Introduction: Modern Recurve Bow From Skis!
This is my first Instructable about, well, anything. I have been building PVC pipe bows for almost two years now and after seeing this instructable by Yoshinok, https://www.instructables.com/id/Make-a-takedown-bo... I was really inspired to try building one out of wood and skis last spring. I made the bow following his 'ible almost to the letter. The riser came out great, but I was a little disappointed in it's lack of power. But it was a great first experience which led me to design and build this bow that would hopefully have more power.
Step 1: Different From the Other Ski Bows Out There
This is an Instructable that has been done several times before I know, but I think that this take on a recurve bow made from skis is a worthwhile change from the other quality Instructables that have been done before along the same lines. Using a decent pair of used cross country skis and this riser design, this bow pulled much stronger than the other bows of this type that I have seen.
Where the limbs attach to the riser is nearly vertical at a slant of only five degrees. This keeps the ski tips in front of the handle by about 3 inches in its unstrung profile. When the bow is strung, the handle is forward of the limbs creating more brace height without adding greater flex to the limbs when at brace. This helps to make the draw smoother and eliminates stacking at the end of the draw. It also provides more power.
Step 2: Materials and Tools
Materials: All of the wood, hardware, and glue to make the riser cost less than $12, but may cost more or less depending where you are and what you use. I got the wood for free, the glue was $3 at the hardware store, the screws were $5 or so for stainless steel, and a box of drywall screws was $4.
1 16" to 20" piece of 3/4x4 oak or other hardwood of your choice, scrap works fine, usually your local lumber store will let you just take scrap wood
2 3"-5" pieces of 1x4 oak or other hardwood, I used maple because that's what I had
1 1"x3" strip of hardwood
1 3"x5" piece of pine
primer if you use paint
paint or stain of your choice
a pair of cross country skis, got mine from craigslist for $10 ***make sure they are a composite/foam/ core ski. Wood will NOT work***
small piece of softer wood like pine for the handle grip (easier to shape)
5 1" long drywall screws
4 1.5" round washer head wood screws
2 2" round washer head wood screws
550 paracord for your string or you can make your own endless loop or flemish twist string
3" to 4" of the fuzzy side of adhesive velcro tape.
I used a band saw and a stationary belt sander for a lot of the work, but this could all be done with a couple of hand saws, rasps, clamps, and sand paper. I'll list what used here:
rasps and files
dremel tool with sanding bits
drill and drill bits
various grit sand paper
Couple of bar clamps and "C" clamps
Step 3: Plan the Design, Cut Out the Riser Shape
One of the issues with bows that are made from cross country skis seems to be their lack of power. Alpine skis are generally stiffer and give better performance, however the look of the limbs seem overly wide and unattractive to me. The design of this riser follows a more traditional, almost but not quite, deflexed unstrung profile allowing the slimmer and IMHO, more attractive cross country skis to be used while maintaining the power that the alpine skis produce.
For me it's always easier to work from a drawing and to have a template to trace the design from onto the wood than to wing it or draw it freehand. I used an illustration program to make the final design from sketches I had hand drawn. I printed it to scale to have a template to trace onto the wood. It was held in place with small pieces of tape. Once the design is transferred to the wood, mark out the lines for your relief cuts. The relief cuts enable your saw to work less hard by removing smaller pieces of excess wood faster than one big piece all at once.
Once the riser is cut out, sand or file all the rough edges smooth. I wanted the look of this bow to be almost aerodynamic, so I rounded almost all of the hard edges (not where the limbs mount, leave those angles alone!) over using rasps files and sand paper. A router with a round over bit would have been really handy here!
Step 4: The Handle Grip
There's quite a bit of test fitting to this step, mainly against the size of your palm. It's all about what you find comfortable. This is what worked for me, something else might work better for you. Do some experimenting and go with what you like best.
Basically, shape the piece of wood till it's comfortable in cavity of you palm. I shaped this piece of pine to size and shape first with the sander and then rasps, files, and finally sand paper. I liked how it looked and felt so I stopped where I was with it. Spread glue evenly and thinly over the back of the grip and where it will mount on the riser. Place the grip on the riser where your hand feels most comfortable and clamp it in place.
The grip will not be a perfect fit at first and that's fine. Go ahead and start rasping and filing it to fit the riser as neatly and evenly as you can. I was going for as smooth a look as possible and used wood filler to take care of a couple gaps at the front and rear edge of the grip.
On the opposite side of the riser I ground out a recess for my fingers to help make the grip more comfortable using a dremel tool with a cone-shaped grinding bit. Again, this was for my fit and comfort, yours might not need this at all.
Step 5: Adding the Limb Mounts
Cut the smaller pieces of hardwood to match the shape of the riser as closely as possible, this will save on grinding/sanding time afterwards. You will want the upper limb mount to be fairly short in length down the riser so that you have as large a sight window as possible. If the riser is 20" long from end to end, with the arrow rest top being right in the middle of the riser, you'll want your upper limb mount to be no longer, really, than about 4.5", giving you a 5.5" - 6" sight window.
Once shaped, glue them to the riser using the wood glue and clamp them in place and let the glue set. After it sets, use one 1" drywall screw, screwed in from the opposite side, centered on the limb mount. How you finish this is up to you. You can leave it flush or countersink it and plug it. However you want it to look.
Once everything is dry and and the screw is in, sand the back of the mounts and riser so everything is smooth and nice. I did my best to flush the mounts at their bottoms to the riser so that when the finished riser was painted it would look like one piece of wood. How you finish yours is up to you. Do what you think looks good.
Step 6: This Is Where This Design Gets a Little Different...
The skis need to be cut to match the shape of the riser.
That's not usually how it works. Instead of building the wood up to meet the thickness of the limb, I reduced the size (at the mounting point) of the limb to match the width of the riser. This makes the riser lighter, just as strong longitudinally, if not laterally, and is much quicker to make. Saved a lot of shaping time this way. It works.
Cut your skis to the length that you want them to be. In this case, the skis were cut to 23". Once they were cut, I traced the shape of the riser to the back of the ski and then removed extra material.
***You will note that these skis have a wood core. They seemed flexible enough while I was working on them and thought (hoped) they would be fine. I really liked the color of them too. When I first went to string the bow, the top limb snapped clean at its weakest point, mid-limb. I replaced the wood core skis with fibreglas skis and made new limbs. All the pictures were shot with the wood core skis though, so consider them for reference only. Once you see the blue skis, those are the replacements. Make sure to use all foam, all composite, or all fibreglas skis!***
Then comes the fun part - the first test fit! Now is a good opportunity to make your ski's mounting points shaped as close to the riser shape as possible. This bow is 58" from tip to tip unstrung. The limbs are mounted 4" down onto the riser, making their working length 19". Okay, set the limbs aside for now.
Step 7: Arrow Rest and Final Shaping of the Riser
With this arrow rest, I shaped it to better fit over the knuckle of my left index finger to allow my whole hand to be snug up against it.
A small strip of wood is needed for the arrow rest. The one I used is approximately 2.5" long by .75" wide. I tend to make them a little longer and wider than necessary to make sure there is plenty of material to remove to get the shape that I want. Use wood glue to glue it to the riser where your hand is most comfortable, but with this riser's design it is best if it lines up with the protrusions at the front and rear of the riser. If yours doesn't have these, then no worries, place it where you think is best. Clamp it in place and let the glue set. After the glue has set, and this is up to you, use a countersunk 1" drywall screw screwed in from the opposite side of the riser to add a little strength the arrow rest. This is optional though.
I used a little wood putty to fill some gaps and get a smoother overall appearance. This, with its tight corners and small working areas was the most difficult area to sand and get smooth. A dremel tool with a sanding drum really helps here, but it can absolutely be handled with sand paper, time, and strong fingers.
Step 8: Attaching the Limbs to the Riser
This part I did more or less by eye. I laid the trimmed ski limb on top of the riser at the mounting point and eyeballed where I wanted the wood screws to be. I marked those points with a Sharpie on the skis and then drilled the holes. With the holes drilled, I screwed in the wood screws just so far as the tips of the screws poked through the other side of the limb. I then placed the limb back onto the riser in its aligned position and squeezed it a little. The screws made an indentation into the wood of the riser marking where I needed to drill.
More eyeballing here. You want to make sure that you use wood screws that are of a length that will be strong enough to hold the limb under some considerable stress, yet have them be short enough not to go through the back of your riser. The wood screw closest to the handle is 2" long. By holding it to the side of the ski and the side of the riser at the same time I could tell that this screw would still have a 1/2" of wood in the back of the riser to hold it in place. The other two screws mounted above this one are 1 1/2" long each and have roughly 3/8" of wood behind them.
Mount the limbs to the riser for a test fit. Make sure the tip of the limb aligns with the inside edge of the arrow pass where it meets the riser. This is your adjustment time, should you need to. If all has gone well, there shouldn't be any need. :-)
Once you are satisfied with your dry fit, step back and admire your work!
Step 9: Cutting the String Nocks
Cutting the nocks is not as easy as you might think. I measured down 1" from the tip of the skis and drew a perpendicular line across the width of the skis. I then used a hacksaw with a carbide tile-cutting blade to make the initial nock cuts. Since the blade is round, it really does a nice job and is easy to handle. You want to make your cuts as shown in the first photo; so that if you were to hold the limb up vertically like it would be on the bow unstrung, the cut would be just about parallel to the floor. Make your nocks a little bit less than 1/3" into the limb.
Next, take a fine round file or a chainsaw sharpening file and smooth out all sharp edges of the nock so that there will be nowhere for the string to catch or get cut. I the used 400 grit sand paper to finish the nocks as smoothly as possible.
Step 10: Primer and Paint
I chose paint for the riser instead of staining it because the wood I used to make the riser was pretty plain. Had it been fancier or prettier, I would have used either stain or oil on it to have a natural finish.
Once you have the riser sanded to your liking, clean off all the sawdust as best you can with either a tack cloth or compressed air or what-have-you. Just so long as it is reasonably clean, the primer will stick to it. One of the additional benefits of using primer is that it works like a very fine filler as well as a great surface for paint to adhere to. A lot of the wood grain that I wanted to go away on this riser did because I used primer.
If you're working in an enclosed space, make sure that you have adequate ventilation, the primer fumes are particularly strong.
Let the primer dry for the recommended time at the recommended temperature. Once dry, apply multiple light, even coats of your spray paint. Let them dry completely between coats. I did a very light sanding in between coats as well with 400 grit sandpaper. I was going for as high a polished finish as I could get. When you are satisfied with your riser, set it aside in a warm place (like room temperature warm) for 4-5 days. Yep, let that paint cure HARD.
For painting the limbs, I didn't use primer since there was already paint on the surface of the skis. I just scuffed them up using 200 grit sand paper. I then applied paint the same as on the riser; in light, even coats. For a little extra zing, I added a coat of metal flake (okay, glitter) spray to the limbs at the tips and faded it on the way down. I let these dry for 4-5 days too. I then put two coats of gloss clear on top of the limbs. I let them sit in a warm place for, you guessed it, another 4-5 days.
Step 11: Finishing
You'll note that I have added a drywall screw to the limbs to act almost as a locating pin. Not only does this help the limb align to center, but it's also an extra peace of mind in keeping the limbs attached to the riser when drawing and releasing the bow.
The string is a (hopefully) temporary 550 paracord type. The string was cut to 52" and bowlines were tied to make the loops at the ends. The bow stretched the paracord, so I tied a couple of knots into the string to shorten it up again. Not ideal, but works for now.
Take your fuzzy-side velcro tape and make your arrow pass on the arrow rest. Just stick the velcro to the rest and to the side of the riser and trim away the excess with an x-acto knife or razor blade.
The last bit was the decorating of the bow. I named the bow "Albatross" because the shape of the riser and the length of the limbs reminded me of an albatross. This project also took a good deal of time so this thing began to feel like an albatross around my neck, wanting to finally be done.
I have a buddy who works at a print shop and he made up these vinyl stickers for me for next to nothing from a design I laid out. Just peel away the adhesive backing and lay it down smoothly and evenly. I then burnished it down with the paper still on with a plastic putty knife. I then carefully and gently removed the paper backing to leave the letters and design on the bow. Your bow should look like how you envision it, do whatever makes you happy.
Were all the time I put into this in one go (minus the paint and drying time), instead of spread out over four months, I figure it would add up to about 14 hours total.
Step 12: Shooting
This bow pulls 40 pounds on my portable luggage scale and has a very smooth and progressive draw, adding weight steadily throughout the pull till the string is at my cheek, or approximately 28". It doesn't stack at all. There is no hand shock upon release.
Based on three tests with a chronograph app on my phone ( the best I can get, I'm afraid - a chronograph ain't in the budget) is an average of about 186 ft per second. These are completely open to interpretation, but the speed with which the arrow hits the target seems as fast as my 25 pound fibreglas-limbed takedown recurve which is at about that speed. Shooting was at 10 yards with 425 grain carbon arrows spined to a 45-60 pound bow.
I am really happy with how this bow turned out.
I hope that this Instructable has been informative and helpful to anyone wanting to make a bow from skis. It was really great for me to see my idea of how to get more speed out of a cross country ski limbed bow by the shape of the riser work out satisfactorily. Give it a shot, rework the design, come up with something better and share it with everyone! Have fun!