Started build, will post every move here: http://www.rcgroups.com/forums/showthread.php?t=2431902
(already got shadows)
A Start, Error Found, Suggested Correction, Correction made …
A previous post was scrutinized by Claudio - the designer, and he pointed out an error. I had cut the templates too large and forgot about leaving room for the strips of the layup. This naturally caused some concern as I had broken my last narrow bandsaw blade and had to special order.
In discussion, Tarmstro noted my error as well and offered a unique and very quick solution. Flipping each template over, I penned my new cut lines on the back side of the template. Where I was going to use a compass to scribe the 2mm needed to meet Claudio’s design, Tarmstro suggested two small pieces of wood glued together but off set at the end by the required 2 mm. After gluing up the wood, I clamped the wood jig to the top of my scroll saw table, and I could slide the oversize template underneath and against the edge of the wood, which was set back by 2 mm. Once pressed against the “jig” I was able to move the template around, and using a very fine marker I was able to mark cut lines on the back of every shadow template.
This allowed me to quickly and accurately mark the new cut lines, and a cut on the scroll saw followed by a touch to the belt sander brought each template to the size as originally drawn by Claudio. Fortunately my initial cut was too large, so making the templates smaller was easy.
Thanks to Claudio and Tarmstro for finding my initial error, and to Tarmstro for providing a simple but very effective solution for marking the new cut lines. I should now be ready to set up on the building board and proceed.
I also found a jig to use with my tablesaw that will allow me to cut the very thin strips I want to use for building the hull. Once I try it and if it works, I will post a photo of how to make one for yourself. It is fully adjustable for strip thickness and the fence is moved toward the blade for each cut, with the strip coming off on the left side of the blade. More on this later.
Just wanted to shout out a thank you to the two who helped me recover from my error.
PHOTO 1 - the amount I needed to remove for 2 mm planking
PHOTO 2 - the template under the jig and being marked for the needed removal
Had some time this afternoon, so thought I would write up a short article on a little jig I have experimented with to rip very thin wood strips on my tablesaw. Before going forward with photos and process, here are a few recommendations I want to make for my future jig and YOUR first jig.
You are able to cut 1 or 2 mm thick strips, or any size thickness since the jig is adjustable - BUT …
- Use a narrow kerf sawblade.
- Use (or make) a zero clearance table insert to prevent strips from falling into the blade.
- If cutting long strips, consider removing your miter gauge before each cut so it is out of the way. For short strips, just pull the miter gauge towards you once you have thickness set.
- Keep the top of the blade as low to the wood as possible, use a push stick, and some type of hold down to keep the uncut wood tight to the table top.
The jig you see in the photos is a temporary one I made up to see if it will work. It is merely a scrap of wood, with a rather large flat head wood screw in one end. The wood jig is clamped to the miter gauge, although a larger unit that can slide in the miter gauge slot on the table might be one with a bit more repeating accuracy.
- the thin strips will be coming off the LEFT side of the blade.
- the original stock is on the RIGHT side of the blade (between blade and fence)
- the fence is moved toward the blade after each cut.
- the flat head screw is adjusted to the strip dimension desired. Use a screw driver.
- the distance from the screw head to the left side of the blade is the thickness of your finished strips. Be aware of your blade aand watch for alternating blade tooth offsets when setting screw thickness gauge.
- move the wood stock towards the screw head until it just touches. This should set your thickness of strips
- move the fence until it touches the stock wood.
- make a test cut and measure the thickness of the strip coming off the left side of the blade.
- If too thin, screw the wood screw further into the board (moving the screw head away from the blade)
- If too thick, adjust the screw head closer to the blade.
- use the screw head as a thickness gauge and bring stock wood close until it just touches. Then move fence to the stock wood.
- Don’t push against the screw head too hard when moving wood and fence toward the jig. You are simply setting the strip thickness.
Might consider making the strips a bit thicker and run through a planer or sander if you have one.
I just used my carbide rip blade for the photos and test. Will probably use a nice, well sharpened plywood or cross-cut blade for actual strips.
PHOTO #1: A general view of the entire jig
PHOTO #2: A view of the stock wood just touching the screw head - set for 2 mm
PHOTO #3: Jig is moved out of the way. Wood has been moved against screw head. Blade has started cutting a strip (on left side of blade)
PHOTO #4: A cut strip. Was trying for 2 mm but it is about 2-1/2 mm so screw head needs to be adjusted (screw driver) TOWARDS the blade for a thinner strip.
CAUTION: If you use a clamp to hold jig to front of miter gauge (like I did for photos) - be sure not to push the fence too hard towards screw head as the jig may move away from the blade and fence.
Dick, you are not planking with balsa? Will be hard to hit the target weight using other woods…
Tom - Actually, I am using some thin mahogany or cedar strips to “force” the waterline stripe and the chine stripe to stand out and be different in color as well as size, as at the moment, I still would like a clear finished “Woody” hull. My proposed build is to strip build from keel to waterline, and then for the freeboard areas, use a 1/20" thick wood veneer (about 1.27 mm) although if I can find it, I might go with 1/64" veneer which is about 0.39 mm - either of which should offset any added weight from the strips. Strips might be Western Red Cedar as I have a bunch of clear 10 foot long x 1/2" thick boards.
I wouldn’t use the strip jig option for balsa as it is already soft and easy to strip. But for a Marblehead or other all wood hull where weight is a concern, but not a priority, the jig would work - especially if you go for 1mm or less
Dick,
as already told you I’m afraid that the final hull weight will be around 2 times heavier compared with a fiberglass -epoxy hull.
Assume :
500g/dm3 mahogany wood = to 50g/dm² /1 mm thick = 5g/dm² / 0.1mm.
If correct, 0.3mm veneer will represent 15g/dm². Not the full hull be covered with mahogany or similar wood, thus the hull will weight about 10g/dm² . If iberglass 120g/m² would be used with 2 layers : 2.4 g/dm² + 2.4g of epoxy = 4.8g/dm² projected weight .
With a hull surface of about 14 dm², the wooden hull will be around 140g while the composite hull will be around 75g with fin reinforcement !
During design it is generally decided which type of planking will be used as final skin. This notion will be taken into account for the displacement calculations.
n/Arrow5 is born to be a composite construction.
The water plan is about 395cm² therefore each 1mm variation close to LWL is representing 39.5g displacement variation. The excess of weight of 140-75 = 65g will suggest a water level variation of 65/39.5 = 1.65mm !! not very much if this will be the only variation during construction !!!
Dick I think you need to control strictly each item to avoid exceeding weight.
Good work then !
Cheers
ClaudioD
Claudio - understood.
Once I finish trimming the templates and cut notches for waterline and chine strips, I will rethink. Always appreciate the reminder - then the stubborn “German” in me, takes over and get’s me into trouble. 
Hi Dick,
another point about the famous “notch” you intend to introduce, hope it is in line with the RG65 Rules Appendix 1.
Further I wonder about the efficiency of that “notch” you intend to make considering the low speed of our models. Another story will be with motor speed boats at 20-25kt !
I’m sorry to disturb your thinking !!
Cheers
ClaudioD
Claudio - the “notch” in each template is simply to hold the chine stringer in place and locate it relative to the location of the chine positions from templates on either side. 0.3 cm = .118 inch (less than 1/8" ) I marked up one of your provided templates to show where the “notch” will be and any significant change in the cross section shape of the hull. Obviously the waterline “notches” will remain horizontal while the chine “notches” will have a gradual rise from transom toward bow as seen in your side view drawing.
If it doesn’t look good or not what I expected, you will never see it - I will simply plank over it. 
BTW - I am expecting your design to easily reach 20-25 kt. in a good wind ! Ha Ha
While I am still (slowly) moving forward on the build of Claudio’s “nARROW” design using balsa and some nice dark red cedar wood for waterline stripe and the hard chine, … I couldn’t resist and just received a new Dragon Force 65 for myself. I’ve helped local new sailors on two occasions by building (assembling) the boats for them, so decided I should at least have one of my own. As I understand, mine will be hull #8 or #9 locally so perhaps we will have a decent size local fleet in which to compete. Anyway, I’m doing a few things to mine they didn’t want so will be excited to see it when finished. In the meantime, I am busy cutting strips for the full race “nARROW” and hope to begin gluing up strips soon. I’m tire of seeing the building board every day without any strips added tot he hull templates.
Some moments of spare time allowed me to proceed with the layup of the new RG65 (Design by Claudio). I decided NOT to notch the templates for waterline and chine location. In the photo, you can see the hull strips already in place. Also, the darker (red cedar) waterline is located and visible with a single balsa strip added and held in place by my “BullDog” clips and paperclips. This allows the plank to be held down and pushed up tight to the strip immediately adjacent.
Dick Lemke
Earlier in the thread, I posted a tip on using the “BullDog Clip and a paper clip” to help hold planks in place against the templates and also to the strip directly next to the one being applied. At the time I hadn’t gone far enough to identify the problem when using the clip method to hold a plank in place when there isn’t enough room between the planks. As more planks are added, there is less and less room to use the clips. I solved this by fabricating a set of clamps that I saw being used for a full size stripper canoe.
Basically the clamps are simply wedges made to slide between planks. They have a small “step” cut in them to hold the plank down and at the same time apply pressure to the side of the clamp. If not wide enough, a straight strip of off-cut plank can be used as a spacer to increase the width of the wedge.
Reading this may not make a lot of sense - just look at the photos below to help you understand. Obviously, you can hold planks in place using pins, but their small holes leave dark spots on the hull.
Photo #1 Plank “wedge”. Balsa with step cut. Push this wedge down between planks and it will hold new plank tightly to plank already in place and also down tight to the section template.
Photo #2 Showing two wedges being used and one Bull Dog Clip where it would still fit.
Photo #3 Starboard side of the RG65 with most planking done above the waterline. Still need to fill in the openings in hull below the waterline, and then complete the other side. Building board is set on it’s side to show starboard side of hull.
@ CLAUDIO …
Hi Claudio. Some good news on the nARROW build. Seems the Gougeon Shop has taken up some interest in the build and offering a bit of sponsorship help ! I was after them for some WEST System logos and have a feeling once done, this design might set off some internal winter building for an inter-company build and race competition. That would really be neat.
The reason for my post is to ask about a sail plan for the nARROW. Is there a specific/special sized set? Should I just find and use the plans you posted for the Esterel? Being so thin, I wanted to be sure to ask. If nothing specific for this design, I’ll drop back and look up some of your other previously shared and posted sail/rig drawings.
Regards, Dick
Hi Dick,
in principle all existing Sail Plans as well Fin length are OK for this nARROW model.
So far the displacement is not modified, you can play with the righting arm : Fin length x Bulb weight being constants.
In attachment some examples.
Cheers
Claudio
PS: Very pleased and found interesting that Gougeon Shop alias “West System” may be sponsoring your construction.
Claudio:
In the sail plan diagram, mast height is 1010mm. Why not 1100mm which is maximum by rule?
Regards
Me.
You are right almost right !
The real mast length is 1030mm from datum line.
Shorter Mast help to support stronger winds.
Certainly with very low wind conditions it may be better to use 1100mm long mast.
As said, all rigs presented on various RG65 sites are fully compatibles.
Thanks for the clarification Claudio. So you are on the same page as the DF65 designers. And yes, we already proved that in very light conditions a longer mast is better (a guy here put the DF65 rig on a Goth, and it was clearly slower…)
In my opinion, is often a gamble to rely on the wind speed between 0 and 100 cm of height. On sea side, small waves are producing turbulent conditions.
It is instead important for me to keep the lateral stability, too much heeling is not good either due to form drags.
CE low position is helping to keep power.
Long Fin may also introduce to much wet area that may be a drawback during running.
For what concern the righting moment, one should consider that the bulb weight is limited by the design displacement.
Personally, under low wind conditions and therefore less power in the sails, I would prefers to use lower bulb weight than a longer mast. With lower bulb weight the boat will be lighter and the LWL will be shorter thus the wet area will be reduced.
Once I see and get dimensions, I am looking at the shorter Dragon Force keel and bulb for light air. Pricing certainly is attractive - but right now a lot of replacement parts are back-ordered for the DF65 so perhaps others are having similar thoughts. Until I have bulb weights, I can’t do much in calculating best alternative, however, the two keel lengths for the DF65 are 317 mm for standard length (long) keel and 240 mm for the shorter, alternative keel. I probably should pull the bulb (standard) and have it weighed. They probably use the same bulb - just different keel lengths. Maybe I will do that today. Will add post when I find bulb weight.
I am not sure how close the long keel and bulb will be in coming close to Claudio’s suggested weights.
Just went back to look at some of Claudio’s drawings and it looks like in some he called for a 300 mm deep keel (bottom of hull to top of bulb. I will have to get my bulb weighed in order to finalize a keel length with (probably) a lighter weight bulb to meet Claudio’s specs for a bulb weight of 675 gr. on a recommended keel length of 275mm