- Thread starter
- #61
Builder 2010
Staff Sergeant
Ryan Sizmanski wondered why the rudder was so fabricated. i suggested that it was to reduce weight. While this seems to be a non-issue with somthing that already weighed 47,000t empty, it really is a concern. Every ton of extra weight means less armor and less magazine stores. It's already drawing 36' feet of water. And a lighter rudder would have faster helm response. It's hard enough to turn a 25' high slab of steel into a water flow generated by a 57t ship moving at 33 knots, you don't need that slab to be overweight.
As to the model, it also meant I could build them in two parts. First, so it would fit on my printer, but secondly, as a single component, there would be no way to assemble it with the single-piece rudder forging.
I got the new rudder hub glued together last night, and, with a little relieving here and there, got the rudder to smoothly turn 35º in each direction. The SINGLE weld flange is now correctly located. There was a pinhole in the model that was weeping some uncured resin. I sealed it with Bondic.
There is a positive stop built into the hub that prevents going beyond that limit.
The latest version of ChiTuBox places supports everywhere they're needed, even in recesses and places that are not visible. Past versions would only place supports where they had a direct connection down to the build plate, and in many cases wouldn't let you place supports from one part of the model to another. That said, it results in hundreds of supports on a part this complex. Removable was slow, but steady. You have to be careful not to remove actual part when manhandling the supports. For the frames I used all medium supports with heavies only on the bottom most portion to the build plate to ensure that the base connection is strong.
This was when half of the supports were removed.
I had to remove some stock where the frames entered the confines of the rudder forging. I was expecting this since I used "Interface Surfaces" to locate the interacting contact points and knew that it would be an interference fit. After several cycles of fit/sand/fit, I got the frames to nestle into position.
I then, working slowly and carefully on the 1" belt sander, removed the high spots on the stringers and faired the leading and trailing edges into the frame.
This pic is before any surface sanding.
And lastly, here's an oblique view showing the sanding.
This whole part of the job came out much easier than I envisioned. When I saw John's rendering and how complex it was I ran through several scenarios. One was to make the ribs separately and use strip stringers to tie them together a la model airplane construction. But it meant that the web frames had to be individual pieces needing gluing and fitting. They simply couldn't pass through each other as seen on SketchUp. But, once I drew them all together with the stringers, the printer didn't care.
Next up is skinning. I can use styrene or balsa. Styrene has a better surface, but isn't really good to glue with CA or even epoxy, and solvent cements don't work on resin. Balsa glues well with both, but requires tons of filling and finishing to give it a metal-like finish. I have enough styrene in the shop. I'll go this route, using epoxy and small screws to hold the plates in place until it cures and then fill the screw holes aftwards. Any thoughts?
As to the model, it also meant I could build them in two parts. First, so it would fit on my printer, but secondly, as a single component, there would be no way to assemble it with the single-piece rudder forging.
I got the new rudder hub glued together last night, and, with a little relieving here and there, got the rudder to smoothly turn 35º in each direction. The SINGLE weld flange is now correctly located. There was a pinhole in the model that was weeping some uncured resin. I sealed it with Bondic.
There is a positive stop built into the hub that prevents going beyond that limit.
The latest version of ChiTuBox places supports everywhere they're needed, even in recesses and places that are not visible. Past versions would only place supports where they had a direct connection down to the build plate, and in many cases wouldn't let you place supports from one part of the model to another. That said, it results in hundreds of supports on a part this complex. Removable was slow, but steady. You have to be careful not to remove actual part when manhandling the supports. For the frames I used all medium supports with heavies only on the bottom most portion to the build plate to ensure that the base connection is strong.
This was when half of the supports were removed.
I had to remove some stock where the frames entered the confines of the rudder forging. I was expecting this since I used "Interface Surfaces" to locate the interacting contact points and knew that it would be an interference fit. After several cycles of fit/sand/fit, I got the frames to nestle into position.
I then, working slowly and carefully on the 1" belt sander, removed the high spots on the stringers and faired the leading and trailing edges into the frame.
This pic is before any surface sanding.
And lastly, here's an oblique view showing the sanding.
This whole part of the job came out much easier than I envisioned. When I saw John's rendering and how complex it was I ran through several scenarios. One was to make the ribs separately and use strip stringers to tie them together a la model airplane construction. But it meant that the web frames had to be individual pieces needing gluing and fitting. They simply couldn't pass through each other as seen on SketchUp. But, once I drew them all together with the stringers, the printer didn't care.
Next up is skinning. I can use styrene or balsa. Styrene has a better surface, but isn't really good to glue with CA or even epoxy, and solvent cements don't work on resin. Balsa glues well with both, but requires tons of filling and finishing to give it a metal-like finish. I have enough styrene in the shop. I'll go this route, using epoxy and small screws to hold the plates in place until it cures and then fill the screw holes aftwards. Any thoughts?
