Skymaster F-4 Operating Canopy Instructions

Thank You for purchasing the Details 4 Scale SM F-4 operating canopy system. Very few parts are required in addition to the factory supplied system contents to complete the installation. 2 servos, Robart spool valve, fill valve and that's it. All other parts are included in the canopy system kit. (See list below for servo details).

Tools, materials and parts required to complete the installation:

dremel tool with following bits: 1/8" spiral carbide cutter, sanding drum large and small, 1/4" ball end cutter or conical grinding bit, diamond cut-off wheel (Harbor Freight has a good set cheap).

Robart spool valve and fill valve or equivalent

scrap piece 1/8" ply approx. 1"X 2"

Optional equipment:

Electronic canopy sequencer: Details 4 Scale part# ECS1000 (available thru the online store)

Parts Bags

First, locate all the bags and match them against the check list below. Make sure all parts are accounted for before beginning the installation.

Bags and Contents:

1 bag each: Front fixed canopy (fiberglass), center operating canopy (fiberglass, pre-hinged), rear operating canopy (fiberglass, pre-hinged)

1 bag: 3 clear canopy sections

Air System hardware bag: 1 air bottle with fill nipple, 30 1/16" "T" fittings, 2) canopy cylinders, locking servo tray w/ 8 servo screws, 4ft white airline, 4 ft. black airline, Robart spool valve/servo mount w/ 4 screws.

Locking units/ pushrods bag: 4 canopy lock units (2 left, 2 right), 4) 1/8" X 6.5" carbon fiber pushrods, 4) .032 X 7.5" pushrod piano wire.

front canopy dowel bag: 2) 3/16" X .75" fiberglass dowels, 2 molded dowel blocks.

front fixed and center canopy mounting unit bag: 4 angle canopy mounting blocks, 4 screw flange blocks, 4 flange spacers, 8) 2-56 X 3/8" cap screws.

rear cylinder mount cross bar:

front cylinder mount cross bar:

front canopy side rails, caps, hooks bag:  2) side rails (fiberglass), 4 molded caps, 2 hooks

rear canopy side rails, caps, hooks bag:  2) side rails (fiberglass), 2 molded caps, 2 hooks

cylinder link brackets bag: 2 cylinder link brackets w/ 2-56 X 3/8" cross bolt each

canopy speed valve bag: 1 canopy speed valve with knob, 2 nuts, 2 star washers

Installation Instructions

NOTE: In order to show the canopy installation from any angle, a flat ply mounting surface simulating the top fuse flange was made. The canopy sections could then be photographed from below or what would be the inside view of the airframe without trying to get the camera inside an actual fuse. All dimensions are as accurate as if the canopy parts were actually mounted to an actual airframe instead of the copy.

Wash all fiberglass parts with warm soapy water to remove any traces of mold release before beginning.

1. Be certain the canopy flange measures 3/8" down both sides of the fuse when measured from the outer edge transition to the inner most edge of the flanged lip. If not, trim or sand until it is. The rear lip should be left alone.

2. The cockpit will need to be trimmed until it can easily fit under the canopy flange lip on the fuse. IT CANNOT SIT ON THE TOP. Once you've fitted the cockpit, remove it and set aside until later.

3. You must make the rear canopy hinge clearance cut out before the canopy sections can be placed on the fuse. Using the template provided, mark as shown in the photo below at cut out the section using the 1/8" spiral cutting bit and a dremel tool.

The top edge of the cutout must be all the way up to the skin on the upper surface of the fuse to within 1/64" of the top skin on the rear fuse deck in order for the hinge unit to fit. You may sand the upper surface of the hinge plate as necessary to clear the inside surface of the top of the fuse.

Reaching thru the cutout, rough sand the inside surface of the middle section where the hinge tab mounts to the bulkhead. Aeropoxy the 1/8" X 1" H X 1.25" W scrap ply in place behind the rear fuse canopy bulkhead. This will serve as backing for the rear canopy hinge mounting tab. See photo below for hinge example.

Left: Photo shows how the hinge tab will eventually be positioned. You can see the location where the screws will be placed and why the ply needs to be behind the bulkhead to hold the screws.

4. Once the slot for the rear hinge is completed, place each of the 3 new canopy fiberglass parts onto the canopy flange. Adjust the rear slot as necessary to allow the hinge to fit with the rear canopy section flat and all the way back on the fuse flange. Sand the remaining parts until a good fit is obtained. Very little sanding should be required, but try to only remove the material from the rear edge of the (front fixed) canopy, the front edge of the center canopy section (operating side only). Do not remove material from the rear canopy or non-hinged portion of the center section. Due to the design of the canopy hinges, a near "zero" clearance between the hinged parts can be maintained. Once you've fitted the canopy parts to the fuse, Tape the center fixed section and the front fixed section to the fuse. Remove the rear operating section and raise the center operating section. Mark the fuse using a pencil as shown in the photo below.

Left photo shows the hook slot cutouts for the front canopy.

Right photo shows the rear canopy hook slot cutouts. Each of the slots should measure in 1/8" to the center of each slot from the outer edge transition on the fuse. The outer edge is represented by the solid black line extending behind the canopy sections shown. Mark the slots on each side of the fuse as noted below.

Cut out slots using the 1/8" spiral dremel bit.

Mark the front and rear of the center canopy fixed section (right and left sides) and the rear edge of the front fixed canopy., remove the tape and the front and center sections from the fuse. Rough sand the undersides of the fuse canopy flange forward of the front fixed canopy mark and in between the two center canopy marks on each side of the fuse. Apply a small amount of Aeropoxy to the flat side of the mount spacers and glue in place. Be sure the spacers are centered exactly between the mark on the center canopy section and about 3/16" to 1/4" forward of the front section marks. Allow the Aeropoxy to cure. See photo below.

Underside view: Proper mounting placement for the spacers under the fuse flange.

While waiting for the Aeropoxy to cure, you can rough sand the inside of both the front fixed canopy (fiberglass) and the center fixed canopy (fiberglass) where the side rails will mount. See photos below for rail placement. 90% of the fitting is done at the factory, so only a minor amount of tweaking of the rail is necessary to achieve a good fit. Rough sand the edges of the rails all around about 1/16" in from the edges. See photos below. Glue the caps onto the rails using CA before Aeropoxying rails to canopy sections.

All rails should be approx 1/16" away from lower edges of canopy frames.

Above: Rear canopy rails and caps glued in place.

Allow Aeropoxy to cure fully before proceeding to the next step.

Installing the canopy hooks:

Referring to the next photos, make slots into each canopy rail above where shown in photo. Measure each corresponding slot cut into the fuse flange and transfer the slot location to the corresponding canopy rail. Make cut-outs using the 1/8" spiral cutting bit. There is a bevel on the flat end each canopy hook. This bevel faces the outside of the canopy frame when gluing the hooks in place. Each hook is the precise length necessary to match up with the locking hook in the fuse so DO NOT sand the bevel at all. The center of each slot should be approx 1/8" from the outside edge of the canopy lower frame edge. The ultimate goal is to have the canopy hook install so that it precisely matches the locking unit that will install later, so keep all 4 hooks uniform when mounting them. See photo below.

Left: Center canopy hooks installed.

Be certain the hooks line up fore and aft exactly with the slots for the locking units on the fuse or the canopy will not lock down properly. Once the all the hooks have been glued, allow the Aeropoxy to cure fully before proceeding.

Below: Rear canopy hooks installed.

Installing the front fixed and center non-moving canopy section mounting units:

Once the mounting unit spacers and canopy rail glue has cured, place the rear canopy section back onto the fuse and tape it in place. Place the center section on next and tape the center non-hinged section to the fuse. Wax the flat surface of each tapered mounting unit from below the angled top and the entire surface where the two holes are for the cap screws. The only surface that will glue to the fuse is the upper surface of each flange block. Allow wax to dry fully and assemble the 4  flange blocks (3/8" sq. X 1.5" molded blocks) onto the tapered mounting units using the 8 supplied 2-56 X 3/8" cap screws.  Rough sand the undersides of each spacer previously mounted to the fuse. Rough sand the upper surface of each flange block where it will contact the spacers. Install the center section units on each side as shown in the photo below. This step only glues the units to the fuse, not the canopy sections. Allow the Aeropoxy to cure completely. Once the epoxy has cured, remove the center and rear canopy sections from the fuse.

Left: The mounting units must mount exactly in the center of the non-hinged center section.

Notice the slots are missing. This is only for clarity reasons. This step needed to be completed before the other steps for the prototype assembly only.

Tape the front fixed canopy section in place on the fuse. Repeat the steps above and install the 2 front mounting units as shown in the photo below.

Left: The front fixed canopy mounting blocks should be at least 3/16" -1/4" forward of the rear edge of the canopy frame.

Remember that this step is only to mount the fuse side of the block and not the canopy side.

Installing the locking units under the fuse/canopy flange:

Rough sand the area under each slot cutout in fuse flange. Re-tape the rear canopy section in place first. Then, working thru the forward opening, apply a small amount of Aeropoxy to the front and rear flat portion of the locking units for the rear canopy. Be careful not to get any glue near the slot opening of the locking units. See Photo below.

Note the direction the lock is facing when installed. The cap screw should be visible when installed and the sloped part of the lock unit faces aft. Be sure the locking hook engages the canopy before tacking the locking unit in place. The hooks are both visible thru the 5/32" hole shown just to the aft of the cap screw on each unit. You can verify the hook's engagement thru this hole on each unit. After verifying each hook placement, tack each locking unit in place using CA and kicker to hold  until Aeropoxy cures.

Once the Aeropoxy has cured, remove the rear canopy section and repeat for the center section. After completion, the locks should look like the photo below.

Both locking units installed on the right side of fuse.

Installing the locking servo tray:

Locate the tray, 2 locking servos, 8 servo mtg. screws and the 4 #1 X 1/4" button head sheet metal screws. Plug servos into receiver and center each servo, The elevator channel works well for this with the ATVs set to 100% both up and down. Mount the servo arms so that each servo output places the arm facing straight up away from the tray with the servos in the tray. Install the servo mounting screws.

Left: Servo orientation in tray. When mounted in fuse the servo output shafts will be facing to the outside of the fuse on each side with the output shafts and wires are toward the rear of the fuse.

Below: Locking servo tray mounted using the 4 sheet metal screws. The front of the tray should be mounted so that if you were to draw a line straight down along the front canopy/fuse bulkhead, it would line up with the front of the front set of 3 holes in the tray.

Drill 4 holes using 1/16" drill bit. Mount the locking servo tray using four

#1 X 1/4" button head sheet metal screws.

Hooking up the locking units and pushrods:

Assemble the locking unit pushrods as shown in the photos below. First make one of the "Z" bends, then slide the carbon pushrod tube over the pushrod wire, then make the second "Z" bend. Repeat for all 4 pushrods. Center the carbon fiber tube between the "Z" bends and tack the tube to the wire on each end using CA. The carbon fiber tubes add a great deal of stiffness and almost no weight to the pushrod assembly. See photos below.

Be sure to make only one bend then slide on the tubes, or you can't get the tubes on.

Once the pushrods are assembled, carefully unscrew the cap screw from the front canopy locking unit and remove the locking hook from each unit. Remember the orientation of the hook as you take it out so it get's put back facing the correct direction. If you forget, just look at the rear unit. Once you've removed the lock arm/hook, install the front pushrods onto the servo arms and swing the pushrods backward toward the front lock unit. Install the rear end of the pushrod into the larger outer hole of each front locking arm. Re-assemble each front locking unit arm using the cap screws. Once both front units are assembled again, repeat the same process for the rear units. Remove the locking arms from the rear units and install the pushrods into the small holes on the front unit's locking arms. Install the rear wire into the small holes on the rear locking arms. Re-assemble the rear units and the completed setup should look like the photo below.

Left: Front locking unit pushrods installed.

Below: front to rear pushrods installed.

Beveling the hook receiver slots:

It is necessary to put a slight bevel into the top slot of each locking unit to ensure the canopy hook can find the opening even in windy conditions that might distort the canopies slightly when trying to close. See photo below for proper method.

Use a 1/4" ball end bit to cut bevel on both sides of slot at once.

Installing the rear canopy cylinder mount crossbar:

The rear cylinder crossbar mounts directly under the rear canopy hinge set. See photo for proper placement of the crossbar.

 Left: Notice the relief slot for the cylinder to clear the rear fiberglass cross piece.

Below: Notice the rear edge of the crossbar is 1/4" forward of the rear bulkhead. The relief slot needs to extend to the center of the crossbar. Cut the slot, 1/2" wide.

Rough sand the underside of the fuse where the rear cross bar will glue. Glue the rear crossbar as shown in the above photo using Aeropoxy. Tack the bar in place using CA and kicker and allow the glue to cure.

Installing the center canopy cylinder mount crossbar:

The center canopy cylinder mount installs in the exact center of the center canopy mounting units and glues to the inner surface the taped mounting units between the cap screws. This will allow the bracket to be removed when both sets of mounting units are unscrewed. See photo below. Repeat the same procedure as with the rear bracket and glue the center bracket in place.

Left: The cylinder swivel bracket mounts so that it faces forward.

Notice the crossbar is in the exact center of the mounting unit. Glue should be applied to the entire surface around the crossbar where it makes contact with the inside of the mounting unit. DO NOT get any glue on the flange blocks on the other side of the cap screws.

Allow the Aeropoxy on both the rear and front crossbar assemblies to cure overnight before moving proceeding.

While waiting for the above to cure, the following steps can be done.

Installing the rear canopy hinge tab:

The rear canopy hinge tab mounts using 2 flanged #2 X 5/8" servo mounting screws. Before mounting the rear canopy hinge, cut out the canopy glass area on the fiberglass. This will allow you to work right thru the canopy frame. In the photos below the glass was left intact to show how difficult it is to do before removing the glass from the canopy frame.

Once the glass is cut out, tape the rear canopy frame in place on the fuse flange. Be sure the hinge tab is up and facing forward. Once the frame is taped in place, lower the hinge tab in place against the rear canopy/fuse bulkhead and drill two 1/16" holes thru the holes in the hinge tab. Install the two screws to fasten the canopy in place. Remove the tape and test out the canopy action. If the rear of the canopy hits or rubs on the rear bulkhead, remove the screws and shave the inside of the top of the rear canopy until it's almost razor sharp to allow the canopy glass to clear the rear bulkhead. It is possible to maintain a "zero" clearance for this setup, so DO NOT oversand.

The installed screws with the glass still in place and the canopy raised.

This is how much the rear canopy hinge will protrude behind the rear canopy fuse bulkhead.

Once satisfied with the rear canopy, close it and tape it in place once again.

Installing the center canopy mounting unit to the canopy glass:

Remove the clear canopy area from the center canopy unit fiberglass. As with the rear unit, this will allow you to work right thru the canopy frame without the glass in the way. You only have to rough cut the glass, it can be finished sanded later. Rough sand the tapered top side of the canopy mounting unit and the insides of the glass center section where the mount will make contact. Apply a clean amount (neat, not sloppy) of Aeropoxy to the tapered mount and position the center canopy section in place. Tape the center section to the fuse making sure the canopy is centered side to side and touching the rear canopy front edge snugly. Remember the "zero" clearance. Be sure there is adequate glue contacting the inside of each canopy side and the tapered mount surface. NOTE: Be sure no extra glue remains above the top surface of the tapered mount. Excess glue will be in the way of mounting the clear canopy sections later. Allow the center section mount glue to cure completely.

Repeat the above procedure for the front fixed canopy section and mounts. Allow the glue to cure completely.

Installing the front cylinder push pull block:

See photos below for proper location for mounting the push pull blocks. The blocks are very easy to mount thru the canopy frames while the glue for the canopy mounts are curing. You may glue the push pull blocks at the same time as the canopy mounts.

Left: Photo looking forward. The cylinder push pull block mounts onto the bottom rear edge of the front carbon fiber plate that's attached to the movable center canopy. The bolt should be oriented with the bolt side of the bracket closest to the bottom of the carbon bulkhead.

Notice the cylinder setup and the location of the push pull block.

Installing the rear cylinder push pull block:

The rear cylinder push pull block mounts as shown in the photo below. See photo below.

Left: Notice the push pull blocks mounts to the inside surface of the canopy hinge. Mount the bracket with the bolt side down (closest to the cylinder).

Installing the front fixed canopy dowel/blocks:

Unscrew the two 2-56 screws from each front canopy mount and remove the canopy section from the fuse. Repeat the process for the center unit as well. Using the front canopy drill template, drill two 3/16" holes thru the front of the canopy and also two corresponding holes thru the front canopy bulkhead. Use CA to glue the dowels into the dowel blocks, making sure one side of the dowel is flush with the end of the dowel block. Apply a small amount of Aeropoxy to the dowel block; the side with the dowel sticking out and push the dowel thru the hole in the canopy as shown below. Repeat for second dowel block.

The dowel blocks should parallel the top skin of the canopy section. Allow the Aeropoxy to cure completely.

After the epoxy has cured, re-install the canopy section and fasten it place. Adjust the holes in the front canopy bulkhead as necessary to get a good tight fit of the canopy to the fuse.

Ghost view of the dowel as they would appear on the other side of the front canopy fuse bulkhead.

Adjusting the canopy rim clearances:

Re-install the center canopy unit with the canopy open. Refer to the photo below and carefully grind/sand the rim of the center operating canopy unit until it will close without and interference (rubbing) from the front canopy rim.

Sand the areas between the arrows for the adjustment of the center canopy front rim to allow it to open and close without rubbing against the front canopy rim frame.

Once the center canopy frame has been adjusted, install the rear canopy unit and repeat the same methods for the rear canopy unit.

Adjusting the canopy locking units and adjusting the canopy hook's fit:

Work on the center canopy operating unit and get a perfect fit between the hooks and the locking unit by carefully sanding the outer or inner tip of the bottom radius of the canopy hooks until the canopy section seats properly onto the fuse flange with the locks swung into the locked position. DO NOT sand the radius on the backside of the hook as this will substantially weaken the hooks. Repeat this step for the rear canopy hooks and locking units.

A special note about setting up the air/lock units:

Due to the complexity of the dual canopy system on the F-4, it is recommended that a canopy sequencer be used to operate the canopy air unit valve and locks. Servo slow and simply timing are NOT adequate to operate the units. You can use the Details 4 Scale canopy sequencer or a simple gear door sequencer like a Mini Hobby unit will work. Just think of the canopy system just like gear and doors. The canopy air valve mimics the gear and the locks are the doors in the system. The gear can't extend if the doors are closed; neither can the canopy open if it's locked. Of course the opposite is true if the canopies are open and the locks are closed; the canopy can't close all the way, nor can it lock.

If you plan on using the Details 4 Scale canopy sequencer, there are a couple of built in safety systems included in the electronic programming of the system to prevent accidental opening of the canopies in flight. The door sequencers will not have ANY safety features. If you flip the switch by accident in flight, the canopies WILL depart the aircraft. If you plan on using the Details 4 Scale Canopy Sequencer, simply follow the setup instruction manual included with the unit to set up the dual canopy F-4 system. The unit is extremely simple to program and operate.

Setting up the system using a gear door sequencer:

Follow the manufacturer's instructions for setting up the sequencer. Remember to think of the system just like the gear/door system.

Installing the canopy air cylinders:

Once the sequencer has been programmed, the air cylinder unit can be installed onto the cylinder cross bar units. Starting with the rear unit, install the cylinder snap clip on the end of the cylinder so that the opening side of the clip faces forward when snapped onto the push pull block's cross bolt. This requires the cylinder snap to be installed from the bottom side of the push pull block. Once the snap is in place, lower the cylinder downward until it can be snapped into the cross bar cylinder swing block. Once the cylinder has been snapped in place, manually extend the cylinder to the maximum open point. Pull the canopy to it's maximum open point and place a brace under the canopy to hold it in place in the full open position. Apply a good bead of either silicone or Aeropoxy around the cross bar swing block and the brass cylinder tube. This will lock the cylinder permanently to the swing block. Allow the glue to cure fully before removing the brace from the canopy. After the glue has cured, attach a hand pump to the upper air nipple of the cylinder and pressurized the cylinder. The canopy should gently close at around 60-80 psi. The cylinders are manufactured in such a way that no restrictors are necessary and they will never just "snap" open or closed.

Left: Rear canopy cylinder installed. Notice the push pull block cross bolt is visible thru the cylinder snap fitting showing the snap installed correctly. If you can't see the bolt from the front, the snap is in backwards and will pop out under pressure from the canopy cylinder.

Center unit hooked up. Adjust the center canopy using the same method as the rear canopy before gluing the cylinder tube to the swing block on the cylinder cross bar.

Installing the air system and final checks before installing the canopy clear sections:

Place the Robart valve/mount where it is to be permanently mounted in the fuse. The canopy speed valve installs between the air tank and the input (center) of the Robart valve. Mount the speed valve where it is easily accessible. Preferably under the turbine hatch area. Route the open/close airlines from the Robart valve to each of the air nipples on the canopy cylinders. Be sure that they airlines are installed correctly for "open" (bottom set of nipples) and "closed" (top set of nipples). Be sure the locks are all open. Once the airlines have all been installed, pressurize the air tank. Manually move the valve from one side to the other slowly. Allow the canopies to open and close. Make note of how many cycles the canopies can make on one fill of air. Also make note which direction the valve is set for both up and down. You will need to know this later when doing the final check of the sequencer, locks and ATV settings. DO NOT exceed 120 psi when filling the tank. The cylinder design does not allow for over pressurization. Carefully check to see that the canopy hooks go in and out of the locking slots without hitting the edges or binding in any way. The canopies may not seat all the way down, but this will be taken care of when the locks engage as they pull the last few thousandths of an inch closed.

Final adjustment of the locking servos, ATVs and timing for the sequencer:

With the canopy units open and the air tank empty (no pressure). Press the test button on the sequencer (if using the Details 4 Scale unit) or cycle the canopy switch on the transmitter. Watch which way the Robart valve moves. If the valve moves to open when it should be closed, simply swap the two sets of airlines to fix the problem. This step is only necessary if you are not using the Details sequencer. A simple re-programming of the sequencer will change this automatically.

Testing for "closed" to "open" : When operating the switch or test button, the locks should move from "locked" to "open" first when the canopy valve is in the closed position, then the canopy valve should move slowly after the locks have opened to open the canopies. The locks should then remain in the open position.

Testing for "open" to "closed": When operating the switch or test button, the canopies should close, followed by a brief pause (fully adjustable on the Details unit), then the locks should engage.

Once the tests have been made and all is functioning properly, close the canopies, cycle the switch on the transmitter to the canopy closed position. Flaps down full if using the Details unit. The locks should automatically engage. You may then pressurize the air tank. The air cylinders will pull down on the canopies once again.

Test the operation of the system by cycling either the transmitter switch or the flaps (Details unit). The canopies should open and close without effort. Be certain the locks engage fully (DO NOT allow the locks to bind the locking servos however). Just be sure the locks are seated against the hooks and that the canopies have no gap between the lower canopy sills and the fuse flange.

Final Assembly:

Remove the canopy sections from the fuselage. Final sand and fit each of the clear canopy parts into their appropriate canopy glass section. Once fitted, sand the inside edges of the clear canopy opening in each of the fiberglass canopy sections. The small windows just to the aft of the front operating canopy must be cut out and fit separately. There is no room where the glass installs due to the carbon fiber center bulkheads, so the clear sections need to be sized and flush fit into each opening. This means the plastic window will be the same exact size as the opening. Mount each piece with the plastic flush with the outer surface of the fiberglass canopy center fixed section. Once in place, run a bead of canopy glue around each small window on the inside. Allow about 1/32" to overlap onto the clear plastic. When the sections are painted, the masking should extend to within 1/32" from the edge of the plastic. This method will hide the seam and cover over the plastic 1/32" locking the plastic to the fiberglass. It will effectively reduce the clear window size by 1/32" all around, but it's hardly noticeable. Once this small clear section has dried completely, the remaining clear sections can be installed. Once glued, each section must be re-installed onto the fuse while the glue dries in order to maintain each canopy's shape. The sections can be taped to the fuse for this step; they need not be screwed in place. Just be certain they fit as closely as possible. After the canopy glue has dried completely; usually allow at least 2-3 days ( longer if it's very humid or cold) for the glue to dry completely. Once the canopy sections are dry, paint the sections the desired color.

Re-assemble the entire system and re-test one more time before flight.

Please call or e-mail if you have any questions about the installation, setup or function of any part of the F-4 operating canopy system.

Phone: 208-233-4721   M-F  9-6  MDT    USA

e-mail:  support@details4scale.com