Turn a SUP into a cruiser/fitness machine

Getting away from the car topper there. I have a pair of HDPE hulls from small blue french beach cat type thing meant for easy sailing for those of limited agility. They would be nicer than the US style pontoon in a mini form. Again would need a trailer unless I assemble the frame to the hulls at the ramp. Its worth doing

Which raises the question, is the stabilised SUP with air walker not worth doing?

 

my gut feeling is that the walker mechanism will be difficult on an Sup and much easier to achieve on a small catamaran. The additional weight of the frame and mechanism will add to the high centre of gravity combined with the pedalling action will, I suspect, tend to make the SUp roll un comfortably, unless the stabiliserare substantial and inevitably then draggy. Plus the challenges in fixing to the inflatable with sufficient rigidity, avoiding point loads etc. Andrew Kirk on this forum has built a couple of pedal powered paddlewheel driven boats - see A pedal powered catamaran with sail assistance https://www.boatdesign.net/threads/a-pedal-powered-catamaran-with-sail-assistance.67892/
and
Pedal powered dinghy works at last https://www.boatdesign.net/threads/pedal-powered-dinghy-works-at-last.65795/

also, on youtube this is interesting:



None of these are using the walker mechanism though

 

That pontoon video I posted was the shortest I could find, that shows the concept. I believe the one man version can the packed into a small SUV. There are also other much more lightweight- compact one man inflatable versions made by other manufacturers with stand up railings which can fit a compact vehicle. Water wheels require more space /are heavier, introduce small windage issues, require a rudder affecting the draft, Etc, compared to propeller driven. My particular concern would not be getting enough exercise lifting water for anyone, but instead getting back to home base and out of Harm's Way after an exhausting intense workout on open waters.

"Which raises the question, is the stabilised SUP with air walker not worth doing?"

That depends on someone's commitment to the time, energy, and $$ to achieve an airwalker dream, it may take 20 years to get an acceptable solution because of all the engineering aspects. The Hobie Mirage eclipse inflatable already does most of what is desired except for the airwalker and Electric Power part, but even it- may be top heavy. It might only take half of the time and commitment to explore if and how the Mirage can be altered to accommodate an air Walker and add an acceptable waterproof/ corrosion proof motor system.

My experience comes from a travel and pack-in micro e-boat hobby which I have really enjoyed for over 30 years. My one of a kind product gradually and eventually did everything that was required for my personal use requirements, yet there are still small refinements that are incorporated every year or so.. BTW, the smallest one man pack in boats weigh under 3 lb!

Hope this helps.

 

The swaying of the air walker is my main concern which is why I agree that my beach cat hulls would make a better choice. With the cat, I can fit the air walker frame between the hulls and low to the water. The sailing hulls have a good bite in the water and might even further filter out the sway. But it would never be something that I can just throw on the racks and drive off. For daily use it would need a trailer. Another project for another day

Hmm what's optimum for the SUP then? Issues; standing sail, high COG, capsize righting issues. Am I missing anything else?

Regarding returning to shore after a workout, I suppose the electric cruise system could be persuaded to do that too

I have been reading a lot of what you two have written over time, and your boats and diying. I would like to make good daily use of this board and also take it away on road trips. I got this board at half price at the end of summer clearance. It has a 80 cm beam and 21 cm height, 3 m length

How about this, using the paddle wheel system

Like the new motor trikes with the single wheel at the back. Sitting recumbent, a pair of hand lever driven paddle wheels in forward half. The wheels can be housed in the side of a pair of small hulls fender like. The visual effect would be formula oneish. I can design a drive shaft with an antireverse bearing from a large fishing reel inside each paddles hub. Lines from the levers wrapped churner like together with opposing wrapped bungee can make for a good workout and work the belly area too

Feet can drive a pulley to a stern mounted paddle wheel as direct drive allowing reversing. A v shaped hub may allow turning the rear wheel while its still driven for direction. An aux electric motor would be an obvious addition to the stern wheel

Finished in tidy printed parts it may even generate some complimentary looks. How do you guys feel about this plan to use the SUP for actual fitness purpose as well as fishing. Does it comfortably address the comfort and safety issues?

 

Hi Randy, what about a second inflatable SUP and a couple or 3 spars to strap them up like a flat catamaran, with a gap between, then put whatever on top, stable, but still car compact. Low and stable for supporting most contraptions. I would put a bicycle type thing on it and a paddle wheel, or two, and ride it like a racer, or recumbent. I've seen a similar thing using two small hulls years ago. Think about how much effort and fiddly mucking around you need to do each time you get it on and off the car, assemble, and disassemble whatever you invent. KISS or it will be too much effort to get it ready to use; and packing up is worse.

 

From Randy, "Hmm what's optimum for the SUP then? Issues; standing sail, high COG, capsize righting issues. Am I missing anything else?"

Space, Comfort, and ergonomics if someone will be out all day, is it possible to easily change positions or sit down, get protection from a blazing sun, etc. and what implements are required to accommodate that?

Secure Storage space and retainer systems for accessories like fishing rods / tackle box, spare parts for repair, a paddle for emergencies, snacks and water, anchor, battery, etc.?



Provisions for auxiliary steering and control of the board, when both hands are occupied especially during a fight with a big fish?

If you will travel by airline with it, how will it break down to those requirements for transport?

Paddle Wheels may be incompatible with car topping because of the considerable weight and space, required for their transport?

Just some of the issues that I had to solve, for my particular contraption, ha!

Ps. What is your weight limit for car topping, the total weight of the various ideas mentioned in your descriptions might go above 100 kg, all done? Mine is less than 14 kg, fully loaded including 1 liter of drinking water, motor and batteries for 18 km range, accessories, etc.

 

This is something that I pondered about a lot and kicking myself for not getting two boards when they were on discount. They have been discontinued since. The convenience reason that you mention are very important. I still think something fun and very suitable for daily use can be done with a single board and kept very simple

 

Good points. Are you able to share some pics of your 14kg setup in this thread please?

Let's get some things this particular craft won’t be required to do. Flying, The closest this thing will ever come to flying would be some sort of foiling attempt in the future. Not intending any other transport and car topping only. Some car trips will be more 4000 km round trips between Sydney and Townsville

For now let's think of it as an alternative to an E-bike. I used to be a furniture removalist back in the day and well-trained in manual lifting of awkward items. I agree a low seated position is better on the water, but I do prefer something in between recumbent and astride just for the ability to look into the water. A trike form will have better roll resistance so lets say this thing has to fulfil the role of an E-trike for the water. Non expedition, but rather an alternative to the morning walk or swim. Mostly 2 hours of use a day with some 4 hour sessions that include fishing

Water E-trike (non expedition)
What does she really need. Starting from a base that is an inflatable SUP. Some agility will be good to have. Small 500ml flask of water, one 6'2" PE2 spin jig rod with a Penn Slammer 4 2500 reel. A small pouch with a small selection of lures, pliers, a zip lock bag of some precut leaders and traces. Two collapsible crab traps of the light ring style, insulated vinyl fish bag, small knife, 5" GPS/Sounder combo and transducer, one rod holder set for trolling, sunshade, dry storage for keys and tobacco, phone holder, bluetooth speaker and the battery

The usual area of operation is a calm inside bay with a 850 m long pier at the south end. Longest run would be around 10k and regular about 4k. Most locals here are retirees and use an E-trike to fish the pier and cover that same distance via roads and paths. And carry a lot more rods and gear. I won't be fish the pier. There is an attached creek at the north end which goes in and about 1km upstream has been developed into interconnected artificial lakes in residential areas. Close by is a complex network in a huge estuary system with a large river and its mangrove channels and creeks. An hour inland are a couple of large freshwater lakes from damming projects

I believe the body, running gear and frame of whatever that ends up on this SUP will be under the weight of a retiree style E-trike anyway and the issues of roll, drive type and config is something I need to work out. I am happy to upload all design files so to encourage development, am more than content with the open source DIY spirit. Just about everything for this SUP can be made at hole on a CNC or printer as well as ordered from people like PCBway. I'll source things like bearings and fasteners from Ali. Basically, anything I do on this board can be replicated by anyone

So as it has progressed so far from the issues raised, my personal leanings is towards a water E-trike as an alternative to the road version and for now avoiding things like cat forms that need complex supporting structures. One body, three appendages, compact and self-contained. On the road the frame structure supports the weight, on the water it will be the boards flotation and traction through water wheels

There doesn't seem to be a huge efficiency difference between wheels and props so a device primarily for exercise, the wheels seem more efficient with its simpler powering needs. I am interested in testing various paddle diameters and ratios. The board seems easily driven and a smaller but higher speed wheel may keep weight down. Around 12 to 14" diameter and 10" max width is what I want to try to print first. What do you guys think of this?

 

I should add roughly equal use under human power or electric so for a 2 hour session it will be around an hour under electric

 

PC,, There are several different models based on Tiny pontoons and Float tubes, all have some proprietary features.. here's a clip from the internet of something similar.

PC,, the main idea is that the lighter and more compact the better, so long as it does the job - from basic engineering principles. Nothing is lost if it can be packed down small enough for flying and does the same job, plus materials and storage space might be saved.

PC,, All things being equal, the fewer the wheels the lower the rolling resistance is the way I learned it in my physics classes.

PC,, That's a good list, (mine would have some things taken out and other things not listed) but where will they be stored on a board so that it allows some degree of movement and different postures for the passenger, space for boarding, disembarking, crawling aboard from the water, etc... Will there be permanent compartments/ mountings on the sup board, or detachable each time used, Etc

PC,, that's very generous of you to consider doing something like that! But open source DIY spirit is great in theory, Maybe not good if it comes back at someone because of liability, commercialization of a similar product based on that open source. Maybe also other legal and patent aspects?

PC,, the best designed props and paddle Wheels will have close to the same efficiency, but smaller diameter Wheels tend to be inefficient, heavy, and space consuming compared to a well-designed prop and less efficient than larger thinner water wheels is the way I understand it. A search for human power boat races will give some pictures and ideas what type of water wheels work the best compared to props in all out races.

Some short comments posted within your message above @ PC,,

Hope this helps.

 

The optimum is something you haven't considered, rowing. The electric propulsion part is simple, just a side mounted trolling motor, or you can do your own longtail fixed to an outrigger. A 50W solar panel over your tackle box for recharging on the water.

Reasons:
Rowing is thee best whole body exercise, beats any air walker. You can sit higher if you want, face forward, don't need a rudder. If stability is an issue you can fit small sponsoons under the outriggers, inflatable if you want. The whole apparatus can be disassembled and fits the inflatable board ethos. Separating the electric propulsion from the manual one means you can fish with your hands and steer the trolling motor with one foot, even when standing up. You can also easily make changes to one or the other.

Simplest implementation is to learn to row with your feet. Then you can face forward without any complex apparatus, and sit recumbent as high as you like, but won't be as good a fitness machine like a sliding seat or rigger. Sliding rigger is more efficient then sliding seat, but if you want sponsoons the sliding seat wins.

 

Proper rowing motion is not a real option for me right now and its the reason that I didnt bring it up. Both my shoulders dont have complete range of movements due to badly healed injuries. Strength is there except for certain movements like rotating the shoulders. My left leg was also in bandages for one year three months. The air walker setup is easiest for rehab. I’ll try for something that makes use of some rowing motions but wouldn't be able to do all

 

Keep it coming man, all of it helps. I am very grateful for the work you guys have done in this area already

 

This one needs more work. Two concerns to consider that will tie together somehow. First as you raise is the number of wheels and rolling resistance. Second is increasing the roll resistance to make the SUP safer for all add-on contraption

The only easy way to increase roll resistance is a pair of side hulls making a tri form. Now can the side wheels and its fender/housing serve double duty as added hulls? I can print a wheel rim that has the blades on one side and a face with a shape to accept a pneumatic tyre tube, a buoyant paddle wheel. I can fabricate a fender fairing to cover this for spray. The effect will be F1'ish

I have the means to make something like this if it's a good way to proceed. At the moment I am compiling a shopping list on Ali for some of the hardware. I have selected 8 mm stainless steel rods for drive shafts. Four 500 mm lengths. Also SK8PP or EWC0809 one way bearings. I dont know if this is the correct type as I want the ones that will allow the wheels to freely roll while coasting and engage only one way

I will need to figure out how to retain the bearings on the axle. How to secure the wheel to the shaft

 

I might not mess with too much technical parts matching. Not getting anywhere with that. It's much easier to design from scratch and make my own parts

Progress so far is starting on a design for an AWD system consisting of a ratcheting lever driven front axle and rear axle with rear wheels doing the steering and a motor for cruise and reverse

I'll start with the drive system and would like to hear opinions on ratcheting drives and any past examples