Iowa Class 1:48 Automated Steering Gear Model Start-to-Finish Build

[Builder2010]

Two steps forward, one step back…

The repair of the first Rudder Hub print continues successfully. And I machined the center piece of the manufactured servo horn that’s going on the rudder stock. Those were the good things. My 4th and last attempt to print a new Rudder Hub failed miserably with almost a complete delamination of the base layers. I never had this problem before with this printer and I did print the repair sleeve and the top assembly for the rudder stock in between these failures.

Let’s see the good stuff first.

My sizing on the repair sleeve was dead on. It slide nicely onto the 1/2" brass rudder stock and fit loosely in the rudder hub, but good enough in the printed part.

Here it is after epoxying the sleeve into position. I used the rudder stock to hold the part in alignment while the epoxy set. With this being the actual part I’m going to use, it will need some more cleanup.

For the Servo Arm, I had some 1" round brass stock. First I had to hacksaw a chunk that would fit onn my tiny lathe. If I had a “real” lathe with a reasonably-sized hole through the arbor, I would have just chuck the piece in and got to work. I had to first get my hacksaw at my daughter’s house. My son in law borrowed it and forget to give it back. I rarely use this, but when you need it, there is no substitute.

I turned the lug end to just fit into the hole I cut in the brass arm. It didn’t have to be a tight fit. The whole deal is going to be soldered together.

I turned the part around and turned the o.d. of the body so it coincided with the edges of the arm. I couldn’t cut it all the way back to the smaller diameter, and didn’t trust the relatively light 3-jaw chuck. I also have a very robust 4-jaw independent chuck and put that to use to ensure that the piece is concetric and true. I use a Starrett Last Word dial indicator to get the runout to about 001".

After turning the o.d. I needed to chop off a whole lot and again used the hacksaw to do this. I have cutoff tools, but the lathe isn’t powerful enough to do very deep cutoff operations.

After cutting the excess I faced that end, center-drilled a starting point and drilled through with a smallish diamter pilot drill. I followed this up with the largest drill my machine can handle—1/4"—and then used a small boring bar to open the hole to a clearance fit of the rudder stock.

I turned it around again and shortened the narrow end. I only need a lip on that end for the soldering. I need all the stock on the fat end to handle the set screw, which I will do tormorrow.

Here it is cleaned, but not yet soldered.

I also got reasonably successful prints of the upper rudder support, but there was a drawing error in it. I could still make it work and my upper bearing just about fits. Need to relieve the hole slightly. I have modified the drawings and will attempt to reprint.

Now to the horrow show.
This is what a severe delamination looks like.

Notice that the initial part of the raft is firmly attached to the build plate, but the transition layers are not. I did a Google search to find out causes for this and made modifications to the printing parameters concerning the raft. Those changes made things worse, not better. I’m at a loss since the first print, while incorrect, did actually print. Everyone I attempted after that had some degree of delamination, from mild to wild. The first five layers cure for 8 to 12 times the working layers exposure time. I was curring my rafts at 35 seconds, but after reading about the problem reduced it to 26 seconds. My exposure time is 2.1 seconds. Then for the next five or six layers, the exposure time is reduced by a linear progression until it reaches the working time of 2.1. This is where the trouble is and I don’t yet how to fix it.

It’s why that reject part is so important.

Because of the misshapen supports, there’s a good chance that there is some resin stuck to the barrier film. If there’s even a very tiny bump on the film, the auto-leveling will report an error. This means, removing and emptying the vat through a fine mesh filter to catch anything floating in the resin, removing any bumps on the film and replacing and refilling the vat. It’s a messy part of the process that I don’t relish.

[Dioramartin]

@Builder2010

This is what a severe delamination looks like.

Similar effect for me as after too much horseradish. Commiserations, I’ve no idea the cause but the result could be salvaged as Modern Art if painted imaginatively. Reminds me a little of Roger Dean’s 1970’s album covers for Yes. That aside, fascinating engineering Myles, another great project.

[Builder2010]

That’s for the moral support Tim. I’m still not sure what was going on, but I suspect that the size of the raft was the outer limit of the printer’s capacity. Read on…

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!

[Builder2010]

I posted my printing screwup on a FaceBook affinity group for Elegoo Saturn users. I got a lot of funny comments and many from folks who have done the exact same thing. Then today, I attempted to run a job with the build plate off the machine. I was working away on other stuff. When I checked back I got a “vat level too high” error which stops the machine. When I opened the lid, I see no build plate. It was minding its own business on the table next to the printer. I said I wasn’t going to make the last mistake again. But that didn’t preclude making a completely different mistake.

Got reasonable prints of the cylinders however, there’s some craft work needed to make them workable. I had to run a #22 drill through the crosshead guide holes so the polished stainless rods slipped in. I also had to do a Bondic repair on a small area on the same crosshead guide lug that didn’t have adequate support. I will sand this area smooth next session and when painted will no longer be seen.

I also have to clear out the cylinder bores to remove that excees resin that formed there.

I then machined the crank pins that will hold the small ball bearings for the ram rods. This is for the rudder crank end. After I print the crosshead itself, I will machine two more of these.

The upper rudder frame printed perfectly and the ball bearing fit the bore perfectly. The handwheel and worm gear also printed well and, so far, hasn’t broken.

Here’s the rudder crank with the machined pins. I used thin CA to secure them. I will mask them when painting. I chose to install in the unpainted part because the fits are so tight that any paint in the bores would cause a problem.

The bearing fit on the pins is a slip fit, not press. The lower ram rods are hanging down and the could slip off the pins so I’m going to secure the bearing to the pin using some Loctite thread lock anerobic adhesive. I will also have glue the outer race into the ram rod for the same reason.

Here’s how the upper rudder pieces stack when installed in the ship.

The last thing was machining another thrust collar. I made this one a bit thinner than the first. Fun turning project!

Set screws I’m using are Metric M4.

[Builder2010]

Today saw more successes. The scheme to create realistic and robust ram rods was flawless. The groove to receive the 1/16" reinforcing brass rod was sized perfectly. the rod required a little coaxing to slide down to the bottom. And the bore size to receive the ball bearings was aslo dead on. It took just a bit of pressure from my parallel jaw pliers to seat them to the bottom. It was very rewarding.

I used Bondic to fill and level the gap. You apply it in several layers, hitting each with the little UV LED, it cures in a few seconds.

Here’s what it looks like after sanding, but without paint.

I’m glad I spent the extra time creating that “Hole Sizing” test article. The printed bore diameter was a perfect press fit. All this work was done before post-curing. I wanted the resin to still be pretty flexible so any pressure would be accommodated and not forcing the ends to crack when the bearings were pressed home.

I finished all the finishing work on the ram cylinders. I made extra and used one to experiment on how to best remove that excess plastic what was semi-blocking the bore. At first I tried using the Dremel with a carbide routed, but it was way too rough and there was no way I could maintain concentricity. Chucking it in the lathe seemed like it could work if I was very careful.

It did work. When I did the first piece, I creeped up on the final i.d., but found that if I left the boring bar at the same position, carefully re-chucking each piece in the same orientation and slowly feeding the bar into the bore, I was able to get the finished i.d. in one cut. I repeated this for the remaining cylinders.

Here’s a movie showing the cut being made. The feed had to be very slow, otherwise, the tool would dig in an either rip it out of the chuck or disintegrate it. I’m having trouble getting this movie to run on YouTube. See if it works better for you…

SG Cyl Bore Repair SD 480p

The brass tubing cylinder liners are a slip fit. This is okay since I’m going to secure them with epoxy. The cylinder walls aren’t that thick and a press fit would have invited big trouble.

The ram is going to slide nicely. I will add some very nice grease to make it slider even better.

The foundation print was okay, but had some weird areas that were porous and spongy. Never saw that before. Using the part fails or doesn’t. It doesn’t decompose. I filled all the areas as best as I could with Bondic and it will be okay. The areas are not easily visible.

I placed the cylinders in their respective positions to show how they will be fixed.

Last thing I did was cut the four cylinder bearing liners. Cutting thin wall tubing is difficult. My mini-cutoff saw’s abrasive wheel has been wearing so the diameter is no longer able to cut more than about 1/4" diameter stock. MicroMark doesn’t seem to have any in stock.

Starting tomorrow, work will stop while we take a mid-year trip back East to visit with family and friends. Work will commence after Aug 1.

[Dioramartin]

Beautiful work, leave 'em wanting more! The U-tube clip worked for me

[Builder2010]

Thanks Tim!

Got back from the trip back East to visit family and friends. It was my 81st birthday so we had some celebratiobns. I gained four pounds and my wife and I ended up with puffy ankles due to all the eating, sitting around and the 11 hour car ride to and from. It will take some time to get things back on an even keel.

And I got into the shop today and completed and important and challenging step: finishing up the oh-so-critical rams.

The 1:32 ram scales out to 4.25", I painted some black Sharpie on the approximate place of each ram that represented the cut line, and then hand hacksawed them a little bit long. I used some cutting oil to make the hacksawing of stainless steel a bit easier. Stainless is tough stuff to cut and machine.

I then chucked each piece in my Taig Lathe and faced the end down to the line. I supported the overhanging lenth with a steady rest. I then reversed the ends and faced off the other end. Both ends had a slight chamfer added to eliminate any burr that would snag the cylinder bearings.

The crosshead hole lies in the exact center of the ram. I needed a hole that was 1/4" and directly through the center and plumb. I needed to create a small flat so the drills wouldn’t skid off the surface. I used a flat diamond coated disc with Dremel to create a small flat. I then center-punched the location of the drilled hole.

I used a #33 drill as the pilot hole—only because it was sitting at the drill press from the tapping operation last performed—and then followed up with the 1/4". It was a painstacking operation to ensure that the hole was being drilled down the center of the cylindrical shape and supported. I then used a countersink to chamfer the edges so the brass crank pin would slide in unimpeded.

Here’s the end result.

And after trying on a crosshead, I was rewarded with a nice fit. Tomorrow I will cut the crank pin to length and then machine these ends just like I did for the ones in the rudder crank.

As much as I like to visit with friends and family, my happy place is creating in the shop.

[Builder2010]

Due to waiting for our HVAC tech to arrive, got very little accomplished today. Whenever you go on a trip, when you return something’s not working. This time it was the 2nd story HVAC unit. It’s quite old, but only needed a motor start capacitor.

I did start the machining of the crosshead pins. Got the first end of the first one finished.

Tomorrow, these will be finished and I will start painting and assembling this part of the job.

I want to add sound and Arduino just came out with a 2 channel unit the Arduino Uno-Q. While I’m not certain, I think I can control the motion AND play the synchronized sound track with it.

[Builder2010]

All of the upper motion parts machining is done. I’m now determining the assembly/paint processes to do it most effectively and efficiently.

After measuring the proper length of the crosshead pins, I cut off the excess with a cutoff tool in the lathe. My MicroLux Mini Cutoff Saw needs an abrasive wheel replacement and MicroMark is out of stock so I had to do it in the lathe. That said, I just did an Amazon search and found many 2" wheels with a 3/8" hole on sale. I’m going that route and will have them in my hand soon.

I machined both and they work well.

Next up was cutting the four bushings for the cross head slides. Again, without the cutoff saw, I did it in the lathe.

So all the motion for the machine itself is machined and ready for paint/assembly.

On another front… I printed the first two parts of the disassembled rudder hub that caused so much trouble printing. Those parts are done and draining in the machine. I’ll finish them up tomorrow and print the main upper portion.

As seen by this image, the lower portion print failed. Probably a support failure, but I’m not sure. I awoke this morning thinking of redesigning… again. I don’t have to make the part as in the prototype. The insides don’t need to be displayed.

The difficulty is the taper. The whole part that extends out of the hull is tapered towards the bottom. Making assymetrical tapers in SketchUp isn’t easy. I’ll keep you posted…

[Builder2010]

The previous post was Friday’s. Today i cut the four cross head guides after changing the abrasive cutoff wheel on my MicroLux Mini-Cutoff Saw. MicroMark sells this, but the unit and all the wheels were out of stock. I found many on Amazon. They arrived yesterday so I was able to cut the parts today.

I completely redid the drawings for the rudder hub, both simplifying and skinning the parts to eliminate the skinning process afterwards. I also eliminated all the interior cavities shown on the real forging and instead, hollowed out a solid part with plenty of drain holes to remove any liquid uncured resin remaining within. I uploaded both parts: the lower and middle sections are now a single part, and the upper another.

I uploaded both as STL files to my slicer and prepared them for print. Today, I was able to start the job, but was concerned about the failures and partial failures I was having and, using a technique I recently read in an Elegoo Saturn Group on FB, I checked the LCD screen. It’s been in service over 2 years and has done many jobs.

The test showed dead pixels.

Where there are dead pixels there is unexposed resin which is a failure. Those spongy sections I was seeing in my latest prints on some parts was due to these dead pixels. And the failure of the last print could also be from it. If the dead spots happen to fall on supports that are being formed, those supports will either be missing or flawed so they can’t perform.

I’ve ordered a new LCD from Amazon and will rebuild the machine in a couple of days. I’ve replaced LCDs on both of my previous Elegoo printers. It is considered a wear item with a life of 2,000 hours. I don’t know if I’ve reached that. If do know it’s been in operation since June of 2024. Screens are killed by several factors including: long exposure to strong UV light and excessive pressures created when failed print resin that’s sticking to the barrier film applies high spot loads onto the LCD. The new printers have strong glass shields to help protect them from the latter.

Stay tuned…

[golikell]

There is really never a dull moment with you, is there?

[loncray]

Your threads are like going to a really great movie, just split up for months at a time.

[Builder2010]

It’s a great movie with dangers, cliff-hangers, successes and failures, but no kissing parts. And you have to provide the popcorn.

I replaced the 12k Mono LCD on Thursday. Elegoo has a method on video that has you literally disassembling the entire chassis to get to the underside fo the LCD and then popping it out. It’s held in place by strong double sided adhesive strips. Then on FaceBook I found a simpler method where you use a heat gun to gently heat the edges of the LCD from the top to soften the adhesive. Using a spurger (flat bladed thin tool) you gently pry the old screen up from the corners until one side lets go and you can remove the screen. You also have to remove the back panel to expose the motherboard and disconnect the LCD’s ribbon cable. A new one is included with the new screen as well as new adhesive strips and upper sealing strips. This is the method I used successfully. Took a little over a half hour.

After assembly, but before replacing the rear cover, I tested the screen and reward with this.

Edge-to-edge perfect blue light. You have to be very careful to not capture any dust or dirt between the LCD and the Fresnel lens that lies below. The lens evenly spreads the intense UV light that cures the resin layers. Any dirt would show up as a missing pixels.

With printer back in commission, I immediately reprinted the mess of a foundation. While I patched up the original, it still looked awful to me and not up to my standard. The reprint was perfect. The first iteration was also missing all those neat bolt heads that hold the upper to lower portions.

While cleaning that up, I printed the lower half of the newly-redesigned rudder hub that caused so much trouble. This image was taken just before it was finished. Some supports broke loose on the part of the surface, but after inspection, this should not cause a problem. I will have to remove the vat and clean it as there may be some errant resin stuck to it. That’s what can cause LCD failure.

This part was hollowed out on the slicer, so even though it’s a bit massive, it didn’t consume much resin.

On another front: I’ve created a very respectible sound file of a hydraulic system. It’s 7.9 seconds long, so I use that timing for the motion to synchronize it with the sound. I’ve also been corresponding with Arduino, the micro-controller manufacturer, who helped me specify the little audio player/amp controlled by the Arduino Uno. While the Uno is a single channel controller, with some specific programming techniques it can operate both the servo and the audio module. It just sends a start and stop pulse to the audio, and then control the motion. it should work out nicely. The audio module is very inexpensive. Can’t say that for the mini SD card to hold the file. They’re expensive!

On deck next week: printing the rest of the parts designed so far, and start to paint the ram systems which are all printed. I’m designing the rudder and it’s bearing and will start designing the hydraulics room. Ryan’s going to get me some specific images that I need for proper scaling of this complex unit. I’ve gone through all my images and merged some to provide a more comprehensive view, but there’s still a lot of missing/ambiguous areas.

[Builder2010]

The lower rudder hub printed beautifully. The only thing that didn’t were most of the plugs that are created when you “drill” drainage holes in hollow objects. The plugs are tapered so they can be pressed in. With a little sanding, the holes disappear. All of them save one ended up stuck to the barrier film, and yes, I had to empty the vat and remove any stuck resin. I will fill the holes with Bondic. Takes a little longer, but with good results. The rudder shaft sildes perfectly through the hole I created.

By drawing the skin and printing with it, saves me a lot of painstaking work in applying a skin.

The upper large part of the hub just finished printing too. In this case ALL of the plugs printed, but a part of the welding flange that wasn’t attached to the part’s body, failed to print. This is a non-important detail which I, frankly, am not sure how to incorporate into the model.

If I’m keeping this detail, I will fabricate it. Not worth wasting the resin to reprint.

The next part that’s going on the printer is the leading edge part (fairwater) that goes on the that squared-off front wall. It will have an aircraft-style water-dynamic edge when finished.

Ryan sent me some more images of the hydraulics room, specifically the gauge panel. He also sent me the entire index of every blueprint the ship has. There are hundreds of them! I sorted out those that pertain to steering and then further chose those that would contain the information I’m seeking. On some I wasn’t sure if they would provide value, so Ryan’s going to review them for me to make that determination. He’s then going to photograph those that are pertinent so I can use them to finish up the project. It’s great to have a man on the inside.

[Builder2010]

The upper part printed well except for the welding flanges. I going to remove the bad ones and reprint just the flanges and glue them on. There was no errant resin stuck to the barrier film.

The leading edge just finished printing and is perfect.

I didn’t realize that the curved inner surface of the bottom part was very thin. It started separating due to post-cure shrinkage.

I chamfered the outer edges a big to give more surface for the Bondic and then used it to close the gaps. Worked fine.

I tried fitting the two parts together and they work very well. I will epoxy them together once I do the final cleanup on the part.

You can see the missing welding flange. Should not be a problem.

Still have to fill all those drain holes. I have a lot of good plugs from the top part print and I’ll use them on all the viewer facing faces. For those in the back, I will fill the holes with Bondic. All the holes need to be sealed. They could continue to weep water, or any uncured resin that may be lurking there and that ruins the paint job.