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| Home Made Boards (6188 Posts)
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Home Made Boards |
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DH
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On 11/10/2004
Brad
wrote in from
United States
(206.165.nnn.nnn)
Yan0,
I thought you were talking about skating downhill. Killington is the only place to go for serious skiing, and they're open today with 8 trails.
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Don't do it
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On 11/9/2004
Greg Olsen
wrote in from
Canada
(206.172.nnn.nnn)
Don't mount trucks on skis!!! I did it once and it was a disaster. Unless you have a truck/wheel combo no wider than a ski(not possible..unless you mount roller blade wheels in the middle of the ski somehow) then you will have to ski with your feet in a wide stance to prevent the inside wheels on each ski from hitting each other. Inside wheels hitting each other results in the phenomenon that happens to open-wheel racing cars rubbing wheels. One wheel climbs the other and disaster. Also the wide stance puts your legs at a non-vertical attitude and puts the trucks into a turning mode...turning in.. so your tips will cross just trying to go straight. One has to only have ONE ski on the ground at a time. Difficult. I managed to do this for awhile down a bike path until I tired of it. Unfortunately I was going too fast to stop and there were none of the normal ways of braking available to me. I tried to go straight on one ski for a stretch and switch over to the other by hopping up so both were in the air and the other would then land. I eventually tired of this too and got sloppy. For just the slightest instant both skis were on the ground. Within milliseconds the tips were crossed and I was flying over the tips. My arms went back as I did my flying impression and the ski pole baskets(yes I was using poles) got hooked together. This held my arms back as I now could not pull them forward to protect me from the impact. I was fortunately aimed toward the grassy edge of the path and hit with full force on my unprotected ribcage. The wind was knocked out of me but there was no blood. But to add insult to injury the unprotected body forwar, no arm involvemnt nature of my collision with the ground left on of my gonads(don't remember which one) susceptible to the crushing impact it then recieved trapped between the ground and my thigh as I decellerated into a heap of writhing, unable to get a breath, 'Gawd my nuts hurt' pain that ensued. The the skis released and whipped around on the safety-straps(it was before skibrakes)and one of them hit me in the head causing the first blood in the side of my scalp. Yikes that was in 1975. Now at 46 I am back into boards and loving it ... but no silly experiments please.
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DH's
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On 11/9/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
I have skiied a couple FIS DH's at Sugarloaf and Whiteface, never checked out the western mass scene, no FIS events there. Might be worth a trip down though. Ill look into it, thanks.
Yan0
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Downhill
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On 11/9/2004
brad
wrote in from
United States
(64.136.nnn.nnn)
Yan0,
for downhill in the Northeast, the Berkshires of Western Mass is all you need!
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x
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On 11/9/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Svarteld
As far as speed goes, I mostly do Super G. I have done a few DH's, but the "hills" in the North-Eastern US are not well suited to DH . I got to go to a few speed/race series elsewhere in the US and in Austria, but opted not to go the DH's, they eat up about a week. I can still get up enough steam in a SG to get an enormous Adrenaline rush, and thats all that matters. It is only a matter of time before I chop down an old pair of skis and mount trucks on them. Its just anotehr creative way to visit my friends down at the ER.
I actually got into building Longboards because I wanted to build skis. Most of the fundamental characteristics of a longboard are those of a ski. You need to think about flex paterns, flex points, and torsional stability, and stiffness. In a longboard, you just don't need to worry about getting the sidcut perfect, and (at least the decks I have been making) aren't tapered from front/middle middle/back like a ski is. Still no idea when the first "Yan0 ski" is going to come out, maybe this summer??
Glad to hear the zero degree board worked out well, its interesting that the rear truck is so easy to lay over. Maybe because the kingpin is 90 degrees from the deck (riding platform) and all the force that normally would go into turning the hanger goes straight to the bushings??
Yan0
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On 11/9/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Sounds interresting herbn, let me know if you build one. Think you'll need a narrow wheelbase even when trying to make speedboard-geometry. Mine are 76 and 81 cm, both 45 degrees front, feels really calm and mellow.
I noticed you need pretty hard bushings for the rear to make it feel like a normal truck. And, you'll have to do without tall bushings on both sides of the hanger with normal wheel sizes (like gumballs), because the kingpin gets really close to the ground. I'll try to use the duck-tail for rear foot support in speed-stance.
YanO, have you been doing competition skiing in FIS? Speed-skiing?
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On 11/9/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
starting with the center beam ,i'll seperate the baseplate into front and back halves, i think i'll interlock the pivot end on the bottom of the board, and do the bushing end as a drop through from the top.hhhhmmmmmm.
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On 11/8/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
I think if i made a board with a shallow geometry truck front or back(or both) i have a real unusual way of making it handle correct a shallow truck needs to have some distance between the board and the pivot,to make room for the bushings. kind of like a riser pad built into that side of the baseplate,this puts your feet to far above the roll center.i'd fix this by.......
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On 11/8/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Thanks for the comments everyone!
I just got back from the virgin ride with the zero-rear-steer 15 mm all-birch. It's 1.15 AM in Sweden, quite cold, and wet patches on the asphalt. But I'm in total bliss :-) Because...
It works. I've set it up with just standard DH trucks - no ball-joint pivots, no kingpin ball-joint, no damper, no trick bushings, to know what it's like without the sweet stuff. Feels like... nothing. Transparent maybe? Low, calm, a doodle to steer with both rear and front foot. Just mount and ride, as usual, no strange behaviour. The steering seems instant but slow at the same time, reminds me of linking long sweeping speed-turns on a snowboard, without letting the rear slip, just cut.
But turn it backwards and everything feels the opposite - actually almost impossible to ride, with lots of time-lag between steering input and actual movement sideways. Guess that's what you get with all-rear-steer. And I think that's the sweet thing with it, that it moves sideways instantly when you steer, even though the geometry is speedboard-slow. But I've only bombed a small hill so far, the big ones will have to wait half a year :-(
Since it's the lowest board I've built so far, it has (what I think is) the usual feeling of a low deck when you initiate a turn - you don't pressure the edge as much, just kind of fall into the turn with looser ankles. It's effortless, but also seems so make the deck more prone to wiggle if you loose balance slightly over some rough stuff on the road. It seems to share this both positive and negative feel with my other low boards.
Another possible negative thing is that it don't feel as surfy as a normal longboard, since the rear won't kick out in turns, it just stays put, trailing. Loose some, get some - what's boring at low speeds usually tend to be good when bombing.
YanO: the black thing on it is just paint.
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On 11/8/2004
Julien
wrote in from
United States
(69.240.nnn.nnn)
I had this idea the other day but don't really have the skills/machines/technique necessary to do it at this point.
Basically, what I was thinking of doing was using the deck as a base plate for the hangar. Maybe with a thin metal piece (about the size of a drop-thru mounting) that the pivot and kingpin could go thru. So basically drill angled holes in the board (1 for the pivot, 1 for the kingpin) then reinforce them with metal and and what not. The deck would be nice and low and probably have a good amount of weight reduction compared to conventional trucks. Getting the trucks on and off would be a lot easier too (1 bolt instead of 4).
Tell me what you all think, what are potential problems/improvements on this design?
Thanks
Julien
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On 11/8/2004
brad
wrote in from
United States
(206.165.nnn.nnn)
Hey Svarteld,
I wasn't sure if you were still talking about the decks with the
steep angles. It would be possible, because you can cut out decks
with kicktails, but with those steep angles, it might get a little
dicey.
Beautiful job on that deck! The finish looks superb! it looks like you're
doing fine with the jigsaw anyway.
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On 11/7/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
good point Herbn,
The foam you should use for the outer part should compact, and not rebound. I think the foam that they use in ski helmets is polystyrene, but I am not sure. If it is polystyrene, it is a dense variety. The softer foam that does rebound is used on the inside for padding/comfort, much like a ski/motorcycle/bike helmet.
Yan0
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On 11/7/2004 herbn
wrote in from
United States
(64.12.nnn.nnn)
soft foam for helmets is not really the way to go ,you push through it on impact or it rebounds sresses back into your skull,high resilience is not a big selling point on helmet foam.
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On 11/7/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Svarteld,
Firsly, that board looks incredible, what is that black stuff, formica?
As to helmets, a few years ago I started talking to people about how to go about it. What I came up with is taking my current helmet appart, thinning it down in places, and using bondo and foam to shape the rest. Then put a layer or two of fiberglass on the outside, and put on mold release. Lay up acouple layers of carbon and kevlar, and take it off. Then make a rough mold of your head, leave space for a softer foam for padding. Set your head mold inside your carbon/kevlar shell, and pour foam into it. Take out the head mold, and trim the edges, put in fabric and softer foam as needed. I ended up not doing it for several reasons. 1) my coach told me he wouldnt let me train in my helmet, and 2) FIS wouldnt even think of letting me race in a homemade helmet, unless I made a whole bunch of them and sent all my freebees in for testing. To the best of my kowlegde, there is no helmet requirement, or "helmets must be "safe" certified" requirement for longboarding, so you should be all set.
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On 11/7/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Brad,
Thanks for the tip. I wish I could use a router, but I think some of the shapes I want won't let me?
Our shop is pretty scarse, the jig-saw is actually not even ours, we borrowed it a year ago from a very patient friend... Time to build him a free board :-)
(These (mobile phone) pictures are from the 15 mm all-ply zero-rear-steer deck. The small bump next to the nose looks like an accident, but it's a cutot to allow the linkage for the steering damper to move freely.)
We're going to build some speed helmets soon, I'm planning to use the interior of my crashed motorcycle helmet, and using fibreglass/epoxi to build a aerodynamic shape, possibly taking the cell padding down somewhat to make it smaller. Anyone with some tips?
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On 11/7/2004
Brad
wrote in from
United States
(64.136.nnn.nnn)
Svarteld...
Jigsaw? If you have the means, use a router table and a template.
I use a 3/4" bit on a table I built myself by attaching a router
upside down to a steel "workshop-type" table. a bearing on the bit rides along the template...Very cost effective.
This is a very effective machine, as long as you don't
climb cut, which is feeding the board in the direction of the router's spin.
....very dangerous. So you feed it against the spin, and you get an excellent
job. The cut is very clean, and it vastly decreases the amount of
sanding you need to do after using a jigsaw.
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On 11/7/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
I've shaped, drilled and mounted trucks on the oak-carbon-birch laminate deck this weekend, and it's about 400 g lighter than the previous all-birch deck, and hard as nails - totally stiff :-) Sag is a few mm. Both bending and twisting strength seems higher, and thickness is only 11+ mm, in relation to the previous 15 mm all-birch. But it's 5 cm shorter also, meaning it's got it a little of the stiffness increase from length. Can't say anything about the damping.
Jig-sawing it out zapped two blades - the carbon made the teeth round in no time. Also generates a lot of heat. The oak cover looks the business :-) The coarse grain makes edges loose slivers quite easy when shaping. I'll use this oak-carbon shell on my next board (with a lighter core), I think it's very promising.
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On 11/6/2004 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Arron,
On the board that I just did I didn't fill the holes with anything, and I am sure that some epoxy dripped into the cavities. For my next one I will fill the cavities with foam before I do the lamination
Yan0
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On 11/6/2004
Aaron W
wrote in from
United States
(24.52.nnn.nnn)
What would fill the holes? Will you put foam in them? If not, will the epoxy fill the holes partially and give you added wieght? Sorry if these are stupid ?'s but I plan on doing something similar.
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On 11/6/2004
yan0
wrote in from
United States
(69.164.nnn.nnn)
Svarteld,
Drilling after pressing makes tons of sense. Come to think of it I have a blank just waiting to try do do this. Not dropped CG, but I pressed a 13 ply blank for a heavy friend who wanted a stiff board, then he decided he wanted 10 ply with carbon. I think I will just drill the crap out of the 13 ply and coat it with carbon.. It might be a while befoe I get around to doing it..
Yan0
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On 11/5/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
YanO,
I was thinking of drilling the core *after* wet-pressing it, not before, so I hope that makes it possible to use hollow cores together with small radiused bends. Actually, I'll probably also glue the core before drilling, to avoid later problems with hole alignment and extra resin spill on the wall of the holes. But, that makes the building process reach five stages... 1) wet press all, 2) glue press core, 3) hollow core to honeycomb style, 4) glue press all, and 5) shape. Not made in a snap. But, as you said, winter is here...
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On 11/4/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
svarteld,
I did put a layer of three ply on either side of the cut out core. As far as the pattetrn, look at Toothless's luge, the weight reduction pattern he did is simmilar to what I did. I will post pics of the cutout soon. In any case, I wanted to try the construction before I layed it up with carbon, I am thinking of doing exactly what you did with the plastic coated birch ply. I havent done it in speed boards yet, this was a pintail, and the flex is just about perfect. I think my next project is going to be a board like that with carbon, but I am going to cut out more, might even put a few holes in there too... I like that honey comb idea. I dont know if the same thing would carry over into making a Dropped CG board, I doubt the 5 ply, even when cut out, would make those radiuses without breaking. in any case, we have got all winter to tinker.
Yan0
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On 11/4/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
YanO,
Nice.
Did you put 3ply om each side of your triangular cutout 5ply core? Or Carbon? I've had a similar idea, but drilling the core out with lots of holes, so the core finally start to resemble a honeycomb, with less wood where there's less stress, etc, and then cover it in carbon, and/or hardwood veeners. Pretty similar ideas, but you've just done it. Bugger :-)
I took my second no-rear-steer laminate out of the press today, but my situation resembles yours – I can't do much more than to kick around on my constructions until spring, since Sweden is cold and wet now. So it's contruction without feedback for half a year for me...
In this first try with veeners and carbon, I settled for a core of 2x3,9 mm birch, total 6 ply, and covered it with thick carbon and 1 mm longitude-grain oak veeners om both sides, pressing it all between extra birch plys of the same shape, without glue and covered in many layers of thin plastic foil. Total thickness is 10,6 mm. First test shows plenty of rigidity (speedboard type I think), but I need to cut it to shape before I can say anything about weight. The coarse-structured oak veener (top sheet) did not split in the small sharp radiused bends, probably cause of the support of the extra supporting plastic-covered plys in the press.
I'll finish it this weekend. Next up is a drilled-out birch core, or a light-wood balsa-like core. In any case, I'll cover it with thick carbon and oak veeners, since this shell seems to work well with my press and shapes.
YanO, keep posting about your work, it shares a lot with what I'm building.
What better decoration for windows could there be, than birch plys drying in the sun?
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On 11/4/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
I just took that 5ply cut out core out of the press and cut it out. I am extremely happy. It isnt the lightest thing in the world, but it was about what I planned on it being. I cut an 8 ply board and a 10 ply board out to the same shape. I left the exact weights in the shop but 5 ply cut out core was only a few grams ( I think about 5g) heavier than the 8 ply, and about 400g lighter than the 10 ply. It also had just about as much torsional stability as the 10 ply, and just as much (if not more) stiffness. The 8 ply is going to need some serious torsion help.
Its snowing.. and people are starting to look at me funny when I am riding around. I have got a week at most before longboarding on ice becomes an everyday reality. Better hurry up.
Yan0
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On 11/2/2004 PSR
wrote in from
United States
(24.53.nnn.nnn)
Duane, thanks for the tip on the A/C unit. I got one that's a bit old, sitting in the barn back at the house. Nelson and I have been planning on getting some heavy-duty vacumn bags, and the A/C pump fits in our plans rather nicely. For a mold, I'm going with Balsa blocks, cut on the bandsaw. We'll take thinner,long blocks, and set them on edge once they're cut, putting in shape lengthwise, but adding angled cuts on the outer strips. This should allow for any concave or camber/rocker/kicktail shapes we want to do. I'm starting to source out veneer strips of select woods to add to the birch and maple ply that Rutland Plywood offers. The only bummer is that by starting out in the late fall, we won't get to ride any boards until April!
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