Frank's Rainbow 2000 (.45-.55 size) build

[Frank v B]

John's Hobbies asked me to assemble a plane for a customer.  This post will cover all the assembly steps and the reinforcing details.  This plane is for .46-.55 size motors but the Customer wants an E-Flite .60. Remember the advice: "Always overpower an airplane.  You can always throttle back.... if you have to". There will probably be a fair amount of reinforcing around the motor box and the wing mount.

Details:
- Rainbow 2000 1/5 scale ARF by PhoenixModel.  It looks a bit like a mid-air fusion of a Taylorcraft and a Sig Cadet Senior.
http://phoenixmodel.com/Product.aspx?ProductId=595
- 78" span, 61" length
- 4 channel set-up with individual aileron servos
- 8 lbs
- E-flite .60 on 8S 3200 16 x 8 APC E prop
- ESC- not chosen yet.

Gentlemen, start your insults. 
When I retrieve (find) my camera in my car I will charge the batteries first and post a photo.  That will start Andy's critique of my (non-existent) photography skills.  It will start Bruce's helpful posts like "The rudder goes on the back end Frank", and the normal abuse from the Morning Crew.

Looking forward to it.  If this is "work", give me more!!!


Frank

[Frank v B]

Gentlemen, start your insults!

Opening the box:
All the parts wrapped in plastic, small parts bagged, cowl wrapped in protective foam.
Photo 33- the outside of the box
Photo 34- the inside of the box
Photo 35- the fuse, wing tubes and small parts bag.
Photo 36- transparent covering shows the part numbers.  I checked the wings, the balsa under the covering does not say "Left wing, stupid!"
Photo 37- This weird device was found in the box.  Looks like some alien pill bottle.  Will have to research its purpose.

Frank

ps: Andy, sorry about the glare in photos 34 and 35.   PhotoShop does not live here.

[Frank v B]

Started with the fuselage, opposite to the instructions.  A fuselage is easier to tinker with when there is nothing attached to it.  While working on the nose, the plastic bag surrounding the fuse was left in place.

Attached the plywood E-motor mount on the stand-offs per the instructions.  When I saw the motor was larger, I added washers on the bottom of the stand-offs where they touched the plywood firewall.  This was done just to spread the load over a greater area.  See photo 38

Problem: remember the .60 size motor I outlined in the first post.  It was a Power 90!!!  Holy crap!

Step 1- the X-mount was larger than the width of the firewall.  Found a smaller 46-60 E-Flite X-mount kit.  This created a new problem.  The mount holes were too close to the motor housing so they had to be elongated.  See photo 42.  On the right is the mount that came with the motor, on the left is the new smaller one with elongated mount holes.

Step 2- remove the T nuts from the motor mount so new holes can be drilled.  Removing the T-nuts was easy.  Insert the 4 screws into the T-nuts (see before photo 39) and one light tap of a hammer and they came out cleanly (see photo 41).  Photo 43 shows the 4 T-Nuts dropped down.

Step 3 is tomorrow.  Drilling the new holes for the new T-nuts.

[Frank v B]

Now to fit the motor to the firewall.  problems:
1) the smaller "X"mount needed to have the holes elongated.
2) one of the screws to hold the firewall in place was always in the way.
3) Some of the hold down screws were getting close to the edge of the plywood

Solution-
- used one of the firewall bolts as one of the four bolts to hold down the motor.  This bolt had to have the head tapered so it would clear the stationary part of the motor. The head of the bolt was tapered by holding it to the grinder. Photos 1747, 1748 and 1749
- removed all of the T nuts and sanded the back of the plywood motor mount.  photo 1750
- glued the motor mount to a larger piece of plywood so the part holding the T-nuts was larger.  Used 5 minute epoxy and glued and clamped it.  Will let it cure overnight and then pass it through the band saw.  Photo 1751

Note: I plan to attach the motor "as is" to the front of the plane.  Because the motor is larger (longer) and the plywood is thicker, the motor will probably be too far forward.  When the cowl is first slipped on, the metal stand-offs (posts) will be cut by the correct amount to put the prop in the correct place.  No need to worry about it now.

Frank

[piker]

I was wondering about 6 cells on an E-Flite 60.  Then I saw the "90" comment.  Um.  Ya.  That's a lot of power for that plane.  Better reinforce the wings along with the nose... and maybe the tail surfaces too   

[Frank v B]

Piker,
I will definitely be looking at the strength of the tail feathers.  My advice would be to not prop for full power but economical power (lower pitch prop).  The nice thing about the 90 is that it is heavier. The .90 weighs 15.8 oz, 2.4 oz heavier than the .60.  Cabin planes tend to be tail heavy.  Also, it is much safer to fly with the CG further forward.

Finishing the firewall.
- Cut the new firewall on the band saw.  Photo 52 shows the firewall from the front with the old .46-.55 holes.  You can see the new firewall piece sticking out all 4 sides at the back.
- Photo 53 shows the back of the firewall with the firewall mounting holes (plain holes) and the motor mount holes with the 3 T nuts in place.  The bottom hole with the arrow is the firewall mount screw that is doing double duty as a motor mount screw as well.

Didn't get a chance to do much more because tonight was training night.  My instructor Bruce said I did well.

Frank

[Frank v B]

Got back at it tonight and installed the motor.  Everything fits now and can be tightened.  The aluminum stand-offs will probably have to be trimmed but I will wait to do that at the cowl stage.

There was a lot of fiddling because the motor mount screws just cleared the Xmount.  In two places I had to reduce the size of the washers so they would not interfere..... but it is now done.  In the photos you can clearly see the firewall in now almost twice as thick.

Installed the aileron hinges in the starboard wing.

The detail work (covering, glue joints, etc.) on this plane is superb.

Frank

[bweaver]

I  hope that 5 minute epoxy set before you moved on...  Took two nights this time?  Sleep tight Frank. 

[Frank v B]

Bruce:

re: your "Took two nights this time?" 

Yep.  576 "5 minutes" later.  That's what happens when you don't push the start button on your 5 minute timer.

Frank

[bweaver]

Frank:

re: That's what happens when you don't push the start button on your 5 minute timer.

Or in your case, you likely did set it. The alarm did go off. You hit the snooze button, only to wake up two days later to find you are in the land of Lilliput, where washing machine motors are installed on the front of electric model airplanes...   

Great instructions by the way on how to mount such motors.

[Frank v B]

Bruce,

re: "Great instructions by the way on how to mount such motors."

Do you realize that was a compliment??  Are you feeling OK?  Sunburn ?  Windburn? Alzheimers?  Just plain old age?

Today's progress:

Servo rails- I always hate the servo rails in ARF's.  They are usually lite ply, they split and are generally light.  Installed plywood doublers underneath where the servo screws were to go.  Cut two pieces of plywood (photo 1757) and drilled servo holes in the original servo rails.  Applied glue (5-minute) to the plywood doublers and used the servo screws as clamps (photo  1758).

Landing gear- this kit comes with two sets of wheels.  Smaller wheels for use with wheel pants and larger wheels for grass flying.  Made the smaller wheels because this way they can be switched back and forth.  The wheel pants were fiddly and needed to be drilled and fitted. Photos 1761 and 1762.

Hinged the second wing half as well.  Both wings are now done.

Frank

[Frank v B]

No photos today because I am prepping to go for my first casual flying session of the year tomorrow morning. Gotta get there early before the leaf blowers arrive.  Re-scheduled Jets Day.

Done today:
Increased battery space- the owner wanted more room for bigger batteries.  The pilot (full body) was in the way.  Could not break it from the seat and could not break the seat from the bottom of the fuse without splintering some wood.  The plane now has a paraplegic pilot.  Broke the legs off at the hip.  This pilot was made in pieces. More leg room for the battery.

Reinforce the firewall- applied 20 minute epoxy (don't wake up Bruce!) with a brush to the area where the firewall meets the fuselage sides.  Applied a piece of fibreglass (2-3 oz weight) cloth to the epoxy and then brushed on some more epoxy to work out air bubbles.  Applied pieces of waxed paper on top so I could squeeze the air out of the cloth.  The waxed paper forces all the fibres flat while the epoxy cures.  Tomorrow I will remove the waxed paper and will not have to sand it smooth.

Frank

[bweaver]

Frank, re - "...applied 20 minute epoxy (don't wake up Bruce!) with a brush to the area where the firewall meets the fuselage sides."

You did wake me up!  I new you would be mixing epoxy again.  Except now you are using 20 minute epoxy to justify the extended curing time? Or was that it that it would take you 15 minutes to get the bubbles out of cloth and waxed paper before the epoxy naturally cures and you can't do no more?   

Now I think I'm understanding your approach to the use of epoxy and allowing for the unnecessary cure rate time.  First you mix and apply the epoxy.  You take time now with 20 minute epoxy to spread it evenly, get the air out of the glass cloth and from under the waxed paper. Then you go to bed assuming everything is hunky-dory (get a good nights sleep for fear that if you made a mistake and found it earlier...), so that you can be excited when you peel back the waxed paper hoping that it is so smooth, you don't have to sand it. 

I might try that sometime, but I don't think I have the patience. 

[Frank v B]

Just to tick Bruce off.... just finished some more fibreglassing with 20 minute epoxy.  He is going to be soooo confused.

- finished fibreglassing the firewall. Applied pieces of fibreglass with 20 minute epoxy and covered them with waxed paper.  The entire firewall is now glassed from the upper part of the fuse side all the way around the bottom and up the other side.

- Glassed the landing gear mount.  Removed the pilot's legs and half the battery tray to get at the landing gear mount.  ARFs with a small plywood plate always have the mounts knocked off in harder than normal landings.  The landing gear becomes a lever and pries the mounting plate loose.  To avoid this, I put fibreglass at the back and the front of the plate to triple the length of the plate.  This spreads the land over a much larger area.  Oh, yes, covered it with waxed paper.

Let it dry overnight.  Or as Bruce would understand, 68 mixes of 20 minute epoxy (23 hours) until I get home tomorrow.

Frank

[Frank v B]

Here are the photos:

- gone are the pilot's legs.  More room for the batteries.  Photo 82

- the nose as viewed from the open hatch.  The right half of the photo behind the firewall is fully glassed.  The left half of the hatch is the glass reinforcement for the landing gear block.  Below the plane is the balsa battery tray.  I cut this half away to access the the landing gear blocks.  The pilot would not budge so I had to leave him in place.  Photo 81

- the cockpit showing the extra room now that the legs are gone.  The main former in front of the pilot has glass in the bottom to strengthen the aft portion of the landing gear block.  Photo 80.

Frank