Design work continues. I’m working on several fronts simultaneously; the ram, rudder and operating mechanism. I have many decisions to make. While engineering the rudder stock bearing system under the base was easy, I don’t have a clue. The 3D printed rudder forging, rudder bearing support and rudder stock are complicated parts and there’s no apparent place to squeeze in a ball bearings. I may have to rely on sleeving with brass to prevent resin-to-resin surfaces.
The rudder forgings are hollow structures with is helpful in making resin parts. Save resin without sacrificing strength. You just have to have drainage holes to be able to evacuate the liquid, un-cured resin that resides within.
The ram assembly now has crosshead and crosshead guides. The ram and crosshead guides are polished stainless steel rods. I’ve sized them with nominal dimensions that will allow me to use standard brass tubing with a sliding fit i.d. for crosshead bearings. There’s more detailing on the cylinders. I have to add hydraulic pipe flanges to their ends. And there’s a rudder position indicating device in the hydraulic compartment that’s driven by a rack and pinion arrangement. The rack moves with the cross head and the pinion motion is transmitted to the meter via a stout steel shaft with unviversal joints. I will model, but not animate this.
I don’t have good information about the bottom supports of the rudder top. I have a ragged 3D scan I took of it during my visitaton. Some fragments of views from the still pictures show a bit here and there, but not enough. I’ve asked Ryan to take some more specific pictures of that area. It’s probably where I can hide the upper bearing.
Here’s a progress shot of the rudder hub. I have drawings for four sections with three shown here. Those wings on the upper one are welding flanges to weld this structure into the ship’s framing. I’m going to try to include this feature to help tie the same part into the model. The rudder stock (shaft) scales to 8" and fits my printer (just barely) in 1:32. The lower extension is my added shafting to go below and be driven by the servo. The rudder is just wide enough at the bottom to hide it. If not, I will go to a smaller diameter shaft.
Underneath I’ve started specifying the operating components. I chosed the servo, the bearing pilow blocks that wil faciliate assembly, the micro-controller and power supply. The latter is already in the shop. Rudder travel is 35º in each direction.
There is a bottom pillow block that’s connected to a bottom plate. Having two bearings at the bottom should provide a stable shaft regardless of what I decide for the upper works.
