Alert Class Tug by fnkershner - 3D printed - 1:35 scale

[BenF89]

Thanks for the explanation- that’s way simpler than I was thinking. (I tend to over complicate just about anything...)

[reklein]

Good lookin project there Floyd. Has all sorts of possibilitys. I might've tried using foam,fiberglas,and styrene for thr superstructure. But I can't argue with your results.

[fnkershner]

So first off, Neal is way too modest. He did all of the CAD design for the Tug, and it was not easy. We did receive PDFs from the designers. But there was a lot of detail omitted. Neal did all of this work. Also Neal has had to put up with my constant nagging "when will you have the STL files ready" "Please recreate this part" etc. Once he had completed the CAD design and shared the rendering (see above). I had the fun of sending everywhere and getting all the excited feedback. I believe it is that rendering that really sold this project. Also once we had the rendering Neal had to figure out how to slice the design so it would fit on the various 3D printers. Not an easy task.

 

For this project I broke it into 3 major parts -

 

Part 1 - Neal would do all the CAD work for the Tug

Part 2 - Per would do all the CAD work for the Barge with support from Neal

Part 3 - Floyd would handle all the admin (contracts, NDA, communication) & the 3D printing, assembly and painting of the models. And this includes the manufacture of the oil containment booms.

 

Bill - You are exactly right. I will never do a project of this type the same way. In fact the barge will likely be foam and wood with some 3D printed details.

Edited March 14, 2019 by fnkershner

[reklein]

Maybe if you had a $30,000 printer or at least one with a large  enough bed to print a half a hull it would be practical. I mean after all if a concrete house can be printed whats a little tug boat. the model has turned out really nice though. You should be proud.

 

[thibaultron]

I was watching a video of a car show from a couple of years ago, where Ford had a machine that was 3D printing a plastic 1:1 T-Bucket body and another robotic one that was sanding the finished bodies.

[Haze Gray]

On ‎3‎/‎13‎/‎2019 at 6:56 PM, fnkershner said:

So first off, Neal is way too modest. He did all of the CAD design for the Tug, and it was not easy. 

 

LOL I was trying to keep a low profile -!

 

I actually went through 4 iterations of the hull if you can imagine getting 12-20 hours into something and going "nope, not gonna work".   I'm including pictures showing versions 1,3, & 4
- version 1 was some experimentation I did when it looked like all we would have to go on was 7 photos of low quality

- version 2 had only a few partial frames to work with and no general arrangements - gleefully deleted cause I hated it so much which is why I can't show it

- Version 3 we had gotten just maybe not quite enough and I had to leverage some schematics of a similar tug to get there.

- Version 4  was completed using about 20% of Version 3 and about 60 photos from an on-site visit of the tug which turned out to be critical in completing the design

 

The promise of 3D printing boats (or anything else) are perfect parts, that fit together perfectly, perform and look perfect.

- Unfortunately there are multiple realities (some of them good, quite a few of them bad) when you actually attempt it because the printing part is experience, skill, and science driven - but I don't think that's different than any construction technique - I remember building a FW 190 out of balsa from a Gillows kit in highschool - glued it all together perfectly but the balsa was green and when it dried overnight the fuselage was bent like a banana - totally unusable. 

 

For me - I'm all in on 3d printing - probably because I can do all the design work, planning, and integration of elements which is a very pleasing part (and I do okay with the printing quality!)

 

 

 

 

 

Edited March 20, 2019 by Haze Gray
spelling

[BenF89]

It’s amazing what a difference good plan sets and reference information make! What a convenience getting on the actual tug. I know firsthand how often the product doesn’t match the drawing, or (often) the drawing is simply silent on a detail or arrangement. Heck, it’s even the case on my own designed model!

Edited March 20, 2019 by BenF89

[fnkershner]

Ok, On this site we share both our success and our problems. If only to help others avoid the same mistakes. I have been plagued by a difficult problem that has created a significant delay in this project. As you will see in the attached pictures 2 of the hull sections do not line up correctly, and it is very noticeable. My suspicion of the cause is the many different 3D printers used and many different suppliers of filament. Out of 15 parts for the hull this is the only join that has such a large gap and does not line up. I should also mention that it does line up at the keel. So it is this section that needs to be modified so that if fits. Also the deck is out of alignment.

 

My plan is to very carefully do some surgery on this part to lower the deck line so that the railing is lined up. Then I will use a technique call PLA welding to close the gap. PLA welding takes advantage of the low melting point of the filament and creates a bead in the gap between parts.

 

Wish me luck. I have been ducking this for several days, hoping for a better solution. If I fail it will mean several pieces of the hull will need reprinting.

 

 

[Haze Gray]

Floyd,  have you had successful trials with PLA welding?  when I tried it I got very inconsistent (bad) results but I may have been spinning up to high - 

 

When you lined up the railing, how big is the difference in the deck height?    If you can line up the deck and the hull and the keel acceptably and only have the railing to fix, that would be the way I would go. It's going to be easier to add material/filler and build up a flush surface on the railing than it would be to shave/remove material.   

 

The plastic will hate you from trying to remove more than 1mm of material and it will remind you that the skin is thin, especially in section 5. We could always hang tires over the side too to help hide seam lines

 

Another alternative is to line up the keel and the hull and the railing acceptably and if you only have the deck that's out of alignment then a sheet of wood or other material + filler could be used to bring the main deck up to match. 

 

 

[fnkershner]

PLA Welding only works with 3 mm PLA. The 1.75 is too flexible. And yes I have been able to fill gaps and it does create a bead very similar to real welding.

 

Neal - you and I can discuss this in person over the weekend. I will have the hull with me.

[fnkershner]

Ok, I thought you might like an update and some photos. On Friday last week I had a project meeting with the customer. We did a review of where we are at and we discussed the issue on the starboard side. He decided that he did not want me to do major surgery (Yahoo!!), and we came to an agreement on how to make it look better and that would be good enough. This past weekend we had a meeting of our local model building club and the photos you see below are the result. 

 

So let me explain a little bit of what you see. First of all I have used spackle to fill cracks etc. This is in preparation for sanding. The main cabin is just sitting on the deck. It is sanded and painted. you can also see the smoke stacks coming up thru the deck. the furniture for the pilot house is glued in place. and the life boat canisters are sitting on the roof of the main cabin. the Pilot house is not here because it is in the shop being wired for navigation lighting. It too has been sanded and painted.

 

On the fore deck you will see the emergency hatch just sitting in place, it needs painting. The hole in the bow is for the forward winch. It was decided that since this will get a lot of hands on attention from the students it may need to be replaced & repaired. So we designed it so it could be removed.

 

On the stern is the main winch. Similar to the forward winch it too can be removed. It is not complete yet but you can see the hole in the deck where it will be installed.

 

It was requested that the thrusters rotate so the deck is not in place until they are painted and glued to the shaft.

 

[BenF89]

Looks great! I assume the thrusters will then be manually rotated (not remote?) I’m interested to know what the intent/benefit is if they’re manual- I could see a remote control  set up like the actual ship’s controls being a neat feature for learning the system. But I’m sure there are lots of advantages or uses I’m not considering.

 

Also, I love the Foss seaport museum - I took my kids (1, 3, and 5) a few months back, and they really liked it, especially the interactive old-style fishing boat. I’ll have to catch the next meeting!

[fnkershner]

Ben - I am sorry you missed the meeting. Since this model is to be used as a teaching tool and never leave the classroom. The school declined having any kind of R/C. They were more interested in things moving that would inform the students. Such as the thrusters, search lights, and the winches. We volunteered to have the fire nozzles rotate, and you will see that when I have the wiring done for the pilot house. The school has decided to mount the models to a roll around cart. This way the students can simulate being on the water and the correct angles on the nav. lighting. So when we are done there will be a 4 ft. long cart and a 7 foot long cart in the classroom. They will also use the winches to tie off to each other.

 

A quick note on the Foss Waterway museum - As Ben mentions it is located in Tacoma and it has 3 models that were built by members of our club. They are 1 inch to 1 foot scale. I encourage anyone in the area to go see them. The model of the Discovery (the ship that discovered the Puget Sound) is 10 feet long and 12 feet tall, complete with Treenails.

[Nirvana]

So, Floyd isn't alone in this project as you may have notice.
There's Neal who has done all the drafting from real sketches of the tugboat Alert class named Alert as well.
Neals experience with Fusion360 is amazing who knows a lot of tricks. And he is self taught!
I am behind the drafting and design of the barge, this barge is a hybrid, between two different barges.

One is a 400' and the second is a 250', considering the scale we are working at the barge is very long. Measures 85 inches plus ( 7ft +) or in metric 217 cm plus long.

 

Here is three renderings I have done, there are no post photo editing.

Position lights and work lights will all be fully functional via a switch-board.

[fnkershner]

Ok time for an update! After a day and 1/2 of sanding, filling and more sanding. I think we will be spraying primer later today! Yahoo! With some help from my grandson. We spent much of yesterday sanding the hull, filling cracks etc. and sanding again. I also got a chance to assemble the crane and winches and get some primer on them. And of course I broke some parts. So Today its back to the lab to reprint the missing parts. Note to self - In the future when you need a heavy primer, don't buy the most expensive kind. I went to an auto body supply and asked for the best thick primer that would fill cracks etc. They gave me a rattle can that comes in black and grey. It works great but at $25 a can I am now $100 poorer.

 

The pictures you see are of the Aft winch and Crane with a primer coat.

 

Edited March 29, 2019 by fnkershner

[fnkershner]

And here it is! a picture of the exterior of the hull with Primer applied. There is still a bit of sanding on the interior and primer to go but we can really see progress.  

 

So I have a question. When cleaning your air brush what do you do? Mine is a badger 150 with siphon feed. It appears that after a week of not painting I can't get the paint to feed. I am thinking that the siphon tube is blocked. So tell me what the procedure is to change paint colors?

[Jack12477]

Get out the manual !     Seriously, dissemble the brush, and carefully clean all the parts, Lee Valley sells a really nice set of airbrush cleaning bristle brushes which I use for my Badger 200.  You may have to soak the parts in thinner - make sure you disassemble the plunger (where the air hose connects) and clean it too.   As a  routine when I finish painting I run clear thinner thru the brush even if I am going to continue  later.  Do the same between colors. At the end of your session, run more thinner thru it and clean with the bristle brushes, disassemble as needed. 

[druxey]

Surgical cleanliness is need to keep airbrushes in good working order. The advice above is excellent.

[kurtvd19]

Floyd:

Don't use the wire brushes sold as airbrush cleaning tools.  The interior of the brush is very soft brass and can be scratched.  This is official Badger opinion, not just my personal opinion.  Badger makes a neat little cleaning kit - it does not contain wire brushes.  The link to a decent review of the kit is below - I recommend you watch it for tips on cleaning the brush. 

The kit's got everything you need but you probably already have most of what is provided in the kit.

The other link (dons airbrushing tips) is to one about general tips - good site - note he does use a brush but it's a dental brush and the fibers are nylon (or a similar product - not wire).

The other link is to the Badger 150 manual - with cleaning instructions specific to the 150.

I always follow up a cleaning with lacquer thinner sprayed through the brush.  I keep a small jar with an eyedropper to put just a bit of the thinner into the cup - I tend to use gravity feed brushes a lot - but just turn the 150 upside down and drop the thinner into the suction tube.

 

My cleaning procedure between colors - get the excess paint out of the gun - spray into a rag or cleaning jar.  Use a doubled over pipe cleaner to clean paint out of the siphon tube.  Use a dry section first then a section wet with cleaner.  Spray cleaner through the brush till the brush sprays clear.  Remove the needle and wipe it clean and reinsert the needle.  Clean the tip of the regulator with a swab moistened with cleaner.  Spray the next color.

 

At the end of the day do all of the above then disassemble the front end.  The regulator's tip needs to be clean both inside and out.  Use the tip of a swab or other soft material - not a wire brush.  The tip is tiny - don't drop it - make sure it is clean inside and out - again a thin tapered swab or nylon brush - do not force anything as this piece is delicate and if you spread or split the tip's opening it needs to be replaced.  The head needs to be clean inside and out - same procedures as for the tip and regulator.  Reassemble the regulator, tip and head back onto the airbrush.  You might want to use some beeswax on the threads here to avoid air leakage - DO NOT over tighten.  If there is air leakage use the beeswax.  Reinsert the needle and spray some lacquer thinner through the brush and set aside till the next session.  Skip these procedures and you will need to disassemble and do a heavy cleaning.

 

Full disclosure, I work with Badger and they send me around to teach/demonstrate airbrushing.  I developed Badger's Marine Pains for them.

Kurt

 

https://sites.google.com/site/donsairbrushtips/cleaning 

 

http://www.badgerairbrush.com/PDF/150 Badger New.pdf

 

 

 

 

[Jack12477]

Kurt, the Lee Valley brushes are not metal wire but rather a stiff bristle in a spiral around a wire "stick" - I think they are nylon bristles, same as you get in the store for cleaning kitchen bottles. In fact they look just like the ones shown in Don's video.

Edited March 30, 2019 by Jack12477

[kurtvd19]

I wasn't aware that they are not metal.  There are several sources of wire airbrush cleaning brushes and I assumed they were wire.  I just went to the Lee Valley site and saw these after a search for airbrush cleaning brushes.  I am familiar with this type of brush and the bristles are safe but I would be very careful that the ends of the twisted wire do not contact the airbrush interior as the ends can scratch the brass. 

 

I have some that are similar - longer bristles - and the ends are formed into a rounded end.  Actually they are made by twisting from the bristle part of the brush with the wire doubled over and twisting back to the straight -non bristle - part of the brush that slips into a handle that can be used with several sizes of the brushes.

 

Kurt

 

[fnkershner]

Thanks for the feedback. I have 2 sets of the brushes pictured here. I also keep a siphon bottle filled with Windex. And when I finish with a color or at the end of the day I spray the Windex until it comes clean. But you are correct I have not disassembled the sprayer or cleaned the siphon tube in the paint bottle. I also bought 10 siphon bottles with the plastic nipple to store paint. I am guessing that I need to rinse all these bottles and start fresh.

 

Progress report - The hull has been completely painted with primer. As mentioned above the Crane is complete and ready for paint. The rear winch is also ready to paint. I made a mistake on the forward winch which will require 4 hrs of 3D printing. So that print is underway. I have also started to assemble the Searchlights on the top of the Pilot house.

 

Just a note about the Searchlights - the customer requested that they rotate and shine. We were concerned that the students would rotate them until the wires broke. So Neal designed a pin system that will prevent a full 360 degree rotation. I will take some pictures and post them tomorrow.

 

[fnkershner]

Don't you just love the challenges of Ship modeling? As the primer has dried we have found a few locations on the outside of the hull where the outer layer did not laminate. This is a common problem in 3D printing that I have no learned to solve. But apparently did not catch on this model. The solution is to slow down or increase temp or both. But now I need to try to insert some glue beneath the outer layer. Unless someone has a better idea.

[Nirvana]

Floyd, as we all know..... a picture showing what's happening is helpful.

Maybe it's not to bad, how about epoxy with silica. The combo we used building our T37s.

[fnkershner]

Ok Per you asked for it - here you go. I knew I had a problem but until it was painted with primer. I didn't know it was this bad. the problem is caused by delamination of the outer layer of PLA. I have since learned how to avoid it. But I thought I had reprinted all the parts with this issue. I have tried using a hypo needle and injecting CA. That was partially successful. All that is left is to 1. dry paint and hope the dark colors cover it, or 2. putty over it and paint.

[fnkershner]

I mentioned that I would create a post about the search lights. so here goes. On top of the Pilot house are 3 search lights. The customer has requested that they rotate and the lights work. So Neal has created the design you see in the pictures below. There is the light hood which will hold the LED and there is the shaft thru which the wires will travel. There is also a foot and a cowling. The picture show 2 cowlings. One is upside down so you can see inside. You will notice there is a key inside the cowling. You will also notice that on the roof of the pilot house there is a small copper rod next to the hole in the roof that will hold the search light. So I will place the cowling over the shaft and insert the shaft in the roof. then glue the foot to the shaft and glue the cowling in place. This will ensure that the light does not get removed and the student does not rotate the light until he breaks a wire.

[fnkershner]

Ok, time for yet another update. The pictures you see below are of both winches for the tug. They are now complete and painted. The 3rd picture is of the main winch with the upper deck in place. The thumb wheels are for the students to operate them. Each one has approx. 30 ft of line attached. and each winch can be unscrewed from the tug for repair or replacement. We plan to take the forward winch and scale it down a bit and use the design for the capstan on the barge. I am experimenting with this too.

 

[Nirvana]

Nice work there Floyd.
You should had painted them dark green.......... just kidding

[fnkershner]

So here is where I stand on the delamination problem. As mentioned we tried injecting thin CA. This worked partially but was a big headache. So We shifted to a different solution. The Solvent used to join the hull sections is a very thin liquid and he has a great wicking property. And I have a squirt bottle that has a very tiny metal tip, almost like a needle. So with careful application this has helped with the lamination. We also used Q-tips with the solvent on it. So now the surface is not flexing. The next issue is to cover the cracks. The spackle did not work. In fact it seemed to enhance the cracks as it dried. So I think it is time for Epoxy. We can brush this on and sand a flat surface. My Grandson wants to cover the whole hull this way. He has never worked with West Systems Epoxy.

Edited April 2, 2019 by fnkershner

[hexnut]

Epoxy for structural patches, but good ol' Bondo automotive filler works great for cosmetic fill/surface coating, with Nitrostan/Red Lead as a final skim coat.  Additionally, cabinet scrapers and box cutter blades work well over PLA for knocking down the FDM print lines...