Turn a SUP into a cruiser/fitness machine

Hello
I have a SUP that's fairly boring as a SUP. I would love to turn into something for cruising along the beaches or up rivers and creeks using human power with a standby electric system built into the drive. Like an E-bike. It's a 10' inflatable board with a 140 kg rating, and I am 86 kg

Looking for thoughts on mixing exercise with tinkering with crafting and technology. I have a 3D enabled digital workshop so am able to make parts for some sort of DIY system

Would love to hear some thoughts on some options. Any merit to working towards a foot pedal driven prop with a motor also in the system? Can the motor act as a generator to top up the battery while under human power?

I am drawn to the idea of making a DIY cross trainer that can fit on top of the SUP and be the power source for turning the prop

 

Hobie make an inflatable standup pedal board. Parts are available separately - click through under parts and accessories. . You could add a small kayak trolling motor. Angus rowboats use a bilge pump as a kind of jet drive - cheap but I doubt very efficient.
Mirage Eclipse – Hobie Kayak https://hobiekayak.co.uk/mirage-eclipse/

 

Thanks for the tip. The stairmaster system seems very limited for the money they are asking. There is a serious push away from anything DIY as a response to a lot of queries. I take it that there is a consensus amongst the regular and prominent contributors to discourage DIY and push enquires towards established plans and goods

Is there a more correct category to post this kind of tinkering stuff

 

Consider doing a search under "Selsyn" Drive, on this list and on "bike" drive lists, it's probably the simplest and lightest way to go, if involving Electric. It did not involve a battery, but does not necessarily exclude the use of one. A land bike was constructed using the concept sometime ago, and it was more efficient than expected, considering all the possible slippage points losses. I think the bike gear shifting was done electronically rather than mechanically. Seems like I remember that props are more efficient than the Hobie fins, though maybe not all fins necessarily.

An Australian company used the magnetic principal to construct no contact magnetic force gear boxes, which were essentially frictionless and required no lubrication, much less maintenance, etc. I think some members on this list experimented with the idea, quite a while back.

 

Yes, something like the Selsyn drive sounds like what I couldn't put into words. I have also come up with a concept for a 3D printable self actuating CVT that would be cool to test out

 

Hybrid human/electric 2-person catamaran https://www.boatdesign.net/threads/hybrid-human-electric-2-person-catamaran.813/#post-4030

 

The complexities of all these systems including electric is a bit discouraging. Maybe I should first try something very simple to get a good rhythm exercise and try a standby motor on that for cruise. Maybe a belt driven rear paddle wheel with foot pedals from an old bike frame?

 

Sorry guys, I meant something like this. A DIY cross trainer machine


I was wondering about the merits of maybe making that hub a paddle wheel dipping over the back. I may be able to turn bicycle handle bar mounted brake levers into rudder controls for turning

Would it then be feasible to add a motor to this for cruise and have the motor provide regen from human power when exercising?

 

there's a great deal of information on the forum on pedal powered boats - one very extensive thread in particular. Pedal power is not so hard if you are reasonably handy. Likewise electric power. Integrating the two into one diy system ups the complexity rather, and working with an inflatable board takes it up another notch. I would be inclined to consider building or adapting a rigid board /hull, and running interchangeable human /electric power, unless you cannibalise an existing electric bike in some way.

 

I suspect that Just propelling The craft forward will give you enough of a workout, and you won't get any human generated charging worth having without it being absolutely punishing for small gains. Most people can only sustain in the region of 100w and you'll need all of that to propel the craft at a reasonable speed

 

Sound fair

To be honest this seems more a topic for human power and I can't see where to post it. Since there will be some sort of electric power fitted, I'll continue in this one

Can this be kept to aluminium for the extrusions and PETG for the end joints plus some stainless rubber sealed bearings from Ali? I can print and cut the parts at home. I can even get some things done through PCBWay. My only concern with the cross trainer is the side to side sway. I don't know enough about how a SUP will behave underneath it

 

I prefer this type of machine more. They are easier on my body. Doesn't look all that difficult to DIY into something for the SUP

With this type of machine, there is no rotating shaft. I am thinking about something like ducky feet on the ends. Ones that fold on one side of the stroke. If I can add a 180 degree rotation ability to the handle shaft or its end, then I can have reverse too. My handle bar levers will still work for rudder control and I could possibly slowly upgrade this to a system where I can turn it into an electricity generator to power a stern mounted thruster instead of the ducky feet

I'll mull over this for a couple of days and make a start unless there are good reasons not to go this way

 

Seems like someone standing up functions as a sail in a SUP, without the fine control of a dedicated sailboat, introduces more complications and maybe more inefficiency in wind. The most stable position of a sup with a mounted cross trainer frame is upside down and keeping it upright even with floats mounted at the top seems like it would be a chore once someone is in the water trying to flip it back up..

 

You make a good point. Add the side to side sway motion to that. I could possibly run a pair of pool noodle stabilisers in outrigger. Then it shouldn't really flip. The crossbars of the frame feet can easily be extended out each side and make the cross-beams. A tri form will be useful as a fishing platform. The pool noodle amas will also make useful fenders. This contraption will be carried on the roof racks fully assembled for local use and deflated and folded down for longer road trips

Would this efficiently address the issues raised or does it sound like a lot of messing around for no real usability? The sail effect is an inherent issue with the whole concept of stand up boarding. I do not know how much it will affect usability. Would you guys say there might be a chance to make two types of drive systems for different days? A deck chair type seat with a pedal/pulley driven paddle wheel is also attractive for windy days or more fishing focused days. Clip on frames will allow experimenting with various options leaving the board basically neat

How does this plan sound? I like the paddle wheel over the prop as lifting some water up sounds like a good way to add to the exercise and keep things simple. I can print up to 40cm cubed

 

Instead of pool noodles, why not just make a more stable one man fishing pontoon boat, some existing units have stand up platforms and lean bars or railings, but a cross trainer could be mounted instead.. It can be made heavy and some products even have an inefficient lie flat wheel shape that is hard to push- good if someone needs the exercise..