Hard Dodger design & construction (ProChine)

[RyanN]

I'm building a hard dodger for my Creekmore 40 this summer. I'm fairly good with 2D CAD but have no experience with 3D.

I've got the design to a point where I want to build a mock-up.
I hope to build the top from foam core and the sides out of thin laminated ply with bent polycarbonate windows on the sides and an opening hatch in the front.

I saw the ProChine demo program. This looked like the perfect tool to enter in the design, then get a pattern for cutting out the pieces.

After importing my 2D dxf into ProChine, I spent a long frustrating few hours trying to get my design into 3D. Is this tool going to do it for me? I'm really having trouble geting anywhere. All the tutorials seem to be based on designing a hull, not a cabin top.

Here are my 2D pictures:




The cutout in the dodger top is due to the companionway. The bridgedeck is very high and forward of the cockpit. Very similar to many swans.

[FAST FRED]

Why not just build a throw away mock up?

A computer modeling will never give the correct dimensions to not hit your elbow , or where you will grab while climbing in or out.

Cheap interior ply and 2x2 will suffice as a clearence learning experience.

FAST FRED

[marshmat]

I'd mock it up, myself. You'll have a hard time getting enough precision the way you're going to have the pieces fit perfectly, and ergonomics are a lot easier to figure out full scale. I'd go down to Home Depot and pick up a half-dozen 2x2s and a couple sheets of the cheapest sheet wood you can find (waferboard, crap plywood, whatever). Tack them together with screws, so you can move and adjust things until you like what you get.

[RyanN]

Thanks, This is what I'm doing. Now I need to figure out a non-destructive way of attaching the mock-up to the deck (water soluable glue?). Then the dynamics of bending acrylic. for the windows. If this proves too difficult I may need to re-design with flat windows.

I got a little better at pro-chine with practice but I can see it's not going to offer the solution I need.

[nero]

It might be faster and more accurate to simply draw the dodger, unfold it and plot it on to 1/2 inch extruded polysteren or 1/4 inch ply. Assemble the pieces with epoxy, PU, Hot melt, and or duct tape. Then fit the bottom to the deck camber by scribing. This being the mock up.

Then go back to the computer and modify the design adding the deck curve points you had. Unfold, plot the points onto the final panel material you plan to use.

If you want to, post the width at the bottom, width at the top, length at the bottom, length at the top, and the height from the deck to the top. Don't forget to add thickness for the material. I'll make a plan in TouchCad, unfold it and post the results. It is fairly simple to do this

[nero]

Looking at your designs. Figure in line of sight. Your position at the helm will loose lots of view.

[marshmat]

Acrylic sheet can be bent very easily into conic sections. So panels that can be simplified to pieces of cylinders, cones, parabolas etc. can be made. It can NOT be easily bent into surfaces with compound curvature, so keep your window curvature in one direction only for ease of manufacturing.

[Ausiwik]

Hi Ryan N
If Your Still looking for hard dodger info You Might check My blog I can Help
Steve Marshall
http://marshalldesign.blogspot.com