Thread Tools
May 27, 2008, 11:03 PM
Registered User
Thread OP
Mini-HowTo

Converting Blue Arrow Venus DLG to Entry Level Competition D/E Rocket Glider


If you are interested in flying rocket-boosted gliders, do I have a deal for you!

I'm going to describe the conversion of a readily-available DLG kit into a competition-ready D - E RG. It's also S8E/P-legal, so you can build one and fly it in both this summer's Capital Cup (S8E/P for seniors, S8D for juniors) AND in the D BG event at NARAM-50.

The conversion is based on the Blue Arrow Venus DLG, available from www.bphobbies.com in the US for about$90 plus shipping. Later in this thread, I'll give you details on some of the other items you'll need to do the conversion, but for now, point your browser to http://www.bphobbies.com/view.asp?id...8&pid=C1146735 to get info on the kit, to https://www.rcgroups.com/forums/showthread.php?t=838446 and https://www.rcgroups.com/forums/showthread.php?t=718440 to see other RCGroup threads on the model, and to http://www.f3k.nl/pages/venuspag.html for a Dutch review (with good pix).

Why this conversion? First, it's a pretty quick and easy build. I did it over two weekends and a couple of evenings, but I was working on 3 other models at the same time. Most people with RC model experience should be able to do it in a weekend. Second, it's a good entry-level model for both the NARAM-50 D BG event and the Capital Cup S8D / S8E/P events. No, it's not a world-class model in my opinion... A little too heavy with a boost weight of 235 gr or so with 4 servos and a D7. The best altitudes I got were 377' with a D7 and 607' with an E7 (versus altitudes of about 100' higher with the same motors for one of my somewhat larger World Space Modeling Championships (WSMC) S8E/P's at a liftoff weight about 200 gr). Also, it is a compromise between D and E performance... At about 250 sq in, it is about 50 sq in larger than I prefer for a pure D-sized RC glider and about 25 sq in smaller than I'd like for an E... But it does meet the minimum wingspan requirement for S8E/P.

But it is not a bad performer... Definitely in the same league as my very-light 'Cuda and IMHO, in the same league as many of the other ships at the last WSMC.

My intention is to get some of you people out there who have some RC skills, but don't have the RCRG design experience or don't think they have the time to build one and increase RC glider participation at both the Capital Cup and NARAM. Or you can build one if you just think flying a glider with a rocket motor is cool.

But I want to be VERY CLEAR here... this is not a model to learn RC on. IMHO, no rocket-boosted glider is, including the Arcie. If you haven't learned to fly RC yet, get a beginner-type electric park flier or electric glider... RC rocket-boosted gliders have too short of a flight time and are too easy to get into trouble with on boost. Also, this conversion will use standard RC glider construction techniques and it will help to have done at least one previous RC ship and a few FF competition gliders.

In that vein, point your browser to the Taboo DLG construction guide http://www.olgol.com/TabooGT/build1.html and download the construction notes from here http://www.olgol.com/TabooGT/notes.html. Oleg has posted a wealth of small glider construction information and you want to be familiar with his techniques before tackling the Venus RCRG.

As time is short before NARAM and the Capital Cup, I'll publish the construction guide with pictures here rather than try for a full article. Another reason I won't be publishing a full article on this is that in today's world of RC kits, it is very likely that this kit will only be available for anywhere from the next six months to a year. But, even after this kit is no longer available, the conversion techniques I'll be posting will work with other similar glider kits such as the Art Hobby Colibri (www.arthobby.com), the Podivin Composite Modellbau Mini-Fireworks (see http://www.pcm.at/english/Mini-HLG/index.html and get it from www.nesail.com or www.soaringusa.com, and the Apogee Elite and Apogee Sport available from http://flyecm.com/... But in chosing one of these models for this summer's flying, you want to consider that all of these are either more expensive (Mini-Fireworks and Apogee Elite), heavier (Colibri), or harder to build (Apogee Sport)... And none of them meet the minimum wingspan required for S8E/P.

Also, I'd like to acknowledge a few people... First, Ryan Woebeking for his info on converting a Colibri, which helped inspire this. Second, to the people who posted in the other RCGroups threads and the authors of the Dutch Venus review... I will liberally use your pictures and disseminate your knowledge here. Third, Kevin McKiou, who made the best competition RC rocket glider kits I've seen (with some of the best instructions I've seen in any construction kit)... I will also use some of your tips and notes, especially around launch equipment. Finally, Bob Parks, who taught me most of what I know about gliders in general and rocket gliders specifically and has forgotten more than I'll ever know!
Last edited by gstew; Jun 15, 2008 at 12:11 PM.
Sign up now
to remove ads between posts
May 27, 2008, 11:05 PM
Registered User
Thread OP

Materials Needed


First, of course, you need the kit... See above.

Next, you need RC gear. I STRONGLY recommend you use Dymond D47 servos for the elevator and rudder, the key surfaces for good boosts. You can get them at http://www.rc-dymond.com/order_servo_dymond.htm. For a D BG-only version, I'd leave out the aileron servos... It'll be a bit lighter for slightly higher boosts and longer duration. If you do go for a D BG/S8E/P combo version, the D47s will also work well for the ailerons, but I used a pair of BlueBird BMS-303 servos also available from BP Hobbies as they are a tiny bit lighter. For receiver, I use the Berg 4L which fits ok (BP Hobbies has them too or get them from www.castlecreations.com)... A larger receiver will require different gear placement than I used. I believe some of the new Spectrum 2.4Ghz recievers will fit just as well, but I don't have enough experience with them to make a recommendation. Bob Parks, got a recommendation? For a flight battery, I used a 150MaH 2 cell LiPo pack with the now unavailable Eflight Designs uBEC... Both from BP Hobbies or just the LiPo from www.bsdmicrorc.com. If you want to go this route, instead of the uBEC, get a small brushless or brushed electric motor ESC with BEC and use just the BEC portion of it... Weight will be similar. Sorry, I don't have a recommendation here. Or as Steve Kranish discovered and pointed out below (and I forgot to include at first), IF you use the Dymond D47 servos AND the Berg 4L receiver, they WILL work with the 2 cell LiPo pack directly with no regulator. Or you can use a 4-cell pack of small NiMH... I checked and my 110 MaH packs will fit... and as Ryan W pointed out, you can find them at http://www.cheapbatterypacks.com/ at about $7.00 for a 160 mah pack.

To hook up the servos to the control surfaces, I STRONGLY recommend either steel wire or carbon rod in bondable teflon tubing. For trouble-free boost, you need a freely-moving, but no-slop system and these are about it. The stock non-supported metal pushrods WILL NOT CUT IT! Tubing is available from www.tailboom.com or www.rcbuilder.com and you'll need to size it for your choice of steel wire or carbon rod. You can get the steel wire from either www.smallparts.com (stainless... I'll list a part number later this week) or do what I did and get non-stainless non-stranded banjo string from your local music store (I used .014" for the elevator and .016" for the rudder, but recommend .016" for both. Do be aware that the rocket exhaust will corrode this cable over time and you will have to replace it... or face a possible crash (I've had one from this cable rusting so far!). For the carbon rod (I'd go for .030"), you can try your local hobby shop (LHS) or www.cstsales.com (who also has full pushrod kits in that size) or http://www.acp-composites.com/. For elevator/rudder/aileron horns, I just used the smallest of the DuBro park flier control horns (single post) available from your LHS.

In addition to the above, you'll need:

- a piece of BT-50-sized body tube and matching nose cone. I weighed several and found that balsa was lighter.

- some 1/8" balsa for the horizontal and vertical stabilizers, horizontal standoff, the motor pod mount standoff and keel, and some 1/8" square for a pushrod support.

- some 1/64" plywood for the motor pod mount standoff and keel.

- some 1/8" plywood for the wing mount, along with 6/32 screws (both a metal one for making the mounting and a nylon one for flying), washer (steel or nylon) and a 6/32 blind nut (all LHS).

- some 1/8" brass tubing and the next size down that telescopes into it... 3/32"? I used K&S square tubing because that's what I had on-hand (and because it is easy to glue into the structure, having flat sides), but round will work ok. This is used for the motor pod attachment,our get from your LHS.

- some 1/8" CF rod or hardwood dowel for the front wing mount from your LHS.

- some 1" wide glass tape for reinforcing the center wing joint, rudder and stabilizer joints and beefing up the elevator and rudder horn mounting areas. If you can't get that at your LHS, CST and ACP above will have it.

- Optionally, some CF tow for beefing up the elevator and it can also be used instead fo the glass tape for beefing up the elevator and rudder horn mountings. CST and ACP above will have it.

- some light plastic covering. I used Oracover/UltraCote Light available from either your LHS or www.hobby-lobby.com. Some of the new park-flier coverings will also work, but beware that you'll have to add exhaust protection both on the wing root and horizontal tail.

- some 5-15 minute epoxy and some micro-balloons (LHS for both).

- your typical assortment of sanding bars, a sharp knife, scissors, Dremel tool and some drills, grinding/sanding bits and a cutoff wheel, a small square needle-file, needle-nose, round-nose and offset jaw pliers (channel-locks or similar), thick and thin CA glue (I use the 'black' CA's for thick), masking and clear tape, a soldering iron, and a covering iron.

Note that a full-size sheet of patterns for the tail & fuselage parts are attached to this segment of the thread. To print it full-size, it includes a 5" ruler that you can use to set the zoom level.
Last edited by gstew; Jun 15, 2008 at 05:44 PM.
May 27, 2008, 11:09 PM
Registered User
Thread OP

Conversion Overview


(PARTIAL)

Note that this section is just partially filled so far. I update it as I finish the detail for each section.

While converting this ARF into a RCRG is tons easier than building a model from scratch, there is still a significant amount of work to do. The advantage of this is that noone will question whether you built the model, even though you started with an ARF

Here's an outline of the construction steps:

WING:
- Strip covering off wing root and tips
- Sand in additional dihedral (4.5"/tip) on wing root
- Sand tip leading edge to match airfoil profile
- Add guide notches for the wing mounting hardware into the wing root
- Join wing halves and reinforce
- Recover wing root and tips

TAIL SURFACES:
- Use existing tail surfaces as pattern to cut new surfaces out of 1/8" balsa
- Sand profile into tail surfaces (fully airfoil or just round leading edge and taper trailing edge)
- Cut elevator and rudder loose and sand in hinge bevel
- Add control horn and horizontal stab stiffeners
- Cut and shape horizontal stab standoff
- Glue horizontal stab to standoff

COVERING AND MOUNTING THE TAIL SURFACES:
- remove existing horizontal stab mount
- Cover bottom of horizontal stab & elevator
- Glue horitontal stab standoff to tailboom
- Glue vertical stab into tailboom slot
- Reinforce tail joints
- Cover tops of horizontal stab & elevator
- Cover vertical stab & rudder

MOUNTING THE WING:
- Remove existing wing mounting framework
- Glue 1/8" square balsa to buildup wing mounting surface on fuselage
- Trim new wing mounting surface to fit
- Drill wing LE peg hole in wing leading edge and wing mounting
- Glue in wing LE peg
- Prepare and glue in wing bolt platform
- Temporarily mount wing and drill through wing & wing bolt platform
- Mount blind nut in wing bolt platform and mount wing on fuselage and check for squareness & fix if needed
- Fare-in wing mounting area with epoxy & microballoons

ROCKET MOTOR MOUNT:
- Remove existing servo mounting platform
- Make internal pod mount
- Cut hole for pod mount tubing in fuselage nose
- Make motor mount pylon
- Glue rocket motor mount into fuselage nose
- Fit Canopy and cut hole for pod mount tubing
- Glue rocket tube and nose cone onto pylon

RC GEAR, CONTROL SURFACES AND LINKAGES:
- Modify servo mounting platform you removed above for two side-by-side servos
- Mount servos to mounting platform and glue into fuselage
- Cut slot into fuselage side and hole into boom mounting bulkhead for pushrod runs
- Install 1/8" square hard balsa pushrod support between rear of servo mounting platform and front of tailboom tube
- Size bondable teflon tubing onto pushrods
- Glue teflon tubing from front of pushrod support onto tailboom (through tailboom mounting area) and along tailboom to tail surfaces
- Bend/fab servo ends of pushrods & install into servo horns
- Install control horns on tail surfaces
- Center servos & finish pushrod ends
- Install receiver, antenna, & battery
- RESERVED FOR WING SERVO INSTALLATION
- Range check

LAUNCHER

TRIMMING AND FLYING
Last edited by gstew; Jun 29, 2008 at 01:35 PM.
May 27, 2008, 11:11 PM
Registered User
Thread OP

Wing


Here you will add dihedral to the wing roots, reshape the leading edge at the tips, join the wing halves, and recover the root and tips. Note that you won't be using the included wing joiner rod.


1st - Strip covering off wing root and tips

I recommend you use a soldering iron instead of a knife or razor blade to cut the covering where you will remove it. That way will not leave small cuts in the wood that weaken the area.

The original covering is not stuck down very well, especially on the sheeting and rib edges. So first take your covering iron and tack the covering down in the areas where you'll be removing it.

Use masking tape to mask off the roots and tips where you'll remove the covering. Gently run the soldering iron across the covering along the tape just fast enough to melt the plastic, but not so slow that you char the balsa.

Then strip off the covering in those areas.


2nd - Sand in additional dihedral (4.5"/tip) on wing root

The root ribs are a lite plywood. You'll sand the dihedral angle into them, keeping them full-width at the bottom, but tapering them to just a thin sliver at the top.

If you've done a lot of dihedral joints and are good at it, you can do it freehand. If not, align the wing root so the bottom of the root rib is even with the edge of your worktable or similar surface (I use a 9" x 2' shelf from my local hardware) and block up the tip to the dihedral amount (4.5" / tip or a little more). Use masking tape at the root and over the block for the tip to help hold it all in place. Then while holding the wing root in place firmly on the worktable, run your rough-to-medium sanding bar across the root until it is even with the edge of your worktable.

After you are done sanding the angle into the roots on the worktable, holding the wings in your hand, use your medium-to-fine sanding bar to clean up the dihedral'd roots and make them flat so they mate well.


3rd - Sand tip leading edge to match airfoil profile

The leading edge of the last 6" of the wing are not even well-rounded on all the Venus wings I've seen. Use your medium and then your fine sanding bars to shape the tip leading edges to match the shape of the inboard leading edge and to thin out and taper the tip profile. When I did this, the sheeting got so thin that I sanded through to the leading edge of the outmost rib... This is not an issue.


4th - Add guide notches for the wing mounting hardware into the wing root

Although I used the original rear wing mounting bolt holes, I strongly recommend you instead use a single bolt in the center of the wing root to mount the wing to the fuselage. To prepare for doing this, cut a 1/32" deep and wide vertical notch in each plywood wing root rib 3 3/4" from the leading edge of the wing root.

I used a single piece of 1/8" carbon rod (but you can also use either a dowel or a piece of brass tubing of the same size) glued into the center leading edge of the wing that fits into a hole drilled into the fuselage to position and hold down the leading edge of the wing. To prepare for mounting this, cut a 1/16" deep and wide horizontal notch about 1/2" long into the leading edge of each plywood root rib with the front of the notch at the leading edge of the airfoil and the long-axis of the notch parallel with the bottom of the wing root airfoil.


5th - Join wing halves and reinforce

Follow steps 13-24 of Oleg Golovidov's Taboo Instructions (see http://www.olgol.com/TabooGT/build1.html) for joining the wing and adding fiberglass cloth reinforcement. His instructions are excellent and I follow his instructions almost exactly step-by-step.

I pushed the servo extension plugs into their holes so they wouldn't be damaged or glued during this process. Also, I used CA for attaching the fiberglass reinforcement and used a wadded tissue to remove excess glue before it hardened to keep the weight down.


6th - Recover wing root and tips

I used Oracover Light from www.hobby-lobby.com. Ultracoat lite is the same or similar and will work as well. You can use one of the newer ultralight films such as Nelson Light Film, but then you WILL need to protect the area under the rocket exhaust as these covering are very temperature-sensitive.


7th - Removed un-wanted warps and add needed ones... this is a critical step, do not fly the model unless you've done this and are comfortable that the wing is mostly flat except for the needed washout.

You want the wing to be flat except for about 3/32" of washout (trailing edge higher than the leading edge) in each tip starting just inboard of the tip of the aileron. Use an iron to heat the wing and remove/add warps... a heat gun is too imprecise.

You will likely have to straighten the aileron trailing edge... do this first before tackling the wing structure.

I start with taping the ailerons to the wing so they won't move, then use a couple of straight 12" sticks of 1/8" balsa that I lay and/or tape onto the bottom of the wing to highlight general structural warps... tape one to the bottom of the wing about 2" out from the root and move the 2nd one along the chord of the wing to show where it's warped. To de-warp, it is easiest to have a helper hold the panel over the edge of a table while you apply the corrective twist and heat one side. Hold it a bit past where you want the surface to be while it cools, it will spring back a little.
Last edited by gstew; Jun 22, 2008 at 06:47 PM.
May 27, 2008, 11:13 PM
Registered User
Thread OP

Tail Surfaces


Here you will be making new tail surfaces and a new horizontal stabilizer platform. DON'T EVEN THINK OF USING THE ORIGINAL TAIL SURFACES, THEY ARE TOO WEAK FOR ROCKET BOOSTS!!!

1st - Cut new surfaces out of 1/8" balsa. You can use the existing surfaces as patterns or use the ones I included on the pattern sheet.

I used pretty light balsa AND airfoiled the surfaces, so I needed the CF stiffener you see in the photos. If you use medium balsa and are less aggressive on your airfoiling (or just round the LE and taper the TE), you won't need the stiffener.


2nd - Sand profile into tail surfaces (fully airfoil or just round leading edge and taper trailing edge). Either will work.


3rd - Cut elevator and rudder loose and sand in hinge bevel. Transfer the hinge lines onto the surfaces from your patterns and cut loose the elevator and rudder. Sand a 45 degree bevel onto both the horizontal and vertical stabilizers and the elevator and rudder. The hingeline is on the BOTTOM of the horizontal stabilizer and on the LEFT SIDE of the vertical stabilizer (as viewed from the rear of the ship).


4th - Add control horn and horizontal stab stiffeners. As I noted above, you may or may not need a horizontal stab stiffener. You WILL need control horn stiffeners. If you have it, you can use unidirectional carbon as I did. An acceptable alternative is 1/4" wide strip of light (1oz - 2oz) glass cloth. Mark the location of the centers of the horns... about 3/8" from the top of the rudder and about 3/16" to the right of centerline of the elevator. Lay on a 1" wide, 1/4" deep at the center triangle of your chosen stiffener material on the top and bottom of the rudder and elevator using thin CA.

If you need the horizontal stab stiffener, cut a length of your chosen stiffener material at least 4 1/2" long and laminate it on the top and bottom of the stabilizer about 1/2" ahead of the hinge line, with the top and bottom pieces directly above/below each other.


5th - Cut and shape horizontal stab standoff. To make shaping easier, cut a piece of 1/8" balsa 1" x 1 3/4" with the grain parallel to the 1" sides. Shape it onto an airfoil shape with the leading edge at one of the 1" sides and the trailing edge at the opposite 1" side... you can just round the LE and taper the TE if you are lazy. Then using your medium sanding bar, shape a 1 3/4" edge to match the profile of the top of your horizontal stabilizer and shaped such that the standoff fits at a 90 degree angle to the stabilizer surface. Then draw a line 5/16" above and parallel to the profiled edge, aligning the line so it puts your stabilizer profile (flat topped or airfoiled) parallel with that line. Then make a mark 1/32" above that line at the trailing edge of the standoff stock and draw a line from this mark to the 5/16" mark at the leading edge. Cut the standoff loose at this line so you get a bit less than a degree of positive incidence (down elevator) on the stab when it is mounted... this makes boost trimming easier. Finally, wrap a sheet of medium or fine sandpaper around the fuselage boom (ideally around a tube a little smaller than the fuselage boom) and shape the top of the pylon to fit snugly against the fuselage top.


6th - Glue horizontal stab to standoff. Mark the centerline of the horizontal stabilizer on the top of the surface. Glue on the stab standoff aligned with this line and 90 degrees to the surface of the stab... I used black CA here.
Last edited by gstew; Jun 15, 2008 at 12:01 PM.
May 27, 2008, 11:16 PM
Registered User
Thread OP

Mounting The Tail Surfaces


Here you will be mounting the new tail surfaces on the tailboom. Note that the covering will act as the hinge for both the surfaces, so you'll be covering each side in a single piece (halves of the

1st - Use your knife to cut off the supplied horizontal stabilizer mount. Cut into it at an angle so that you slice it off without cutting into and weakening the tailboom


2nd - Cover the bottom of the horizontal stabilizer and elevator. The covering will act as the hinge Heat your covering iron to the appropriate temperature for your covering material. Cut a piece of covering about 1/4" or so larger than the outline of the horizontal stabilizer and elevator. Start by covering the horizontal stabilizer bottom, tacking down the covering to the wood well. Once you've covered the bottom of the stab, line the elevator up at the trailing edge of the stab and continue tacking down the covering to the bottom of the elevator. After covering the bottom of both the stab and elevator, trim the covering to about 1/8" excess of the outline of the surfaces, then cut slots in the excess so it will fold over and overlap on itself. Then do that with your covering iron.


3rd - Glue the horizontal stab standoff to the tailboom. Start by fitting the vertical stabilizer into the slot pre-cut into the end of the tailboom and tape it in place. Fit the horizontal stab and standoff to the bottom of the boom with the trailing edge of the elevator about 1/8" ahead of the leading edge of the rudder. Place a wrap of masking tape around the boom at the leading edge of the standoff as a marker. Then mix up a small batch of filled epoxy and use it to glue the standoff to the boom, taping around the boom onto the standoff and stab to keep them secured and aligning the stab to horizontal (use the fitted vertical stab to help with this) and the elevator hinge line 90 degrees to the fore-aft axis of the tailboom. Remove the tape holding the stab and standoff and the tape marker afte the epoxy has hardened.


4th - Glue vertical stab into the tailboom slot. Use a bit of filled epoxy to do this, just a bit as most of the strength of this joint comes from the glasscloth reinforcing.


5th - Reinforce tail joints. Cut two patches of light glasscloth that will wrap from the top of the tailboom down around the stab standoff and about 1/4" onto the stab surface. Glue one down on one side, then the other. I use foam-friendly CA, protect my fingers with a bit of polyethylene bag, and use tissues to soak up the excess. You can use epoxy if you want, but keep it light! After the first side hardens, do the other side.

Then cut two patches of light glasscloth that will cover the vertical tail/tailboom joint with about 1/4" of overlap onto the vertical surface. Apply to each side as above.

After the reinforcing patches are fully cured, you can mask off the surrounding balsa surfaces and gently feather the edges of the reinforcing... see the attached picture.


6th - Cover tops of horizontal stab and elevator. Having covered a lot, I used one piece of covering for each half of the surface. If you are a fairly in-experienced cover-er, use a small piece on each side of the stab standoff and then a piece on each side of the top of the stab/elevator. Fold the elevator completely back onto the bottom of the stab before you start covering the top. Start with tacking the covering down to the horizontal stab first, then iron it down around the trailing edge of the stab and leading edge of the elevator to make the top half of the hinge.. Get that all ironed down well before starting to iron the covering down to the elevator... I left it taped to the bottom of the stab and started ironing the covering onto the elevator top, then removed the tape and held it while I finished ironing it down. When done, unfold the elevator and use a new knife or razor blade to trim around the edge of the surface.

See attached pictures taken during the covering process of 1 half of the horizontal stab.

If you sanded the stab/elevator to a thin airfoil as I did, it will likely have warped by now, especially at the trailing edge. Use your iron to heat it up and flatten it before going on.



7th - Cover the vertical stab and rudder. Use the same technique that you used on the horizontal stab and elevator to cover the vertical stab and rudder. Start with one single piece to cover the left side (as viewed from behind) of the surface, starting with the vertical stab and adding the rudder. Trim to about 1/8" excess, cut slots for overlap, then fold over and iron down the excess to the opposite side. Do the right side again with a single piece of covering, starting with the rudder folded back along the vertical stab, covering first the vertical stab, then wrapping the covering around the hingeline before ironing it down to the rudder. Trim the edge and then de-warp if needed.
Last edited by gstew; Jun 15, 2008 at 04:30 PM.
May 27, 2008, 11:22 PM
Registered User
Thread OP

Mounting The Wing


Here you will mount the wing onto the fuselage. Because of the increased dihedral, you are re-shaping the wing mounting area of the fuselage by building it up with balsa and epoxy.


1st - Remove existing wing mounting framework. Although this was glued in pretty well in mine, a little force was all I needed to remove it. You will need to spread the edges of the wing opening to take the structure out. Use needle-nose pliers to take out any remaining pieces.


2nd - Glue 1/8" square balsa to build up the wing mounting surface on top of the fuselage. Use medium sticks of 1/8" balsa and glue them on the top of the wing mounting platform of the fuselage about 1/16" back from the edge of the platform. These will act as the new mounting surface for the bottom of the wing and the area along the outer edge of these rails will be filled in with microballoons/epoxy.

Start by tacking the front of a strip down at the front end of one side of the top of the mounting platform and work it back to the trailing edge, curving it to match the platform shape. Cut it even with the trailing edge of the wing.


3rd - Trim new wing mounting surface to fit. The 1/8" balsa you just glued in will not match the bottom of the wing. Hold the wing onto the wing mounting area of the fuselage and using your medium sanding bar, trim and angle the 1/8" balsa edge to match the bottom of the wing. When done, the center of the trailing edge of the wing will fit against the rear of the wing mounting platform, the center of the leading edge will fit into the front of the wing mounting platform, and the rest of the wing bottom will fit against the trimmed 1/8" balsa rails. If you sand too much off, cut the 1/8" balsa off and glue on new pieces.


4th - Drill wing LE peg hole in wing leading edge and wing mounting. Cut a 3/4" length of your chosen 1/8" rod (CF, hardwood dowel, or brass tubing). Use your Dremel and a 1/8" drill bit to drill about 1/2" into the notch at the leading edge of the wing (remember, you cut this into the ply root ribs before
joining the halves). Then wiggle the drill bit around to enlarge the hole a bit. Next drill a corresponding 1/8" hole into the center front of the wing mounting area on the fuselage. Fit the 1/8" rod into leading edge hole in the wing and trial-fit it onto the fuselage to make sure you have sufficient play to line up the wing when looking down from the top and straight on from either the nose or tail.


5th - Glue in wing LE peg. Mix up a bit of filled epoxy and use the 1/8" rod to push it into hole in the leading edge of the wing, then mount the wing onto the fuselage and hold it in place as the epoxy hardens, lining it up so that the wing is aligned both when looking down from the top and straight on from either the nose or tail. It may help you to fit rubber bands that wrap across the top of the wing and hold the wing onto the fuselage top... if you do this, trial-fit it before starting to glue in the LE peg.


6th - Prepare and glue in wing bolt platform. If you look closely at the pictures, you'll see I used the existing wing mounting holes. I STRONGLY RECOMMEND YOU DO NOT DO THIS! It was a real PITA to get it aligned and installed correctly. The following method is a LOT easier...

Start by cutting a wing bolt platform about 1 1/16" by 3/4". Trial fit it in the fuselage with the center of the platform 3 3/4" from the leading edge of the wing mounting area of the fuselage. Once it fits snugly between the sides of the fuselage just against the bottom of the lip of the wing mounting platform, mix up some filled epoxy and glue it in place.


7th - Temporarily mount wing and drill through wing & wing bolt platform. Locate the vertical notch you put in the wing roots at 3 3/4" back from the trailing edge. Drill it out to 1/8" using your Dremel and an 1/8" drill bit, making sure to make the hole vertical to the wing bottom and when you look from the front or back of the wing. Put the wing back onto the fuselage and tape or rubberband it down, making sure it is aligned 90 degrees to the fuselage when viewed from the top. Once it is aligned and taped or banded firmly in place, use your Dremel to drill straight down through the 1/8" hole and start a hole in the wing bolt platform. Don't drill through the platform, just mark the top of it. Then take off the wing and then drill all the way through the platform with a 1/8" bit. Open up the hole to 3/16" by using in succession 9/64", 5/32", 11/64", then 3/16" (a reamer can be used here too... and you CAN do it in one step, but this tends to keep the hole more precisely located). I don't use a drill for this, just twirl the bits in my fingers.


8th - Mount blind nut in wing bolt platform and mount wing on fuselage and check for squareness & fix if needed. Press the 6/32 blind nut gently into the bottom of the platform and trial-fit the wing on the the fuselage, threading a metal 6/32 bolt down through the hole in the wing (it will be a tight fit) and into the blind nut. Confirm that your wing is still in alignment as viewed from the top... if not, oblong the blind nut hole to one side or the other as needed. Then pull the blind nut off the wing bolt platform, apply a bit of filled epoxy onto the mounting surface, push it back in place, use a part of channel-locks or similar pliers with angled jaws to press the blind nut firmly in place in the wing bolt platform, then mount the wing and confirm the alignment again as the epoxy hardens.


9th - Fare in wing mounting area with epoxy & microballoons. Start by using your Dremel and either a sanding drum or a grinding bit and take off the 'fillet' bumps on the rear sides of the wing mounting area of the fuselage. This will make the fuselage very thin or even break through towards the back... I fitted a couple of pieces of glasscloth into the depressions, pushing them in so they made a slightly concave cross-section. This was filled in as I fared-in the wing mounting area.

Next cover the center of your wing with Saran Wrap. I start with a piece of wrap about 6" wide and 9"-12" long. I place it over the bottom center of the wing and use small pieces of masking tape to secure it on the bottom. THen I wrap it around the leading and trailing edge and tape it down, keeping it flat over the top of the wing with excess in the center that I just fold over an tape down. The leading edge wing mounting dowel will poke through the wrap at some point during this... help it do so if needed.

Next shape a small wedge of balsa wood to help fill in the space on the top of the fuselage aft of the wing. You can fill the whole area in with filled epoxy, but it will weigh more and be harder to shape. Make the Wedge smaller than filleted area so that it is covered with the filled epoxy. Once the wing is protected and the balsa wedge is in place, bolt the wing onto the fuselage and mix up a batch of filled epoxy. I recommend you use something other than 5-minute epoxy here... if you must use 5-minute, plan to do one side, then the other. Use a stick (I use popsicle sticks) to fill and fare epoxy into the wing-fuselage joint... all the way along the bottom and wrapping around the top center and back along and over the balse wedge at the rear. As it starts to thicken, use a finger dipped in rubbing alcohol (with appropriate skin protection) to smooth the joint area. I don't recommend you try to make a fillet... just to extend the fuselage side contour up to the wing bottom, around the wing leading edge, and along the sides and top of the fuselage behind the wing. After it has hardened, pull off the wing and sand it to match the fuselage sides/front/rear. You may need a couple of applications to get it all complete... it took me three.

I'll get updated pictures of the wing-body mount area posted soon.
Last edited by gstew; Jun 29, 2008 at 01:26 PM.
May 27, 2008, 11:25 PM
Registered User
Thread OP

Rocket Motor Mount


Here you will make and install the rocket motor pod and internal pod mount


1st - Remove existing servo mounting platform. Although this was glued in pretty well in mine, a little force was all I needed to remove it. Use needle-nose pliers to take out any remaining pieces.


2nd - Make the internal pod mount, using the pattern in the 'Materials Needed' post. Easy method for this is to trace the pattern onto a piece of 1/64" plywood and cut the ply side out using sharp scissors. Then glue it onto a sheet of 1/8" balsa (I used black CA for all of the plyon and mount assembly, but epoxy works well too) and cut around the ply side to make the pod mount core.

Before you continue and finish the pod mount, you want to fit it to your fuselage as the inside profiles will vary somewhat. Take and insert it into the fuselage and see if it fits in... likely you'll need to remove a bit here and there using your course sanding bar. Once you are done fitting it, mark the canopy opening front edge onto the top of the pod mount.

Next, transfer the locations of the motor mount brass tubes from the pattern onto the balsa core. Then carefully cut the recesses for the brass tubes from the balsa core, taking care not to cut into the ply sides. Glue in over-length sections of brass tubing (you'll be trimming them as you install the mount into the fuselage). Finally, face off the open side of the core with a fine sanding bar and glue the faced side to your sheet of 1/64" plywood. After the glue hardens, cut it free of the 1/64" sheet.


3rd - Cut holes for pod mounting tubes into fuselage nose and canopy. Start here by using your dremel and cutoff wheel to trim the brass mounting tube ends, leaving about 1/8" sticking out of the pod mount, and parallel with the top of the pod mount. Then hold the pod mount against the side the nose and mark on the location of the front pod mounting tube on the top centerline of the fuselage. Drill through the fuselage using your Dremel and a small grinding bit or drill and use a small square file to square the hole. Then gently flex the fuselage sides together at the nose and insert the pod mount. If it doesn't fit, remove it and enlarge the square hole forward or backward as needed and re-fit. You can fill in the oversized area after installing the pod mount.


4th - Make motor mount pylon. Use the pattern in the 'Materials Needed' post and the same technique you used to make the internal pod mount to make the motor mount pylon. Here you will use both the 1/8" and the 3/32" brass tubing to make the pod mounting struts. I did not try to cut the 1/8" tubing at an angle to match the bottom of the pylon, but squared it off such that the end was entirely inside the pylon sides. When gluing the brass tubing into the pylon, I have it inserted into the internal pod mount for alignment. Once you are done with the pylon, round the leading and trailing edges.


5th - Glue rocket motor mount into the fuselage nose. Mix up a small batch of epoxy with some filler (I used chopped fiberglass, but microballoons are ok). Use a small stick to apply some on the centerline of the bottom and top of the fuselage where the internal pod mount will fit, then apply some to the outer edge of the pod mount. Gently flex the sides of the fuselage at the nose and insert the internal pod mount, eyeballing it into place. Then insert the motor mount pylon for an external reference and use it to align the internal pod mount so it is both vertical as viewed from the front of the fuselage and in-line with the long axis of the fuselage as viewed from the top. After the epoxy hardens, use your Dremel and a grinding tool or cutoff wheel to trim the front brass mounting tube flush with the top of the fuselage, then use a bit of filled epoxy to fill any excess hole you made getting it fitted.


6th - Fit canopy and cut hole for pod mount tubing. The rear-most recess on the top of the internal pod mount is for the plywood circle on the underside of the canopy. You may need to adjust it for your canopy. Measure from the front of the canopy opening to the front edge of the rear brass mounting tube and transfer that dimension to the top of your canopy, then use your Dremel and a small grinding bit or drill to make the hole for the tubing. Square it with your small square file and again, adjust it back or forth to fit as needed. Then install the canopy and use your Dremel and a grinding tool or cutoff wheal to trim the rear brass mounting tube flush with the top of the canopy.


7th - Glue rocket tube and nose cone onto the pylon. (NOTE: Wait to do this after your initial glide tests so you can move the motor tube backward or forward on the pylon to adjust the CG.)

I used my Dremel and a grinding bit to hollow my nose cone, then glued it into a 1.5" section of BT-50 that I had laying around. You might want to use a full 3"-length section of BT-50. Then with the motor mount pylon mounted onto the fuselage, epoxy the bodytube/nosecone assembly onto the pylon, aligning the assembly to where you've determined it needs to be for CG (on mine, the front of where the motor ends inside the tube is about 3/4" back from the front-top corner of the pylon). Align the body tube carefully so it is in-line with the axis of the fuselage as viewed from the top as the epoxy is hardening or you will regret it later!

Use filled epoxy to fillet the pylon/bodytube joint. For extra credit, wrap the top of the fuselage and canopy with Saran Wrap or equivalent and use some filled epoxy to fill the joint between the pylon and the fuselage, making sure not to glue the pylon onto the mount!
Last edited by gstew; Jun 22, 2008 at 06:48 PM.
May 27, 2008, 11:26 PM
Registered User
Thread OP

RC Gear, Control Surfaces And Linkages


RESERVED FOR RC GEAR, CONTROL SURFACES AND LINKAGES
- Modify servo mounting platform you removed above for two side-by-side servos
- Mount servos to mounting platform and glue into fuselage
- Cut slot into fuselage side and hole into boom mounting bulkhead for pushrod runs
- Install 1/8" square hard balsa pushrod support between rear of servo mounting platform and front of tailboom tube
- Size bondable teflon tubing onto pushrods
- Glue teflon tubing from front of pushrod support onto tailboom (through tailboom mounting area) and along tailboom to tail surfaces
- Bend/fab servo ends of pushrods & install into servo horns
- Install control horns on tail surfaces
- Center servos & finish pushrod ends
- Install receiver, antenna, & battery
- RESERVED FOR WING SERVO INSTALLATION
- Range check
Last edited by gstew; Jun 29, 2008 at 01:34 PM.
May 27, 2008, 11:27 PM
Registered User
Thread OP

Rc Gear


Reserved for RC Gear
May 27, 2008, 11:28 PM
Registered User
Thread OP

Launcher


Reserved for Launcher

Note I got permission from Kevin McKiou to use these sections from his 'Cuda instructions. I may add some text of my own later, but for now this will get you started.
Last edited by gstew; Jun 03, 2008 at 02:15 PM.
May 27, 2008, 11:29 PM
Registered User
Thread OP

TRIMMING AND FLYING (1st Draft)


Trimming and Flying

Here, you will start by getting the glider trimmed for gliding flight, then setting it up for boost and boosting it to get it trimmed.

1st - Prepare your model for trimming by making sure:

- your RC system is working

- You have performed a range-check

- Your surfaces are going the right direction for your control inputs (back on the elevator stick makes the elevator rear go up, right on the rudder

stick makes the rudder go right as viewed from the rear)

- Your transmitter and receiver batteries are charged

- Your tail surfaces are flat and warp-free and that your wing is flat and warp-free except for the 3/32" washout in the last 3"-4" of each tip

- Picking a fairly calm day for both your glide trimming and boost trimming



2nd - Insert an empty reload casing into your motor tube and tape it onto your motor mount pylon, moving it back and forth to give the desired CG of 53mm plus or minus 3mm from the leading edge (instructions say 46mm, I found that too far forward). If you want to accurately model an expended reload, tape in a couple of pennys, but I never bother to do this. If you can't get this CG with any reasonable position of the tube on the pylon, move it to the farthest point that your feel will work and move your battery and receiver (for very small adjustments) and/or add some weight to the nose or tail as needed. Built as recommended, you likely won't have to do this.



3rd - Start with some straight-ahead glides from shoulder-height. Since you may need to add up or down elevator, it helps to have someone else make these tosses IF you have someone who can do straight-ahead, slightly nose-down tosses at roughly glide speed. Adjust it to a good, slightly floaty glide using your elevator trim. Also watch for a turn to either side and adjust that out with your rudder trim.



4th - Give it some hard overhand tosses, pushing it over into a glide at the top with down elevator. Again, it helps to have a helper who can throw it hard and accurately straight... many people twist it one direction or the other at release. Fine-tune the glide here, especially trimming out any turn. Also get used to the controls while doing this.



5th - Once you have the glide adjusted using the transmitter trims, note where the surfaces are, set the trims back to neutral, and adjust the pushrod lengths to give the needed surface positions for a good, straight glide. Test your adjustment with some more tosses and re-adjust as needed until you get it right.



6th - Prepare your boost trim. Most intermediate and advanced radios now allow you to set different flight modes, so you can have separate adjustments for glide and boost. If yours does not do this, you will need to add downtrim manually and take it out after the boost is done to make it glide. Start with 6 clicks of down-trim for boost... I can't tell you exactly how much to add because different transmitters or different transmitter setups will vary the amount of surface movement per click of trim. Your job during the trimming phase is to find out exactly how much trim you need for a good boost.



7th - Prepare for your first boost. I like George Gassaway's idea of making an adapter for a C6 that fits into a reload casing... this will protect your model in case of a black powder cato, but since the motor tube is mounted above the fuselage, a cato will only take out your tube and nosecone, not any of your RC gear, so this isn't critical for this model. In any case, if you don't adapt the C6 into a reload casing, add weight to the adapter to make it and a spent C6 weight about the same or just a little more than an empty reload casing.

Also prepare a lot (6 at least) C6 motors for boost trimming. Although this is not according to NAR Safety code, I epoxy-plug booster motors. You can also pack the end with wadding and use multiple layers of tape over the motor end to hold it in... but that's a pain, just epoxy-plug them. Make sure they are cured before using them!



8th - Place the model onto the launcher. I ALWAYS have my RC gear on and system checked before I put the glider into the launcher and hook up the clips. The launcher should be facing into the wind... move it if the wind has shifted. Cant the launcher about 15-25 degrees from vertical into the wind. If you don't have a long launch controller (50'-100'), have a helper launch for you. Place yourself at least 50' back from the model and at least 10' to one side towards the sun. If it is a clear day and the sun is in the sky, make sure to have sunglasses on if you need them.



9th - Take a few deep breaths and launch your Venus (or have your helper launch it). It won't go too high or go too fast on a C6... higher and faster than you can throw it, but not by much, only 100'-140'. You have two jobs during the boost. The first is to fly it straight up and out at the angle into the wind. If it pitches down or up, correct it. If it starts to turn one way or the other, correct it. The other job is to notice what type of correction you have to give it to make it fly straight up on that angle. Remember it is going faster than you can throw it, you will need to make small and smooth control inputs during boost or it can get a bit hairy.

After burnout, set it for glide trim (either by switching from boost to glide mode or resetting the trims to glide-neutral) and glide it down. Remembering what control inputs you had to make, adjust your trim a couple of clicks in the direction you corrected. DON"T TRY TO MAKE ALL THE CORRECTION IN ONE ADJUSTMENT, sneak up on the setting, otherwise you might make it worse.

Do another boost, correct and note how you correct, glide it down, and then put in more correction. Repeat until you have it boosting without you having to make control corrections. Yes, you can get it there... it may take a number of boosts, but it is achievable and where you need to have it.



10th - Prepare to do the same thing with D7's. Once you have it adjusted for no-control-input C6 boosts, it will fly safely on a D7, but will not necessarily fly with no correction needed. Be prepared to 'fly the boost again... it will likely require little or no correction, but be prepared for some. If you do have to correct it on a D7, input the correction into your boost mode after you have the model down... but sneak up on it more carefully, make only 1/2 the amount of correction you made with the C6 boosts.

If you plan to fly your Venus with higher power motors (E7's and E6's), repeat the process with those motors. Again, it likely won't need correction, but might... don't be surprised. My experience is that a model set up like the Venus will fly ok on E7's and E6's once you have got it trimmed with D7's, but so far I have only flown the Venus on E7's, so I can't comment on E6's yet.
Last edited by gstew; Jun 22, 2008 at 07:35 PM.
May 28, 2008, 03:57 PM
Just plain ridiculous. Sir.
rdwoebke's Avatar
Greg,

You are an awesome guy for providing all these images/details on your converstion. Great work and best of luck at the Capital Cup (and the world champs).

Ryan
May 28, 2008, 09:32 PM
Registered User
I second what Ryan said. Awesome! It looks as though the motor pod is removable. What a great idea! Got lots of questions but I'll wait till you get further along.

Richard
May 30, 2008, 07:19 AM
From The Lab

Radio without a regulator


Thanks for posting all this information, Greg. Do you have a list of the original, unmodified component weights.

As to the radio gear: According to Castle Creations tech support, the Berg receivers can be used safely with 2S Lipo batteries.

According to the Dymond D47 BOX, the servos can be used at 4.8 to 9.6V, and thus can be used with 2S Lipo batteries.

And according to my (currently very limited) testing, this DOES work OK. No regulator at all.

regards

Steve (who first met Greg when we were both (ACK!) teenagers!)


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Blue Arrow Angel ***DLG*** rdaggett77 Hand Launch 55 Jun 24, 2014 01:20 PM
Discussion Blue Arrow Venus DLG PLATINUM Hand Launch 15 Mar 27, 2008 07:31 PM
Question Blue Arrow Angel DLG helipilot Hand Launch 5 Jul 23, 2007 02:23 PM
Wanted Blue Arrow: Venus DLG PLATINUM Aircraft - Sailplanes (FS/W) 0 May 27, 2007 10:59 AM
Yippee! Best entry level 3-d Helicopter, tons of practice on simulator REFLEX & g3 & AFPD Alkaline Electric Heli Talk 7 Jun 28, 2005 03:20 AM