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| Home Made Boards (6188 Posts)
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Home Made Boards |
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wrinkles...sorry later
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On 11/26/2004
Greg Olsen
wrote in from
Canada
(206.172.nnn.nnn)
Sorry I did not read the image posting instructions carefully enough..but I assure you the images are entertaining...
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plastic bag and a shop vac
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On 11/26/2004
Greg Olsen
wrote in from
Canada
(206.172.nnn.nnn)
For your entertainment I have provided a picture of a foam core fibreglas board I am working on. I have since sanded it flat and done nice smooth hand layups but the first shop vacuum wrinkly plastic bag attempts produced entertaining results.
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Big bushings
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On 11/25/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
herbn,
Funny, I've had about the same thoughts :-) I'd like to increase resistance around the middle, like when bombing straight down to aid stability, but at the same time have less progressive build-up of resistance when turning, more linear instead, and also a longer stroke, to still be able to turn pretty sharp, and not get annoyed by a turn-limiter-feel.
I've figured taller bushings might do it, and these are 2 x 18 mm, to compare with the usual 12 + 16 mm. The truck angle gets a little steeper, but not so much. However, I've discovered the washer size has a huge influence on stroke length, and also linearity - small washers on top seems do the trick, and none at the bottom (more urethane between pressure points), but 'm pretty shure you figured this already. Also, I drill the washers with a hole just about the size to fit to the kingpin snugly, avoiding play and clicks.
I actually made some bushings yesterday, using a large non-cylindrical shape to aid in linearity feel, and they are the closest to this described feeling I know so far, including the common tip of double 16 mm straight black DH bushings with flat washer on top/none at the bottom. But I want to try some more shapes before I show them.
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those bushings
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On 11/25/2004 herbn
wrote in from
United States
(152.163.nnn.nnn)
Svarteldm, do you get the same lien angles that regular bushings getm, i've always thought big ass bushings were the way to go,I thought the height of a big od bushing might have to be a bit greater,1.5 x diameter should = 1.5 x bushing length, actually my trian of thought has been longer lengthm, to reduce the progressiveness of the spring ratem, BUT m, start with a higher spring rate,ie higher durometer.For instancem, add a 1/4 inch to the height of th bushings but increase bushing hardness from 75a to 85a, to do this with the inner bushing requires major truck mods(making your own)my own trucks havn't gone to that point ,yet.
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Trucks
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On 11/22/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Aaron, no worries, i'ts a good point.
If anyone are interrested in the trucks on this deck, I've just posted some in the truck forum.
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Braking
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On 11/22/2004 Aaron W
wrote in from
United States
(24.52.nnn.nnn)
I didnt relize we were talking about that board. Im sure that board will not be ridden on very twisted roads, but in any case, you still wont get the stopping or slowing power that you would get from putting your entire foot on the ground.
I guess it all depends on the situation, if the roads that he is riding do not require full footbraking, then toes off the side will be fine.
But another point is that the board is very low, making it that much easier to take your foot all the way off.
Sorry for rambling about footbraking in this thread I just thought I could offer some advice.
In the weeks to come I will be posting some pics of my own. I am nearing the completion of my vacuum pump and will start on the mold soon. I plan to start simple with some 11ply hard maple drop thru speedboards with mild concave to get used to the vacuum process. Then I will start to play around with foam and balsa cores with carbon fiber.
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Svarteld braking
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On 11/22/2004 herbn
wrote in from
United States
(64.12.nnn.nnn)
while i tend to agree with you aaronm, you may have over looked these points; Svartelds board is extremely low, his toes may reach the ground very easily,big sized feet may improve that aspect also.His board doesn't steer very much, with a 0 degree rear truck so liening a bit won't change direction much,for example,braking for a toeside corner,he positions himself wide, and then drags toe as the corner approachs,liening brings the toe even closer to the ground and he need's to head towards the inside of the turn any way.
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asymetrical
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On 11/21/2004 Aaron
wrote in from
United States
(24.52.nnn.nnn)
Svarteld
I try and keep my foot with as much angle that is comfortably possible. You definitely want your rear foot flat on the ground (with even pressure from toe to heel) at the side of your board. If you put your foot behind the board you risk doing 45mph splits, ouch.. Plus to much weight will transfer to the rear of the board causing instability and you will lose to much turning ability. Slowly build up your speeds dont go any faster until you are confident with the previous speed. The number one issue is determination, once you have that your not for from comfortably braking in the 45-50mph range. There is a ton of info on this subject in the stopping thread, check that out as well.
Good luck!!
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Brake
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On 11/21/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
YanO, 5 hours, quite some labour of love! Hope both your boards turn out right. I'll send a report when I've tried drilling with bigger holes.
I guess the asymmetry will make the flex uneven, especially around notch at rear right. I'll try to build it very stiff, and see what happens.
Aaron, thanks for the comments, I'll think think it over. Maybe the notch could also allow for more braking when doing normal foot-braking. Do you move your front foot to be parallell with the board when foot-braking non-mongo, or leave it at an angle, to steer better? Have you tried braking right behind the board? Guess it requires a really short board. I'll start next season with a lot of brake training!
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Asymmetrical deck
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On 11/21/2004
Aaron w
wrote in from
United States
(24.52.nnn.nnn)
Hey Svarteld,
first off this is not a slam to your creativity or board design because I think that both are amazing.
I believe that your design would allow for very light braking only. If you drag your toes off the side of the board you can only apply a small amount of pressure without weighting that rail of the board, causing the board to unsettle or turn. Also, if you need to turn while braking, or set up a turn while braking you are limited to turning in the direction of the side the braking foot drags the ground. (In your case I believe you are regular footed so you would only be able to turn right while braking). On many of the roads that I skate I need to be able to turn in both directions while braking. Braking with your rear foot flat on the ground is the safest, most stable and gives you the most turnability of any technique available.
Nothing can make up for a good technique, I learned this the hard way. I skate mongo style (push with my front foot) and tried to learn to footbrake this way which is fine for low speed skating but as soon as you add speed you lose stability and turnability. I wrecked myself over and over again trying to brake like this because I didnt want to train myslef to brake with my back foot. Finally, I got fed up and forced myself to brake properly, It took awhile but it was well worth the effort. Many roads opened up to me that I would have never even thought that I could skate before I became comfortable braking.
Thank you for all your informative posts on this thread as that have helped me with some board designs of my own.
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holes... lots of holes
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On 11/21/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
Svarteld,
Looks like you have your work cut out for you, it looks awesome. I am curious how (if at all) the assymetry will affect the flex pattern.
I just finished honeycombing that 8ply deck. I ended up using a 1/2" boring bit, and spacing the centers 5/8" appart. Next step is to foam the whole board. When the deck started out it was about 1.25kg now it is .695 kg, total loss of 330g. Proportionally, the cutout was much more effective, I removed around 400g from a 5ply core. As far as labor intensity goes, I spent around 5 hours getting the deck set up and drilled. I spent around 1 doing the cutout.
I haven't ridden either board yet, so I can't give any kind of evaluation on how they preform, but it seems that if you are going for weight savings without using balsa or a "real" honeycomb for your core, the best way to go about it is with a cutout core... or one of herbn's air railled winged deals.
Yan0
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Asymmetrical deck
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On 11/21/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Here's a shaped drawing, with the flat part of the concave marked darker.
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Brake stance
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On 11/19/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
herbn, that deck sounds special, though my english won't let me quite understand what you mean.
There's snow everywhere here now, luckily I got some test rides done to get some ideas of improvement (?). The angled duck-tail of the no-rear-steer decks seems like a nice place for the rear foot when in air tuck. Since the decks are short it's OK to foot brake right behind also, and the low platform makes normal foot braking (just) possible with a heel still on the deck.
But rear foot could use some more room on the duck-tail, and dipping toes when foot-braking would be easier with no concave under the foot, and some support for the heel. I might try an asymetrical shape and concave to help when in these stances, and to lock the feet more. Here's a drawing of 1) air tuck, 2) dip-toe braking, 3) front foot braking with dropped knee, and 4) drag foot braking. The deck will get more rounded once I get everything sorted (though probably never good-looking) :-) I've done this rough shape after drawings for nine stances I use when riding/braking/kicking.
Anyone made something similar? Advices?
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balsa
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On 11/19/2004 herbn
wrote in from
United States
(205.188.nnn.nnn)
i would like balsa in crossgrain,48 x 10 (or so)amybe 2 inches thick so i can cut them into slices on my table saw,and fine tune the thickness of my core,and just splice it together with harder wood,like ash or spruce (loggrain),just splice the whole thing together with the right wood in the right place,carbon wrap the balsa,fiberglass skin top and bottom over the whole thing.
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Try again
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On 11/18/2004 Ted
wrote in from
Canada
(69.197.nnn.nnn)
Try this again:
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Longboard Veneer
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On 11/18/2004
Ted
wrote in from
Canada
(69.197.nnn.nnn)
Finally got stock in from New Brunswick for our next production run of kits.
I also bought 700 sheets of 1/16" 48 X 10.5 Canadian Hard Maple to sell as full sheets to boardbuilders.
The price is $19.00 for 7 layers plus shipping. 5 long and 2 cross grain.
The five layers of long grain are face material. There are no knots with some of the sheets actually having nice curly grain in them.
The two cross grain layers are core stock, most of this material is clean but once in a while there will be a small knot on some of the sheets. This is typical for core cross grain stock in most decks. Still looks good.
Have a look at:
Click here for link
I am sellng the stock, in only small quantities, 1, 5 decks, as I know it is hard to get a hold of deck veneer in small quantities for one off projects.
Ted
[IMGhttp://www.roarockit.com/assets/images/prodimages/refill/veneer_uncut_lg.jpg'>
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Foam and balsa
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On 11/17/2004 Duane
wrote in from
United States
(68.15.nnn.nnn)
Yea the end grain sheets are pre-cut and sanded to 24x48" by nominal thickness. I'd like a "mixed box" but no one will sell it, so I figure 3/8" will allow the best compromise. 10 sheets per box if I recall correctly. Nothing to keep you from laying them up for thickness, and they cut real well with a very sharp knife or can be sanded / dremeled pretty well.
That supplier is a boat supplier primarily so the shore it must be. My gf is from Berkely Heights so I make it out there regularly, and have shot a few good hills around Clinton and vicinity. I'm afraid Mays Landing is Cape May area, quite a drive from up there. Shipping would be cheaper than gas.
You can increase the density of the foam by cooling the cans before mixing. The advertised density is at 23C / 73F usually, it expands on exotherm so cooling it down reduces the bubble size and reaction rate-> denser foam. It is my experience that the 2 lb/ft3 type will blow some very large bubbles and cell size uniformity may be poor. Remember the larger the thickness poured the less dense as the heat builds up in the middle. That stuff actually gets hot if you pour a large chunk.
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air beam
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On 11/17/2004 herbn
wrote in from
United States
(205.188.nnn.nnn)
middle of the night, drug induced(anti inflamitories and pain killers, for my back),so how can i NOT make this board:) 3/32 birch ply;cut two identical sheets,38x10. Drill mounting holes in both. Cut grooves with table saw(3/64 deep.125 kerf)which is a bit loose.trace shapeon both grooves are strategically located,like right next to mounting holes. The number of grooves can be varied.Now cut strips of 3/32 depth I'm thinking about 1/2 inch.Tracing shape of board on grooved side ,you can see where the "air chambers" cross the template. The thickness of the board will be 1/2inch+3/64+3/64=19/64 plus the carbon i'm gonna put onto the grooved side of the skins.The carbon will corregate as i press things with epoxy. I can make pieces of hardwood to fill the gaps where the chambers cross the template lines,so i don't have holes of weakness in the edge, though that might look cool. Cross grain beams might be cool,it complicates things a bit by requiring notches for the beams to inter lock,very winglike. Herbn's skate wing.
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balsa
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On 11/16/2004 herbn
wrote in from
United States
(64.12.nnn.nnn)
I AM interested mays landing sounds like the shore,i'm from the mountains of nj,up north but it my be worth a sunday road trip or a short shipping i'll buy and split it with you. Do you get sheets in vert grain,the prefered compression resistant, if not i'd like big chunks, like as thick as my table saw can comfortably cut,to splice it together at a fine tuned thickness of my liking.
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foam, boards
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On 11/16/2004
Yan0
wrote in from
United States
(140.233.nnn.nnn)
Thanks Duane,
I actually already bought foam from fiberglasssupply long ago in anticipation of a project like this... Unfortunatley I got the 2lb/cuft variety.. we will have to see how it works out. As far as balsa/honeycombed cores, I am sure that they offer better structural integrity, but I don't have either at the moment. I am probably just going to fill up whatever holes I make with foam, and coat with carbon, hopefully the foam will help stop the fibers from buckling, but if not.. I still have the 85%ish efficency. It seems that unless you are using prepreg over a cutout/honeycomed core,the best option is to put foam in the cavities, that way epoxy dosent drip in, and you can maintain a better weight to strength ratio. I'll post pics of what I end up doing.
Yan0
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Pour foam
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On 11/16/2004
Duane
wrote in from
United States
(68.15.nnn.nnn)
The pourable, carve type is called polyisocyanurate, which is a rigid type of polyurethane foam. It is two parts mixed 1:1 and is commonly found in hobby stores for making train sets and stuff "mountains in Minutes" was an old brand name.
Yes plastic taped on would work fine, the foam would not stick. It sands easily so no problem smoothong it on each side. Cutting it first with a hacksaw blade might make sense, it would be nearly flush then.
Several of the early carbon skatecars I worked on had aluminum front and rear bulkheads which were tied together with aluminum tubing. We then filled the spaces between the tubing with pre-formed pieces of flat sheet polyurethane foam, which were painstakingly fit, then filled the small gaps with pour foam and smoothed. Then all of this was put into a tubular female mold and covered with prepreg carbon both sides, and vacuum bagged with a toroidal shape vacuum bag (putting the bag on, then pulling one end of the bag through the center of the tube and sealing), and baked in a home-made 8 foot oven.
All of this effort at complex core design was, in the end, a waste of time. Later versions had simple one-sheet nomex cores, the main structure made in clamshell halves and glued together. Lighter stronger, faster, and way more durable. It is my experience again and again that a simple, one-material core is superior, with an exception made for hard blocking inserts where compression may be an issue (bolt holes). Even then it is better to glue stuff on if possible rather than using bolts.
To give an idea of strength, we stacked 540 pounds on the center one of the obsolete car bodies, supported only on the ends, it weighing under 10 pounds fully enclosed, before it broke loudly. In practice it carried perhaps 90 pounds, well distributed. We then burned it for the hell of it. For future reference, poly foam and carbon / resin go up nicely, with lots of pretty colors but acrid smoke.
Yes the balsa is preferably end grain, and several manuf. make sheets 24 by 48 inch standard at 1/4" 3/8" and 1/2" stock, the most dominant being Baltek in fact they may make all of it. I've seen results showing several times the max load in shear before failure, as compared to foam. With foam you can shear chunks away with your fingernail, with balsa no way. Watch out most of the balsa is scored into little blocks held together with scrim, if you want solid you better ask, it is much more rare.
The pour foam can be found in a range of densities, I'd recommend a middle ground like 8/ft3 http://www.shopmaninc.com/foam.html these prices are high if you ask me, stores like West Marine may have some as well but in any case it is a common material.
Now, who wants to split a box of balsa ? I know where to get some, and would personally like some 3/8" to play with. One distr. is in NJ close to herbn perhaps ? namely,
Mahogany Company of Mays Landing Inc.
5450 Atlantic Ave.
Mays Landing, NJ USA 08330
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graphics
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On 11/16/2004 frank
wrote in from
United States
(24.170.nnn.nnn)
Also I can print on fabric and apply it to the boards. This is pretty expensive and the fabric tends to soak up alot of resin.
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graphics
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On 11/16/2004
Frank
wrote in from
United States
(24.170.nnn.nnn)
I can print images on rice paper that can be applied like fiberglass. I am also working on printing on to the veneers itself. I have a friend trying the rice paper application now so we'll see how it turns out. I'm still working on the details but it should be fairly inexpensive. This will work with any image. Basically you can put a picture of you on the board.
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Give me a brake
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On 11/16/2004
Svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
I'm glad the discussions here are so good - lots of knowledge to learn :-)
Has anyone experience or comments about asymetrical decks? Here's the story...
I'm a novice, and foot-braking (standup, rear foot) at speed makes me nervous. Two of my friends have eaten it while doing this. I tend to drop knee and brake with front foot instead, grabbing the board - feels much more stable at speed to me, and you can brake quite hard. BUT, it takes some time to drop and grab, before you can brake. I also quite often brake by dragging rear foot right behind the board, holding the nose, but it also takes some time to get down, grab, and extend leg - a little faster than drop knee/front foot, but you can't brake as hard.
When I rode my latest deck (wich is the lowest usable I've built), i noticed I could dip my toes on ground with rear foot, still having the heel on the edge/ducktail (Gumballs). Feels more stable since you have two legs on deck, not one, and front foot don't have to change position. Now I'm thinking I could zap the concave in just this area, and make the edge move inwards here, in a way that makes it easier for the toes to reach ground and still have good heel support on the duck tail.
This means both asymetrical concave and shape. Maybe the front could also be made more custom-fit for front foot placement and braking.
I might try this on the next deck. Comments would be a great aid.
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honeycomb
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On 11/15/2004 herbn
wrote in from
United States
(64.12.nnn.nnn)
drilling honeycomb, definitely a labor of love,keeping the core from chipping and splinters from gapping the short distance between holes,tough. If you didn't drill through the core(close but not quite) things might get a bit easier,but that's a lot of holes,holey skateboard batman. Your nomex and balsa are very appealing,i'm sold, but i was just making reccomendations /defending the project,rather than saying "you f'd up ,throw it away and start again. Buckling skins and big gaps just lower the efficiency of the materialsm,true honeycomb or balsa carbon may be 99 percent efficient but yano may be perfectly happy at 85 percent(guess) because it may be higher than stuff you can buy.
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