I will use this space to add photos of the build process I use. Please feel free to add pictures or comments as necessary.
I always start with mounting the wing to the fuselage. Below are the steps I use to mount the wing. Note: The molded saddle in the fuselage may be narrower than the wing chord. Care should be taken to make the wing fit the fuselage prior to drilling and tapping the wing bolts.
To start, I drill through the wing using a tap drill for 1/4-20 for the front bolts and a tap drill for the 10-24 rear wing bolts. When drilling through the wing keep the drill bit perpendicular to the top of the wing at the point where the bolt passes through and centered within the counter sunk molded in locator. I have some 3D printed items to help with this and are seen in the MFL build thread.
CMAD Shadow Build
CMAD Shadow Build
- Attachments
-
- Mark the location of the wing bolts on the fuselage to reference where to add thread doubling blocks. This also shows how I remove material from the fuselage to allow the wing to sit flat at the rear. Some notch the wing to fit the fuse, I tend to do a little of both.
-
- Mark the front bolt location, this allows a visual reference when installing thread backer blocks. Also note that I have marked with a black line where I trim back the part of the fuselage that wraps around the LE of the wing.
-
- cut and install 1/8" blocks to the front using 5 min epoxy
-
- cut and install 1/8" blocks to the rear using 5 min epoxy
-
- I clean up the area that mates to the LE of the wing, sandpaper, a round file and some sanding until you get the wing to seat nicely into the fuse.
-
- Using a square edge of a file you can clean up the rear, I also tend to use a zona saw. Key feature is to use tape to prevent unwanted scratches on the fuselage.
-
- This is the cleaned up rear saddle area.
-
- Tape the wing in place, using the centerline of the fuselage and the centerline of the wing to prevent movement while drilling and tapping the fuselage.
-
- I drill and tap one hole at a time. Start in the rear then opposite corner front. Install screws after tapping prior to moving onto the next hole. Continue this process until all 4 holes are drilled and tapped.
-
- remove the wing and fill the holes with thin CA. Once the CA is dry, RE-TAP the holes prior to installing the wing.
-
- Fine tune the fit after drilling and tapping using a razor saw to allow for clearance at the TE.
Re: CMAD Shadow Build
Next install the V-tail.
- Attachments
-
- Lay the tail onto the fuselage and mark the location of the torque rods on the fuselage.
-
- Clearly mark the area to accept the torque rods
-
- Cut a hole to all the ball links to pass through the fuse.
-
- Use a drill to mark the location of the V-Tail torque rods on the bottom of the fuselage.
-
- Open this hole to allow a screw driver to enter the fuselage to press on the ball links to snap them onto the balls during the assembly process.
- S18.JPG (30.75 KiB) Viewed 1676 times
-
- I cut an additional hole between the bolts to make sure the pushrods are not crossed during assembly.
-
- Tape the stab in place to prevent movement. Drill and tap to accept 10-24 bolts. Use the same process as the wing. CA the threads and re-tap.
-
- Tape the bottom of the stab as well.
Re: CMAD Shadow Build
Next install the blind nuts and motor mount.
- Attachments
-
- Drill a 1" hole in the center of the firewall. This hole allows access to the backside of the firewall to install blind nuts.
-
- Tape you mount in place to prevent misalignment while drilling. I drill through the face of the mount with a bit that fits my mount hole. I start in one corner and install a screw before moving onto the next hole.
-
- Drill through your mount starting in the top right as shown and install a 6-32 screw.
-
- I normally move onto cross corners. The first hole was top right and this one is lower left. I am also marking the location of the shutoff using a larger drill bit BY HAND, only mark the center.
-
- This is the HAND marked hole in preparation of drilling the 1/8" hole for the shut off guide.
-
- Drill the hole for the shut off guide.
-
- I tape a flashlight to the fuselage to provide light during the install process.
-
- Next drill out the 4 holes to accept blind nuts.
-
- I use hemostats to hold the blind nut through the 1" hole. Install one nut at a time using mount to pull it tight against the firewall.
-
- Another view of the install process. Complete all 4 mounting holes.
-
- Install the shutoff guide tube. Sand the tube prior to installation. I use yellow Nyrod for this process.
-
- All 4 blind nuts are installed as well as the shutoff guide tube.
-
- I use oil to prevent screws from being permanent fixtures in the fuselage while securing the blind nuts with epoxy.
-
- Also if you plan to pour epoxy into the nose to secure the blind nuts, be sure to tape over the 1" hole otherwise you may glue your mount to the fuselage.
-
- lastly back fill the firewall with epoxy to secure the blind nuts.
Re: CMAD Shadow Build
Ball links and torque rods.
- Attachments
-
- Use JB weld to secure the balls to the V-Tail torque rods. Clean the threads first with alcohol.
-
- Make sure the balls are the same distance from the bottom of the stab.
-
- Clean up the hole in the bottom skin to allow for the nut and tool to be used to secure the vertical component of the torque rod. In addition open up a hole at the root to allow for JB weld to be added during the installation process.
-
- Assemble each vertical component for the wing as shown. The 1/4" dimension is critical to prevent the 4-40 screw from passing through the top skin but yet pass through the top of the torque rod.
-
- Fill the end of the torque rod with JB weld and install the vertical part of the torque rods. And tighten the jam nut.
Last edited by kane on Thu Jun 06, 2024 2:57 pm, edited 1 time in total.
Re: CMAD Shadow Build
Final assembly.
NOTE: I don't have pictures for the landing gear. I use 4-40 screws and blind nuts.
CG: 2.88" to 2 15/16". In order to achieve the correct CG the servos need to be as forward in the fuselage as possible. Recently, Tom and I have been using a 1/4" spacer between the motor mount and the firewall as well as having the battery in the nose to obtain the correct CG. If these spacers are needed reach out to either Tom or I and we will help.
NOTE: I don't have pictures for the landing gear. I use 4-40 screws and blind nuts.
CG: 2.88" to 2 15/16". In order to achieve the correct CG the servos need to be as forward in the fuselage as possible. Recently, Tom and I have been using a 1/4" spacer between the motor mount and the firewall as well as having the battery in the nose to obtain the correct CG. If these spacers are needed reach out to either Tom or I and we will help.
- Attachments
-
- Balsa spacers are used on both sides of the fuselage to support the servo try at the correct height to prevent interference with your aileron servo and still provide enough clearance for the switch. IF you are using other components check the fit prior to gluing your tray in. Sand the fuselage prior to gluing your servo tray in. I ALWAYS USE Shoegoo for servo tray installation. The corners of these balsa spacers need to be rounded to fit the radius of the fuselage.
-
- This picture shows the approximate location of the tray spacers.
-
- I created a 10" long stick to act as a tool for proper spacing of the servo tray.
-
- it is 10" from the back of the firewall to the front of the servo tray. This puts a tetra tank center on the CG. If you wish to move the tank and servos forward you can. I am showing what I do.
-
- I add balsa screw supports to the back of all of my servo trays.
-
- I always add thin CA to the holes and edges of the tray before installation. SHOEGOO to install the tray.
-
- I am showing a bent pc of pushrod being used as a tool to mark the front side of the switch.
-
- Shine a flashlight onto the pushrod from the inside and mark the outside of the fuse for the switch activator.
-
- I use wire to operate my switch. Use whatever method works for you.
-
- I add 1/16" balsa to my charge jack prior to installation onto the tray to allow for easy removal.
-
- I drill to small holes for charging. You can pass the entire connector through or even leave it inside the fuselage.
-
- I am showing my switch activator and charge jack fully installed.
-
- Servo location and pushrods.
-
- Shut off arrangement
-
- Tank and RX installed
-
- Aileron servo tray, note balsa installed on the bottom as well as a vertical support to prevent crushing.
-
- The aileron servo is located as far back as possible to prevent the servo from exiting the top skin.
-
- Typical aileron linkage.
-
- This is the process I use for installing the ball links. I listen for a positive "CLICK" while pressing down on each link.
-
- This picture shows the 1/4" motor spacer and battery location. NOTE: I also use a 1.5" spinner
Re: CMAD Shadow Build
Dan thanks for sharing this was a great read. Regarding the blind nuts. Is there anything special about what type of blind nuts are preferred? Seems over the years some are rock solid in taking the 6/32 screws and torque, others collapse on themselves. Just curious.
Also when you put the epoxy over the blind nuts, are you just reaching in the firewall hole with your fingers or ?
Thanks
Mike
Also when you put the epoxy over the blind nuts, are you just reaching in the firewall hole with your fingers or ?
Thanks
Mike
Re: CMAD Shadow Build
I use DuBro 6-32 blind nuts for a couple of reasons. The OD of the flange is the smallest I have found and fits into the fuse corners nicely and they seem to be the best for staying and not stretching or stripping. I tend to over fill with epoxy creating additional threads on the backside as well that helps too.
Seeing the top two nuts is nearly impossible, unless you cut a small hole between the front to wing bolts. I tend to install epoxy through the saddle and hope and pray that I made it onto the top two bolts. Unless I cut the hole and then you can see. I don't go through the hole in the front, only because I usually have it taped up and the mount in place when adding epoxy to the back side of the firewall.
Last edited by kane on Thu Jun 06, 2024 2:55 pm, edited 1 time in total.
Re: CMAD Shadow Build
Deleted: Duplicate