Large Scale Central

Early Style Dreadnaught End Panel

Modeling
#1

Bob had asked about doing the stamped-steel end on his wood-sheathed box, and I thought this project might provide some ideas. I guess there’s no question that you want to get the first rib done nice and symmetrical, but I didn’t go the the trouble of building one half a rib then duplicating it. Here’s a shot of the initial rib and dart. That’s not actually true–these are actually both castings made from the first rib and dart and they’ve both been modified from the original, but they’re very close and I don’t have the right photos on my machine:

From these masters I just molded a bunch-o-parts, then assembled the parts onto a styrene backing plate:

I did a little measuring here, a little eyeball, a little measuring. To get filets, I gobbed on a bunch of putty:

…then benched out all the putty with files and sandpaper.

So all that was the first attempt. On the second attempt, I split the panel into two pieces, but the process was pretty much identical. To the two resulting masters in v2 then, I added a lame attempt at rivets and seams, etc. This photo is actually of a casting made from that master:

I did two versions of this pattern, correcting some errors in measurements and rib placement, etc. Here’s a shot of both the original and the final modified Dreadnaught, each with a shot of paint:

May seem a tad tedious, but it’s the only way I know how to do it. A possible advantage of this stepwise approach is that you can make some corrections along the way, and this design at least lets you use the bottom half of the end panel separately from the top–so in otherwords if I want a lumber door or a 5-rib upper panel, I only have to make just those halves, which can then be assembled to the bottom half which remains unchanged. Not sure how big an advantage that really is, but it seemed like a great idea at the time. The highly-skilled observer can see that the ends of the ribs are actually not symmetric–so in this case my problem wasn’t end-to-end symmetry but top-to-bottom: the point of the rib is not on the centerline of the rib. Hey, who’s askin’?

#2

Excellent, thats exactly the kind of thing Im looking for. Thank goodness the ribs I need to make are fairly angular, it should be easy to make a mold of 1 or 2, then cast up from there. Off to the shop!

Thanks for the mini-tutorial.

#3

Good luck! I noticed that the end panel you need to do has a heck of a tapered portion around the perimeter, just like some of the Camel doors do. I suppose that will add a substantial thickness to the finished master, and of course to the cast part as well if you choose to do a one-part mold. Going with a two-part would then make it worthwhile to make the master include the wrap-around steel portions of your panel as well–one cast part to get the whole thing. How cool that would be–and it would be one of your easier two-part molds I suppose, since you don’t care what the backside looks like.