Building the Guillows B-25 (26.5" span, now 31") with RC and brushless motors.

Started by Frank v B, November 17, 2020, 10:56:08 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Frank v B

Adding aileron hinges- I cut a CA hinge into 4 small pieces and used it to hinge the starboard aileron.  The hinges will not be glued in until after the covering is finished.

trick: cut the 4 corners off the hinge to make it easier to install.  It doesn't catch the edges of the slots.  Photo 3176 shows the aileron hinges in place.  The extra hinge has one of the 4 corners trimmed.

Next problem- how to connect the servo to the rudders. 

Opted for a tiller arm inside the fin area (see photo 3180).  The tiller was made of 2 layers of 1/64 ply epoxied in place.
The photo is of the bottom of the stabilizer (photo 3181) and shows the pushrod clamped into position.  The pushrod was made of thin plastic tubing with very thin piano wire running inside it.
By using a tiller arm the pushrod only has to make one 90 degree bend.  A normal horn would require two bends and all the slop that comes with it.

Frank
"Never trade luck for skill"

Frank v B

Installed the rudder (top) and elevator (bottom) servos.

F.
"Never trade luck for skill"

Andy Hoffer

Quote from: Frank v B on December 26, 2020, 09:40:41 PM
Installed the rudder (top) and elevator (bottom) servos.

F.

Hi @Frank v B

So glad to hear that you're putting the rudder on top and the elevator on the bottom!  This is inspirational!  :D

Andy

Frank v B

I hate electronics!!

Decided to test the electronics and motors before trying to figure out how to attach the wings.

Bad luck.  How bad was it you ask??
- one ESC I had attached did not spin the motor.  One of the leads had broken off.  It was 2S limit anyways
- found a twin ESC (3S) set-up and connected it.  One motor did fine.  The second one would not spin.  Switched things around.  Conclusion: one of the ESC's was toast.  Clipped the wires and chucked it.
- found two matching 9 Amp Castle Creations ESCs (3S).  They worked fine after soldering on new (smaller) bullet connectors.
- tried to bind a Spectrum AR 6115 and it would not bind, tried an Orange receiver and it would not bind.  Finally tried a new Spectrum RX and it bound immediately.  It's a keeper.

Once all the plugs are connected and everything tests out, I will try to assemble the wings.  Will not glue them in place until after covering them.

Frank

Photo shows the 3 RX.  The top right one worked.  Both 9 amp Castle Creations ESC's worked fine.
"Never trade luck for skill"

Andy Hoffer

Quote from: Frank v B on December 27, 2020, 05:12:53 PM
I hate electronics!!

Decided to test the electronics and motors before trying to figure out how to attach the wings.

Bad luck.  How bad was it you ask??
- one ESC I had attached did not spin the motor.  One of the leads had broken off.  It was 2S limit anyways
- found a twin ESC (3S) set-up and connected it.  One motor did fine.  The second one would not spin.  Switched things around.  Conclusion: one of the ESC's was toast.  Clipped the wires and chucked it.
- found two matching 9 Amp Castle Creations ESCs (3S).  They worked fine after soldering on new (smaller) bullet connectors.
- tried to bind a Spectrum AR 6115 and it would not bind, tried an Orange receiver and it would not bind.  Finally tried a new Spectrum RX and it bound immediately.  It's a keeper.

Once all the plugs are connected and everything tests out, I will try to assemble the wings.  Will not glue them in place until after covering them.

Frank

Photo shows the 3 RX.  The top right one worked.  Both 9 amp Castle Creations ESC's worked fine.

I LOVE electronics! I guess that's why @frank and I get along so well!!! ;D

(Wondering if the binding issues could be a DSM2 vs DSMX compatibility issue for your particular TX/RX combinations. I'm sure one our sages like @bfeist , @Oscar , @pmackenzie , @electroflyer , @Gil.E or @deltawing  could offer more polite insights into your e-troubles than I could possibly publish in a public forum!!)  8)

Glad you sorted it out before your maiden flight !   :D

Andy

Frank v B

All the electronics work now.  Motors are spinning.  The servos are working.

Attaching the wing. Figured out a simple way to handle the wing attachment and spar re-enforcement, dihedral setting etc.

- Held one wing in place and drilled across all the ribs with a 10" drill bit. (photo 3188)
- Cut out the slots around these holes to allow the flat carbon spar to slip through all the ribs in the first wing half.
- Cut two slots in the fuse- one on each side. (Photo 3189)
- glued the spar into one wing half with 5 minute epoxy. (Photo 3192)
- do the other wing half the same way.

I will cover the wings first but leave the bottom of the second wing half open.  Once the second wing is covered on the top, I will glue the wing half in place with the access through the bottom.  Then cover the bottom.

Frank
"Never trade luck for skill"

Andy Hoffer

Quote from: Frank v B on December 27, 2020, 10:45:20 PM
All the electronics work now.  Motors are spinning.  The servos are working.

Attaching the wing. Figured out a simple way to handle the wing attachment and spar re-enforcement, dihedral setting etc.

- Held one wing in place and drilled across all the ribs with a 10" drill bit. (photo 3188)
- Cut out the slots around these holes to allow the flat carbon spar to slip through all the ribs in the first wing half.
- Cut two slots in the fuse- one on each side. (Photo 3189)
- glued the spar into one wing half with 5 minute epoxy. (Photo 3192)
- do the other wing half the same way.

I will cover the wings first but leave the bottom of the second wing half open.  Once the second wing is covered on the top, I will glue the wing half in place with the access through the bottom.  Then cover the bottom.

Frank

Hey @frank,

Are you referring to the plane or yourself?!  ;D

Andy

(P.S. Elegant solution.)

Frank v B

Finished the wing attachment.

Added a wood dowel to the back end of the wing to lock it in place.  Used the same long drill bit and drilled through the fuselage and two ribs.
It does not have to be glued in now because both ribs are accessible through the plastic cowling to glue the dowel in place permanently.

The photo of the fuselage side shows the slot near the leading edge for the carbon spar and the wood dowel hole near the trailing edge.

F.
"Never trade luck for skill"

Frank v B

Spent two hours getting ready for the covering process:

- went over every joint to make sure they were properly glued.  Found four without glue.
- removed excess glue with an X-acto knife.
- went over every part with sandpaper
- properly formed the taper in the leading edges of the two wing halves....then blunted them outboard of the nacelles to avoid stalls.
- sanded the stabilizer to lighten it.
- added a balsa floor behind the nose gear for the flight battery.
- opened up all the insides of the 3 fuselage formers near the servos and battery area.
- added some balsa webbing in the tail section for the elevator pushrod.
- removed any excess balsa around the servos, tail section.

Ready for covering after dinner.

Frank
"Never trade luck for skill"

Andy Hoffer

Hey @Frank v B

Couldn't you just snack or something while you're working and just keep going?  I've been waiting ALL afternoon for you to get to the "cover photos" !!  The anticipation is brutal!  ;D

(Any photos of the glue bits and sawdust from your final prep work?!)

Attentively yours,

First Officer Hoffer

Frank v B

Started the covering.  Starboard wing done.

Note- the aileron is not covered until the wing is finished so I can locate the hinge points on the wing.  Once found and the covering is sliced, I then transfer the hinges and cover the aileron.

F.
"Never trade luck for skill"

Michael

Michael

Andy Hoffer

Quote from: Frank v B on December 28, 2020, 10:35:08 PM
Started the covering.  Starboard wing done.

Note- the aileron is not covered until the wing is finished so I can locate the hinge points on the wing.  Once found and the covering is sliced, I then transfer the hinges and cover the aileron.

F.

@Frank v B your creative use of flare is exemplary.  It actually looks like one of the theatrical masks of tragedy and comedy.  Your choice!  8)

Bravo!!

Andy   

Frank v B

Just about finished covering the separate elements.  Some detail work to go before final assembly.

The one wing is not covered on the top outboard of the nacelle because the two spars have to be glued together.  Once assembled, the wing can be covered.

Frank


BTW: This covering job is more time consuming than a .40 size airplane!!  Tedious as hell.
"Never trade luck for skill"

GuyOReilly