there is a lot of trial and error coupled with looking at the curvature map of the surface. One other trick I do is that I will engrave on one side of the rib the smaller profile for ribs with large changes in profile, then you just "sand between the lines" so to speak. make ample use of the curvature combs for all splines as to get a good surface, it must be good in the curvature of the driving geometry. also keep the number of points per section the same along the entire length of the hull. that hull was modeled with 3 primary lofts, one bow, one stern and one that goes from ~0.25 inches from the bow to ~.75 inches from the stern. you will get very good at surface modeling as you may find it easier to model each surface then knit.
What method do you use to get the initial hull lines into the cad system? It would be easy if everything on the plans had dimensions on it (I assume if you can track down original builders plans, that they would be dimensioned?)
sketch pictures. I scale & section in gimp or photoshop since most cad packages have a pixel limit on import and reduce dpi if you exceed it. Then I orient all the pictures with the white background set to transparent so all one sees are lines in the model. Trace the sketch. The profile morskie plans are convenient since they are already in electronic format but some of the hull lines are not very good (at least in the littorio case) in this case I talked a fellow out of a 3ds model of the hull based on the builders plans and have verified dimensions based on the limited subset of those plans I have access too (Could have had the whole thing but I was unwilling to spend ~350 euros to get them copied and sent over from germany) which made the hull modeling go a bit faster, although the process is exactly the same.
You do really nice work Greg. I cant wait to battle one of these. Too bad she isn't legal for most of fast gun.
. Initial ribbing, keels and decks completed. will probably stick with as much 1/4" ply as possible for most parts as it is stiff and consistent... this one will probably not go into the rediculous detail of the littorio internal placement as I have learned building the L, as tech changes (particularly battery and cannon) so does the layout a skosh. what will go in is powered center shafts with gearbox, rudder along with mounts and designed transmission, and some kind of turret/turret rotation mechanism that is blank, allowing for easy mounting of many styles of turret to a part designed to rotate readily. superstructure will be built out of ply and part of the kit. Not sure what to do about turrets, but I may just make ply blanks that can be easily either molded or used directly as turrets.
Hmmm... not legal in MWC. Appears that I will at long last build a Treaty warship. Maybe I can fight Mike M
well, I am targeting the end of feb to have the bulk of the design work done... right now I am trying to decide where to part the removable portions of the deck from the nonremovable. the curve of the deck makes that more interesting than it might otherwise be.
With her armor and guns, how does she only get labelled a battlecruiser? I love the final pic there next to Roma. Very pretty!
I tend to think that late war battleships should match either in size or performance the big guns of the best comparable operating battleships. The baden's 15" and the other late war ships starting to show up on the other side were going to 15" if not already there and the followon to the mackensen was to have 15's as well. She would likely have been slightly under armored over much of her length compared to other new british battleships (she would have been fast, no way to keep that up and armor up at the same time with the knowledge of the time), but she might have been nasty ship that as with most end of conflict ships seem to defy easy boxing into groups... to heavily armed and armored for a start of the war BC, but too fast to be a start of the war BB, and then the advances in battleship tech moved so quickly anyways, she will be great for combat. as an aside, scale rudder area is 1.82sq inches PER rudder, giving her 3.64 sq. inches scale, but with the 1.25 big gun multiplier, that gives 4.55 sq. inches. that compares very favorably to the fast gun rudder sizes, meaning that this will be a reasonably fast ship in big gun with a nice amount of rudder area, located in a nice position relative to the screws
Alright folks, I am looking for a gearing option that allows an angular misalignment between shafts. the rudders are each 9 degrees off of vertical. I would like to maintain that. that means that the included angle between rudder posts is 18 degrees (rather than 0 as desired by spur gears). Any good ideas on getting it geared up? space is tight in the stern
You might want to take a look at "angle winder" gears for slotcars. Even a combination of crown and pinion gears might work with some creative engineering..... in simplest terms of describing what I'm thinking, mount a crown gear to a servo, then mount the servo so the teeth of the crown is facing the rudder shafts and meshing with pinion gears mounted to the rudder shafts?? I don't know if it would be possible to get the diameters you would need, and more gearing would be necessasry to get the proper ratio or the rudders would rotate ridiculously fast. Another possibility is to take a look at this: www.theindependentscratchbuilder.co...winder.htm If the spur gears in this high speed application tolerated the alignment, with the low speed/ small degree of rotaion a rudder requires, meshing the gears on an angle could be a non issue. Another possibility might be to align spur gears like the guy in the link did, but give them a little better mesh / engagement by beveling the edge of them a bit where they mesh to the point of interference.
Valid point. I had considered that. If you happen to have any 32pitch gears floating around, could you see what it qualitatively feels like (I haven't used gears in years so I only have belts and chains)
I think all of the gears I have are 48 pitch, but I'll double check. How much room do you have back there roughly? I'm sure there are a few configurations that would work, but my head is hung up on a gear on each rudder shaft (both angled 9°) and an idler gear between the two ( flat as in horizontal ) . The "idler" gear could be attached directly to a servo, making it the drive gear or it could have a sprocket attached to the top of it to be driven by a belt or chain if there is no room for the servo that far back. Now I'm curious... even though its past my bedtime I have to go hunt down whatever gears I have to see if they play nice together on an angle.
