The wing is two pieces that obviously stays together.
I was thinking that we would have two outer wings to attached so the business part
would all stay together (again, time will tell on the design).
Struts will be needed.
I'm probably going the way of the P-61: 1/2" on the mains and 7/16" on the nose.
VQ and I think Robart has these.
All hinges are CA type: I'm using Great Planes medium nylon pinned hinges (GPMQ3972).

She looks nice, even in the 'loose' assembly stage.

warks62

My Feedback: (140)

I too had thought that the outer panels would be removeable but guess I can't have everything. Picking mine up this weekend and am ready to start to build right away. Does it look like you could do bomb bay doors?

samparfitt

My Feedback: (43)

With the bottom removable instead of the top, it seems like bomb bay doors are going to
be difficult to do.

I take that back, looking at the size and the strength of the removable part,
you may be able to put a 'self contained' mechanism in there.

samparfitt

My Feedback: (43)

I read through the manual last night.
Picture 46 in the manual says elevator servo: this is really the rudder servo.
Picture 61 shows how the elevator is connected: the traditional way with the
servo in the middle of the fuse and a dowel and two rods coming off of it to connect to
the elevator on each side of the fuse.
The rudders are controlled by two mini servos out on the end of the horizontal stab,
or with one servo in the center moving two wires in guides that route to each rudder.
I'll probably go the one servo, wire guide route to save weight back there.
Page 17 of the manual shows these 'wire guide' alternatives to controlling the flaps and rudders.

samparfitt

My Feedback: (43)

Excellent data on 'heavenly body':
http://www.b25.net/


www.vqmodelaircraft.com has the struts that we need:
two 1/2" straight struts.
one 7/16" right offset (from pilot's view, want fork pointing back and offset to the right).
I'm going with the short offset: 2-2 7/8" wheel.
They also have the long offset: 3-5" wheel.
they also have machine guns: looks like at least 10 are needed.
(he has good prices on these struts and the guns are presently on sale).

mtrounds

My Feedback: (1)

I think the way you are going to go will work out better. I am going to install battery packs in place of the fuel tanks,as I am doing elect powered.

samparfitt

My Feedback: (43)

mtrounds,
please post on here your electric conversion.
Also, exact part names, numbers, pictures, prices, purchase location, etc so we can see what
is actually used since most of us have little knowledge on what to get for electrics
and also use for possible future projects.
Thanks,
Sam

mtrounds

My Feedback: (1)

Sam,

Iwill do so. I am new to electrics,also. The guys at Hobby Lobby have been a great help.

Thanks, Mike Rounds

TLH101

My Feedback: (90)

Dynamic Balsa: http://www.dbalsa.com/ has a 1/10 scale cockpit kit that is designed for the Wing MFG B-25. Might fit just right. They also some 1/10 machine guns.
Who has 1/10 pilots?

samparfitt

My Feedback: (43)

Fake radial engines.
Dare design ( www.darehobby.com ).
9 cylinder scale radial engine, diameter 3 1/2" ,part # 1028-12.
One per package but very 'cost effective'.

I noticed the rear gunner's canopy has paint on the back portion of it.
I believe this is suppose to be clear.
Mine has a light coating so I'm going to try auto polish to remove it.
If that doesn't work, it should be an easy fix to cut out the old and put a
new piece in since it is flat.

>>EDIT: You need a space on each end of a URL. wr.

mtrounds

My Feedback: (1)

So far I have 2 #JESA 700P-JETI 70-3p opto controlers. 2#PM4120-18 AXI rotor motors. 2 #PM41002 Radial mts w/prop adapter 8x1 mm. 2#PE13080E Master elect props 13x8.5". 4 TP420032 Lith Poly packs 3S2P4200mAh 2 for each motor.
As a test bed for this set up I built 84" T-REX. This is what was told to me by the tech guy at Hobby Lobby. I said it would be 8 to 10lbs. of airplane. He said fine. When I get some time, I will take some photos of each set up.
_________________________________

Mike

samparfitt

My Feedback: (43)

Mike,
Thanks for the pics and info on the e-motors.
That e-motor's size looks respectable.
What's expected flight time?
Do they say what the motor is equivalent to in gas?
Able to handle 8-10 lbs, it sounds like it's equivalent to about a .61.
Also, the cost of motor, controller and battery pack to give us a price comparison
to gas?
Thanks,
Sam

mtrounds

My Feedback: (1)

Sam,

AXI 4120-18 motors are $139.00 ea.
JETI 70-3P opto controters are $147.20 ea.
or Combo #PM412018C is $265.00 saving $21.20 ea.
3S2P4200 mAh packs are $139.00 ea. x 4packs. The batterys are killer cost of bigger electric.

But they can go in other aircraft. That is why I have a GSP Mosquito 73", T-rex 84", GSP Hellcat 70", Quality Fiberglass XC-47D on floats 95". Sportsman Aviation F4U that I rebuilt as a Goodyear F2G Corsair, GP DR-1 Triplane and GP AT-6. All set up for AXI 4120-18 motors.

On the other hand I have Q.F. AC-130 102" that is powered by 600 geared motors at $38.00 ea. One big 140 amp controler for $115.90 and about $50.00 for battery.

My VQ P-61 will need larger AXI 5330-24 motors, I think?

______________
Mike

mtrounds

My Feedback: (1)

AXI 4120-18 = Power of 4-stroke .90 With that size battery packs, twin 3S2P 4200mAh 11.1V.

Mike

mtrounds

My Feedback: (1)

Sam,

This is the DR-1 I rebuilt for the AXI 4120-18 setup.

_____________
Mike

dajensen

To All,
Sorry I don't have pics posted yet, I went to use my digital camera and found that it had been dropped so now I must replace it. As to the construction question, I have found no evidence of any hot glue, mostly epoxy with microballons and CA. I could not see any bad joints and all the covered structures seem to be sound and secure. (read as no voids or skins not glued to ribs etc.) the fuse, cowls and nacelles are all fiberglass construction and the level of detail that has been molded in is excellent. It will be a while before I start my build on this as I have 2 projects in front of it. I am presently debating with myself as to what to power it with. I was originally going to use a pair of OS Ultimate .70's because of their low profile but they will still stick out the side of the cowls by about 15-18 mm. So now I am asking myself about the RCV 91-S engines (the ones where the cylinder and prop shaft are 1 piece and with the 2:1 reduction) the advantage is a completely cowled engine spinning scale 16x10 3 blade props. My concern, as I have no experience with these engines, is cooling and reliability. The OS Ultimate .70s that I have purr like a well oiled sewing machine and don't even hesitate on transision to full power. Are there anythoughts on the RCV 91-S's out there? Oh BTW the B-25 had a double 7 cyl radial enginge not a double 9. Just an FYI if you want to know

samparfitt

My Feedback: (43)

Well, I was working on my TF GS P-51 but the B-25 kept calling me.
(not good when you start hearing your planes talking to you!).

Hinges:

First picture:
Tonight I installed the Great Planes pinned hinges gpmq3972.
I put triangular grooves on both surfaces so the pin area has a place to move freely.
I use an Xacto knife to cut it and the back side to widen the slot for the hinge to slide in.

Second picture:
While putting the hinges in, I noticed that the wing tips have 'washout'.
Should help prevent some tip stalls.
(not the best of pictures but it's way past my bedtime)

Third picture:
I use small scissors to cut the fabric covering away for the hatches.
I like leaving 1/4" around the edges so the wind doesn't lift it up.
This is the aileron.

Fourth picture:
I'm using one servo in the center of the wing to control all 4 flaps.
The guide tubes are in the wings but not wire.
I'm using Sullivan Gold-n-cable #515.
This wire fits the white guide tubing perfectly.
You could also pull out the white and use the tubing that comes in #515.
There are two sets of servo covers.
One set for using servos at each flap and rudder having the traditional elongated
holes for the servo arm
The other set has small square holes for the guide tubes (I'll be using these).
Note: there is much brevity in the instruction manual.
I'm interpreting things as I see it so if I make a mistake, let me know.

samparfitt

My Feedback: (43)

hinges (continued)

First picture:
All pinned hinges are in the wing.
It takes awhile to cut all those triangles and grooves.
I put oil on the pins before epoxying the hinges.
One side of the hinge first and after it dries, the other side.
After sliding the ailerons and flaps to the wing,
before it dries, I check to make sure the ailerons and flaps move
the distances I want them to. This insure our servos won't be overworked(like us!).
Keep lots of 2"X2" paper towels and alcohal (not that kind!) around to clean up excess epoxy on the plane
(and your fingers): Those finger marks will show up rear good on that mat finish.

Second picture:
The center wing section is cut out for the flap servo.
There's a small bag with a servo tray that I used (in picture).
I used my trusty razor saw.
The outline that is to be cut on the rib is already laser cut but not all the way through.
There's no outline for the sheeting.
I cut to within 1/4" to the next rib.

Third picture:
Here's the dry fit.
Top view.

Fourth picture:
Bottom view.
Looks like we'll be routing all out wires, air lines through this hole.

samparfitt

My Feedback: (43)

hinges (stab area)

First picture:
The horizontal stab.
I'm also going to use one servo and guide wires to control the rudders.
The stab is symmetrical but there is a bottom and top (bottom has servo hatches).
Again, I'll be using the hatches with the small rectangular holes.

Second picture:
Vertical fins and rudders.
Also left 1/8" covering for where the stab goes into the side of the vertical fins.
The vertical fins are multiple layers of balsa (rudders are built up).
All pinned hinges for all tail surfaces.

Third picture:
A better view of those triangular slots for the hinge pins.

Jeffpro

My Feedback: (1)

Thanks for the invite to join the thread. My KMP B-25 arrived yesterday and I'll be starting the build as soon as time permits.

The manual doesn't say much about what type of servos to use. (It does note that a couple of the servos should have "large torque".) Are you using hi-torque servos throughout, or do you think standard servos such as Futaba S3004s are adequate?

samparfitt

My Feedback: (43)

I'm using Hitec HS-475hb (76 oz at 6 volts).
(same as I used on the P-61).
I like them because they are very 'cost effective'!
I like using 6 volts: as far as I know, all servos have a higher torque rating at 6 volts.
I'm using HS-605BB super torque (94 oz at 6 volts) on the flaps.
Not sure if this one is still made.
I'll be using a mini on the retracts.
At about 1.5 oz per servo, that save 6 oz on using one servo on the flaps/rudders versus 4 on the flaps and 2 on the rudder.
I think that extra weight in the tail (using 2 servos) is important (much easier to make
a plane tail heavy than vise versa).

As with the P-61, the JR X8103 transmitter will be used.
Power is two OS FX .91 moving MAS 3-blade 14X7 props.
Over powered but easier to move the throttle forward from half throttle than when the
throttle is already at max for when you need more power!
No stats but I think the engine runs better, uses less fuel and lasts longer running her at 3/4 throttle than full bore.
Again, no stats, but it also may be easier on the glow plug
(good to not have a flame out on one engine on a twin).
New engines also seem to burn out a glow very quickly
so I like to replace them after breakin.
Maybe there's pieces of very small metal in there after the turning at the shop that contaminates the glow wire.
No facts on this stuff, just my limited observations.

I noticed that my decal set only has 1 'heavenly body'.
Let me know if yours are the same and I'll contact Andrew/Matt at KMP.
(must be the same manufacturer as the P-61!)