Best hull for Hobie Mirage drive?

[leaotis]

Ever since my brother and I pedalled his 2 place Hobie from Minnesott to Oriental NC in 2 hours I’ve been wanting to put two Mirage drives in a decent boat. I imagine a fat kayak about 18’+. (I promise not to refer to it as a kayak.)

Any thoughts?

Thanks, Mack

[Rick Starr]

Those drives are absolutely incredible. I pooh-poohed them for a long time, but the example I finally tried had been in rental service for years when I tried it and was still going strong on it's original drive. No drips, no sweat, faster than paddling over longer distances. Incredible.

[mike hanyi]

I seen a guy at the mid atlantic small craft get together who built a one person setup, I had a try at it and it was really fun,you still need a paddle as reverse does not exist. yea, something about 18ft and multichine, In my opinion the finns do not have enough surface as you need to kick too often to acheave a comfortable speed. bigger fins would be more efficient.
go for it, a great project

[leaotis]

you can buy larger fins... like gearing up, or a larger prop.

http://tinyurl.com/2n5cox

[Woxbox]

Why a fat kayak? Wouldn't a skinny one be faster?

[JBreeze]

Thanks a lot, guys I searched for a used mirage drive several years ago w/ zero success. This thread got me looking again and I found a lightly used one for $200, and drove 290 miles r/t to pick it up on Saturday.

A chesapeake 17' was built a decade ago, just before the 1st of two extensive spine surgeries.... I don't have much upper body strength left, but the legs are fine. I plan to enlarge the cockpit, build some sort of sponsons or something for stability, and use it for fishing and general touring around Jamestown. Too many project right now, so this will have to wait until winter /spring. Wish me luck!

[leaotis]

Congratulations on your find.I've got a eBay "Saved search" for "Hobie Mirage drive" and have yet to see one become available here in Australia.

If you've got the time, consider making glassed, hot-wire-cut foam drive wells. They have less volume and no corners.

[Frank R]

I see a business opportunity here.

Make for sale these drive wells. Or make for sale the plugs.

Plugs would be easier to make and cheaper to ship.

Or sell the plans.

Or post them here for all to see and copy.

Congratulations on your find.I've got a eBay "Saved search" for "Hobie Mirage drive" and have yet to see one become available here in Australia.

If you've got the time, consider making glassed, hot-wire-cut foam drive wells. They have less volume and no corners.

[keyhavenpotterer]

I see a business opportunity here.

Make for sale these drive wells. Or make for sale the plugs.

Plugs would be easier to make and cheaper to ship.

Or sell the plans.

Or post them here for all to see and copy.

The Mirage Drive I bought came with a GRP moulded housing and the mould tool to produce more housings. I had wondered if others might be interested in a moulded housing? With a drawn plan set, making from plywood seems fairly straight forward.

Brian

[leaotis]

The Mirage Drive I bought came with a GRP moulded housing and the mould tool to produce more housings. I had wondered if others might be interested in a moulded housing? With a drawn plan set, making from plywood seems fairly straight forward.

Brian

I'd love to see pics of the GRP moulded housing. I never knew a tool to produce housings existed.

Next weekend I can scan and post the template for hot wire cutting. They are the templates that are pinned to the sides of a block of foam to guide the hot wire. Cutting a precise shape using a hot-wire is fun, glassing the inside of the foam well is not.

Once I glued up a stack of the templates and made a drive well but it weighed about 10 pounds.

Mack

[leaotis]

.....Next weekend I can scan and post the template for hot wire cutting. They are the templates that are pinned to the sides of a block of foam to guide the hot wire. Cutting a precise shape using a hot-wire is fun, glassing the inside of the foam well is not.
Mack

Here's the template for making a hot-wire cut foam core.
over all length- 35.75cm x 17.75cm.

[Chris Ostlind]

There was a guy over in Hawaii who made a really nice (I think it was) cast fiberglass Mirage trunk unit that he was looking to market. This was about three/four years ago, or so, and I have since lost track of his personal info due to a failed hard drive. He was into fishing and snorkeling with hand shaped SOT craft. Perhaps somebody knows of the effort and can post some contact info here?

As to actually producing the unit for commercial purposes... there may be a bit of a conflict on that end of things for the Hobie Company, but I don't know that for certain. They have nicely gotten out of the way of outside design efforts to create boats that utilize the Mirage, so there is some possibility that they'd do the same for a very small volume builder of the trunks. They do enjoy enhanced sales for the drive units themselves due to the homebuilder efforts we see here, but I don't think that the numbers are big enough to cause a stir at Hobie as to legal design issues. So, maybe there is an opportunity if one were to give a call down to Hobie's offices and talk with Greg Ketterman as a start.

The i Series Mirage drive boats use a PVC well for the drive unit that is glued in place in the inflatable floor, so Hobie already has a part in their inventory that would be a very good starting point. Or... one could simply hose down the well/trunk of an existing, rotomolded boat with a good release agent, take a cast impression off that dude, pull the resulting part and use it to make a molded trunk shell. Just another idea.

[leaotis]

Skinny is certainly faster but a fat kayak would still be a very narrow boat. I’m thinking of a more user-friendly boat that would appeal to the masses.

[Woxbox]

Aha -- something for the non-boater who wants to spy ducks and herons? Or a simple fishing platform? That does sound like a fatter, flatter-bottomed boat with a big cockpit. I had an 18' fold-up kayak once designed for two - but when I used it alone it had the fine advantage of being big enough to stretch out in and take a nap. It looked like a Klepper but wasn't.
Another model would be the Wee-Lassie type decked canoe, maybe drawn out a bit. That would be a pretty thing to have.

[leaotis]

yeah, sorta of a general purpose picnic boat. I like the look of the Klepper.

[mcdenny]

How about a Mill creek 16?


CLC sells plans and kits.

[htom]

Stretched Cosine Wherry?

[Cuyahoga Chuck]

There seems to be a lot of stabbing around because leaotis did not specify a starting point.
If you say what kind of kayak (or wharever) you and your bro. were paddling we will intantly know what you see as "skinny". If you and he were paddling a Hobie "Odysee" Double you were already in a "fat" kayak at 33". Hobie's fishing kayak, "Adventure" is 28". These boat are exceptionally wide because they are sit-on-tops. They have a high center of gravity, both, because they are designed to be self-bailing and because of the big hole in the bottom where the drive passes thru'.
I have seen numerous discussions about building an ordinary sit-on-top from wood which generally got hung up because conventional SOTs can be bought for about what it would cost to build one. And the number of features in the rotomolded version could not be easily duplicated in wood.
When you consider a Miragedrive hull also needs the inevitable hole in the bottom you have to come up with suitable bulkheading to insure enough floatation should the mirage drive weep water. The whole thing sounds like an engineering task with a lot of difficulties.
If you know someone who has already done this and you can steal his ideas it sounds like a go. But, wading thru' all this from beginning to end with the possibility that there will be likely teething hang-ups makes me think this project would be a head-banger.

The picture of the guy peddling his Miragedrive powered Mill Creek says it all. About ten minutes out in water with some modest wind and wave action tossing him around would quickly convince him that it's not wise to play fast and loose with a boat's CG.

[Spokaloo]

Paul has a drive system with a prop designed for the boat, but this is a good fit for a Mirage:


http://www.gartsideboats.com/catrow2.php#pedal

Has a little extra beam for bigger water, and the guy that built it took it on an EPIC trip with some serious open water.

E

[kenjamin]

How about the Tred Avon 21' tandem kayak on page 13 of "Another Forty Wooden Boats" ? You might have to spread out the seating a little more but I bet it would really move and there are sprit sails designed for it already. Keep us posted if you precede with the project.

[Cuyahoga Chuck]

How about the Tred Avon 21' tandem kayak on page 13 of "Another Forty Wooden Boats" ? You might have to spread out the seating a little more but I bet it would really move and there are sprit sails designed for it already. Keep us posted if you precede with the project.

The Tred Avon was an old Kulczycki design. All his other old designs have been superceded and I think Tred Avon has been too.

[kenjamin]

Yesterday I called my local Hobie dealer and he said you can only buy the Mirage drive as a replacement part. In other words, if you haven't got one, you can't buy one. I've e-mailed Hobie and I'll let you guys know what they say about this "dog gone" development.

On the Otter, just how much hull speed do you expect to gain from another couple of feet of length? Would the "masses" notice the increase in speed or would they rather have a less tippy hull? Of course if you made it long enough, it wouldn't be more tippy but then you'd have a heck of a time getting under 150 lbs., right? If you read the description on the Otter carefully, you'd see there is already a very similar design that is lighter. You just have to track it down.

[G. Schollmeier]

If I was to put that drive in a boat for myself I agree with Spokaloo, the Gartside “Blue Skies” or very similar.
Gary

[Chris Ostlind]

I did a short tutorial for the installation of Mirage drive units for Duckworks about two years ago. For those interested in installing one of these bad dudes in their small craft, the tutorial may be able to help you with some of the less obvious details.

http://www.duckworksmagazine.com/05/...irage/free.cfm

Contrary to much hearsay evidence, these drive units are truly remarkable with very few serious limitations if used in a boat that is appropriate for the system.

Personally, I wouldn't install one in anything that weighs more than 150 pounds. The lighter the better.

They do have a reverse. All you have to do is pull it out of the trunk rotate it 180 and get to business with your leg stroke.

The trunk can be fitted with a very nice, soft enclosure around the top that allows the pedals to be used while keeping out the water. Picture the shift boot on an old English sports car.

If sealing the Mirage trunk is problematic, then any centerboard or daggerboard will be quite a bit more of a hassle, so why bother building a sailing boat?

Over the last two years, I've converted some dozen different boats to a Mirage drive setup and none of them have had a problem. Canoes, beamy kayaks and other small craft have the best potential for a successful installation. The Mirage provides many hours of hands free propulsion, using the biggest muscles in your body while you recline in a comfy seat eating a sandwich, shooting photos or just quietly watching the world go by.

Really guys, shouldn't we be addresing the possibilities of this product rather than the imaginary limitations?

[leaotis]

The Gartside “Blue Skies” certainly looks more boat like. Maybe instead of saying "fat kayak, I should have said said "skinny sharpie".

[leaotis]

Old Dude Surfer!

That was just what I wanted to hear.

I was greatly impressed with the speed and ease of propelling a boat with Mirage drives. The limiting factor with the Hobie 14 was hull speed. I imagine a longer real boat with two Mirage drives with the turbo fins would a joy.

I have a vague idea of a "touring" boat that could be used without getting your butt wet. The boat would not necessarily look like a kayak or canoe.

Will the boat need a slight V bottom to prevent the fins from hitting the hull?

[Chris Ostlind]

I have a vague idea of a "touring" boat that could be used without getting your butt wet. The boat would not necessarily look like a kayak or canoe.

Will the boat need a slight V bottom to prevent the fins from hitting the hull?

The design does not have to look like a kayak or canoe, but their shapes do represent a fairly optimal target for low speed hulls. If you want efficiency from the Mirage blades, go for a hull form that looks to be as narrow a beam as possible for a given length overall without snuffing the stability necessary to keep it upright. There's a reason why the Hobie SOT kayaks are as wide as they are. You could get away with less beam if you have good natural balance.

The hull does not need to be slightly V'd to provide clearance. That is achieved in the setup of the height of the Mirage drive in the trunk.

Ideally, you'd like to be able to fold the blades flat against the hull for beaching. Really, the drive will take a beaching on sand or mud, it's that rugged. I wouldn't try to land it from a shorebreak onto a large gravel/stone beach, but sand and mud are easily handled, as long as the blades are flat against the bottom.

Chris

[P.I. Stazzer-Newt]

Sounds like a pair of long VERY narrow hulls might get the job done well.

Or a shell with either foil or float "training wheels".....

[kenjamin]

Hey guys, how about this sailing skiff from the cheap stitch&glue people?

http://www.bateau.com/studyplans/OT1...rod=OT16#specs

It's only 10 lbs. overweight and it's a real boat - not a kayak.

[upchurchmr]

Leaotis,

Much as I have never liked the idea of central "pods" in a cat, I bet I could make enough of one to prevent problems with the fins and not materially affect the drag. How small is small becomes the question. Too bad I don't know anyone with a Mirage where I could borrow the drive for a test.

Marc

[leaotis]

Leaotis,

Much as I have never liked the idea of central "pods" in a cat, I bet I could make enough of one to prevent problems with the fins and not materially affect the drag. How small is small becomes the question. Too bad I don't know anyone with a Mirage where I could borrow the drive for a test.

Marc

I envisioned more of a plate skimming in between the hulls but perhaps a pod would have less wetted area plus could place the fins lower in the water.

[leaotis]

My brother's Hobie. (I'm in front.) You can see from the wake we're near hull speed.

[leaotis]

the Otter 16 looks good, -now if it were only longer, narrower and lighter.

[upchurchmr]

If I was going to make that hull a pedal drive/ mirage drive I think I would want a more comfortable seat/ chair. The only thing I don't like about that row boat is the the tiny seat perched out in "mid air". The boat shown is capable of carrying 125# with 4 inch freeboard. When I get on it (240#) there is 1/2" freeboard. Not at all comforting - good thing it is a sliding rigger, instead of sliding seat.

[leaotis]

If I was going to make that hull a pedal drive/ mirage drive I think I would want a more comfortable seat/ chair. The only thing I don't like about that row boat is the the tiny seat perched out in "mid air". The boat shown is capable of carrying 125# with 4 inch freeboard. When I get on it (240#) there is 1/2" freeboard. Not at all comforting - good thing it is a sliding rigger, instead of sliding seat.

We built recumbent seats which are comfortable but two seats add 12lbs to the boat.

[leaotis]

kenjamin, I found Dober boats which lead me to Jones boats. The boats are certainly pretty but rated for 2hp. I need a design good for about 1/4hp. I think a longer, lighter and more narrower boat would be significantly faster especially with only 2 people power.

As C. Ostlind said, I need something with a canoe or kayak bottom.

BTW, “adventure1609” on ebay sells Mirage dives for $US390.

[Pericles]

http://lancet.mit.edu/decavitator/

http://www.humanpoweredboats.com/

http://www.newscientist.com/article.ns?id=dn7414

[upchurchmr]

Leaotis,

The boat shown is 50#, take off ~10# for the sliding rigger and you would be "about" even. The boat could have been built 5-8# less. It still would be a reasonable weight to pedal.
This is a fairly minimal boat. Rick Townsend's outrigger stabilized monohull could be even less, with no issues of cavitation.

Marc

[kenjamin]

here's the e-mail reply from Hobie:

Ken,

Yes, the Oasis is configured for the sail kit, but only as a single
sail.

We do not limit who can buy the MirageDrive and have sold some (throughdealers) for custom boat use.

We have tried the twin sail idea and it is difficult to sail with
independent sail controls. Likely would go a larger sail and maybe a
tandem Island.

Matt Miller
Hobie Cat USA

Note: the Island model has the pontoons

[leaotis]

http://www.swallowboats.co.uk/

Has anyone seen anything similar to this?

[kenjamin]

Nope! but if you go to the the blog site for this design, you can sure get a good look at the bottom of it –

http://winsomeboat.blogspot.com/

Looks like a dory and a sharpie had a fling and this was the result. Seems like a stable hull that can cut through a chop with ease.

Have you seen the cover of Small Craft Advisor? It shows a race version of the Wa'apa trimaran. It looks like it could use a couple of Mirage drives and set a bunch of sail too. Kinda long though at 24' but there's a nesting version too in 8' pieces.

http://proafile.com/view/weblog/comm...anoe_launched/

[leaotis]

Unlike Wa'apa, Winsome's bottom doesn't strike me as being particularly easily driven. But then Winsome's crusing speed is 4MPH.

Wa'apa is certainly a canidate for a mirage drive.

[kenjamin]

How much do you think Wa'apa weighs in the double outrigger configuration? I could not find that information. If one were to go with the Wa'apa with Mirage drives, you'd want the trimaran configuration for a balanced helm wouldn't you? I think the Wa'apa could also carry a little 2HP Honda somewhere and you'd have yet another way to get home – the more ways, the merrier in my book. Of course if you carried the little motor the proa could have a motor mount between the main hull and the ama and run very happily there. Still, I'd rather have a sealable motor mount behind the aft crew member and maybe give the main hull (in the tri) a tiny bit more hips to carry the motor better. The racing version of the Wa'apa on the cover of Small Craft Advisor seems to have more flowing lines to the main hull rather than the parallel lines of the ones at Gary Dierking's website. Seems like the parallel lines for the main hull would be slower, right?

[switters]

I love this thread, I really want to do a fishing boat for two, truck toppable (80 lbs) roomy for two people next winter. I would like to mate the drive to a wineglass wherry hull, based more on the looks and not the hull performance.
Thoughts? the question in the thread was kind of broad. I have been on the hobie outback and like the drive, but I am used to my canoe and the need to have beer and tackleboxes scattered around. I hope I dont offend anyone, but a rotomolded boat has no soul. Granted my coleman 15s have very little soul and it has taken 15 years to develop.

freshwater lakes, trout, beginner building skills

[Spokaloo]

Any thoughts on shallow draft?

Selway-Fisher has a line of relatively light and efficient wherry-type boats called Thames Rowing Skiffs. I built one, pretty quick to go together, and handles chop up to 2' with dry aplomb, depending on payload. Could be built at around 80lbs if you kept the wood selections light (okoume ply, spruce gunnels, etc).

E

[switters]

Any thoughts on shallow draft?

Selway-Fisher has a line of relatively light and efficient wherry-type boats called Thames Rowing Skiffs. I built one, pretty quick to go together, and handles chop up to 2' with dry aplomb, depending on payload. Could be built at around 80lbs if you kept the wood selections light (okoume ply, spruce gunnels, etc).

E

*I'm 90% sold on the idea, I spent last night looking at designs and I like the thames at 14'. One question for you, the mirage will require a center case, do you know what the draft is at capacity on your wherry? Next I need to work out a tiller that can operated facing forward. Ive had several ideas ranging from a small wheel and pulley system to a push pull tiller and some other fanciful ideas inbetween.

good day,

[Spokaloo]

On our 17' boat, she drafts about 5" with me (200lb), 8" with both of us and the requisite water and goodies. Its a very shallow boat, and I think the hull would be well suited to putting in the case as the garboards have a very flat run for a good distance. If you shoot an email to S-F, he will give you the ppi (pounds of displacement per inch of draft) of the hull in your length. I believe the 14 has a bit more freeboard than our boat as well.

Ill be excited to see this come together, make sure to post photos!

E

[Steve Paskey]

What about the Bee or Linnet rowing boats from Woods Design (the British catamaran folks):

http://www.sailingcatamarans.com/dinghylist.htm

Both are 16 feet long and weigh 49 kg (about 108 lbs.)

[switters]

Chris O, saw the D-works article. Can we have some more information on the hull?

Steering, couldn't really tell from the video but looks like a hobie type set-up?

skeg?

dimensions?

plans available?

come on man, why are you hiding this from us, inquiring minds want to know?

[JBreeze]

After letting the Mirage Drive sit in the trunk of my car for a month I decided I couldn't wait for winter to convert the Kayak to pedal drive. Why complete interior and exterior house projects when I can start a new one ?


Here is one photo from my album...if you follow the link below, you can see all the pics (eight at this point) and comments. I hope to do a "sea trial" on or about 10/1/2012.

[IMG][/IMG]


http://s185.photobucket.com/albums/x92/jbreeze_albums/