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hacking up my yak
Well, I've been thinking of taking the plunge for a few years now. I've discussed my idea with Jim Day, and he also decided to give it a try. We both went and bought almost everything we need, made a brief start, and put it away to move on to other things. Well, something happened that lit a fire under my hiney, so I'm back at it again. So what the hell am I up to you probably asking; well being a previous owner of a Hobie Outback, I came to appreciate their pedal drive, but simply hated their hull designs, so I decided to make my Current Design, Alutra into a pedal drive. So I started with making a fiberglass mold that the pedal drive sets into. I did however, mold in 14" stainless so I would have a solid mounting of the drives mounting clips. Here are a few pictures.
The glass mold http://i333.photobucket.com/albums/m...g?t=1297743050 Mold and supplies http://i333.photobucket.com/albums/m...g?t=1297743050 Stainless pieces http://i333.photobucket.com/albums/m...g?t=1297743050 Stainless glassed in place http://i333.photobucket.com/albums/m...g?t=1297743050 Today I cut holes in the yak, so I can glass the fiberglass drive housing into the yak. I'll post those pictures of me cutting up a perfectly good kayak sometime tomorrow. |
your pictures are so tiny i need a microscope to see whats going on
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Fiberglass to plastic? Will this work?
I've only worked with fiberglass once, helped make a hatch cover for a old Bayliner but that was it. I'm curious to see how this will look at the end........good job on the mold!!! |
Tuna Taxi, no, no plastic at all; My yak is a glass composite yak. I seriously don't see a glass to plastic attempt holding water for long. The part of the glassed mold that will be visible is a carbon kevlar composite. I'll be posting pics later, and as I go. Thus far it's looking good.
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Much better! I don't know what I am looking at, but I would love to see how this piece would fit when the mold is completed.
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Much like my marriage of 20years, it makes sense now.
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Interesting idea, I have thought about trying to do the same to one of my kayaks. I just never got the balls to seriously start hacking. Good luck and keep us updated.
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What he's doing (and yes I'm making one as well) is putting a Hobie drive into a Current Designs Altura... http://www.cdkayak.com/products/prod...ra677_cust.jpg The Altura is a Kevlar composite kayak that's fifteen feet long and about 55 pounds they were marketed as a high end alternative to plastic fishing kayaks and retailed for just under two grand. These kayaks are very fast, handle well in the surf and they stronger and lighter then anything on the market in their size class because they are made from Kevlar which is something like as strong as steel though lighter weight then fiber glass. Since Kevlar is laid up with the same process and resins as glass it's fully glass compatible, and in fact the production Altura has both glass and Kevlar elements in it's construction. Here's the stats: <table width="100%" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td colspan="2" valign="top" align="left"><hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td colspan="2" valign="top" align="left"><hr></td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Length : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">15' 0" (457.2 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Form : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">Swede <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Width : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">31" (78.74 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Depth : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">12" (30.48 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Chine : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">Soft <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Hull : <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">Shallow arch <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Cockpit size: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">55" x 20" (139.7 cm x 50.8 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Cockpit type: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">Open <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Forward Hatch: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">16.5" x 11" (41.91 cm x 27.94 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Day Hatch: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">8" dia. (20.32 cm) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Front Hatch Volume: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">35 gal. (133 L) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> <td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Day Hatch Volume: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">25 gal. (95 L) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td> </tr><tr><td class="BreadCrumbs Bold" valign="top" width="25%" align="left" nowrap="nowrap">Max. load*: <hr></td> <td class="BreadCrumbs" valign="top" width="25%" align="left" nowrap="nowrap">450 lb. (202.5 kg) <hr></td> <td class="BreadCrumbs" valign="top" width="10" align="left" nowrap="nowrap"> </td></tr></tbody></table> Current designs usually builds touring kayaks, and the reason they make them out of kevlar is not only are they lighter weight but also stiffer then other materials which makes them faster. The less flex you have in the hull the more paddle energy goes into forward progress. So this design is actually about the fastest paddle driven sit on top fishing kayak ever produced even though it's now been discontinued. As soon as I saw it I wanted it as I already knew their specs, but also for a while I had been toying around with the idea of putting a Hobie drive into a non-Hobie yak, and the Altura with it's strong specs and composite construction was the perfect opportunity for me to do that without building another kayak up from scratch. I've long been a fan for the merits and technology of the Hobie drive, but have never been a fan of their actual kayaks. So the idea for me was to take their superior drive system and put it into a superior kayak, that should out perform other yaks even stock Hobies especially in the surf. Naturally when he brought it by the shop topic turned to what I planned to do with it which got him interested in the idea of putting a Hobie drive in his Altura as well. We got a hold of a Hobie made some molds purchased our drives retail as replacements and ever since then for me the projects been on the back burner. I always have a ton of projects and this happens a lot for me but Gary is now boldly going it on his own, partially he claims to get me off my ass and building my own :biggrinjester: So what he's done is made a glass plug off a mold that will now hold the drive in the new yak.http://i333.photobucket.com/albums/m...e/P1010182.jpg That looks like the form upside down laminated out of carbon, kevlar and a glass composite. http://i333.photobucket.com/albums/m...e/P1010183.jpg That looks like a detail of where the drive locks go. http://i333.photobucket.com/albums/m...e/P1010175.jpg Looks like he's cut out stainless that's going to be tapped for the locks mounting screws.http://i333.photobucket.com/albums/m...e/P1010178.jpg...and there he has glassed over those mounts.. So Gary it looks great. I would of probably predrilled the mounting plates and tapped them, then glassed them in place with bolts already in them. That said you've made great process. So when are you going to cut the hole in the hull? Your welcome to bring it by when you want to do it. If I was you I'd find someone with a Revo and measure the distance from the slot to the seat again. It's the old Rastifarian proverb, measure twice cut once... :D That applies to boat hulls more then anything. :biggrinjester: Good stuff.... Jim |
Gotta say that looks like one hard core project!:sifone: Always wondered if and when someone would attempt this.
Question for either of you: How are you lining up the "drive" to the keel to keep aligned? Are you fabricating some type of form or chalk lining the drive & keel for alignment? If your off a bit will you go in circles?:biggrinjester: |
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Well considering that the Hobie Outback (I purchased brand spankin new) I owned did a 10 foot radius, I figure I can do much better than Hobie, seriously.
Actually I used several methods in lining up my drive; the bottom side of the yak has a shallow arch, so one can simply turn the yak upside down, line up a chalk line with the center of the yak, clearly visible at the front and rear by it's pointy sections. I did the same on the topside, I also measured it in several ways, in addition to using a laser. Since the topside higest points are flat, it's pretty easy to use a square and bring it around the yak, i.e., bottom, top, and sides. Considering that you really need a rudder with a pedal drive, the rudder should easily compensate for any minor maladjustment; yet I'm confident in my alignment. |
that's going to be one heck of a hot rod kayak...will follow this post, I am sure it will turn out bitchin...excellent
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As Yogi Berra might have said, " You don't know what you don't know". I am a happy Revo driver and while the design is not perfect I do not find much to complain about. I am curious as to what Jim and Gary object to about the Hobie hull design.
I can see some advantages to the kevlar hull. The stiffness and smooth skin should enhance both speed and handling as long as the mirage drive is installed in a location that does not fight with the fluid dynamics of the hull. The lighter weight should also be a plus. On the other hand, I can bang my yak into just about anything without causing any damage. Can the same be said about a glass kayak? So tell us what we don't yet know. What's wrong with Hobie hull designs? Bob |
Bob, Hobie has designed their hulls for stability, instead of efficiency and tracking, as such, it's pretty common knowledge that Hobie's don't track for shit, and down right suck in the surf. However, the Revo has to be hands down their best fishing yak hull. But if you don't believe me, just try pedaling it around with the rudder up, and see what happens. The Altura hull, is about as good as one can get to a cross between an efficient touring yak and a yak designed for fishing, unless one goes to the effort of a complete ground up design.
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Looks like we might be needing some popcorn for this one.
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imo,
He may be pretty hard to keep up with when he is on the "pedals" when this is all completed |
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yep, your right, I am trying to build a better mouse trap, and I probably should have left it as that; sorry. |
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As with most things, accommodations have to be made by the manufacturers so that products will appeal to the widest range of potential customers. Experiments such as yours may open a few eyes as to what can be done. I look forward to seeing the results. Here is something to think about. Your comment about Hobies not tracking well is true when under peddle power. My Revo, when in paddle mode tracks much better, even without using the rudder. I wonder if the turbulence or some other factor that is introduced by the Mirage Drive has anything to do with this. Your experiment will probably shed some light on this. If the modified yak retains its excellent handling characteristics after the Mirage Drive is installed, you will have probably proved that the Hobie hulls need some work. If, on the other hand, the peddle system induces tracking problems similar to what we Hobie users experience, that would be another lesson learned. Please keep us posted on your progress. Bob |
Bob, sounds to me the hobie is not your "bag", perhaps you would be better off with a paddle kayak? Complain..complain...bitch ....bitch...time to go fishing bob!:)
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Bob, you've made some very insightful statements here, much more eloquent then I. Your 100% right on with a manufacturer appealing to a wide range of potential customers; you just don't stay in business if you don't do this to some degree; and in doing so, everyone gets a little bit of what they want. Obviously Hobie has a product that appeals to many people; their roto-molding is excellent, the pedal drive system is simply ingenious. But there will still be a few picky bastards like myself, that want a little bit more; and from a $$$$$/profit perspective, it may not make any sense to give us picky bastards what we want. In consideration of tracking, if we compare the difference in tracking of the Revo vs the Outback, we find a huge difference, in both paddle and pedal mode, So I would conclude that hull design would make a difference; but that is nothing new considering the two hull types; and is very predictable. But I do think your on to something with the turbulence factor of the drive, and considering the low slope design of the Altura's hull, I don't think I will end up with the best tracking (once done) from the Altura, without some minor modifications to the bottom of the hull. Basically, I guess what I am saying, is that to end up with a pedal drive yak that tracks well, you need to start with a hull that tracks very well. I also think that that turbulence effect you speak of, may be amplified in the surf zone as you have water going in the same direction as the yak, and against the intended water direction as it travels past the drive unit (not to mentions side currents and what not in the surf zone). I simply don't know if a better tracking hull design will make a difference in the surf zone; and considering the slight slope hull design of the Altura, I have my doubt's that it will preform any better than your Revo, unless I try some minor hull modifications, and then I still wouldn't bet one way or the other (in the surf zone). Someone had mentioned that I may have the fastest yak out there once done; I'm honestly not sure about this. I would say I would end up with a more efficient kayak. I guess what I'm saying is that it should be faster off the line, i.e., more efficient. But when it comes to top speed, I think it's a combination of hull design and the pedal drive units abilities; and I feel that the design of the drive unit has it upper speed output limits. So I don't expect to gain any significant speed over another pedal drive yak, given consideration for hull design/speed ability. But I do expect the yak to do what ever speed with more efficiency It's that efficiency that makes the Hobie's so damn appealing and well worth the extra dough. |
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And I thought he was noting his observations, :doh: |
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Apparently there are exceptions to this rule. Racing kayaks are an exception. These boats can go reach speeds that are nearly twice their theoretical hull speed. I have no idea why. My guess is that since your hull is a faster design to begin with you will have a higher hull speed than the Hobies. I also think that there is a good chance that the increased efficiency of the hull will make it so you will get more thrust with the same energy. This should help improve your maximum speed as well. Time will tell. Regardless of how everything turns out, it looks to be a fun project. Bob |
[QUOTE=dsafety;76126]I am not a naval engineer or anything close but if I remember correctly there is something called "hull speed" that determines the maximum speed that a single hull vessel can reach without coming to a plane. It has something to do with displacement, drag and probably some other factors.
It's waterline length, there is a mathamatical formula, and unless you can plane, you are limited to that speed. It's something about wave formation or something. I do know on my 28' displacement sailboat it's about 6.2 knots, I could put 400 hp and not go faster, it will go 6.2 knots with the 15 hp diesel, I have. And use 1 qt per hr. |
Cool idea!!!
It doesn't surprise me that a former outback owner would feel this way, specially if you owned a 1st gen hull (with the round front hatch). And didn't you return your hobie because it didn't steer itself? :doh: I think Hobies "ill handling hulls" are actually designed that way. You have to consider that the large majority of people out there are using them in calm waters, and really enjoy the quick boat-like response of the Hobie hulls. Not to mention, who actually paddles these things? Remember the Outback is still, by far, the best seller.Having a hull that tracks well will not feel as playful in the water, and would also scrub off a lot of speed every time you do turn. Enter the Adventure....long and sleek (27.5"W vs. 31"W) and as close to a true SIS touring style hull as I've seen on any SOT (besides maybe the 160i, prowler and expedition)....granted the area under the cock-pit is a little flatter, giving up some tracking but not much. I can't imagine someone into speed and efficiency "hating" this hull design.....although I do imagine that there are plenty of people out there who are a little afraid of trying to fish from a 27.5" wide platform. Maintaining speed/efficiency, especially in rough water has a cost, and generally it is stability. As for the surf...well, IMHO it has a lot more to do with the skill and strength of the paddler along with the weight distribution in the kayak. Hull design and width, not so much!! Anyway, I can't wait to read the rest of the build along with the testing and tuning afterwards. Hopefully you can hook-up with a local Hobie guy "roadrunner" and do some performance testing. In the past he has put most of the Hobie hulls though some pretty extensive tests. FYI, the "calculated hull speed" debate has already been beat to death...the equation is antiquated and has little use when discussing kayak hulls. |
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Nope, it wasn't a 1st gen, and no, I didn't return it. |
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Bob |
I admire your spirit of adventure, big balls for cutting up a yak and the brain work that goes into a project like that. Without folks like these we would all be still using these things called "paddle" to move our yaks around.:D
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Matt, I'm not sure I deserve such accolades,although there nice to hear. After all, being a bit older than most yakers, I have some advantages (I don't even want to discuss the disadvantages of being older :biggrinjester:). When I went to school, there use to be industrial arts classes (shop classes), that actually taught real world applications, practical skills, and trade skills; where geometry wasn't some foreign/abstract idea, but just a part of completing a layout. Those classes simply don't exist in California public schools any longer, and the emphasis is now on book knowledge/academia. I think those classes gave the students of those (my) days some good basic skills, knowledge, and abilities; but more importantly, the confidence needed to tackle such projects as this one. Unfortunately, nowadays, most youth in California are not exposed to industrial and trade arts. I guess what I am saying is, that times have changed, and at one point in time, what I am doing would not have been considered having big balls; having a sense of adventure, perhaps. I mean, it's not like I'm inventing something new, nor am I taking two separate things and putting them together, for a first time. Yet it is a bit of an adventure, and I generally do derive great satisfaction when a project comes together as planned (and functions as expected). But I do appreciate the encouraging comments! Now I've got to figure out how to get the new pics from the darn phone to here, so I can update you all. |
Gary...
stay off the computer... get back into the garage and build the dang thang already! no more internet banter untill you make more progress....:doh::rolleyes: I wanna see the big ass hole in the bottom of that yak... and how about wearing a heart rate monitor and video the heart rate from the time you bust out the jig saw to the actual hole cutting...be interesting to see the effects on the body when one cuts a big gnarly hole in the bottom of the yak... I know I pooped a little when I drilled a 2" hole in the bottom of my "brand spankin' new, never been in the water yet" Revo... my heart rate went through the roof...:eek: |
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Hey Josh, long time no see! The hole is already cut, both topside and bottom. I need a decent weather window to start putting it back together, as I don't have have an enclosed heated place to work on it. What! One little 2" hole did that to a guy that cuts, hacks, and slashes for a living, I can only imagine:biggrinjester: |
Greetings all!
New member with a first post. I currently own a CD Altura and was surfing the web, doing some research on possibly getting another one when my search led me to this site. I'm interested to see how your project comes out. I looked at Hobies, but they didn't seem to "fit" me very well and I liked the Altura's design better. It's already a speedy SOT (I started kayaking in Greenland-style sea kayaks when I lived in SE Alaska and Washington state, and I think the Altura is comparable to them as far as flat-out speed - not AS fast, but it can certainly hold its own for such a heavy/beamy boat). A "hands-free" propulsion option would be kinda cool, though. Quote:
Great forum, BTW. Ron |
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