Building the “Valdivia”– Part 1
by Patrick Matthews © 2006
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Robbe has added another elegant r/c schooner kit to their lineup, the “Valdivia”. The gaff rigged prototype for this 1:20 scale model is an 1868 Swedish-built vessel which now plies the waters off Germany. Built as a private yacht with a Grand Banks fisherman’s rig, she sailed under her original name “Vanadis”– the Norse goddess of love and beauty– in a series of private and government roles in Sweden before coming to Germany in 1956. Renamed “Valdivia von Altona”, she was fitted with an auxiliary engine. In 1978-81, she was overhauled and began operation with a maritime museum in Flensburg, Germany. In 2003, she went again into private hands for further restoration, and her original name “Vanadis” was restored (1). Robbe’s model depicts the schooner in her museum configuration, carrying the name “Valdivia” and her auxiliary drive.
Robbe’s first schooner, the sleek 1935 yacht “Atlantis”, is rather imposing at 54” length and 68” overall height, so the new model of the “Valdivia” might be a bit easier to manage for some at 41” length over the hull, or 61.5” over the bowsprit, and 53” height. While Robbe recommends the model for advanced builders and rates the build time as “long”, certain details speed the build significantly. The hull and deck are vacuum-formed ABS, and many parts are preshaped, requiring only to be pushed out of their die-cut sheets or trimmed to length.
One aspect of scale fidelity is compromised due to physics. When we scale down an operating sailing vessel, we find that hull volume and displacement are reduced by the cube of the scale factor, while the sail area is reduced only by the square of the scale. In other words, the righting torque exerted by the keel’s weight is reduced much faster than the force acting on the sails, so that a truly scaled model boat might be unsailable in even the lightest breeze. Model yachtsmen make up for this with very long extended keels, with all the weight concentrated in a keel bulb. Some “scale sailors” will build a keel extension that can be removed for display, and reattached quickly for sailing duty. Robbe chose another approach- by widening the keel itself, some displacement is added and space is provided for putting the ballast down as low as possible. The extra girth is noticeable only when viewing the bow from a low angle; from all other directions, the trick is completely hidden. But even with this trick, Robbe recommends the model for sailing only in light winds, or with reefed or removed sails.
While it’s possible to order directly from Robbe (www.robbe.com), you may find it easier to let someone else worry about the details of importation. Al Matava at Ships n’Things (http://shipsnthings.com/, (908)722-0075) regularly brings in Robbe product, and says that he can have a “Valdivia” within a few weeks. Robbe has a long list of recommended options for the kit. Some items can be locally sourced, such as radio, servos, and leads, but two kits are not so optional at all– the No. 1141 “Ballast Keel” and the No. 1142 “Fittings Set”. The ballast set is actually four bars of lead weighing in 10.6 lbs. Their extruded shape is just right for setting into the keel of the ABS hull. The Fittings Set includes a number of detail items from life preservers to the anchor winch, but also critical rigging hardware and the deck planking, much of which is needed early on in the construction. The No. 1144 “Power Set” is truly optional- you may choose to use other gear for the auxiliary drive (more on this later), or leave it out altogether if modeling the early “Vanadis” (in which case you’ll need to fill in the prop’s notch in the keel).
Even without an auxiliary drive, you’ll need a battery to run the receiver and servos. Robbe recommends a big 6v 1400 mAh NiCad receiver pack; my preference would be a NiMH pack due to friendlier charging characteristics and higher capacity. The pack has five large ‘A’ cells ( not ‘AA’). Also on the options list is a 9.6v transmitter pack– but this is intended for use in the recommended Robbe F14 Navy radio set, not in the model.
A Word on Tools and Supplies
Most of this kit can be assembled using the standard tools and materials, but here are a few that are particularly helpful:
You’ll need to drill many holes, and the sizes are all given in millimeters. Most of us don’t have metric drill bits, but with a drill index loaded with English bits numbered 1 to 60 (0.228” to 0.040”), one can usually find something suitable for making, say, a 1.6 mm hole. You’ll like to have a conversion chart or calculator handy too! Remember, divide millimeters by 25.4 to get decimal inches. And to go along with the drill bits, a set of suitable pin vises will let you do the delicate work quickly without resorting to power tools.
A box-load of spring clamps will be necessary. I used quite a few different sizes, from clothespins to steel clamps that’ll about take your finger off. Whoever built the model in the instruction book seemed to have access to a large number of battery cable clamps, which appear to have just the right reach and gripping power for many of the jobs.
ABS is a notorious material when it comes to joining. Solvent cements are available, but I’ve never been able to make joints that have the integrity of cemented styrene joints– the ABS just doesn’t seem to weld as easily. And for joining wood or metal to ABS, cyanoacrylate (CA) is sometimes marginal. Robbe recommends “Stabilit-Express” (S-E), a wood-colored two-part methacrylate that sets hard and machinable. And it sticks pretty well to ABS. I found out later that even S-E isn’t perfect– if the joint is flexed, the S-E can still peel or pop off. But in well braced applications, it will do just fine. S-E is available in the US from Hobby Lobby (www.hobby-lobby.com).
But since S-E is rather expensive for even the small 30g package, and methacrylates are otherwise unavailable here except in industrial sized containers, I looked for alternatives. I’ve found that epoxies also tend to peel right off ABS, and CA isn’t suitable for the big jobs. Instead, I use a lot of “Amazing Goop”, a clear viscous adhesive that dries to a slightly pliable condition, and which forms a truly tenacious grip onto the most difficult plastics and metals. I used it, for example, to set the lead ballast bars. Caution– used between two surfaces that don’t allow for evaporation of the solvent, Goop won’t set at all. Goop is available at any hardware store.
Another handy European material is “Milliput”, a two-part putty that also does well adhering to ABS and styrene. Milliput can be ordered from Micromark (www.micromark.com). This will be useful in filling several seams on the hull and bulwarks.
Upon opening the large kit box, we find the main ABS sections, masts, precut sails, some die-cut plywood and ABS sheets, a few miscellaneous bits, and the instructions and plans. The documentation is a marvel. The main instruction book is 86 pages of detailed illustrations and German text. A secondary book has another 75 pages of text in English and French, less the illustrations– so one will be referring to both books at any one time, perhaps learning a bit of German along the way. Six sheets of plans provide general arrangement and rigging layout, parts finder, and the sail construction plans. If you care to peruse the instruction book, it can be downloaded as a PDF file from Robbe’s website (Adobe Acrobat required). Another detail that caught my eye– all the drawings are created the traditional way, hand drawn and carefully inked, no CAD.
The first job after unpacking, reading the ENTIRE instruction book, and assembling the plywood boat stand, is to trim the hull and deck moldings. Both have molded-in edges to provide a cutting guide. You’ll want to cut just inboard of these edges, keeping the finished parts as wide as possible while ending up with two flat flange edges. These flanges will eventually be glued together, sealing the deck to the hull. Small cuts inboard of the edges won’t hurt, as the flanges will be cut back a bit after joining. I found aviation snips useful during the heavy trimming. These come in straight, left and right cutting versions. First, make a rough cut within a few millimeters of the final edge, then use either the left or right set to peel off a curl of material to either side while trimming right to the line. If you’re in a trimming mood, you can go ahead and cut out the bulwarks and cabins from their respective moldings at this time too.
We start assembly by attaching a small keel extension to the hull– this is a place for the S-E, and Milliput for filling the seam. The rudder tube, rudder (a very nice resin casting), and footing go together easily after this. The rudder tube is another good place to use the S-E, as it builds a strong fillet where the tube pierces the hull. Finally, some supporting parts for the bowsprit are fitted and glued into the stem.
A die-cut bulkhead fits into the stern to carry the steering servo (any standard ball bearing servo will be adequate) and the Robbe power unit. The motor/gearbox arrangement is compact, with the 2:1 reduction unit and motor mounting neatly on the bulkhead. However, I found mine had noise issues. The stuffing tube was pressed into the gearbox case off-angle, so that it wasn’t parallel to the motor’s centerline. I tried shimming the motor to correct the gear mesh, and was rewarded with some improvement. But given the fine nature of this model, I decided to use an inherently quieter gearbox, one with precision mounted fine pitch gears. Robbe has several good choices in their catalog, but I had a nice 2.33:1 Graupner unit with a Speed 400 motor handy, which I was able to adapt to the hull while retaining the original stuffing tube and prop shaft. There’s plenty of room to work with here, so other designs could be accommodated too. Also look for me to substitute a brass prop for the 3-bladed plastic item. 35mm diameter and M4 threads will do the job.
I also chose to upgrade the steering linkage. Robbe provides some rods with Z-bends for attaching to the tiller and servo horns, but I used some nice ball links instead.
Ballasting the model is easy, as Robbe has figured the weight and placement for us, and even provided the lead bars in just the right sizes. The bars come tightly packed in their own laser-cut package. Three of the bars merely need to be laid into the keel and secured. I used Goop for this job, applying generous bead along the outside edge of each bar. The fourth bar needs to be cut, and instructions are given for shaping one piece to fit the fore part of the keel. I didn’t relish having any more lead dust in my shop than necessary, so I found that the shaping could be avoided by merely turning this piece on it’s narrow side. Since the mainmast is stepped onto this bar, it will later need to be shortened a bit to make up for the bar’s extra height. Do take care though to contain and remove lead “saw dust”, and wash up after. Short dowels are laid in to support the sides of the stacked lead bars against the hull. The entire arrangement should be adequate to retain the ballast if the model is laid sideways pond-side, but you won’t be inverting the hull from here on. Therefore, it’s wise to lightly sand or steel-wool the hull exterior prior to this step in preparation for painting later.
If one wants to modify the model for sailing in heavier breezes, alternate designs should be considered here. The enterprising modeler could build a permanent or removable keel extension, moving some the ballast even lower. This will likely require extra bracing inside the hull to react the righting loads from the keel.
To finish off the work in the hull, we need to first do some deck-work. The mast steps are to be placed onto the ballast bars, and for this we need to pre-attach the deck to the hull. First, the five deck beams are laminated up from strip stock bent over a provided form. These beams are then attached to the underside of the deck with S-E. Later, when working on the planking, I discovered that the beams were not difficult to pop off, so I recommend securing them from above with small countersunk wood screws. This is a good place to note that after attaching the deck, access into the hull will be severely limited, so all joining should be carefully checked for security.
The deck is then laid on the hull, and working from the stem aft, a series of holes are drilled through the flanged edges, which are immediately (but temporarily) secured with small screws. This ensures that the deck truly follows the sheer of the hull. Note that the hull’s beam may not be true, so you may need to push it out from within to match the deck’s edge before drilling the holes. Also, mark the centerline on deck and hull at the stern, and ensure that these stay lined up as you work.
With the deck in place, and holes made for the masts, the mast steps can be positioned along the ballast bars, and the masts installed. Each mast’s rake is set per the drawings, and the steps are then glued in place.
One more job to do- bend the chainplates. Robbe provides four aluminum angles which are to be trimmed and drilled to make the chainplates. The straight pieces must be curved to fit the hull sides, and then holes are drilled through the hull for mounting. The instructions might not be clear- you don’t actually beat in the curvature, but instead use a small ball-pein hammer on the horizontal underside of the chainplate. The dimpling actually expands the outer edge of the chainplate, inducing the required curvature into the vertical portion.
This completes the major work on the hull. In Part 2, I’ll attack the deck, which includes some striking plank work, the R/C sail winch apparatus, and all the deck level detail.
(1) Greis, Volker (2003). Vanadis
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