Best hull for Hobie Mirage drive?

[potomac]

I was thinking of a Guideboat. How about Robb White's Sportboat?
Any more word on exactly how to get the drive and what it would cost? The website doesn't indicate much.

[keyhavenpotterer]

The Guideboats have the central plank keel which seems best for fitting the drive unit. It seems getting hold of a drive is not easy, but some dealers will sell one as a "spare". I have managed to buy one off eBay complete with GRP housing and mould tool to make the housing.

Brian

[upchurchmr]

Leaotis,

If you want something efficient, try a catamaran. Take a look at this one I built for my wife as a row boat. The hulls are very fine, so you would need the 18' to get enough displacement. The hulls shown are strip planked, but a plywood deck and sides with the round bottom done in strip plank would make a very low resistance boat, very stable. Done well it could be the same weight as a fat kayak. http://forum.woodenboat.com/showthre...t=fast+rowboat post # 47. The boat shown is only 11' and 6" wide (per hull) 5' total width - to fit in my pickup bed.
Actually I have been thinking about making another set of hulls out of skin on frame construction with aluminum tube ribs. should be quite lite. You probably would want a rudder. The interesting part would be making the cross beams to support the drive and a seat.

If you want even more speed check out the Pedal power thread where the fastest configuration is a single (main) hull with stabilizing outriggers. That would be easier to mount the drives, but might seat you higher and seem more tippy.

You might also check this thread for a SOF sliding seat skull. http://www.kayakforum.com/cgi-bin/Bu...lly-different/

Marc

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.)

Marc

Any thoughts?

Thanks, Mack

[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.

[keyhavenpotterer]

Well done JBreeze, and I wish you good luck. Wish me good luck too! Dizziness issues cause my interest in these drives (sitting still, facing forwards helps). Seeing Tim's lovely craft got me looking again and a set turned up just this week on eBay, with a Buy it Now I just had to press the button. The drives come with a moulded housing and the mould tool to make more housings. Currently on their way to me, looking forward to seeing how everything fits together.
I asked John Harris at CLC how his new Guideboat kit was coming on and he mentioned that she was going to the Wooden Boat Show, and most important the build manual was finally close to completion so the design could soon be released for the market.


Brian

[keyhavenpotterer]

Hobie drive in use on the Rangely Guide Boat along the Thames.

Click to 3:15 in

[Timmo]

Hi, Surprised to see myself pedalling along there. The gesticulation was an indication to Chris rowing in front of me that he needed to swing left to avoid a tree.

Have to say Zelva isn't actually a Rangeley Guide Boat. It was among the boats that inspired me but her final hull shape probably owes more to Oughtred and Walt Simmons boats. She's designed to be loaded and propelled differently which made different demands on the hull shape, particularly below the waterline. The mid section is significantly different to a guide boat while the distinctive sheer does echo the Rangeley somewhat.

What I wanted was a long distance cruising boat. Easy enough to push along with the mirage drive for long distances with little effort while carrying gear for a week or more. Stable enough to stand in comfortably for paddling in tight spaces and for embarking/disembarking at unfriendly landing places. Finally I needed space to sleep and cook aboard comfortably (well, relatively comfortably, I'm used to a small tent!)

So far Zelva's delivered on all fronts. At 5 metres long and a fraction over a metre wide she slips along at 4 to 5 mph with little effort (in the UK that's all that's allowed on most inland waterways.) I'm safe standing and moving around in her and I've spent 5 comfortable nights aboard her already. So far only a temporary tarp arrangement for a tent but it worked well enough. I'm working on a design for a proper tent now.

If the decks look a little odd it may be because they're removable. Means I can open up the boat for more people on occasions and get at the interior for maintenance.

There's an article heading for Watercraft magazine sometime soon so I'll say more about her there.

Might actually get photos in that too. I've tried uploading some here several times and it keeps failing. If I work out what the problem is I'll try again!

[keyhavenpotterer]

Hi Tim, loading from computer doesn't seem to work, just loading from a URL, ie a photo host site, such as Flickr or Picasa, and for some reason you have to untick the ticked boxed on that pop up to make it work. I think Zelva is really special and am sure forum members would love to see more pics of her in build and in use, and look forward very much to seeing and learning from the Watercraft article.

Brian

[potomac]

Yeah, I'll second the request for pictures. She's lovely. How do you find using the Mirage drive? How would you characterize the effort vs. rowing or paddling? I'm six months out of shoulder surgery now so the Mirage has some obvious attraction for me. The apparent quiet and freedom to use your hands for photography or fishing does too. Thanks. -Aaron

[David Geiss]

Tim, yes please keep us posted on the article.
Lovely vessel, and seems to be moving along very efficiently.
Can see a sun top as part of the mix which, for me, would make it a very appealing way to explore a bit in the summer sun.
Nice job!
Best, David

[keyhavenpotterer]

Paul Gartside has a 20' design called Blue Skies, Design No 92 which is a pedal drive with a fairly complex drive system. http://store.gartsideboats.com/colle...kies-design-92


a little while back Chris Partridge on his excellent rowing blog, featured a builder, Don Polakovics, on the Chesapeake who built a Blue Skies and fitted her with a Mirage Drive.

http://rowingforpleasure.blogspot.co...peake-bay.html

The article has a link to the builders Flickr pictures http://www.flickr.com/photos/doooo/w...oto_5211063011

Here's the drive in the hull,



and the well housing



It took 2 1/2 years to build this lovely boat, but perhaps Paul Gartside might just be talked into releasing a Hobie version in the Water Craft series of free plans, which are usually accompanied by a low cost digital download option.



Brian

[tprice]

We(USNA) built a Human Powered submarine and installed 2 Hobie Mirage drives for the 2 crew. It's a flooded Sub with the crew breathing SCUBA. It went 6.2 knots with the large Hobie flippers. We are now working on larger flippers with an internal armature of carbon with fibers oriented to control twist and camber, potted in a compliant rubber airfoil.
We won the International Submarine races last summer with it. Now the Navy SEAL community is interested in it for a low cost swimmer delivery vehicle. Would post phots if this forum wasn't so ridiculously cumbersome to do so.

[leaotis]

....... It went 6.2 knots with the large Hobie flippers......

6.2kts underwater?!! That's amazing. I'd love to see it. Is there a link?

Or, send me the pics. I'll post them.

mack -at- mackhorton dot com

[Gib Etheridge]

Timmo and TPrice,

It's actually very easy to post photos here.

Upload your photos to Flickr.

On Flickr....

Left click on the photo.
Right click on the new photo and select medium 500 or medium 640.
Copy and Paste.

I'm looking forward to lots of photos from each of you.

[Thorne]

How about Ruth or Sweetbriar with small fore and aft decks?
Ruth -


Sweetbriar -


A 20' stretched Cosign Wherry would be beamier and more forgiving, as my 14 Cosign really moves nicely under oars and is relatively lightweight.

[JBreeze]

Here is a video link to the human powered sub competition. You can see a few seconds of the USNA's submarine w/the Hobie Mirage drives in action near the end of the video (1:48 - 1:50).

http://www.navy.mil/viewVideo.asp?id=15970

Here is a link to the International Submarine Races - the USNA's is in ISR #11

http://www.isrsubrace.org/

I, too, would love to see some static photos!

[leaotis]

.......We are now working on larger flippers with an internal armature of carbon with fibers oriented to control twist and camber, potted in a compliant rubber airfoil. .....

I've wondered if thin, solid foils might be better for higher speed craft...like a rowing shell fitted with 4 or 6 Hobie drives but you're way beyond me. Please keep us updated. I'm fascinated.

Thanks, Mack

[JimD]

Leaotis,

If you want something efficient, try a catamaran. Take a look at this one I built for my wife as a row boat...

Marc

[leaotis]

The Mirage drive needs to operate under a hull. They need a "cavitation plate" above the drive otherwise the fins sucks air instead of water. This limits the use of super efficient designs like cats.

[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.

[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.

[keyhavenpotterer]

Matchstick is rather beautiful. Need to know more! http://mackhorton.com/Mack_Horton/Videos.html



Brian

[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

[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

[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.

[keyhavenpotterer]

Chris, is there a chance of your Nagare 17 plans becoming available?

[Chris Ostlind]

I just sent you an email, Brian.

[Chris Ostlind]

Back in '05, I did a short, basic tutorial for the fabrication and installation of a Mirage drive trunk and posted it to the Duckworks Magazine pages, complete with a few photos of the install I did on my A18 trimaran. As it turned-out, the boat, when fully rigged and assembled, weighed too much (450 lbs.) for a single Mirage to push it around with any gusto, so the concept was scrapped from the prototype. Still, the build exercise was fun to sort out. If it can be of any help to you guys who are thinking of building a Mirage capability into your new projects, then, by all means, help yourself to the tutorial. Ask any questions you may have.

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

[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

[keyhavenpotterer]

This is the grp housing. It's made from two halves bolted together.



I had always thought only a flat bottom panel could be used to fit a Hobie Drive, but you will notice the moulding has considerable V, to match the Veed hull.



Fortunately the mould tool half has the hull section as a removable part of the tool so that the moulded part can be extracted from the tool. This means I can unscrew this section, adjust the angle to the hull angle, and then screw back on and make a new moulding.





I also have an insert which you glue the removed section of hull and this makes a blanking off piece to reduce turbulence when the drive is not being used and the boat is being paddled.





Hope these pics make sense.

Brian

[leaotis]

This is the grp housing. It's made from two halves bolted together.



Brian

That's simply brilliant. Light weight, minimum volume and adjustable.

What is the steel shaft taped to the well?

Shipping cost from the UK to Aus are pretty reasonable.

Thanks for that Brian.
Mack

[keyhavenpotterer]

What is the steel shaft taped to the well?

You need a way of holding down the drive after it is dropped in place. So the alloy tube goes down the slot at the side that the axle locates into, and then a small alloy bracket holds the tube down thus holding the drive down. One tube and one small bracket each side.

Once the housing was installed there was then a side web glassed between the housing and the hull on each side to side brace the housing.

Is it going to be best to adjust the tool for zero deadrise, ie a flat floor.

Brian

[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.

[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/

[JBreeze]

Finally made it to the water - twice this past week. Also added some photos and a short video to the photobucket album.

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

Overall, I like it! I have a lot more to do, such as a coaming, fishing rod holders, permanent outriggers floats, etc., but the Mirage concept works well.

Thanks to Mack Horton, Chris Ostlind and the others on this thread for photos and inspiration, and to LeeG for some specific information that applies to the Chesapeake 17.

Here are are some video scenes with my buddy operating the kayak while I tried to manage the camera:

(for some reason the video won't appear (1/2 hr after uploading) .....you can get there by clicking the album link above. and moving to the 12th image).

[Dryfeet]

I've been thinking of trying something like this with the Mirage drive but in the video, it sure doesn't look very comfy....

[leaotis]

JB, nice job. You might benefit from the larger "turbo" fins, your hull looks slick enough to use the extra thrust.

Dryfeet, typical kayak seats are for paddling. Pedaling boats can be more comfortable with seats modeled after recumbent bicycles.

[JBreeze]

I should mention the Mirage drive is adjustable for different operator heights/leg lengths ... I should have adjusted the drive for better leg extension. Much is temporary - the seat, the floats, etc., - the immediate goal was to have a couple test drives before winter. I will probably add the turbo fins when permanent modifications are made in the spring.

[leaotis]

I should mention the Mirage drive is adjustable for different operator heights/leg lengths ... I should have adjusted the drive for better leg extension.

In this case more is better, adjust the Mirage drive crank arms so you have more leg extension than for a bicycle.

BTW, here's Tim O'Connor's recumbent seat that I copied.

[JBreeze]

Thanks for the seat pics. 14 of my 24 spine vertebrae are fused, so seating comfort is important!

I'm going to send this thread to my spine surgeon in Boston, who is one of only two spine surgeons who does the extensive reconstructions in town. Similarly, to my General Practitioner, who is a boater. Both probably know of a few patients who miss being on the water due to upper body problems, and they may not know of the "pedal drive" system and applications.

Finally, I'm already thinking about installing a well on my rowboat:



Specs. available here:

http://www.bateau.com/studyplans/R13_study.htm?prod=R13

It should be quick to do, especially since the floor is flat vs. the shallow "V" of the kayak.

Thanks again everyone for this thread, as it is great for an old fart like me, who can't walk 50 ft. without canes, to be able to pedal miles at a time over the water without exhaustion.

[Timmo]

Two quick stories.

In this post I'll show my first Mirage Drive installation and later I'll post about the construction of Zelva. This is an experiment to see if I've worked out the photo posting process.

This one is a conversion to a Walt Simmons designed canoe:














Key things I learned were first that the lever system for clamping the drive in place worked well (though the beautiful oval mounts shown earlier in this thread are also very elegant.) Second that pedalling from a kayak seat was only sensible for a short distance. Hence designing and building the reclined seat that has featured elsewhere in this thread. Also decided that I wouldn't want to install it in too narrow a boat. Without a paddle in your hand you feel more susceptible to the wash from other boats etc. and a little extra stability is appreciated. Finally I learned that the Mirage Drive (with ST Turbo fins) packed quite a punch and could drive a bigger boat!

I suffer from a bad back and pretty much destroyed knees (though the installation of an artificial one has helped a lot) but find the combination of the ergonomic seat and the gentle to and fro motion of the pedal action very easy and sustainable.

Tim.

[Timmo]

Now to Zelva, featured in a video earlier in this thread. An article about her has just appeared in Watercraft

After the open kayak installation of the Mirage Drive my mind moved to creating aMirage Drive propelled inland waterways cruiser. I needed a boat stable enough to stand and move around in, big enough to camp aboard yet lean and light enough to drive easily with the pedals.

The original inspiration was the Rangeley Guide boat though the end result really only retains the swept sheer. The signature flared gunwhales were replaced with a slight tumblehome (I won't be rowing!) and the underwater lines were drawn pretty much from scratch.





Since it was the first boat I'd designed myself I kept it simpler by using lapstrake following construction processes I knew well.

Being a broader boat, and wanting to keep the 'living area' clear of thwarts, I had to make sure there was a firm structural base for the seat. Pedalling hard puts a lot of stress into the seat mountings. Also needed to keep the floorboard in the living zone above any bilge water so I could sleep in the dry.



The seat shown here is actually the one from the canoe I first installed the Mirage Drive in. I adapted it with a new base. Since Zelva was completed I've put that seat back in the canoe and built a new folding version for Zelva... but that will be another story!



Since there's a limit on the number of photos I'll continue in the next post!

Tim.

[Timmo]

Continuing the Zelva story (Želva means Turtle in Czech)

The drive box in Zelva is shallower than in the canoe, her greater load carrying capacity meant she will sit higher in the water. I stuck with the lever clamping system though. It really holds the drive very firmly. Mack's moulded drive cases are truly beautiful though.







End result was stable:



Very comfortable:



And easy to propel keeping up with canoes and skiffs with relative ease. Even into a vicious headwind encountered on the Thames I could keep going, experiencing no more pain than others!



The decks can be removed should I want an open boat for a day, also facilitates maintenance.

That was the six photo limit, so one more post:

[Timmo]

Final part on Zelva:

I have slept aboard for several nights. The cover here is a very temporary tarpaulin arrangement. She's in the workshop now to have a proper tent fitted. Still scratching my head over a number of details. Hopefully inspiration will strike soon.



The new folding seat (so I can stow it at night) has been made. Photos will follow. Just one here as a taster...



Think I've finally worked out this photo posting process. Thanks to those who advised! Means I now have a flickr account, not sure if my children will be impressed at how connected I am or depressed by how long it took me.

Tim.

[keyhavenpotterer]

Thanks Tim for posting more about Zelva. I really do think she could be very popular if you can one day make plans for her available. Quite how many forum members have dodgy backs, sciatica, balance issues ( I have all three) I hate to think. What a lovely craft for wandering along quiet waters and sleeping aboard.

The article in Watercraft that Tim mentioned is in the new issue no96 pages 31 to 35. http://watercraft-magazine.com/wc_contents.html

Brian

[heavyweather]

Did you do it. I am also looking for a hull for the m drive. Found the fast rowboat hull from sass.
http://sassdesign.net/
Maybe there is something to learn.

The guide boat would also be a nice option. I don't want to go to big though and speed is not really an issue for me.
There is polgers mippet which is also on my list of boats to built.

It will definitely be some SOF craft big enough to carry me and two children on the Old Danube.