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| Home Made Boards (6188 Posts)
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Home Made Boards |
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Graphics
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On 11/15/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
YanO,
My guess is that you can easily use a bigger core disruption than 1/8" without foam, if the first shell layer is wood, curving in a smooth way between disruptions (well, you've done it already, by miles). With weave it's another case, 1/8" seems reasonable.
About the graphics: I print the graphics on paper sheets, taped together if bigger than one sheet, and tape it all to a book-protecting self-adhesive film, backed by a waxed paper. Then, using a scalpel, I cut through the paper and the film following the graphics, but not the waxed backing paper - you'll learn to use the correct amount of force for this after some practice with scalpels. Then fix the top film with stripes of tape so they'll hold togeter when the backing papaer is removed (or better, use soft adhesive transfer paper on top of it all to hold it together). Then, put the film on the deck, one edge first, and carefully the rest, avoiding air bubbles. Remove stubborn air bubbles with a small sting of the scalpel - the cut will be so clean that no paint will get through. Remove what shoud get paint, paint, remove rest of film. Clear coat.
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Holes, Foam
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On 11/15/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
wow,
Drilling all those holes at 1/8" would be.. alot of holes. But then in proportion to how thick the wood would need to be (still guessing here) around an 1/8", the ratio of removed material vs. (end result) material would be fairly low.. or lower than a bigger hole with an 1/8" gap. Duane, could the holes get bigger if you foamed them? That is/was the plan for a honeycombed board (to keep the epoxy out, and to give the skin more contact area).
I have never foamed a board before so.. I was planning on taping some plastic, LDPE, to the bottom, letting it sag a bit, not too much, and pouring the foam through the crossmembers/holes onto the bag, and then the foam would rise through the holes/crossmembers and fill the gaps. Would a teflon pan do a better job? and where can you find a 40" + teflon pan?
Svarteld, that board looks great. Its kinda cool how you can see the grain through the paint. Speaking of painting, are you just making a template, putting it onto masking tape, and putting the tape on the board, or.... I am looking to start putting graphics.. beyond spray paint stencils on my boards and it would be helpful to know how to get such fantastic results.
Thanks
Yan0
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Foam
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On 11/15/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Duane,
What kind of foam is that? Is it available in spray cans? I've never used foam. Could you just wrap the cut-out core (truss or honeycomb) with plastic foil on the back, fill the holes with foam, then sand down exess on top, plus foil and some more on back?
I'll see if I can get hold of some balsa also. Guess the grain should be running between the shells, vertical (?)
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Holes
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On 11/15/2004 Duane
wrote in from
United States
(68.15.nnn.nnn)
Any disruption in the core (gap, hole, etc) should be less than 1/8" if possible. After that you have big problems with the skins buckling. There was a lot of work done to arrive at the cell size used in aluminum and nomex honeycomb cores.
Putting that cut-out deck onto a teflon pan and pouring in foam, then sanding flat would be bang-up though. The skin on such poured foam tends to be heavy (it forms smaller bubbles at the edge), so it would be best to space the deck up above the pan so that both sides would have to be sanded, thus removing the heavy foam skin.
I still think balsa is easier. If you rough-cut the deck, and soak the edges in thinned resin, it'll toughen the impact up more than you might believe (just be sure to add hardener at the thinned volume rate). It then gives a crush zone at the edge, and tends to mash a little rather than splinter, easily fixed by making the deck just a little smaller in a re-sand :P
I bet balsa handled this way would give birch ply a run for its money in a head to head "curb-off" contest.
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Home made honey
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On 11/15/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
I think your truss core can be very light, YanO, will be exciting to read how it turns out.
Just one thought of hole size when you drill your honeycomb-like core: The smaller the holes, the more total side surface inside the core with the same core weight. I think the tricky part with this core will be not to let too much epoxi run down the side surface of the holes, when glueing on the first shell layer to the core - in my case, one hardwood veener. Smaller holes might mean more risk of resin added weight, but the total flex might get better and more uniform. Also, smaller holes means a lot more work - number of holes will be square proportional to diameter, and the precision requirements for drilling will be higher. So, I'll try bigger holes, choosing between 20 or 30 mm diameter, and drill out 1/2 to (if possible) 2/3 of core weight. Seems like YanOs truss core will be much lighter. The tricky part there might be to get good bonding between the shell and those thin trusses?
Just got some paint on my oak-topped no-rear-steer deck (the second one). The grain structure is really coarse;
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YanO's
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On 11/15/2004 Dave G
wrote in from
United States
(207.69.nnn.nnn)
Ahhh.. Sorry for the "jumping to conclussions" I feel much better now! Good work YanO..Keep us posted!
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more on the cored board
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On 11/15/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Dave G,
firstly, nothing is as good as constructive criticism. With the core you see below, I skinned it with two layers of 3ply bb, one on each side. From "preliminary" tests (see: me screwing around) The torsional stability seems to be just about that of a "regular" 10ply deck. Had I skinned directly with carbon, i would have foamed first. My next deck, honeycomed or cutout will be foamed so that the carbon has a consistent flex throughout the deck. ... I think that is what you were saying with longitudinal flexes.. could just be me.
yan0
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truss vs honeycomb
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On 11/15/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
as far as what reduces more weight, I am not sure. That is why I want to make two decks, identical dimensions except one is honeycombed and the other is cutout like the one you see there. I am tempted to say that honeycombing will remove more weight, but only when it is done right. If you leave too much space between the holes the weight of the deck picks up. I don't know how thin you can get the bb and still have it be structually sound 1/8" seems about right, but who knows, you might be able to push it to a 1/16". The same goes for the trusses in the cutout. The thinner they get, the lighter the core gets, but the oveall strength of the core decreases, where is a happy medium? The other thing that I am curious about is what truss angle promotes the best torsional strength, and is that somethign I should worry about seeing as the core is going to be skinned.... questions questions questions.
herbn, I like the idea of drilling the mounting areas (a bit like in svarteld's drawing). I don't know how deep I could cut wheel wells without opening up a foamed/hollow part of the core. it seems that if I sanded through the skin , and into the core I would loose a good deal of strength, because not all parts of the skin are supported. Yet again.. questions.
Svarteld, I want to make identical decks and compare them mostly for the sake of knowing what is lighter/more effective. As far as production goes, I will build an occasional board for someone else, but its mostly just me.
Yan0
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YanO's
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On 11/15/2004 Dave G
wrote in from
United States
(207.69.nnn.nnn)
Herb, The voids will still need to be sated w/ material of some sort, No? Ply or non ply, the diagonals and lateral/longitudnal will flex at verying rates, hence seperating from a "skin" . Maybe a thin veneer, top/bottom, then skinned?
How about a herring bone pattern originating from a 1.5"/2" "backbone?<<<<<<< <<<<<<<<<<<<<<<<<
Just my edumacated .02
Enjoy,
Dave G
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yano's core
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On 11/15/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
when you stress analyze yano's project, remember, it's only the core.The skins hold the weightm,it levers off the top skin, the top plys are for the grain. I kind of see the bit of extra strength in the diagonal beams, though i think a bit of thickness on the edge of the board would do that, and toughen things up against impacts.One thing about longboards,they don't take as much hits as other types of boards(normally)though i'm sure someone can dazzle us with a 30 mph lost board running into a sewer,but you can't build boards with that kind of impact in mind.I wonder what removes more material svartelds honey comb,or yano's truss beam,yano could still drill holes in the nose and tail and by the trucks, nice big beveled blended wheelwells lighten things up and taper off the flex pattern.
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p.s
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On 11/15/2004 Dave G
wrote in from
United States
(207.69.nnn.nnn)
YanO,
The weakest part of your design is the lack of integrity from base plate to base plate. If you were to leave a "stringer" down the center a few inches wide, and beef up the rail section by 2x or better. It'd be stronger, but, you'll still get alot of torsional weakness. Not bustin' your chops, just pointing out design flaws..Even the oldest bord makers have learned that a "stringer the length of the board is mandatory! You've got to join the 2 trucks via strength. Foam core consructed boards have solid foam cores and only break the foam off at the edges for weight and strength reduction!
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Cut -it -Out
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On 11/15/2004
Dave G
wrote in from
United States
(207.69.nnn.nnn)
YanO,
First off..Beautiful work! But what you have devised,is known as a "truss" and is meant for the sole purpose of vertical load, not lateral! ie: if you'd set the deck on edge and stand on the edge, it would have a great weight to strength ratio. But standing on it the way intended, it will SNAP !!!all the weight from the rider is transfered to very small intersections of beams and inherently weak...Even filling the voids w/ foam won't help. Because the foam isn't a continuos mass. Think of things designed to spread load over a large area (air mattresses etc... you'll never find that geometry used because it is no stronger than it's weakest point! Not to belittle your effort, but I'd hate to see all that work time effort and money spent, to only result in board failure causing injury and a broken up piece of art!!! Think of bridges and you'll see what I mean.. The voids are too large for lateral support!
Keep at it!!
Enjoy,
Dave G
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Hardcore ;-)
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On 11/15/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
YanO,
Nice to see some pictures. I think you're right. I'll try honeycomb-looking birch cores covered with carbon, probably with thin hardwood plys (like oak) on the outside of the carbon to help distribute forces, and maybe on the inside also, to get a surface to glue the carbon weave to. I've been doing some reading of laminates, and carbon seems very brittle - lots of rigidity, but can crack easily if the shell takes a beating. So I'll probably routinely coat all my carbon decks with a thin hardwood veener - it also makes finishing easier, and if you use a simple press like I do, easier to squeeze out excess epoxi.
I've been doing some sketches - mostly thoughts, not with precision. I'll leave extra birch on the edges and around the trucks, and use a hole pattern to leave some of the grain running untouched the whole length of the deck, like this. Make the holes smaller if you want to put more work into it, and more narrow to lessen weight. To make speedboard-stiff decks, I think it's good to thicken the core, and win back that weight by putting the holes more narrow - thicker core means more leverage to load up the fibres quicker: more rigidity, less flex. But, if you want flex, I guess a thinner core would be better, and maybe switch to glass fibres - they weigh more and are weaker, but are more elastic and won't break so easy when they bend as carbon, guess that's why glass are so common in skis and snowboards.
You're very serious, building another similar deck in another way to compare weight, flex and work needed! Are you planning for small-scale production?
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skins on the core
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On 11/14/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
I put 3ply bb on either side of the core (total 11ply). I thought about it for a bit, and it seems that a honneycombed core is a better option for the reasons you listed, the skins can "flex in" or "flatten out" between the crossmembers the way I went about it. I should have put foam in there, but I don't know if that would completely fix the problem, Thoughts? The next hollowed core will be foamed. I am going to start with one layer of 6.8oz carbon on either side (8ply core) and see how she feels, then go from there.
svarteld,I don't know how you went about honey-combing, but I was planning on using a 1/4" (ish) bit and spacing the holes 1/8" + hole dia away from eachoter, so that there is 1/8" of wood between the holes.
I need to make two identcial boards, one with a honeycombed core, one with a cutout, and see what the weight differences are like, see what the labor intensity differences are like, and see if they ride similarly. There is pretty clearly a huge benifit in a lighter core/deck, I just don't know what way works best.
Yan0
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honeycomb
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On 11/14/2004 herbn
wrote in from
United States
(205.188.nnn.nnn)
how thick are the skins? is there wood sandwiching that core,with carbon on the outside or between the wooden components. Seems like thin skins might flex in,or feel soft. You could fill those triangle up with foam or balsa, for gluing surface and solid feel.
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cutout core
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On 11/14/2004
Yan0
wrote in from
United States
(69.173.nnn.nnn)
Here is a pic of the cutout core I did a little while ago. I have an 8 ply deck in the press that I am going to honeycomb and put a layer of carbon on either side. After thinking for a bit I decided that honeycombing is probably a better way to go, the carbon gets more contact points, wheras whith a cutout like mine, it can "flatten out" between the holes.
Yan0
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Light trucks, Light board
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On 11/12/2004
silversurfer
wrote in from
United States
(24.62.nnn.nnn)
herbn your project sounds more interesting the more you describe it.
I'm intrigued by the idea of a very light and very low board.
With light and low trucks.
The Carbon and Balsa would be awesome. With some kind of bumbers,
like you said. Or a birch core.
Or how about some of that 1/4" aircraft wood Tyler is experimenting with?
I think some 77mm Abec 11 Strikers would be cool on there.
Or Cherry Bombs. Or those blue 78mm Power Paw Giant Aluminators (Nicotine Prototypes) I saw in one of the pics of your shop on hugh r's site.
Please keep up us updated on the progress of your parking lot board with the
light trucks.
Thanks!
-Eric:)
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light trucks
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On 11/12/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
i have a pair of 9 inch axle trucks that weigh in at right close to 300 grams,less than all short board trucks except grindking. I'll have to get pics up soon, they're sweeter than anything i've sent pics to hugh of,in the past. The kingpin threads into sort of a billet gullwing style bracket that interlocks and bolts into the baseplate with a single small bolt, the other end of the kingpin is clamped in the baseplate. The bearings(micro) that the hanger pivots on support most of your weight,and impacts ,so the kingpin is no longer a highly stressed part,so it's aluminum (7075 t6) hell it's even hollow. The truck has an axle height of maybe 40mm so the board needs to be cut for full clearence,and drop through isn't really needed,I think i'll machine a beam of birch ply with pockets for the trucks,with a carbon wraped inlay, edge glued hardwood tips, or maybe aluminum tube bumpers.I want to play with carbon and balsa, but i don't want to bang it up, it's got to be kept away from the edges, though seriously the edges of carving bord rarely take a shot,just the tip and tail.I was thinking of narrowing my baseplates,a narrower base lets the beams on the side of the trucks be wider and still clear the wheels.
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Turf Ski
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On 11/12/2004 Dave G
wrote in from
United States
(207.69.nnn.nnn)
There were several brands of "turf skis" of the alpine nature, The best and most popular had rollers and a belt. Similar to a tank track! And sod hurts worse than snow
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parking lot board
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On 11/11/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
i'm gonna use my light light trucks on a smaller the dh board ,a board that will fit more easily behind the seat of my car , a board that won't fill a shopping cart, and knock stuff off the shelves of the supermarket,a board that's just a bit less conspicuous than my 46inch dh speed carver.
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Roller Skis
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On 11/10/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
Tom,
The skis you saw were probably Nordic Roller Skis, Basically a bar with two wheels on either side and a binding in the middle. They come in all kinds of variations, with pnumatic wheels, with resistors, with racheteted wheels to simulate cross country etc etc. A good long while ago someone came out with an alpine roller ski. It was a long bar of (I think fiberglass, dont quite remember) with quite a few wheels on the bottom. I think the wheels were staggered from side to side to simulate sidecut, but I am not sure. I was 13 at the time so..
I doubt that any four wheeled contraption can accurately simulate the "skiing experience" most notably because your CG is significantly higher.. unless Icook up dropped CG ski boards.. hmmm.. but even then, the pivot point (fulcrum) will be above the riding surface (probably somewhere through the boot), wheras the fulcrum on a ski is the edge that you are rolling up onto. Also, the turning radius of a carving ski has to do with how flexed it is, not how layed over it is (granted, the two normally come hand in hand, but you can have an edge angle of lets say 45 degrees, you can make drastically diferent radiused turns based on your pressure distribution, with trucks, the radius is pretty much dictated bt the angle of the board). Basically, I am not trying to make a ski board for crosstraining, but more as something new to try out.
If anyone has any experience with makking skiboards, I would love to hear your feedback. I was thinking that if I really wanted to getinto it maybe using a modified flowlab truck would be the best way to go...not quite sure.
Back to boards.. Not quite sure if a hollowed out (havent decided if I will honeycomb or remove triangles like I did before) 5ply core filled with foam and coated with carbon on either side (2x2twill, 6.something oz) will be really flexible. I doubt that one layer on either side will do the trick, so I was thinking one on top, two on the bottom. Thoughts?
Yan0
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ski-boards
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On 11/10/2004 tom meakin
wrote in from
United Kingdom
(84.66.nnn.nnn)
Hey, i may be a complete noob when it comes to board modding, but i have seen some people with wheeled skis, though they were less skis and more langlauf training things, when i was in switzerland in the summer. They didnt have proper trucks as such, more of some staight unturning fixing to the board. the guy had poles too, and was using it as a langlauf ski, ie lifting each foot to turn, stamping down on each step to start moving, but hmm... just thought i could help :) ..oh, and langlauf is cross country(i forgot as i'm used to the swiss for it lol) :P
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Downhill
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On 11/10/2004
Brad
wrote in from
United States
(206.165.nnn.nnn)
Yan0,
what kind of speed do you attain on you DH skate runs?
Also, are you using a luge or are you standup?
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skiboards
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On 11/10/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
greg, that sounds slightly painful.
As far as the trucks/canting issue, i was planning on using a cut down truck, with relatively little pivot angle, so that they would be stable at higer speeds. I ski with a pretty wide stance anyways, approx shoulder width, but if I need to go wider I could put cants under the bindings (basiclly just wedgjes) so that when the soles of my boots arent perpendicular to the ground, the base of the ski is.
Yan0
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Skiing...again
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On 11/10/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
I will check out the Birkshires for sure next summer. I am 45min away from killington, and will be there tomorrow. I am somewhat of a Sugarbush fan myself, but that's because I grew up skiing there.
see you up there
Yan0
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