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Author Topic: Building the Guillows B-25 (26.5" span, now 31") with RC and brushless motors.  (Read 5288 times)

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Offline GuyOReilly

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Love following your build of the B-25.
Great work!

Online Frank v B

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Thanks, Guy.

Building further:

Installing the motor. 

1) Check the alignment of the firewall o make sure it is at 90 degrees to the root rib.  I used a triangle with one side parallel to the root rib.  The 90 degree angle shows where zero thrust line is.  Photo 130
2) I measured one side with a red line on the on the piece of balsa wood. Then moving it to the other side showed there was waaayy too much (inward) side thrust.  Photo 131
3) sanded the angle to zero thrust.  Then added two layers of balsa to the back of the motor as a spacer to bring the prop out past the cowl.
4) put a pin in the firewall (photo 133) , mixed some 5 minute epoxy and pinned the motor in place.  Photo 134
5) Put the cowl in place and fine-tuned the centring of the motor.  Photo 135.

Letting it cure.

F.

« Last Edit: December 16, 2020, 09:50:54 PM by Frank v B »
"Never trade luck for skill"

Offline Andy Hoffer

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Elegant @Frank v B !  We just need photos of your accompanying facial expressions. 8)

Andy

Online Michael

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Nice work Frank.
Michael

Offline Andy Hoffer

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Thanks, Guy.

Building further:

Installing the motor. 

1) Check the alignment of the firewall o make sure it is at 90 degrees to the root rib.  I used a triangle with one side parallel to the root rib.  The 90 degree angle shows where zero thrust line is.  Photo 130
2) I measured one side with a red line on the on the piece of balsa wood. Then moving it to the other side showed there was waaayy too much (inward) side thrust.  Photo 131
3) sanded the angle to zero thrust.  Then added two layers of balsa to the back of the motor as a spacer to bring the prop out past the cowl.
4) put a pin in the firewall (photo 133) , mixed some 5 minute epoxy and pinned the motor in place.  Photo 134
5) Put the cowl in place and fine-tuned the centring of the motor.  Photo 135.

Letting it cure.

F.


Hey @Frank,

I love the perfectly focused Flyzone B-25 box, baseboard and floor tiles in photo 3134!!  ;D

Andy


Online Frank v B

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Finishing the port wing to see where everything should go.

Photo 136- Found two matching 6 Amp ESC's.  These are two cell ESCs.  They are light and they are new.
Photo 140- the top of the wing showing the aileron servo in place and the ESC connected.
Photo 141- The bottom of the wing showing the servo installation. The aileron servo arm will protrude from the bottom plastic belly thingy. The edges of the servo bearer balsa will become the fasteners for the plastic belly thingy.
Photo 142- out-of-focus photo bottom of the wing showing the servo/esc installation.


F.
« Last Edit: December 17, 2020, 10:14:03 PM by Frank v B »
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Offline Andy Hoffer

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As you can see, @Frank v B can focus when he puts his mind to it, and that usually occurs when the subject matter is of sufficient import, such as:

Photo 3136- If you squint really hard and use copious amounts of imagination you can indeed see two matching 6 Amp ESC's.  But I won't comment on that.
Photo 3140- Focus check acknowledged.  The little red scraps on the floor, the package of Norton sandpaper, the small sheet of sandpaper, the instruction booklet, the short lengths of black and red electrical cable, the ruler, and two of Frank's knot-tying practice ropes are indeed perfectly focused.
Photo 3141- Notice that Frank's hand is perfectly sharp and in focus.  As for the servo and motor... and the gratuitous use of inflammatory red pins .....  Never mind...  I don't want to bother Frank....
Photo 3142- The focus of Frank's thoughts are clearly evident in this one.  Once again the relative importance of the subject in Frank's intellectual hierarchy  are manifest in the distribution of focus in this insightful image.

Salvador Dali has nothing on this guy!   8)

Andy
 

Online Frank v B

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Back to work:

- The port wing is done... more or less.  The aileron is cut out and hinged, the aileron servo arm is cut through the nacelle, the landing gear mount is installed behind the firewall (3 layer), the nacelle mounts (screws) are done.  Photo 3146 shows the bottom of the wing with the nacelle in place.  Photo 3147 shows the bottom of the wing with the nacelle removed.
- put the wing on the fuse just to see its size. Photo 3144 and photo 3145

Notice I found a setting on the camera that makes the close-ups a lot more in-focus.  Now what will Andy bother me about?  Do you think he will notice?  Nah!  ;)

Next are the tail feathers.

F.

« Last Edit: December 18, 2020, 10:26:06 PM by Frank v B »
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Offline Andy Hoffer

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Back to work:

- The port wing is done... more or less.  The aileron is cut out and hinged, the aileron servo arm is cut through the nacelle, the landing gear mount is installed behind the firewall (3 layer), the nacelle mounts (screws) are done.  Photo 3146 shows the bottom of the wing with the nacelle in place.  Photo 3147 shows the bottom of the wing with the nacelle removed.
- put the wing on the fuse just to see its size. Photo 3144 and photo 3145

Notice I found a setting on the camera that makes the close-ups a lot more in-focus.  Now what will Andy bother me about?  Do you think he will notice?  Nah!  ;)

Next are the tail feathers.

F.

This must have been done by an impostor.  The real @Frank v B would never lower himself to such a high standard of close-up photography!

Andy

Online Frank v B

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Andy,

Admit it you are stunned that I can find both the fill-in flash setting and now the macro setting. 
Listening to you is getting some results...eventually.

Frank
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Offline Andy Hoffer

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 :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D

@Frank v B,

"Stunned" is an understatement, but "ecstatic" better describes my immediate reaction to your superb close-ups. (Peripheral observers will recognize this as positive reinforcement for @Frank v B's epiphany, and an expression of hope for its longevity!)

Andy 

 :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D

Online Frank v B

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Was just looking through my collection of covering and have decided on the following livery.

There had to be invasion stripes on it to get visibility for such a small and twitchy model. 
Googling "B-25 invasion stripes" brought up the following photo.

F.
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Online Frank v B

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Building the stab and elevators (Photo 148)  and one rudder (photo 149, needs 2).
The elevators have been joined with a wire and it has been glassed to the wood.

Note: I thought the tail feathers were overbuilt so I have used thinner wood.  Plenty strong.  That's why the wood does not match the drawing.  Also note that I leave all pieces long because it is easier to sand it to shape afterwards than to fiddle with a knife during construction.

Figured out the main landing gear.  Photos `150, 151

No photo but have installed the landing gear mount for the nose wheel.

F.
« Last Edit: December 19, 2020, 10:38:40 PM by Frank v B »
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Offline Andy Hoffer

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Photo #3148: Good focus on the x-acto knife and forceps at the very top edge of the photo!

Photos #3149 and #3151:  Oh good. I was waiting for a good opportunity to move on to the depth-of-field (a.k.a. depth-of-focus) lecture. I have been holding back until we got a good foundation! (Quoting @Frank v B from Reply #37: "Notice I found a setting on the camera that makes the close-ups a lot more in-focus.  Now what will Andy bother me about?  Do you think he will notice?  Nah!  ;) ")

Nice build Frank.  8)

Andy
« Last Edit: December 20, 2020, 02:24:31 AM by Andy Hoffer »

Online Michael

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Good work, Frank.

Well thought out.
Michael