wturber
1 MW
Here's a better video with testing of Polymaker's Polymide CoPA filament. I get the feeling that Stefan and Justin would get along with each other famously.
[youtube]Q_i-57SEGlo[/youtube]
[youtube]Q_i-57SEGlo[/youtube]
Shamrock, 25 foot sailboat electric conversion with an ebike hub motor
- Thread starter justin_le
- Start date
nicobie
100 MW
Impressive filament for a hobbiest looking for strength. Pretty darn pricey though.
DogDipstick
100 kW
That is alot of power for a set of solar panels, right? 5+kWh in the day? Seems like alot ( of power).
God Damn. Look at those ball screws. Them are some ballscrews. I have a teacher inthe family who does nothing but CAD and 3d printing destign and schooling. I have learned alot from him, ad he always says ( has said)rigidity is key.
I just spent on Hiwins.
(7) (1060mm) linear rails and 14 angular contact bearing blocks. Spent5 more than I feed myself in a year. Now time to empty that bank again for the ballscrews.
I love boats. We did do our Electric - powered steamer. It went... fast. Wake for days. Javelin's bow was six feet out the water.
3000 psi design boiler, 300psi working load. Then the Feedwater pump failed and burnt all the gaskets in the entire superheater stack. Lol Every one.. Dust. Cut new carbon fiber/ graphite gasketry and away we went.
Keep up the cool stuff, you make it easy for us, Justin. You do make it look easy. I spent two days wiring that boat and thought I did a good job... 5 relays, and standard circuitry. Watertite conduit and gland nuts, Properly sized, code meeting boxes in plastic. Gaskets on the entire electrical system. everywhere. Its so deep in there.
I would like to see more pictures of your wiring scheme: How you handle power, sensor circuitry, if you separate them, or what you do,: with redundancy and reliability in mind: for my educations.
.. Or some reference to the standards you follow.
wturber
1 MW
nicobie said:
Sure. But at 2-3 times the price of ordinary PLA, it isn't exactly exotic. And it is only about 50% more expensive than the Carbon Fiber PETG that was initially used. The problem with these things is the cost of experimenting. But if Grin is going to be using 3D printing more and is willing to spend thousands on a high quality industrial printer, then having $67 a kg for a filament that can make many parts shouldn't be a deal breaker. It isn't even outrageous for a hobbyist if there's really a need.
nicobie
100 MW
Well, that's true.
After going through the whole thread I'm getting more and more excited about my catamaran conversion. The extruded aluminium mounting is such e brilliant way to put things together. I'll be at my boat next week to do the measurements, but I'm fairly confident it'll be perfect for my boat, even if it means adding an additional motor mount, or getting slightly longer shafts. I'll be at my boat again in 3 weeks, so I'll be able to do all the measurements then.
Two motors at lower power should give me great efficiency, and maneuverability too. The catamaran is 30 feet long and probably weighs between 4 and 5 tons, so two of the 47mm stator motors should be plenty. I'm planning on 3200w of solar, I think I'll be able to move along quite well just on solar power, possibly even marginally charging the battery bank at the same time!
Two motors at lower power should give me great efficiency, and maneuverability too. The catamaran is 30 feet long and probably weighs between 4 and 5 tons, so two of the 47mm stator motors should be plenty. I'm planning on 3200w of solar, I think I'll be able to move along quite well just on solar power, possibly even marginally charging the battery bank at the same time!
Gordonstein
1 µW
Great project.
My interest is in converting a 34' monohull. Rather than day trips, the goal is "off-grid bluewater" sailing. The major thing restricting me is the cost of (lithium) batteries. With the increase in output/reduction in cost, of solar panels, together with your direct drive REGEN motor I think it should be possible to size a battery bank at a more affordable level.
Convensional wisdom is that hull speeds around 6kts (with a 9" prop) are required to make regen viable. Your videos seemed to suggest reasonable figures could be achieved at around 4kts (have I got this right?)
The next piece in the puzzle, I think, is the efficiency of the propeller. Cracking this element would reduce the energy requirement (and hence required battery size) to power the boat when there is no wind, whist also boosting regen vrs hull speed.
You've mentioned your ability of producing prototype aluminum props, and with your load cell/torque measurement, you have an excellent "development platform". I wonder if you have considered the toroidal propellers "designed" by MIT. These seem to show significant efficiency over conversional designs. I know people are DIY 3d printing props for drones with tremendous success. Sharrow marine are also producing props (mostly for power boats, I think). The difficulty is in getting accurate figures as to their effciency - I guess your setup may be ideal, here.
Sharrow propellers are expensive, but given the potential saving in lithium batteries, this might not be prohibitive. The (potentially) improved efficiency and (hopefully) regen at lower hull speeds, could be very interesting.
My interest is in converting a 34' monohull. Rather than day trips, the goal is "off-grid bluewater" sailing. The major thing restricting me is the cost of (lithium) batteries. With the increase in output/reduction in cost, of solar panels, together with your direct drive REGEN motor I think it should be possible to size a battery bank at a more affordable level.
Convensional wisdom is that hull speeds around 6kts (with a 9" prop) are required to make regen viable. Your videos seemed to suggest reasonable figures could be achieved at around 4kts (have I got this right?)
The next piece in the puzzle, I think, is the efficiency of the propeller. Cracking this element would reduce the energy requirement (and hence required battery size) to power the boat when there is no wind, whist also boosting regen vrs hull speed.
You've mentioned your ability of producing prototype aluminum props, and with your load cell/torque measurement, you have an excellent "development platform". I wonder if you have considered the toroidal propellers "designed" by MIT. These seem to show significant efficiency over conversional designs. I know people are DIY 3d printing props for drones with tremendous success. Sharrow marine are also producing props (mostly for power boats, I think). The difficulty is in getting accurate figures as to their effciency - I guess your setup may be ideal, here.
Sharrow propellers are expensive, but given the potential saving in lithium batteries, this might not be prohibitive. The (potentially) improved efficiency and (hopefully) regen at lower hull speeds, could be very interesting.
If you really want to improve efficiency, use a boat with the least hull in the water / least crosssection/surface area that creates drag. It will almost certainly make a lot more difference than the prop. 
I don't know enough about what hull is best for that...but I know some are definitely better than ohters.
I don't know enough about what hull is best for that...but I know some are definitely better than ohters.
goatman
10 MW
putting a toroidal into something like these river generators mounted on a pole you can lower into the water while underway, might be your best bet for efficiency
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