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| Home Made Boards (6188 Posts)
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Home Made Boards |
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Autoclave?
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On 11/7/2005
Geezer-X
wrote in from
United States
(63.138.nnn.nnn)
I got a 4' length of rectangular residential furnace duct and a register vent. I use this for the post cure step in making my composite decks. The cured deck goes in and rests on some scrap aluminum posts, a small 2500 watt electric heater / fan blows into the bottom. I've got 2 cheap thermocouples plumbed in at the top and bottom which I can connect to my VOM to see the temp gradient over the length of the chamber. You control the temp by how open the register is.
Cost about $25, can't catch fire, works very well, and keeps your shop toasty warm in the dead o' winter...
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herbn hinge
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On 11/7/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
herbn,
I've read about the D-beams you posted about the hinge deck a while back - thanks - but I can't really get my head around it. Could you explain so I can follow with my less-than-good english?
---
"Oh yeah on the Hinge deck, think D-beams,flip them around like you can do with regular trucks(but not reccommended) they worked(sort of) without the post, and now you're just molding a set of high tech composite flipped d beams right into your board ,axle and all. I think a short parabolic rocker at the ends of the board to about 45 degrees or so. It may work better if the whole end of the board isn't flexing,imagine if the middle two or three inches of the board has a round rocker and is made flexy,while the sides of the board,just narrow beams,goes straight or at an inverted rocker curve,they meet at the ends. You have leaf springs set at 45 degree or 30 degree angles,with the hangers molded onto the middle of the spring,or clamped on and slidable(adjustable) to differently angled parts of the spring,different geometrys."
---
YanO, Shapy, Duane 'n all - thanks for the comments.
Cheers, Peter
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Updated holes in X-Grain Veneers
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On 11/7/2005 EBasil
wrote in from
United States
(207.200.nnn.nnn)
That's excellent news regarding your X-grain plies, Ted. It's not hard to deal with the issue on the old plies, but it can be inconvenient. I can attest to the fact that the "old style" plies are plenty durable.
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Veneers from Roarockit
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On 11/5/2005
Ted
wrote in from
Canada
(69.197.nnn.nnn)
Nick
I think you bought a pre-cut deck kit and not uncut veneers from us.
The uncut longrain 1/16 Maple veneers we sell for deckbuilders are clear, knot free and 99% blemish free with no cracking. We order all our longrain, face grade stock. This means that it is the best skateboard veneer you can buy.
I suspect the problem you had with the deck kit veneer you bought is with the crossgrain pieces. Our kits come pre-drilled and cut to shape. Because of wood expansion in the crossgrain pieces we had to drill larger holes in the front 4 truck holes to make the aligning pins aligh properly. Even with this quick fix, the veneer expansion was so great the crossgrain holes eventually extended beyound the longrain holes. We had no idea that cross grain veneer would expand as much as they did when we did our first production run of decks. Big surprise! The veneer is not any weaker because of this problem and will still make a quality deck. We are in the process of doing our second production run of longboard veneer. The new material will be slotted to compensate for wood expansion in the crossgrain layers. This will work a lot better I think.
All skateboard manufacturers use crossgrain veneers (Xband)that have knots and some open holes through it. To my knowledge you cannot buy xband from a mill clear. So your crossgrain material may have some small knots. It would be great to offer crossgrain material knot free but unfortunatly it is not possible.
When they mill and process deck veneer the crossgrain layers are almost always glued together pieces of veneers. The kit you bought is like this. When these pieces are handled and shipped sometimes they will break apart at the glue seam. An easy fix is to glue them back together or be carefull in aligning them when you are stacking while vacuum bagging.
If you go to any woodworking veneer retailer and look for hard maple veneer you will find that it will be 3 times the price as ours. Check locally as there are plenty of veneer sellers in California. There is only one other company I know of that sells this material at a reasonable cost and it is more expensive than our price even when you add in the shipping. Unless you buy the material locally you have to pay for shipping so when you go shopping online remember that veneer is heavy and it will be expensive to send. The retailer doesn't see a penny of that money.
Norah and I work full time making sure people are happy with what we sell. If someone has a problem with any part of a kit, we try to figure out a solution. If there is no way of fixing the problem we send them repacement material ASAP.
Ted
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Other veneers
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On 11/4/2005 Erik
wrote in from
United States
(63.206.nnn.nnn)
Nick,
You found 1/16" veneers in California? Turn me onto the source. I can't find anything but the super-thin, furniture veneers.
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experience
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On 11/3/2005 nick
wrote in from
United States
(71.102.nnn.nnn)
i made a board from the roarockit and it turned out alright. i want to make another but roarockit plys are too expensive and just bad. in california, i had a couldn't find baltic birch or canadian maple. we got regular birch, red oak, and luann. have any of you ever used the regular birch or luann(not sure how to spell). those are the main three here so if anybody has experience with birch or luann or oak repost something on the site please.
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It lives! er rides
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On 11/2/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
The balsa board got set up and did a few maiden voyages,gumballs cleared better than gripins, i should swap out the 78a's that are on the balsa for my 75a's for a softer ride, the balsa board definitely has a firm ride. It feels very light with just the trucks on, add wheels and the lb or so that it's lighter becomes less noticable (when picking it up) push off and it definitely feels lighter it seems to launch or just sort of accellerate more crisply. I may end up doing pockets ,it feels tall to me,and they generally add some flex. I got a few drips of epoxy that should be sanded , the final coat was a bit thick,tisk tisk, extra weight, but it coated the edges nice. It feels like it would be confident at speed, no wallowing or twisting on the carves.
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packin' heat
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On 11/1/2005 shapeshifter
wrote in from
United States
(198.160.nnn.nnn)
sounds familiar... until now my oven has simply been a five foot long corrugated box with a space heater blowing through it from about 8" away. the box is allowed to collapse a bit to a squashed diamond with support beams (carbon cut-offs) to keep the lay-up higher where it is hotter. another set of shorter supports are used to prop up it up between the top and bottom corners and it all balances on a makeshift rig of cigar boxes and trucks (heheheh). it gets to around 190°f inside there and it all folds down to nothing. lately though i've been thinking about assembling one out of concrete wallboard and insulation for higher temps in the very near future. then again those silicone heating blankets duane mentioned earlier look like an interesting option.
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ovens and such
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On 11/1/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
I've been sold on prepregs for a long time, I got some back in '83 when it was super-exotic and it was amazing stuff to play with
I just read a neat way to make an oven. The oven is the big hang-up, time-consuming to make and difficult to control. The "oven" consist of a cardboard tube, carpet roll tubing for making small tubes, or something like 12" diam. Sonotube would work well. To one end you place a kerosene garage heater, the kind that blows hot air out a tube. The air blows through the cardboard tube and exits the other end. Stick the vac bagged part in from the far side, and run it for a few hours. No resin mess and much better properties with high temp epoxy, much tougher and more heat resistant
sounds simple and effective, and outdoors sounds good to me. I once opened a home-made oven to discover a burned hole in the flooring, right through the "asbestos" floor tiles which of course were not asbestos, luckily there was concrete underneath. hot air sounds much safer than electric coils.
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that hollow feeling deep inside...
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On 10/31/2005 shapeshifter
wrote in from
United States
(24.148.nnn.nnn)
the key to lateral rigidity and/or total flexural control lies in variations in thickness. i'm talking about the thickness of the space between the skins in conjunction with the thickness at different locations within the skins . the surface areas should flex at differing rates and differently depending on the location that the pressure is applied. it is critical to also have the support structure within also flexible in such a way as to be complimentary to the function of the whole. designing a deck like this is deceptively simple yet at the same time no easy feat. try to picture the subtly contoured upper skin stretched across a slightly bowl shaped lower skin. both function to maintain the integrity of the other's shape such as a drum in one section and like two leaf springs conjoined at the edges in others. we're talking 3d here, the one thing that would be good to get away from is parallel lines and linear concepts, because when you want to do more with less...
...shape is everything.
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Hollow Core Suspension
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On 10/31/2005 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Svarlteld.... Looks phreakin sweet.
I certainly never have done anything like that, and I don't know that anyone has. So from here on out its pure speculation and hypothizing. I would think that with that setup the part that does the "flexing" would bend radially, meaning that the pivot angle is changed. This would be because even though you have grain (for that part of the board) running crosswise (no fore and aft strength from the wood) shear strength is maintained, meaning that the skins are held back from "slipping" over eachother. To do what I think you are trying to do, you need the top and bottom part to be able to slip over eachother... You could do this with two swingarms each side, four total per truck, eight per board. One on the top of the riding platform, attached to the top of the "truck platform" and the other running from the bottom of the riding platform to the bottom of the truck platform. Make both have the same radius and have them parallel to eachother so that the angle of the truck platform is maintained. You could put a skin on the top or bottom to serve as a kind of spring, or you could use a striaght up spring to suspend the deck..... Taking it a step forward you could use this kind of a setup for an adjustable drop using a screw with an anchor on the riding platform and on the truck platform.... or preset holes with a pin or something...
Basically what I am saying is that I think the concept is extremely promising, but I am unsure if using composites for the suspension part is the best way to achieve what you are looking for. Then again, I have never done it, and unlike some who regularly post here, I can't tell you for sure. could make one sweeeeet board if it works out right.
Yan0
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Building for Beginners
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On 10/31/2005
EBasil
wrote in from
United States
(63.206.nnn.nnn)
It's heady stuff, reading the banter about cutting-edge ideas for board construction here!
On a different level, we just completed another "Longboard Building 101" course at UCSD, using the simple and nearly elegant Roarockit vac-bag systems and TiteBond III for 7-ply maple decks (3&5 at x-grain). I remain convinced that this is an excellent, and easily produced method to teach people to create their own decks, whether they have already got experience with tools, have no experience with tools or are engineering students (who, these days, are scared of tools, heh heh).
If I tell you where I'll host some photos of the completed decks, Adam will delete my posting (he may do so just for referring to his unannounced program to delete references to that other place on the internet), but if you surf the 'net on longboarding and want to see results and commentary about Ted & Norah's excellent system...you'll find what you need.
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Hollow core/suspension
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On 10/30/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Guys,
Interesting reading about autoclaves.
Here's an idea that leaped on me a while ago, thinking of hollow cores: let's say you build the parts of the core closest to the trucks with only spruces running from edge to edge sideways, not along the deck, but still keeping the skins wide apart, and some slight concave on the skins on top and bottom. If the rest of the deck is built stiff, maybe these ends of the deck could work as parallell suspension arms, plus springs, all built into the deck... maybe.
The idea is sort of to use the skins as parallell arms and springs, and using spruces running only sideways (edge to edge) to allow for flex along the deck, but keeping stiffness sideways, wich might become torsional stiffness at the same time...? Keeping the skins parallell through the flex means they might flex without the truck changing angle, so the steering maintains unaffected of flex/suspension, a good thing on many other vehicles. Yes, you loose the ability to steer with flex,and maybe to pump and all that. But maybe it could be useful at higher speeds, where flex steering and torsional flex might be a bad thing. The more the concave of the skins, the more spring resistance. Dampening might be a good thing somwhere, so maybe the skins could be birch plus glass/carbon.
Something like this.
Any ideas? Comments? Worth trying?
Thanks /Peter
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Water Board
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On 10/30/2005 Yan0
wrote in from
United States
(140.233.nnn.nnn)
Tommy,
Whenever you soak wood, some bubbles appear at the surface, much like what happens if you put your hand in water and don't move it. If a ton of air came out of the wood, I would guess it had something to do with the wood you are using, the 5 plys are made from a very soft wood, sometimes particleboard/sawdust. The air could have escaped from the voids in the plys and been replaced with water, in which case you may run into a rot problem down the road. Put it in the press, try it out, and see what happens. Water tends to weaken plywood unless it is marine grade. Your board could come out perfect, it could come out alittle unsatisfactory.
In my eyes a better option is to use a better wood, and forgo the soaking. Use Baltic Birch, its the high grade cabinet stuff, it usually comes in 5'x5' sheets. If you still want concave, I would reccomend getting a peice of the 1/4" (5ply) stuff, ripping it into 10+" sections (you will get five, the sixth will be slightly less than 10") and then laminating two of the peices in the same press you have for giving it concave. I use epoxy, others use straight up wood glue or a resin of sometype. A peice of 1/4" bb usually runs for about $20 and you can get glue for next to nothing. Don't know what your budget is like, but its worth the $$ and you will come out the other side with a much better preforming, longer lasting and lighter board. Not to mention you can make two boards for twenty bucks, Not half shabby.
As to the homemade Autoclave/oven thread: Could you make one from steel pipe and a thick sheet metal ( I don't know my metals so well, but something like 1/8") Basically build a box of the sheet metal reinforced with the steel pipe, Run hoses for the vaccuum and compressor, and find a way to heat it (I was thinking heat lamps, but they might break under the pressure)... Or do you need the cylindrical shape to make a hommeade one work? If you needed the cylinder, yould you shape one out of foam, cover the crap out of it with glass and proced from there (not unlike a composite water tanks)....?? Although it seems like an autoclave is designed for prepregs, its use could probably extend (and probably has) to using wetted out cloth? I ask because it looks like I am going to have a good chunk of time around thanksgiving that I may be able to dedicate to the construction of one of these bad boys.. A friend could help me with the metal work... Hopefully not another dead end road.
yan0
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water in board?
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On 10/30/2005 Tommy
wrote in from
United States
(24.125.nnn.nnn)
im new to making longboards, and longboarding in general. im a surfer who is lookin for something to do while im landlocked. i shaped a deck this weekend; 48" pintail carver, similar to the pintail from sector nine. made from cheap 3/4" 5 ply that i found in a dumpster. anywho, i put it in the tub with some hot water to get it prepped for adding some concave and there was a ton of air escaping from the wood. should i be worried? i know im probably being over protective, but after all that shaping effort (fixin the screw ups) i really didnt want it to get screwed up while i am so close to the end.
thanks
tommy
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autoclaving
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On 10/29/2005 duane
wrote in from
United States
(165.121.nnn.nnn)
you vac bag it, then put it into the autoclave. the vacuum hose goes through a fitting and stays as vacuum, and the 0 psi (absolute, -14.7 psi gage) adds to the 50-100 psi pressure. in practice you could turn the vac off once the pressure starts up but the vac helps keep things from shifting
prepreg is expensive in small amounts, it has to ship in a dry ice package, but there are some new resins that are ok at room temp but I have not used them. a 300 degree oven is easy to build, 2x4 and sheetrock and tuffR foam, you can use space heaters rigged to a temp. controller. I would like to try the flexible silicone sheet heaters, they look good for flat objects
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auto clave
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On 10/29/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
so, you bag up your project,do you need a hose to the outside so the air around the work piece is reg air pressure and can escape? This would be vacuum bagging in reverse.Can you do wet epoxy? how about sources for the pre empregnated carbon/glass? Oh yeah on the Hinge deck, think D-beams,flip them around like you can do with regular trucks(but not reccommended) they worked(sort of) without the post, and now you're just molding a set of high tech composite flipped d beams right into your board ,axle and all. I think a short parabolic rocker at the ends of the board to about 45 degrees or so. It may work better if the whole end of the board isn't flexing,imagine if the middle two or three inches of the board has a round rocker and is made flexy,while the sides of the board,just narrow beams,goes straight or at an inverted rocker curve,they meet at the ends. You have leaf springs set at 45 degree or 30 degree angles,with the hangers molded onto the middle of the spring,or clamped on and slidable(adjustable) to differently angled parts of the spring,different geometrys.
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big 'claves
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On 10/28/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
yeah check these dudes they are right down the road from me, they make masts for sailboats, more than 100' long sometimes
http://www.hallspars.com/AboutHall/Tour/2.htm
it would be surprisingly easy to build a little one, just some flanged pipe w/ bolted end caps, probably could get surplus steel pipes for scrap price, and the pressure from a little air compressor
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autoclave
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On 10/27/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Yeah, they're huge - there's railroad tracks leding all the way into the tubes.
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autoclave
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On 10/26/2005 shapeshifter
wrote in from
United States
(24.148.nnn.nnn)
man, that just takes my breath away!
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Hinge etc
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On 10/26/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Thanks guys for the info,
Guess this isn't a beginners project, so I'll put it on the shelf for a while.
Actually I've been inside those big autoclaves at SAAB here in Sweden, where they bake stuff for the Gripen fighter (I'm a photographer). I've got some friends working there, and it's said that employees have built some pretty hitech composite stuff off-duty, like sea kayaks. Have to ask them to bake a project for me some day :-)
Autoclaves:
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hing deck
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On 10/25/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
I've seen a board ,pics actually of a "nearly famous" dh board from like 1976/7 signal hill ,3rd place i believe. It has the wheels coming straight off the frame of the board,no "trucks" the turning geometry (angle) is the sag of the board,not much, "doesn't really turn at all below 30 mph" i think if you molded a board with upturns ,double kick, and had the axles coming straight out of the narrow ends ,it would turn,not a whole lot, it would have to be really flexy and you may have to split the board(right and left)with flex mounted axles ,it would steer. Test rides would need to be done very carefully and in a wide dh parking lot with a lot of slippery pads,but i think you'd be surprized.
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composite springs
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On 10/25/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
check out the www.flexboardz.com site, they played with composite flex to achieve turning but abandoned it later. I guess they couldn't get it to turn enough.
My version of your drawing has the "trucks" underneath, very much like the Uptrucks, but the truck is the carbon from the deck, turned underneath at 45 degrees and carved into a triangle shape similar to a conventional truck. A polyurethane foam damper could be installed in the gap between the "hanger" and the board. That way you need no living hinge, but just twist the narrow portion in the area where a normal pivot cup would be. The dampner would be needed otherwise you'd go sky high over the first bump, giving a whole new meaning to "bucked off"
I think it would take lots of unidirectional carbon, some nice resin that has good elongation, and an autoclave. I wouldn't trust the pressure of just vacuum for springs, I don't think its enough to get the fiber loading you would want.
I'm sure it can be done but it would take astack of rejects to work it out.
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Carbon spring/hinge
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On 10/25/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Anyone tried making the deck and "trucks" in one piece of carbon, using the flex of the material instead of bushings/springs? If it's bossible it could turn out to be extremely light, and maybe with a lot of undamped spring response in trucks/deck. Not very easy to adjust though, since everything will be in one piece. Just an idea, a little like those Up trucks, but in one piece carbon, together with the deck.
The idea is to use some kind of "living hinge" that you can see in cheap plastic one piece constructions, to give both the hinge and spring. Something like this:
Well, it's just a rough schematic drawing. The striped areas are the hinges. The idea would be to make this area thin, narrow and long. The deck might have a foam core. The whole thing would be one piece of carbon, foam and two wheel axles, molded together.
Maybe this question might suit Duane, since you've mentioned carbon springs earlier?
Thanks /Peter
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