Small steam tug

[PeteThePen1]

Well done Rolph

That looks like some excllent work. I also like to see that you are applying 3D CAD to our hobby. I bet our Edwardian forebears would have loved to have a tool like that.

I wondered what material you are using for the core piece of your propeller. From the photo it looks like plastic but I would wonder if plastic would be strong enough for the job. Presumably it is painted metal.

Good luck with the next stages and do tell us what happens.

Regards

Pete

[rolphill]

It's starting to look more like a boat. And the propeller is starting to look more like a proper propeller, or propereller.

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Yeah, the hub is currently PLA, as I haven't had a chance to machine one out of aluminum yet. It's a pain to drill and tap those angled holes so far deep past the rest of the part, I really only use stub drills and I don't have any extended length taps. On the 2 blade hub I actually drilled and tapped those holes from underneath. However the PLA should hold up to the low forces (<50lbf 300rpm) anyways, especially since the forces work to push the blade mounting points into the hub. If it was machined plastic I would trust it 100% after all at these forces.

[rolphill]

I hated that propeller hub so I made a smaller one. Also I have everything together now, except for a longer stainless steel shaft which should be arriving today. Other than that it's time to get all the stainless steel bolts and such for putting the seats and such on the boat.

Unlike those fancy folks on youtube who have racks of filament colors and change rolls every print to make every part a different color, I buy a spool, print the spool, then buy another spool. It's halloween season, so today's color is orange.

I was going over my steam engine spreadsheet and I added a section to calculate fuel usage. Looks like I should use a little under 9 pounds of wood pellets per hour. That seems about right?

[fredrosse]

I made a 15 ft plastic canoe into a little steamer about 20 years ago. Some of the ideas for that boat (Z Drive, Cartop Travel, Removable Steam Plant, etc.) may be of interest to you. Have a look at Radow's website

https://steamboating.de/steamboat/steam ... propulsion

[rolphill]

Little progress. Mostly waiting for parts to arrive and budget for parts. I was finally able to place my order for stainless steel bolts to actually finish putting the boat together. The lack of progress plus the impending cold temperatures are causing my attention to wander.

Since my engine no longer exhausts up the stack, I'm free to think about possibly condensing the steam. My current water tank is just a 5 gallon bucket, but I want something a bit smaller. I got a 2 gallon bucket which should theoretically cover a couple hours, but I may want to set up a way to pull and filter water from the (freshwater) lake. I'd probably just set up a series of valves to reroute a feed pump to fill the tank from the lake.

Speaking of feed pumps, I have a small 12v electric pump (RV water pump) that I've used on steam projects before and is far more convenient than a hand pump. I made a little box with a push button and 3x 18650 batteries in it that the pump bolts to to make a small self contained electric feed pump assembly. This way I can have an electric feed pump without having to deal with wiring and battery placement and such. The batteries should be good for about half an hour of pumping, which will be more than plenty since the pump has a pretty high flow rate and I only need it when the engine pump can't run.

Oh, and since progress on the big boat was stalled, I got bored and started playing around with a small dinghy I had laying around. I built this as a sailboat last year but didn't finish it in time to try it out. Since my engine and boiler are so modular, it's easy to install and swap out. I may or may not get this out in the water this year. If not, I'll have plenty of time to install the engine in the bigger boat. Either way it's no harm to try, especially since the dinghy fits in the living room to work on.

[rolphill]

Slow going on any work that must be done outside, so I made some work that I could do inside. First, it took entirely too long, but I am almost done with restoring the 14ft aluminum v-hull.

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It looks really nice. I'm going to spend the winter figuring out how to install the engine and boiler, and probably adding some sort of flat floor.

In the mean time, I got bored and did this:

Everything barely fits, but this hull just does not have the displacement for all the weight. Measuring the displacement in CAD put the water line way too high to be comfortable in anything but glass still waters. At least it was fun to put together. I did do a quick steam test yesterday sitting in it and it ended up burning off the first half foot of cotton insulation between the superheater and the engine. However the o-ring on the engine water pump failed, so I have to figure out why and how to make that not happen again. In any case, it was fun putting it all together, and it helped me make sure I had all the required systems set up and working.

[PeteThePen1]

Well done Rolph

I have greatly enjoyed your story of progress this Autumn. The big boat is looking nice too, so we will be expecting to see picture of her afloat in the Spring (Or whenever - I don't know when the steamboating season start in CA).

Regards

Pete

PS You have a PM from me in your account (If I have pressed all the right buttons!)