I’m curious if anyone has built or modded prop guards for the Blue Boat. We have broken three props recently during archaeological surveys in shallow water. We are probably hard on our gear and sometimes have to work in challenging environments. We were recently working adjacent to a site that contains both the remnants of a 19th century mill and pre-Contact native shell deposits. There was quite a shelf and I suspect the props hit bricks that extend out into the shallow water. I noticed the manual steerage became barely responsive but managed to get to shore, where I noticed one prop completely destroyed and only half the second prop remaining. We have a draft design using PVC but if anyone has a successful build, please let me know.
From a quick look at our relevant Printables collection, it seems like someone’s made a propeller protector for travel, but there aren’t any for during operation.
Thanks. Yes, I saw the travel version but, as you say, that’s not for operation. Thanks for the link to the 3D print designs. I don’t have access to a 3D pinter but see I can have that done online. Unless I get some otber info, we’re going to try a more DIY design from hardware store PVC. I’ll post the design if it works.
I know that there are teams competing in the RoboBoat and RobotX competitions that have created prop shrouds (they are also 3D printed). Our team at Georgia Tech has a design for an easily removable shroud.
That’s cool! Would it be possible to share that design for Bryan and the community? If you upload to printable we could add it to the Blue Robotics collection!
I was considering suggesting something like this, but figured it may not be advisable given the circumstances (where damaging the site could also be problematic):
For what it’s worth we’ve had some stainless steel props manufactured before, with a few different technologies if I’m remembering correctly
We’re looking at a lower tech guard build out of metal for now. It’s 5" exhaust safety seal, with a length of 3". I’ll pass on the test results. Ultimately, we may try one of the 3D printed designs. I think harder prop designs such as metal would be a problem since it could damage archaeological sites or fragile ecosystems.
It’s worth noting that any guard is going to severely reduce efficiency! I would estimate 30-50% more power consumption at a given speed, which could reduce endurance significantly…
Yes, I was concerned about this. I was wanting to create a narrow guard with minimal impact, but that will have to be fabricated. We’ll see how much a 3" long guard will affect things. It’s certainly better than destroying props in some of our challenging sites though.
