It happened one more time—which makes 5 attempts to print a successful rudder hub—so it’s time to rethink the problem. I was told that probably breaking it into sections and printing that way would solve the problem, and that’s what I’m doing. I 3/4 through redesigning the rudder hub in three sections. They’ll print on the machine better and much faster since the printer is only concerned how high something is (number of layers) to determine printing time.
Meanwhile, the reprinted rudder top frame, rudder crank and ram cylinders printed well and will be used. So it’s really a function of the large size of the raft that seems to be causing the trouble.
With just running a 1/4 drill by hand through the crank’s pivot hole, the 1/4 brass rod, that’s going to ultimately form the pivot points for the ram rods, fit perfectly.
I have to turn the ends down to the snug fit inside the small ram rod ball bearings. Will do on Monday. I hadn’t even post-hardened the crank nor did final finishing when I took the pic. Also shown on the above is the turned thrust bearing that will help support the weight of the rudder stock and focus its weight on the lower bearing’s rotating inner race.
I printed extras along with the rudder upper frame and redid the frame to make the handwheel more robust and did better job of supporting it. So it’s perfectly formed in this interation.
The cylinders are okay, but there will be some post-print trimming needed. There is some unwanted extra resin in the bore opening that I will have to remove. Something about the support scheme promoted this malformation. I can always remove stuff. Much easier than adding anything that’s missing.
After cleaning out the vat for the 5th time, I reset the printer to print the cylinders. We went out to the movies and when I got home saw the job was showed “COMPLETE” on the LCD panel. When I lifted the lid, I saw this.
In my haste to get something accomplished on the printer, I started the job without installing the vat hold down screws. The suction on the barrier film is so high, that after printing a few raft layers the entire vat was now rising and lowering with the build plate, and it lifted the whole deal to the finished postion while printing absolutely nothing! Since nothing was actually printed other than some prelimenary raft layers, nothing was stuck to the film. I just popped the errant layers off the build plate and started the job again… this time with the hold down screws holding the vat down. This was probably the most bone-headed stunt I ever did with the printer. I will not repeat it.
Work up yesterday morning at 5:00 am, and laid in bed for a couple of hours building the project in my head. I came up with 13 decisions on moving forward. I got up at 7:30 and wrote them down so I wouldn’t forget them.
I discovered that if I printed the upper foundation frames as I drew it, the crosshead and lower ram rods would have no where to go. The frame needs to be open on top at least to foreward cylinder.
I also decided to print the rudder framing complete and do it in sections like I’m now doing on the rudder hub. Still haven’t decided on sheathing with styrene or balsa. Both have their pros and cons. Styrene won’t require filling to get a smooth metal-like finish, but balsa responds better to gluing with epoxy or CA.
I also with need some metallic thrust washers wherever there’s UV resin-on-resin contact.
And I did some research on adding a sound module driven by the Arduino so I can have hydraulic motor sounds sychronized to the rudder’s motion. I was able find and download hydraulic machinery sounds and found that with some clever programming, the Arduino can control two things at once. The little Mini-SD Card player is less than $10 for two of them. And I have a speaker that would work. So it will not be expensive and adds another dimension of interest to the project. I have no idea what the steering gear actually sounded like. There are no operating battleships to hear it. I suppose other large ships with massive rudders would have similar sounds, but how do I capture them…. Hmmm.
The real fun of these kinds of never-before-done models is the imagination I have to generate to pull it off. And I’m turning 81 next Thursday. Age is just a number!