Thread Tools
May 31, 2019, 11:10 AM
Registered User
Cycotravlr's Avatar
Thread OP
JimboPilot,
Thank you for your info. I have heard the same thing about inverted engines. If I can make this engine fit inverted. I guess I like a challenge. I do plan to start it upside down on a stand before flight. But, there again, I think the airplane will look much better if I can make it work. If it fails it could look rather ugly!

Thanks again,
Perry
Sign up now
to remove ads between posts
Jun 19, 2019, 02:22 PM
Registered User
Cycotravlr's Avatar
Thread OP

Back at the Smoothie


It's been just short of a month but I'm not done yet!

Per the instructions I assembled the engine to the motor mount to determine the desired location of the Firewall. I will be using an OS 55ax mounted inverted and because of the size of the 55ax I had to move the Firewall Aft 1/2" and build a taller Firewall due to the taper of the Fuselage in that location. I then Pinned the Fuselage Sides to the Plans. One right-side-up, and one upside down to make sure that I had a Right side and a Left side. Next I marked the locations of the New Firewall, all the Formers, and the Cross Braces on the Fuselage and extended this lines above and below the Plan Drawings. Because of the new location of the Firewall I now cut the Fuselage Doublers to support the new Firewall location and glued them in their respective location. Then cut the excess Balsa off the Aft end to match the Tail Post. Having moved the Firewall 1/2" Aft, the 8oz. Fuel Tank now no longer fit in the allotted space. I had to create a hole in the Forward Former to allow clearance for the rear of the Fuel Tank. I used 1/8' X 1/8" Basswood to reinforce that Former. Then, I cut a hole near the upper corner of the Front Former for the Battery Wire. Due to moving the Firewall and mounting the OS 55ax inverted, I lowered the Fuel Tank and now plan to locate the Battery above the Fuel Tank.

Until next time,

Perry
Jun 23, 2019, 06:32 AM
Registered User
Steve Merrill's Avatar
thatís a lot of engine for that plane, but I think you will be fine. I built one a couple,years ago. Mine is e powered. Just flew it yesterday I had forgotten how well they fly
Jun 23, 2019, 09:05 PM
Registered User
Cycotravlr's Avatar
Thread OP

More on the Smoothie Fuselage


Once I had pre-fitted the Engine to the Firewall, and modified the Front Former to accept the move of the Fuel Tank, I Tack Glued the Firewall and both Formers to the inside of the Fuselage Rt. side. I used some 1-2-3 Blocks to square them in place. When the Glue dried, I then Tack Glued the Left side of the Fuselage to the Firewall and Formers, using a Square against the Nose, the 1-2-3 Blocks, and a Sandbag to keep it all lined up while the Glue dried. Next I marked a Centerline on the Rear Former and cut the Top and Bottom Cross Braces to length. I also marked a centerline on them. Carefully placing the Fuselage upside down on the Top View of the plans, I lined up all the Centerline marks that I had made with the centerline on the Plans. Once again I used my 1-2-3 Blocks, Sandbag and Square to keep everything in place while I Glued the Rear Former in it's proper Location. Once that was done it was time to install the Top and Bottom Cross Braces. After checking all Centerlines to the Plans, and the Fuselage Sides to the Square, I re-Glued all the joints that I had previously Tacked Glued.

More to come....

Perry
Jul 17, 2019, 10:10 PM
Registered User
Cycotravlr's Avatar
Thread OP
I'm still working on this build. I'm just losing my mind working on how to make everything fit with the OS .55ax mounted inverted. Stay with me on this. More to come soon.
Jul 18, 2019, 11:10 AM
Registered User
The tank/carb geometry looks pretty good. I hope you have enough room to wrap the tank in foam so it doesn't bubble from vibration.

When you put in an engine other than what's shown on the plans, all kinds of issues come up. One thing to consider for down the road is the extra weight of that engine and the CG of the plane. You should be able to mount the battery behind the servos and be fine. Maybe.

Prop ground clearance might be a problem too, if the legs aren't long enough. Then there's additional rudder throw/area to compensate for takeoffs with a bigger engine. You might not even need to worry about that one.

carl
Jul 18, 2019, 03:42 PM
Registered User
Cycotravlr's Avatar
Thread OP
Carl,

Thank you for your suggestions. I don't get many from other users. It seems that not too many people have built a 40 size Smoothie or are just not interested in this build. On to the Build suggestions; I will have room to wrap the Tank in foam. It will be tricky because the Throttle control will have to be routed through a very narrow space beside the Tank. I think I have that worked out.

As far as the CG, I have had that on my mind since the start. I hadn't thought about moving the Battery behind the servos. The plans show the Battery below the Fuel Tank. I had been considering placing the Battery above the Tank. I plan to build in rails along the inside of the fuse to allow me to move the servo tray forward or aft to help with CG. I will certainly keep the relocation of the Battery in mind.

Also Thank you for the reminder about the Prop Clearance. I hadn't thought that far ahead yet. The OS .55ax does use a large prop than the .46. I don't think the Rudder will be of concern. I'll be able to add or subtract any additional Throw.

Thanks again,

Perry
Last edited by Cycotravlr; Jul 18, 2019 at 11:37 PM.
Jul 22, 2019, 10:52 AM
Registered User
Steve Merrill's Avatar
Iím interested. I just built one last summer. Mine is e powered. But I did have one powered with an OS .40.

I agree wrap the tank In foam. Youíll still have room for the throttle pushrod. Ground clearance should still be ok. CG is an issue. But better to be nose heavy than tail heavy.

Good luck in your build. The Smoothie is a great flying airplane
Jul 31, 2019, 12:36 PM
Registered User
Cycotravlr's Avatar
Thread OP

Pushrod Tubes and Turtle Deck


Since the last time ....... I've been working on Radio and Pushrod installation. I will be using "Gold'N'Rod" Pushrods so as recommended, now is a good time to plan and install Pushrods before the Turtle Deck is in place.
Routing the Pushrods is very standard. I cut and shaped the exit holes at the rear of the Fuselage on both sides at a location to line up with Control Horns for Rudder and Elevator, to be installed later. I made supports for the Pushrods out of 1/8" Lite Ply and drilled through the last Former for the 3rd support. The front Pushrod Support is to be installed after the Servo Tray location is determined. I then glued the Pushrod Tubes at the exit hole and where they passed through the middle support. After the Glue had dried I cut the Pushrod Tubes as close to the Fuselage as I dare and then sanded them flush with the sides.
Next, using 1/8" Ply, I built a Servo Tray for the 3 main Servos. Then, as I usually do, I added a 1/4"X1/4" Rail along the inside of the Fuselage. These Rails will be used to slide the Servo Tray forward or aft to adjust the CG as needed. I had originally planned to place the Battery above the Fuel Tank, but I may opt to locate it somewhere along this Rail also.
I then Glued the Turtle Deck Formers in place per the Plans. After the Glue had dried I glued the Turtle Deck Sides in place leaving some excess to be sanded for proper fit later. Gluing the Turtle Deck Top in place was next. Then I trimmed and Sanded the Turtle Deck Sides and Top to mach the angle of the Turtle Deck Formers. I'll wait until later to Round the Top to shape.
On our next visit I will be working on Installing the Wing, which currently doesn't look too awfully difficult.

Good Day,

Perry
Aug 08, 2019, 07:54 AM
Registered User
Cycotravlr's Avatar
Thread OP

Smoothie Wing Install


Here we go with the Wing install,
As suggested in the instructions, I carefully re-opened the 3/16" hole in the center of the Leading Edge of the Wing where the 3/16" Dowel will be located. I used the center of that hole and the Wing Rib to mark both sides of the Fuselage. I will use those marks to measure and mark the location and Drill the Mounting Hole in the center of the Front Former. After making sure that the 3/16" Dowel was a good fit in the Wing Leading Edge, the Dowel was glued into the Wing.
Next was to Locate and Drill Mounting Bolt Holes in the Wing just forward of the Trailing Edge center. Then I installed the Wing Mounting Block. When intstaling the Wing Mounting Block I added an additional support to both ends where it meets the inside of the Fuselage, I used scrap pieces of 3/8"X1/4"X3/4" Balsa for this. After the glue had dried I re-aligned the Wing, and using the previously drilled Wing Mounting Holes as a guide, I drilled the 13/64" holes in the Mounting Block. Once that was done I Tapped those holes to 1/4-20 and strengthened them with Thin CA. Then I re-Tapped them again. Then I screwed my Wing down and admired my work!
Next on the list is the Forward Hatch Cover and more.

Perry
Aug 09, 2019, 10:22 AM
Lipoly Killer
Frank Hurd's Avatar

Smoothie


I had one a few years back with an OS 40. Plenty of power. It was an FSR. The Smoothie is just that, very smooth flier. Mine would no snap roll no matter how hard that I tried.
Aug 09, 2019, 04:22 PM
Registered User
Cycotravlr's Avatar
Thread OP
Frank, It's good to know that the Smoothie flies so well even with an OS 40. I am going to use an OS 55ax because I had one sitting on a shelf that needed a home. Little did I know the challenges involved in making it fit into such a small space.
Thank you for your response,

Perry
Aug 10, 2019, 01:23 PM
Registered User
Looks great! I'll be following your build closely, as I recently started building one from the kit. Mine will have a Super Tigre .51, side mounted. I plan on adding cowl cheeks like a Formula racer.
Aug 10, 2019, 02:10 PM
Lipoly Killer
Frank Hurd's Avatar

Os 55


I have a 55AX in a Killer Chaos. It has the same or more power than a lot of .60ís!


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Balsa USA Smoothie engine mounting question Harlanb Balsa Builders 2 Jul 08, 2018 08:51 AM
Article Balsa USA Smoothie XL- RCGroups Build: Part One Mean Joe Vermillion Giant Scale Airplanes 35 Apr 06, 2017 01:45 PM
Build Log Balsa USA Phaeton II (.40 size) numb_thumbs Glow to Electric Conversions 88 Jul 11, 2016 10:51 AM
Gallery Balsa USA SMOOTHY -kit bashed tony0707 Your Plane Photos 3 Dec 18, 2009 08:36 PM
Discussion Balsa USA Smoothie Conversion twinster2 Glow to Electric Conversions 10 Feb 07, 2006 12:15 AM