1:6 mono waterski

Indeed, amazing achievement!

 

Looking verry good, she runs stable as a rock!

 

Hi thanks ..This blade is only 20 x 4 tapering down to 20 x 2.5 mm but seems very strong , it is flexible but doesn't feel like it would break, flexing might even be an advantage. My problem is it was so complicated to draw I can't get the other side a perfect match.
I don't see why I couldn't draw both at the same time, repeating each operation as I go. To get the twist I used "blend" , but for some strange reason when doing the right side it refused to blend. Will keep trying feel like I am close now.
The reason it looks wider at the end is the printing support is still in place.

 

With the info on RCG I now understand what you mean.
This sometimes happens in 3D software, that the surfaces cannot be generated for a reason.
Maybe you know someone with more experience with this software you are using, or a helpdesk or forum?

I know these issues well in SolidWorks, but every CAD program has it's own annoyances

 

It worked , doing them together, so they are identical. I also found a less complicated way which helped no end.
Printing now for tomorrow, now I have the design I can tweek it no end of ways, wider, longer, anything
I just tried to break the one I printed, it wouldn't, using a lot of force it bent, then I bent it back. Stronger than ally

 

These look neat, will they work? we shall see tomorrow.

 

They are so light it altered the c of g 16 g lighter than last working set ,. So tends to fall over. Solutions. 1st. I have removed 10 g from her legs and I am going to add a fin at the back of the ski that should add weight where it's needed.

 

You dont need weight, jou need to give the center horizontal part off the foil some negatieve pitch. The whole trick with this ski is the ski and the foiltips generating lift, while the center part of the foil pulls everything down. From that you get the balance.

 

Yes I have understood that all along, clever idea. So these are at the same angle as last time , but the difference is not only the weight, but the shape in cross section. These are oval shape 20x4 and tapering down to 20x2.5 at the tips, last time was about 35x6 and rectangular cross section with a sharp front edge, which would definitely create more down force. I have to consider printing which means having the back edge all equal except for the tips which can have supports for breaking off later. So I could have the horizontal section say 30mm wide , flat bottom, sharp front edge, rising up to 6mm thick. The rest could stay as 20x4 oval .

 

For down force you would have to flip the centre part, so the flat surface is topside. That way the foil profile works in the correct direction for pulling down. With the flat side down you get a lifting configuration.

 

I see , easy to do that, like an upside down aeroplane wing. Just for fun I have added a fin to the blade support, do you think it will have any effect? What angle were you working to to get the horizontal at the right position. I find it amazing you did this straight off without loads of testing

 

I fin will have little or no effect I think, except increasing drag.. You already have vour fins: the vertical foil parts that go up and down! You could use the fin to mount the foil to though, to eliminate the doubble support downward.

I hate to burst your bubble, but my skier didn't run well at all in the first! Far from that! I started with a much smaller version (maybe 1/10 or 1/12 scale) some years ago, and then went for the 1/6 scale version. I have used 2 or 3 aluminium foil shapes before I got the right one. Still bending it slightly every now and then, to tweek the way it runs. So for me it is verry interesting to see your work now. If you get a relyable 3D printable shape that could be used as a universal foil, it would greatly ease things for anyone who wants t build one. It would eliminate a lot of testing, and trail en error runs!

 

I am printing a foil now with the inverted wing on the horizontal. Nice of you to help me Lex

 

Fresh of the printer , looks cute with it's little wing. I think my figure weighs 137grams, how does that compare to other figures I've seen on this thread?

 

Not sure. Mine is glued to the ski, cant weight her seperately. Should be about the same through.

 

The foils grew wings but they won't be flying

 

Not much luck today, this is not easy, I need to redraw the curved foil to give more lift at the sides, as I can't bend it I will just have to hope i hit on a good shape.
I will use my ally foils as a guide, they can work well. Another idea is printed round both bends then slot in the ally, glued in, might do both.

 

Heat the foils up with a smal torch or hot air blower, and when it gets soft bend it in the desired shape. After cooling its solid again. Should work at the lake side, at least for testing and getting the shape right before designing the final version.

 

Great idea, we have a workshop in the clubhouse, I have a hot air gun I can take with me. Hope I might get lucky and won't need it.