#541
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Near Enough to Finished
Hi All
Quality ply, nice stuff there Danilo but mostly a victim of the race to the bottom on price from the mega barns here in Australia. Not complaining and I do know where to source the quality stuff if I drive far enough. Top Side - Complete with a DIY beach sand grip surface Top with Deck Grip.jpg Bottom Side - Trimmed up and looking the part Bottom with Expoxy and Fiberglass.jpg Regards Ross |
#542
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One for you Gerald - Honeycomb Wooden Boards
A week or so ago here in Queensland we had the 3rd annual wooden board day.
I missed the date somehow but have attended the previous two meetings. Upon reading the wooden board blog as a catchup, I was impressed to find that a New Zealander flew across the ditch and showed us what they could do with their CNC machines - WOW. http://woodensurfboards.blogspot.com/ Scroll down to "Mike Grobelny from New Zealand with a couple of samples of his high tech approach to wooden boards" Example image from the site and more if you follow the link. Attribution to Grant Newby who also organises the equally creative and successful Alley Fish Fry. DSCN1864.jpg Regards Ross |
#543
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Those are amazing boards!
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#544
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Do those holes fill with water?
some parts are covered but it seems like aesthetic feature? |
#545
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Very nice!
There is a longboard manufacturer that uses the same honeycomb shapes but in aluminium: http://www.silverfishlongboarding.co...s-catalog.html |
#546
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My understanding is that they are all covered, they have cutout the top layer only to show the inside.
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#547
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Ross
Very cool aproach to a wooden board , beats trying to chamber a solid balsa board by hand with a router. Did you get a chance to pick those up, what's the weight and flex like? I imagine pretty stiff compare to the traditional framed approach. |
#548
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Hi Danilo Jed and others
Danilo, my guess is he seems to have a bit if a mix of fully skinned to partially skinned. The pockets would hold water and make turns slower if they were exposed. My vote is for fully skinned but as with any honeycomb design a leak is a disaster if it happens and is not detected. Jed, us surfers are just so predictable aren't we. I did not get the chance to pick up one of the boards as I missed the event. At previous events, picked up "every" board and tested for weight. Some are far too heavy and are really made for the living room wall. Others were marginally heavy, while some are surprisingly light from the talented makers who had an eye on the overall weight in the design criterion. I have chatted to some makers about their weight control and a few trade secrets are required for the lighter stuff. For those of you that looked at the full link you would have seen that some of the boards use an aircraft wing type design. These internal struts being more frequently being cut by CNC these days. Some makers are every inch hand tool sort of people so it will always be a mix. Regards Ross |
#549
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Pablo - Great link thanks.
Regards Ross |
#550
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I'm no surfer, never had & doesn't look like I'll ever be. but I don't get it, I'm very puzzled over the water tight concern. Looking with a pure engineering angle, If there isn't skin on the honeycomb board then what is the purpose of having honeycomb. Also if the honeycomb does not adhere to the skins fully (water tight sealed) than the strength is severely compromised....
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#551
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Ken, the honeycomb pattern just reduces the weight in comparison to the solid wood shape.
Can't really comment on the significance of the top skin with respect to strength. Regards Ross |
#552
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My guess looking at them is that they are going to be pretty damn stiff, no idea about weight but really like the idea, one for the memory banks.
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#553
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Lamination Tests
Glue laminated 2 layers of 200 x 5mm vertical bamboo stock then epoxy glassed the underside with 4 x 4oz cloth and the top with 2 x 4 oz cloth.
Initially the Mechmate was "supposed" to cut out the pre-glassed laminate but a series of comedic errors lead to some holes being drilled in the wrong place and the spoil board moving under the cutter. The composite was now only good for some destructive testing so the pics tell plenty if anyone is interested. IMG_2244.jpg IMG_2256.jpg IMG_2251.jpg Bottom was undamaged expecting pin point loads from an the exposed aggregate driveway IMG_2253.jpg Top has obvious compression failures, a delamination on the inner layer and a set of compression "waves" on the outer layer of glass. IMG_2252.jpg The epoxy was uncured so some improvement in compressive strength could be expected. The conclusion here is where the glass is in the composite sandwich makes a lot of difference in its perfomance. Regards Ross |
#554
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..I love going back to science and engineering school. Skate board & Science would keep the kids attention for sure! Great sharing of information.
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#555
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Foodsaver!
Ross,
I see the bulk clampage use... I laminate balse onto foam cores for my R/C airplanes and use a Foodsaver. The poly bags that come with the Foodsaver do not adhere to epoxy, can be made any length and are great for appying even pressure for this kind of work on a budget. The only limitation is the width of the bags available. Possibly an alternative to the clamps? Dean. |
#556
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Hi Dean
I have started to build a venturi vacuum system that uses an old 40l compressor tank as a reservoir. It will be based upon a Joe Woodworker V2 system. Baby steps on the vacuum system but thanks for noticing my many clamp strategy and suggesting an earier alternative. Regards Ross |
#557
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Ross, you can run the compressor as a vacuum pump, reverse the inlet & outlet, then plunk in a differential pressure switch. good volume & very good vacuum head.
Cost near to nothing & good project to play with. |
#558
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Fridge Vacuum
No problems Ross,
I did some research when I was looking into vacuum clamping and found a few DIY systems using an old fridge compressor. They were all a bit of overkill for what I needed at the time. Good luck with the project! I've been reading with interest Dean. |
#559
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Quote:
Nice flex on your laminates. Innegra cloth might be good in this application (or it may be too "sloppy") Ken, When using a compressor for vaccuum you end up sucking oil out of the compressor. I have dealt with this by having a 2m pipe vertical from the inlet. This acts as a reservoir to prevent the oil ending up on the floor. But the compressor is aging rapidly because of diminished lubrication.. |
#560
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Ross, You will be very happy with the Joe Woodworker V2 setup. I built mine almost a year ago and my only complaint is I wish the vacuum switch was a little more sensitive.
You can make you own reusable vacuum bags very cheaply with thick contractors grade garbage bags. Use modeling clay to seal the bags up. Once done you can peel the bag apart and recover clay and the bag. When you get the bags down look up leach fields and vacuum impregnating. You will never spread resin around by hand unless it is a small job. If you have any questions just shoot me a message. My real job is working on military helicopters doing composite and structural repairs. |
#561
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Hi Ken, Red and Russell
Russell, it's nice to know my decision on the vacuum unit is ok by someone like yourself with some direct experience. I have read about the "dead zone" issue with the mac valve and have accepted this a a part of the learning process. I think we call modelling clay "plasticine" here, so thanks for the tip. Ken and Red, I read quite a bit about the fridge compressors and the oil residue put me off somewhat. Even a standard "cheep and cheerful" vac pump is less expensive than the option I took by the time postage was taken into account. My logic was the vacuum venturi and the reserve tank could pull a large volume down quickly and be done with the oil issue completely. Other people also contacted me directly about the vac bagging process, so once again the forum and its knowledgeable readers have proven a great source of information . Regards Ross |
#562
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Ahhh.... Now I know why oil went into my pipe... Thanks Red.
Ross, reservoir has its limitations, there is only so much vacuum in it... I would suggest parallel your shopvac with the venturi system(c/w with reservoir). Use the shopvac during start-up, when you know your seals are secured, switch over to the venturi system. |
#563
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Hi Ken
A short explanation is as follows. 1 - A high volume air compressor is connected to the venturi 2. This pulls down the vacuum in a vacuum storage tank until a pressure control valve (mac valve) shuts off the venturi. 3. After a set pressure drop of around 4 inches hg occurs the valve reopens the venturi and restores the vacuum in the storage tank. A video of the system pulling down a vaccum in a small dual storage tank is here. The mac valve will alllow the system will cycle on and off as the pressure drops as a consequence of poorly sealed bags and or small leaks. An assembly PDF can be found here that explains all the components and their operation. Regards Ross |
#564
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Hi Ross,
What I'm suggesting is to add an additional help for the venturi press. When bagging a large bag, the reservoir can't cope with the initial suction + the leakages through poor sealing which we can't detect until vacuum is applied. Have a ShopVac hook up to do just the initial stage, use the Shopvac to evacuate most of the air then making good of the poor seals. Let the venturi press take over after that. Regards Ken |
#565
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www.unfinishedprojects.com
I can't believe it but this domain is actually up for grabs - maybe someone was going to do the paperwork and just never quite got around to it.
My drill press is now mobile and a little more stable thanks to my low rider base design. Curves courtesy of the Mechmate but those bolts really need cutting off and the drill press bolted down to the base. IMG_2259.jpg Test assembled the vacuum press and got a great result. It emptied a garbage bag full of air very quickly and after a short time pulled right down past 25 inches of Mercury (27 max). Also got a chance to use my smartphone app that actually converts inches of mercury into some far more intuitive like pounds per square inch. Once I visualized a 12 pound weight resting on "every" square inch of the project in the bag, I was happy the setup had the goods. IMG_20110826_124035.jpg IMG_20110826_124045.jpg IMG_20110826_124123.jpg In keeping with my title line, the gauge and brass fittings will be mounted on the metal handle... eventually. Regards Ross |
#566
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is the vac pump design slimar to one off joe's woodwork?
cool drill press stand might borrow that one. |
#567
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Hi Gareth
Correct, there are a few options available depending on the capacity of the air compressor you have. An improvement would be to use 15mm ply and maybe allow a touch more clearance for the bolts that hold down the drill press to the mobile base. Regards Ross |
#568
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Quote:
Also found in the wooden boat building industry JTCUSTOMS Last edited by cornbinder23; Wed 31 August 2011 at 17:22.. |
#569
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Vac Pump Finished
Got the gauge and fittings mounted and managed to work in a quick disconnect system for the suction hoses.
IMG_2382.jpg IMG_2383.jpg I have started experimenting with making a vinyl vac bag using PVC pipe priming fluid (an Acetone and Methyl Ethyl Ketone solvent) and clear PVC pipe glue. So far got three sides looking good but plasticine failed to seal the open end of the bag. Will test some other closure systems over time now the unit is up and running. Regards Ross |
#570
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Ross,
For closing up the bag have a look at these 2 methods. http://www.joewoodworker.com/veneering/clamps.htm You can use 2 different size pvc pipes rather than buying his products, you will just have to cut down one to size. You can also use this double sided tape to seal up the edges of your bag and use it to close it up. The stuff is incredibly sticky. http://www.ebay.com/itm/Airtech-AT-2...item2a0ee8eafd This is what I use to get the vacuum inside the bag. http://www.airtechonline.com/Airtech...7&ProductID=17 I seen this video the other day and though of you. This guys bag is kinda sloppy but I think you will get the point in Vacuum Infusion. Part 1 http://www.youtube.com/watch?v=ABD1_gCxUTk Part 2 http://www.youtube.com/watch?v=aLgf8..._order&list=UL Another thing to keep in mind is if your going to be making a lot of these boards you might want to research into a vacuum press. You can use silicone as your vacuum bag, this will stretch and have a much faster bagging time. Here is a great example http://www.youtube.com/watch?v=4a0rq...eature=related Edit: Just read about the plasticine. When I go back to work I will have to read the box and see exactly what it is. I am almost positive that it is grey modeling clay, it sticky and seals up very nicely. Last edited by Regnar; Fri 02 September 2011 at 22:06.. |
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