Marking out splashers

[Jon Nazareth]

Can anyone explain to me, please, how to mark up/draw out the splashers shown in this picture?  At first I thought that it was a simple case of dividing the number into 45 or 180 degrees, wrong?  If this was the case, the spokes of the splashers would turn out tapered when in actual fact, the edges are parallel.  Or, maybe point me in the direction of book that would hold the answer.

Jon

[IanT]

I'll try Jon.

I think that you effectively have two circles centred about the wheel centre. Between these two circles there are regular semi-cirlces, which in effect are the top part of the lobes. You then have another inner circle centred (or maybe two, with inverted semi-circles between?) on the mid-point of a chord that exists above the wheel centre at running board level.

I "think" that if the semi-circles were extended to this 'off-set' circle (or connected to the inverted semi-circles), then you could draw the sides of the lobes. I'd have to CAD this to confirm my theory and illustrate what I'm actually rabbiting on about...but it's getting a bit late to do tonight I'm afraid.

..Or it could just be a wonderful example of the draftman's 'Art' of course  :-)

Regards,

IanT

[Jon Nazareth]

Ian

Thanks for the reply.  I have posted this same question on WT and someone has actually drawn it out in cad.  The conversations are still on going but I think that it could do.

Jon

[IanT]

Ok, no problem Jon, just as well.

I did have a go at this earlier over coffee and used a method similar to the one I thought might work but I will admit, it wasn't as easy as I oringinaly thought. As you will see, I've still not managed to quite crack it. I'd have to start over to get something closer to the Jennie Lind outline. I know it should be possible, perhaps by using a variable table (based on a key dimension, such as the wheel diameter) and tying parameters to that to get the proportions right. Still a bit advanced for me I'm afraid.

Happily, it sounds like you've already found yourself a CAD expert, one who actually knows what he's doing! 

Regards,


IanT

[IanT]

Went out to the postbox (well wrapped up - It's freezing!) and it occured to me on the way back, that I was too focused on the 'geometry' and not on Jon's actual problem (e.g. making a useable drawing of the splasher!)

On getting back, about 10 minutes later, I'd copied the Jenny Lind image, pasted it into a Solid Edge 'draft' (2D) and traced over it. A little bit of tidying up and there we go. Not a very 'technical' solution - but it seemed to work and can probably be scaled if required.

So, not much of a CAD 'Guru' but still an ace Bodger apparently!     

 

Time for a hot chocolate!

Regards,


IanT