Twin Stick Build
04-02-2005, 08:46 PM
#1
Twin Stick Build
Well the rains have hit the East coast hard, no flying for at least a week. Te field will be a mud pit, so let's build.
Big Brown delivered my stick last week and just did not have the time to start till today. Opening the box I was impressed. All the assemblies are in plastic bags and are spot glued to the outer box sides to keep from moving around. Nice bag of hardware, two fuel tanks, wheels and ... something is missing, the landing gear. Short email note to Cedar and sure will have the gear on it's way.
Read the instruction booklet a couple of times, and started to build.
Started with the wings, covering is done well, a couple of minor wrinkles, and a few thin seams around one engine nacelle, quick pass with the iron and the wrinkles are gone. Used some scrape Ultra coat to fix the seam. The wings have pull cords installed for the servo extensions and are attached to the center section of each wing half with tape. Attached the Ailerons using 4 supplied CA hinges, looked at using Robart's but the aileron is really thin and would not have a lot of wood holding the hinge. Slits are cut in both surfaces, I did add an extra hing out on the ends of each assembly, felt it was necessary to stop flutter. Glued up wing joiner after trial fit and joined wing halves together. Left to dry will come back later to install servos and horns.
Glued the elevator to the Horiz stab, centered the tail wheel assembly and installed as per the instructions. Next minor problem, the stab is wider than the cut out on the fuselage. Found out when doing the trial fit to see how the tail wheel lines up with the vertical stab.
Had to cut out a section of the leading edge to make it line up correctly. Pictures later. Installed vertical stab and left all to dry.
Next issue, the supplied tanks do not fit into the tank opening when assembled. Tight squeeze to get them with out the stoppers which you can install through the fire wall. The back end of the nacelle has an opening cut out for the servo, to small for standard servo, will have to enlarge to fit. Using Airtronics Std 94102.
Enough for one day.
Photos will come tomorrow.
Big Brown delivered my stick last week and just did not have the time to start till today. Opening the box I was impressed. All the assemblies are in plastic bags and are spot glued to the outer box sides to keep from moving around. Nice bag of hardware, two fuel tanks, wheels and ... something is missing, the landing gear. Short email note to Cedar and sure will have the gear on it's way.
Read the instruction booklet a couple of times, and started to build.
Started with the wings, covering is done well, a couple of minor wrinkles, and a few thin seams around one engine nacelle, quick pass with the iron and the wrinkles are gone. Used some scrape Ultra coat to fix the seam. The wings have pull cords installed for the servo extensions and are attached to the center section of each wing half with tape. Attached the Ailerons using 4 supplied CA hinges, looked at using Robart's but the aileron is really thin and would not have a lot of wood holding the hinge. Slits are cut in both surfaces, I did add an extra hing out on the ends of each assembly, felt it was necessary to stop flutter. Glued up wing joiner after trial fit and joined wing halves together. Left to dry will come back later to install servos and horns.
Glued the elevator to the Horiz stab, centered the tail wheel assembly and installed as per the instructions. Next minor problem, the stab is wider than the cut out on the fuselage. Found out when doing the trial fit to see how the tail wheel lines up with the vertical stab.
Had to cut out a section of the leading edge to make it line up correctly. Pictures later. Installed vertical stab and left all to dry.
Next issue, the supplied tanks do not fit into the tank opening when assembled. Tight squeeze to get them with out the stoppers which you can install through the fire wall. The back end of the nacelle has an opening cut out for the servo, to small for standard servo, will have to enlarge to fit. Using Airtronics Std 94102.
Enough for one day.
Photos will come tomorrow.
04-03-2005, 02:30 AM
#2
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RE: Twin Stick Build
A couple notes to add to Jim's post.
The red and white airplane truck brought my landing gear and wing joiner Friday, so my assembly is proceeding.
Mix up a batch of epoxy and thin it with your favorite solvent, paint the firewalls and the tank compartments, if any is left over to the area for the throttle servos. NOTHING is fuel proofed on this airplane as delivered.
The tanks fit too tightly for any foam, so we have to hope. When you insert the tanks put a ring of RTV around the nose of the tank for sealing, and a line across the top where it will seat in the nacelle. When you put the stopper in remember the side you see is the bottom, so the vent pipe will have to go to the side away from you. As you see it, the vent will go to the bottom.
The engine mounts supplied are all the same, the engine actually mounts a little off center. If you mount the engines upright this offset centers the engines on the wing, it's just enough to counter the low mounting of the nacelles.
If you want to mount the engines sideways as I (and Ed Moorman) do, the side to side distance of the installed blind nuts is just a hair less than the vertical distance. One hole in each mounting bracket will have to be hogged out just a hair, but it will work with no problem.
There is a little clearance in the wing joiner, so when you assemble the two wing halves be sure to use some masking tape to hold everything in alignment.
I'm not at the point of balancing yet, but the plane will probably be a bit nose heavy. In the layout I'll suggest working a battery mount either under the fuselage servo plate or in the after body behind the servo mount. Might want to mount the rudder servo on the rear top, just in front of the vertical fin.
The supplied push rods are hard wood dowels, the slots for the wires are cut too deeply. If you want to use them fill the slots with scrap wood far enough to get the wire even with the surface of the dowel. Be sure to use epoxy when installing the wires, shrink the tubing over the joints before the epoxy sets.
Enough for now.
Bill.
The red and white airplane truck brought my landing gear and wing joiner Friday, so my assembly is proceeding.
Mix up a batch of epoxy and thin it with your favorite solvent, paint the firewalls and the tank compartments, if any is left over to the area for the throttle servos. NOTHING is fuel proofed on this airplane as delivered.
The tanks fit too tightly for any foam, so we have to hope. When you insert the tanks put a ring of RTV around the nose of the tank for sealing, and a line across the top where it will seat in the nacelle. When you put the stopper in remember the side you see is the bottom, so the vent pipe will have to go to the side away from you. As you see it, the vent will go to the bottom.
The engine mounts supplied are all the same, the engine actually mounts a little off center. If you mount the engines upright this offset centers the engines on the wing, it's just enough to counter the low mounting of the nacelles.
If you want to mount the engines sideways as I (and Ed Moorman) do, the side to side distance of the installed blind nuts is just a hair less than the vertical distance. One hole in each mounting bracket will have to be hogged out just a hair, but it will work with no problem.
There is a little clearance in the wing joiner, so when you assemble the two wing halves be sure to use some masking tape to hold everything in alignment.
I'm not at the point of balancing yet, but the plane will probably be a bit nose heavy. In the layout I'll suggest working a battery mount either under the fuselage servo plate or in the after body behind the servo mount. Might want to mount the rudder servo on the rear top, just in front of the vertical fin.
The supplied push rods are hard wood dowels, the slots for the wires are cut too deeply. If you want to use them fill the slots with scrap wood far enough to get the wire even with the surface of the dowel. Be sure to use epoxy when installing the wires, shrink the tubing over the joints before the epoxy sets.
Enough for now.
Bill.
04-04-2005, 08:25 PM
#4
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RE: Twin Stick Build
Jim:
Haven't drilled the holes yet (no, neither mine nor Ed Moorman's was drilled) but I will put them as far back on the plate as I can, with the rear of the gear even with the rear of the plywood inset. The gear (I think) really should be bolted on rather than the supplied wood screws.
Not a bad idea also to add some tri-stock reinforcements in the angle between the gear plate and the fuselage doublers. Paint the area with thinned epoxy, that will add some strength as well.
Might well have better gorund handling with the gear further forward, but that would be more forward weight to balance later.
Bill.
Haven't drilled the holes yet (no, neither mine nor Ed Moorman's was drilled) but I will put them as far back on the plate as I can, with the rear of the gear even with the rear of the plywood inset. The gear (I think) really should be bolted on rather than the supplied wood screws.
Not a bad idea also to add some tri-stock reinforcements in the angle between the gear plate and the fuselage doublers. Paint the area with thinned epoxy, that will add some strength as well.
Might well have better gorund handling with the gear further forward, but that would be more forward weight to balance later.
Bill.
04-04-2005, 09:12 PM
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RE: Twin Stick Build
The gear should always be set-up, (on a tail dragger) so the axle is about even with the leading edge of the wing. Too far back and you will have nose-over problems and too far forward will make it squirrelly on the ground.
04-04-2005, 09:17 PM
#6
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RE: Twin Stick Build
Terry:
The position I noted in my last post does indeed have the wheels just about even when the tail is lifted to horizontal, actually about 1/2" forward of the LE.
Bill.
The position I noted in my last post does indeed have the wheels just about even when the tail is lifted to horizontal, actually about 1/2" forward of the LE.
Bill.
04-05-2005, 07:34 AM
#7
RE: Twin Stick Build
My thougts were the same, Axle even with the leading edge. Already did the tri stock support. I always bolt on the gear and use 10/32 plastic bolts. On those really hard, dumb thumb, landings on grass, the bolts snap before the LG block pulls out. Saves a day of flying and a night of repair.
ON the fuel tank I added a very thin foam rubber to the top of the tank area. Had some foam left over from PC memeory card packaging that fit. Will stuff the side of the tank as well, the bottom is on it's own as is.
Jim
ON the fuel tank I added a very thin foam rubber to the top of the tank area. Had some foam left over from PC memeory card packaging that fit. Will stuff the side of the tank as well, the bottom is on it's own as is.
Jim
04-10-2005, 07:42 PM
#8
RE: Twin Stick Build
I have just started on mine. Yes, the tank compartments are short. I sanded the hole in the firewall out so I can get the stopper & cap in as far as possible. I'd like to get the engines as far back as possible for balance and having them stuck out on the ends of the engine mounts to clear the fuel lines isn't going to help this.
I am using GMS .47s and, as Bill said, will side mount to get the carbs in line with the tanks.
Are you guys saying you need to sink the throttle servos into the wing for clearance?
I am using GMS .47s and, as Bill said, will side mount to get the carbs in line with the tanks.
Are you guys saying you need to sink the throttle servos into the wing for clearance?
