I know it's only early September, but my mind is already working on idea for this coming winter. If anyone has any idea on things I should try I'd love to hear them!
GREAT DESIGN! Your steering design is excellent, except your sled tail wants to slide out away from you. When you hit any impediment with the square side edge of the ski, the sled wants to flip you off (so to speak). Changing to two sets of skis might help, but I recognize the entire steering mechanism is somewhat defeated by doing this. A way to tilt proportionally the back of the skis to the direction of turn is needed, so you get a little slip with a slight turn and deeper edge on a sharper turn (ala an upright skier) thus minimizing direct conflict with the square side edge of the ski. Perhaps two sets of skis, extremely short for the front, and slightly longer for the back. This might require a two point suspension of front (one each side) and 4-points out back (2 on each side). Some how mechanically connect the steering bar to front and back via different mechanisms: the front needs to actually bite and turn the sled, the back merely needs to tilt skis down in the direction of the turn (turn right, the right edge of the rear skis go down). The best would obviously be if there was a way to get the turn warp at the front and a tilt at the back of a single ski (how is the million dollar question). I did an extremely simplified version of a sled like this only with 4 skis back in '82 when I was 12. I designed it, my dad built it (out of oak and two kiddie-plastic skis for the rear and the cut-off fronts of some ancient wood skis for the front). No tilting or warping skis and no shock-absorbent suspension, however. Mine fishtailed all over until we put rib of sorts down the middle of the skis. This was still not the best solution, as the vertical ribs slowed the sled down. Your design is already light years ahead of mine, but I have always been thinking on how to improve mine. The Hammerhead folks made vertical edges on their skis, but that just makes a hard turn into flip city. Good luck! I look forward to seeing your progress.
Your steering system is ingenious, but it does not have enough strength to tilt the back of the ski (your current design might work for a 10-year old, but not us adults) so you will still fishtail all over. In a way, that's a good thing because you are actually inducing a warp at the ski-front; a full-ski tilt will not turn the sled, but the warp is what gets the job done. Now, how do we induce a tilt in the rear of the ski so you are less likely to flip? Would it be possible to run a bar off each front tie-rod connector under the belly slats to a similar steering mechanism on the rear of the ski connecting to the ski near the rear-of-ski suspension points. The trick is altering the tie-rod distance in back to induce less tilt than the front: thus you still get steering warp on the front of the ski, but also get adequate tilt in the rear of the ski. Just an idea..
Thanks for the comments! I was just looking back through them and realized I never responded to you. I entirely agree with your assessment on the steering. I am currently working on version 2 of this sled, which will most likely follow a similar design, but with several improvements. I'm considering a reverse cambered ski; otherwise known as a rockered ski. This should allow the ski to bend into a curve as it is tipped, which is how a skier makes a fully carved turn. By maintaining a sidecut on the inside of the skis, the turning radius will be reduced. Also, I'm moving the steering attachment point to the forward shock mount, which should eliminate a lot of the flex and impreciseness of the steering. Stay tuned as I'm excited to get this new sled out this winter.
Nice work, those Chinese shocks are rated for around 300 lbs each, if you could find softer springs that would smooth out the ride. Also snowmobile ski's have rubber under the mount to increase resistance the more the ski tips and stops it from flopping over completely, and gussets, you need lots of gussets, rivet them all in place.
Agreed on the shocks. They were the softest ones I could find at that size. The spring rate is slightly reduced by the angle, but they are still too stiff. Next time I would like to go with air shocks so you can adjust them. Good idea on the rubber stoppers! I may incorporate that at some point.
Dude. the cinematography is so good. It definitely shows that you put in the extra work to make the video fun to watch rather than just a couple clips of you going down a hill. Awesome!!!
They were some sleds made in USSR in the '80 that were years ahead of everything. They had 2 fixed skis and one mobile linked to a handlebar. Had a foam seat and 2 brakes (on each of the fixed skis). Was made from cast aluminium body with aluminium profile skis. The center of gravity was low and the skis were on the sides, making it very stable. The front ski (the steering) was at an angle (like on bikes), making the front of the fixed skis lift when the direction was changed (reducing drag during steering, preventing the sled going in a straight line). I managed to find one for sale and gave it to my kid. If you want, I can send you pictures. It has some interesting design features (some that your design lacks). Forgot to mention that the skis have a special profile that help keep direction even on ice (something that normal skis can't)
I would love to see that! My email is on my “about” page. I’m always looking for new (or old) sled designs and this sounds like one of the most interesting ones I’ve ever heard about. I’ve compiled quite a few designs here: pin.it/rptrvpmbrj7zdu
Your Instructable was very nicely done, and I love your various video source edits, but the most ass kicking part of the whole for me has to be the old school appeal of the kamikaze in ya. I grew up in S.W. PA riding runner sleds into trees, "cricks", and barbed wire fences, back when kids weren't all precious little orchids, before the pussies began to rule the world. You sir have restored my faith in mankind's future in general, and Millenials specifically. Nothin' says I wanna die like hurtling down a snow covered mountain at 35 mph on an experimental sled. Head first makes it all the better. :) Concept was genius and I immediately started having flashbacks of double wishbone F1 racers, but your basic frame components had me expecting an epic fail due to their lighter thicknesses. Glad I was wrong! Kudos to your Dad too btw, or whoever it was that took the time to teach you all of those valuable skills. Great ad for why we need more shop class and less diversity training in school, but I digress. All great, so consider my suggestions mental floss and not a critique. Maybe epoxy a wider, hardened attachment point for skis to suspension points. Guessing that and frame thickness at stress points are possible material fails over time. Shocks are genius. I first thought of maybe larger, longer travel to smooth it out even more, but given the speeds you were traveling I'm thinking that may have proven catastrophic to your control. Cherry wood is nice, and certainly pretty, but maybe some fir, ash, or a lamination would give better weight to strength and flexibility, although that too might be a detriment to handling (thinking car handling and too much flex in a frame). We built something similar in scouts many moons ago for a Klondike Derby thing where us scouts were the sled dogs. As you can imagine anytime we hit a snowy downhill the sled would over-run the scout/dogs, so we later took it home and ran it down hills with jumps near the bottom 'til it completely disintegrated. Ya got me thinking of a long travel suspension version for doing that again. Imagine a jumping variant that you sit up on (long as you're amused by tempting death). Ah to be young and immortal. ;) Our sled jumps were epic, and the ultimate fun, until the parents got together and dismantled it over some silliness about too many broken bones or something. Pretty amazing how much air you could get on even a short downhill run. :) Random thought; what about maybe cutting the skis down and adapting or fabricating something like the steering skis from a snow mobile? Maybe adjustable camber on rear ski set with parallel links and suspension, but then use the snow machine skis to steer. The rear parallel links might help maintain a consistent lateral attitude during rebound and dampening to aid tracking stability while the separate steering skis could be given limited but more aggressive steering angles? Also might want to think about strapping crampons to you boot insteps for that "Oh Shit!" moment when you discover that the steering idea stopped working at 35 mph. Okay, last bit of mental gymnastics, how about a centipede inspired design where the front, middle and rear are all individual sections that are somehow linked to provide the four wheel steering effect. Probably kill ya at higher speeds, but seems it would certainly be more responsive. That and/or use a thinner section steering ski in front with its own tunable caster and camber, specifically to get more edge control. Fantastic project! Thanks again, loved it all! You and your Dad need to build a CNC and a buy a welder. I have high hopes for your future. :)
Wow! Thanks for comment Jamie! I'll try to address some of what you said here. First, I'm glad you're inspired by my design. That's the whole idea - well apart from me just wanting to make this thing 😀. One thing I did gloss over a bit was how many frame pieces I did end up replacing due to bending or breakage. As shown, I replaced the control arms after they failed, but I also ended up replacing the two box tubes connected to the tops of the shocks. They had started bending over time and I thought it'd be best to replace them before they broke at 30mph. Anyhow, I 100% agree with your epoxied plates on the skis. I actually did this for where the steering brackets attach. After I had the brackets installed, I realized the screws hardly penetrated the skis and so I added a thick aluminum plate, which was tapped for the screws I used to attach the steering brackets. I've kinda been expecting the skis to separate at the other points, but so far they've been amazingly secure. I may just add some plates in the future though. I also love your crampon idea. Slowing down quickly can be a bit of a challenge and that is a super simple solution. In the future I'd love to use nicer air shocks, which may have a tad more travel. Then I could adjust the spring load depending if I'm just bombing a road or doing some jumping as you say. I didn't use them this time cause at $80 each (pretty much the cheapest ones out there) it was a bit excessive cost wise. I also appreciate your ideas about separating the skis. For now I really want to try to get a single ski (two parallel skis) design to work well. I find this a more elegant solution - and I think it should be faster. Maybe I just want to do it because most designs don't do it that way? 😀 Your centipede idea is interesting though. It's like a "body" sled. Anyhow, I think this reply is longer than your message. Great comments though! I love reading comments like yours!
Like it... Try using a door hinge (or similar design) in place of the "A" shaped hinge mounted on the ski's... This will lower the center of the hinging effect to the ski's level and get rid of the rocking issue you are having...
totally inspirational to watch all 4 vids! patent it dude.... with a few mods and further refinements (longer/wider skis, through bolts , longer decks, leaf vs spring suspensions etc) it'll be world class with multiple applications 1. a more efficient dog sled 2. expedition sled that actually allows sleeping OFF the snow 3. safer sledding with control Hey good Luck!! just awesomeness
Searched around and landed here, I just came back from our annual sled trip in Waterville, PA. We have had issues with sleds. We generally use a 66" plastic toboggan sled made by Emsco they work the best for store bought but we shatter most by the end of the weekend. This year we started with 10 sleds and zero came out undamaged, Our mountain run is 1.2 miles of snow and ice with a couple of sharp turns. There are usually some injuries, this year we lucked out with only a jammed finger and some broken ribs. Oak trees don't move out of the way, I was going to try a build with just wood what are your thoughts? can a wood sled hold up?
Thanks for sharing. It’s great to hear how others enjoy sledding enough to take a trip to do it each year! Now I’m curious where you run as I grew up not far from Waterville - and did some testing in Blackwell as it shows in the video. I think you could potentially use wood - although I would use laminated plywood for all of the structural bits. In the future I’m hoping to design a simpler sled around a wood chassis. Currently, I have an updated model I’m testing when I can, but the snow hasn’t been too great this year in eastern PA.
I eventually did this. Although I didn't explain it very well, the reason for the original design had to do with how the suspension would interact with the suspension. And thanks!
That wasn't the main issue, but it is more comfort with it off - and I can move around better. The outside edge of the outside ski was catching, and that is what the problem was. I've since fixed it!
what if you put a seat on it and steer with your legs and negative camber couldbe useful because if you start to tip the wideness of the ski will stop it. just an idea tho
These are great ideas! For now I'm not planning on a seat as I prefer skeleton style sledding. However, I've been thinking about negative camber a lot as this is what is used in Europe on sleds like a Rodeln. Interestingly, I also though that the width of the skis would keep them from tipping. However, I did not find this to be the case - especially if the snow is not packed. My reason for negative camber is to keep a metal edge in the snow at all times - better for control.
makjosher ok i had no idea about the facts about europe it was just an idea i had while waching your dad powerslide but anyways good luck to you from no snow sweden
