|Aug 22, 2005, 01:53 AM|
Update ...Done!... Yet Another Slow Stick Build Thread... The XL...
You gotta love the Slow Stick! No other plane lends itself to mods or upgrades better. No other plane can haul the weight and do it with reasonable maneuverability.
My trusty Stock SS has served me well for almost 3 years… I bought one when they first came out. It’s hard to believe how much technology has changed in that short time. Brushless motors. LiPo batteries, small powerful servos… All can be exploited to make the SS even more capable as an AP platform.
I have been experimenting with filters on my cam mount. The added weight of the filter system and the eventual addition of down link video forced me to look for an alternative to the SS. The plane had to be light, carry a good size payload and fly slow, really SLOW. On top of all that it had to be maneuverable.
After an exhaustive search turned up nothing suitable, I decided to make a Slowstick with a bigger wing span and longer fuse.
You cannot beat the SS high lift, under camber wing! It's strong, light and the price is right! And... if you ditch the duct tape and Velcro bands you can make a rather professional looking ship!
The build follows:
|Aug 22, 2005, 02:00 AM|
I took two, new in box SS kits and some oak, carbon fiber and aluminum tubing and made what has turned out to be a very capable AP platform.
The first thing we need to do is cut the wing… a bit scary but it has to be done so lets get it out of the way.
Take one wing and cut it in half. Next with a flexible ruler, and a sharp, I repeat SHARP! Exacto knife… slice the wing at the point the aileron starts. Use a flexible ruler as a guide and slice it from trailing edge to leading edge. Repeat with the other wing.
Now take the good wing.. DO NOT CUT IT IN HALF! Treat it just like you would a regular SS wing except cut the wing tips off. Using the ruler as a guide slice the tip off. Line the ruler up right on top of the high spot on the rib bay. Repeat with the other side.
Take a sanding block and carefully true up the edge. You goal when cutting the wings is to make a joint that requires little sanding.
|Aug 22, 2005, 02:06 AM|
Next glue the tip extensions to the main wing.
If your cut was true this should be easy. Using foam safe CA glue the tips onto the main wing. Use Kicker while holding the tips in place. I was able to hold the wing up and place the tip on while the wife sprayed the kicker!
|Aug 22, 2005, 02:13 AM|
The next step is to trim the trailing edge.
Trimming the trailing edge serves two purposes… One it gives us a place to glue the trailing edge spar and two, it helps us raise the aspect ratio of the wing.
This increase in aspect ratio, although slight, will reduce drag, induced drag to be exact. Induced drag is the byproduct of producing lift. If we want our wing to fly slow AND lift weight at slow speeds we want to reduce drag.
Take a metal straight edge and line it up from root to tip just far enough in to remove the “Scallops” this works out to be about 3/8”. Do boths sides and true up with sanding block.
|Aug 22, 2005, 02:38 AM|
Lets move on to the spars
Since I had two sets of everything I decided to use the long spars in the back and long spars with carbon tube sleeves on the front.
The back spars are easy. Take one set of the stock long spars and glue them into the new improved spar joiner…. Set them aside.
For the front main spar you will need two 24” 5mm x 3.1 mm carbon tubes. You can substitute longer tubes but IMHO it is completely unnecessary. With the tip extensions of 14” your wing panels will be 32 ¾” at the trailing edge. The trailing edge spars will go to the tip joint and with the 24” tubes, your front spars will go 6 ½” past the tip extension glue joint. Flight testing so far has proven the wing to be very strong. NO ACRO! And watch the high speed dives… remember we are building this to be a light airframe.
OK, back to the front spars..
Build up the stock set of spars. Glue them into the joiner just like you did for the rear set. Now with thick CA glue the tubes onto the stock spars and slide them up to the joiner.
Apply the Thick CA on the Stock Spars and slide the tub over. This will invariably force excess glue to build up as you slide on the tube. No worries… Just be sure to wipe it quickly. We want to make sure our tube is bonded to the stock spar.
You could use the technique of squirting glue in the tube and working the stock spar around to insure you have good coverage. Just make sure you have SLOW SET thick CA… You don’t want to have the spar tube halfway down when the CA starts to set.
You should now have a front (50 ½”) and rear ( 38”) set of spars.
Before we move on Take Foam Safe CA and glue the wing together at the root… Hold it and kick it.
|Aug 22, 2005, 02:56 PM|
Next we glue the spars to the wing
I decided to build the wing without tape. The tape always seems to let go and wrinkle. A good quality foam safe CA is what is required here. I suggest a fresh bottle so it flows nicely. You will also need Kicker.
Test fit the rear spar. You will need to relieve the center portion of the trailing edge to accept the aluminum spar joiner It only takes a tiny bit of trimming to do this. We will glue the trailing edge spar first.
After cleaning the spar assemblies with alcohol set the wing on its leading edge so it is supported it’s whole span. Next run a bead of foam safe CA down the trailing edge from tip to tip. Set the rear spar onto the trailing edge starting in the center and spray a tiny bit of kicker to secure the center section of spar…
As you start in the center and work your way out kick the CA while insuring the spar is centered on the trailing edge. Go back over the joint and run a fillet of foam safe CA along the entire length of the rear spar.
The front is glued on the same way. Starting in the center and working out to the tip. I did however modify the way the front spar is glued to the wing. Instead of gluing the spar to the front of the wing I glued it to the bottom of the lip that makes the leading edge of the wing. This gives the wing a more pronounced leading edge cure. Think of it as extending the radius of the leading edge.
You can use a low tack tape (blue painters tape) to hold your spar in position. Make sure when taping or tacking the spar you do not twist the wing. Again, run a good bead of CA along both sides of the spar and kick it.
Your wings are done! Set them aside and lets work on the easy parts…
|Aug 22, 2005, 03:18 PM|
Making the long fuse
The plastic joiner included in the kit is not acceptable for joining the fuselage sections together. You will need hardwood, I used oak.
Now here is the hard part... You will need to plane, rip, sand a 12" length of hard wood stick to 3/8” square. You can use the basswood sticks in your favorite hobby shop but I would take my fuse and test them. THEY MUST FIT SNUG… if not you will end up with a banana fuse after a few flights.
Take your length of 3/8” square hardwood and cut it into a 4” piece and two ½” pieces. Save the rest of your 3/8" square hard wood for repairs or your second SS XL.
Set the ½” pieces aside we will use them later.
Take one of the extruded aluminum fuselages and cut a section 14” long. A Dremel cutoff wheel works well. Cut it a tad bit long and square up the end with a sanding block or disk sander. This is going to be the nose of your fuse. The SS XL can get tail heavy quickly so we want the joiner to be up front. In fact your fuse joint should come out just in front of your CG!
Take epoxy and glue the joiner in. You may want to take a cotton swab and clean the inside of each fuse half with alcohol... remember we are looking for a snug and permanent bond.
|Aug 22, 2005, 04:02 PM|
Now the Gear
The landing gear on the SS are a weak link… When you start hanging camera equipment the stock gear has a hard time holding everything up and keeping the prop out of the dirt.
Again, with the goal of keeping the SS XL light, I opted to use the stock gear mount and modified the stock landing gear.
You will need 16” 4mm carbon fiber tube and 16” of 5/16” streamlined aluminum tube. You can substitute 3/16” aluminum tube but make sure you8 have at least two 8” lengths
Take the stock gear from one of the kits and cut the axle portions off 2” from the bottom (see pics). Next, take the top portion and cut it off 2” from the top (see pics) rough up the axle stubs and the top piece so they will have a “tooth” for gluing. Set them aside.
If we use just carbon tube the wire pieces will split out the side (see pic with CA encrusted thumb). For this reason we are going to sleeve the carbon in aluminum. The result will be a stronger gear that is light.
Next cut two lengths of 8” streamlined tubing. Square up the ends. Now take your 4mm carbon tube and force it into the streamlined tube. I left my carbon tube long so I could hold onto it while I pushed it through. When you get the carbon flush with the end of the stream lined tube cut the other end off flush. Run some thin CA into the streamlined tube to lock the carbon tube in.
Repeat for the other side.
Your wire landing gear pieces should fit snug in the carbon /aluminum assemblies. Clean them with alcohol and prepare to glue them in permanently.
Using JB Weld or slow cure epoxy, JB Weld is the best choice, glue all your wire gear pieces into your carbon/aluminum legs. Make sure you get the axles oriented correctly and that the streamlined tube is positioned correct as well. Used the other stock gear as a guide… Don’t build it backwards.
Set this assembly aside to dry OVERNIGHT.. check it though to be sure it is still aligned properly.
|Aug 22, 2005, 05:16 PM|
Now the fun part… The Tail!
The tail design sprang from the 2 sets of tail parts. I wanted to use all the airframe parts in the kit. I thought about building bigger tail feathers from Depron but went this route.
Take the horizontal stab and elevator and mark 9” from the tip at the trailing edge toward the root. Using a square cut at the 9” mark. Repeat for each stab and elevator half. You should now have two identical stab and elevator assemblies 9” long at the trailing edge of the stab and leading edge of the elevator.
Save the parts you cut off you will need them later.
Square up the roots of all your pieces. Next take a piece of wax paper and using foam safe CA glue the roots of both the stab and elevator together on top of the wax paper.
Take the one each end part from the stab and elevator and cut a 1 ½” strip. You will use these as joint reinforcement. Note: For the elevator, center up the scallop on the reinforcement strip so it matches the scallop on the elevator(see pic).
Glue these strips to their respective parts on the BOTTOM of the stab and elevator.
Next we glue the vertical fins to the horizontal stab. With a square, draw two lines on the stab 7 ½” from the center section perpendicular with the trailing edge. Do this on both sides of the stab. These lines will serve as a guide to glue your vertical fins.
Using a square glue each fin to its respective side of the horizontal stab using the lines as a guide. I used foam safe CA and kicked it while the square held it perpendicular (see pics)
Brace the vertical fins with 1mm carbon rod. Make sure you leave room on the stab for the fuselage when gluing the rod.
Hinge the rudders and elevator with your favorite tape (I use Blenderm) and now your ready for the linkage…
|Aug 22, 2005, 05:42 PM|
Newport Beach, California, United States
Joined Aug 2003
Great job!!! I have been looking to do this type of mod.....Any Flight Reports? how much weight can she carry?..
|Aug 22, 2005, 05:55 PM|
I have posted hand launch here.
Hold on to your shorts!
It climbs out real good...even with camera on it...
Video shows with camera mounted...1/4 throttle launch, then you can see him "punch it" after he's cleared the trees...(and road sign).
Most excellent construction thread Bert...you're making me want to build one REALLY BAD!!
|Aug 22, 2005, 06:06 PM|
You may have seen the flight report here .
I'll finish this latter today (night.... man these things take hours)
|Aug 22, 2005, 07:35 PM|
This is not too complicated. It did take a bit of experimenting with different size horns and bell cranks. The first iteration used the stock horn on the left rudder. It did not provide enough rudder authority. I made some bell cranks out of 1/16” aircraft ply that provide excellent rudder authority. You can get away with less rudder if you make a Polyhedral wing, like the Gentle Lady wing. But I chose the simple route when joining the wings.
First you need to gather some hardware… 4-40 bolt 5/8” long, Six 6/32” nylon washers (DU-Bro No. 636 work well) and Micro EZ connectors.
Now lets make the bell crank and horn.
Take some 1/16” aircraft ply and cut out two identical bell cranks. One will be a bell crank and the other will be your rudder horn. Drill a 1/16” in each end of the bell crank (see pics). Next drill a 1/8” hole at the bell crank pivot point.
Now take the other bell crank you made and drill a 1/16” hole o the tip of the long end. Come in 1/8” and drill another 1/16” hole. This will give you two positions to adjust your rudder throw. Clip the un-drilled end of the horn about a ¼” in. Seal the horn with thin CA and clean out the holes. Install a Micro EZ connector on the horn in the outer hole first. Glue the horn into the LEFT rudder oriented as the pics show.
Remember those ½” long hard wood pieces? Take one and press it flush into the rear of the fuse. Seal the end with thin CA. Drill a 3/32” hole straight down through the aluminum and into the hard wood. Make this hole about ¼” from the rear of the fuse.
Next seal the bell crank with thin CA. Clean out the holes and bolt it to the rear of the fuse using the pics as a guide. Your goal it to make the horn level with the push rod guide. It is about 5/16” or 5 washers.
I used the stock rods with the “Z” bends. Cut one of your rods and cut it to 7”. This rod will go to the LEFT rudder (see Pics)
We are almost there…
|Aug 22, 2005, 08:51 PM|
Rudder Slave Strut…
By now you should have the LEFT rudder connected to the rudder servo. Now we need to slave the RIGHT rudder to the system. I use 2mm carbon rod and 1/32” music wire. Take and cut two 2” pieces of music wire. Cut a piece of 2mm carbon rod 13 ½” long. Take and cut two pieces of 1/8” heat shrink 2” long. Bend a “Z” bend into each of the 1/32” music wire pieces. Set all this aside for now.
To connect the slave strut to the rudders we will take a micro servo horn and cut 2 ends. Rough up the cut end of the parts with sandpaper to give them “teeth” for gluing.
Mark the rudders on the trailing edge about midway. Make a cut ¼” deep at each of these marks.Using foam safe CA glue the horns in.
Now take your carbon rod for your slave strut and slide on the heat shrink. Take the music wire and slide it in about an inch under the heat shrink. Install the “Z” bend on one rudder horn. Now take the other wire and put it through the remaining horn. Slide the remaining heat shrink on the carbon rod and slide the wire on under the heat shrink. Center both rudders and center the carbon rod between the centered rudders. Use tin CA to lock the heat shrink, wire and carbon rod. Use a heat gun to shrink the tube on both ends. CAREFULL, don’t melt your Depron!
That’s it! You’re done with the tail feathers…
The elevator is hooked up with the stock hardware in the stock manner.
|Aug 22, 2005, 09:57 PM|
Now all that is left to do is to slide the plastic on the stick. Slide the tail wheel bracket on first, then the second tail wheel bracket. This will provide an additional set of supports for the push rods. Now slide on your servo mounts followed by the trailing edge wing support.
For elegance, take two of the battery holders and cut the ears off each side. This will leave you with a nice square platform. Take these and slide them on next. Use Velcro (Industrial strength works best) to mount your receiver.
Next slide on the gear mount/leading edge wing support and your done.
You can take the remaining servo mounts and make a platform for battery or down link. I made mine out of a piece of 2” 1/16” ply screwed to the servo mounts. Add Velcro and you have a universal mount. Additionally you can use another battery holder with the ears clipped off to make a mount for your ESC.
Now take your remaining ½” hardwood block and press it into the nose of the fuse. Seal it with thin CA. Slide on your favorite motor and secure with a screw!
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