3D print a thruster prop?

[Woodstock]

Our bow thruster sucked in a piece of wood and sheared a pin at the prop.
Since the prop is made of ABS plastic I suspect it may be damaged as well where the pin is connected. This prop is no longer made and I have literally searched the world for a replacement and there are none. It's a 7.5" diameter 4-blade prop and I'm considering having one 3D printed. I can use the original prop as a model that can be laser scanned to create the code but this is rather pricey and that doesn't include the actual 3D fabrication. Has anyone had a 3D printed replacement part made? Are there reasonably priced services available?
Is having an aluminum or stainless prop fabricated from scratch a viable alternative? Other ideas? It's a 2007 Volvo QL CT900 belt driven, single prop thruster.
Thanks

 

[rsn48]

There are clubs, some electronics including 3D and some straight 3D which you can join for a very nominal sum and they will help you make one. Even me in podunk hollow has one of these clubs in the area. In my other hobby, model railroading printed items are popular particularly when modelling modern buildings with lots of windows and you don't want to die of old age, cutting windows into styrene.

One neat thing NASA is doing, rather than send a whole tool kit up into space it is lighter and can cover a larger range of tools by sending up a 3D printer and materials and print out the tool required.

 

[RT Firefly]

Greetings,
Mr. W. 5 years from now or maybe sooner 3D printing will be the way to go when the technology filters down to the consumer level. Might it be possible to have one cast at a foundry in bronze or aluminum using the original, plastic prop as a model? Old school casting is fairly cheap in the greater scheme of things.

 

[Chrisjs]

Have you considered that Volvo may actually use the same prop in other models with the same 185mm tunnel? Might be worth a call to the following:

https://www.getaprop.com/bow-thruster-props/volvo-penta-ql-propeller

I guess Volvo does not have great reputation for thrusters or thruster spares!!

 

[MYTraveler]

Rather than scanning your existing prop, you could probably have one designed (based on measurements of your existing prop that you take) far less expensively, and once designed (using 3D CAD software like Fusion360), it is a simple matter to fine tune the design. As far as printing goes, you can buy a printer capable of printing ABS in that size for probably less than $500. For that matter, you can get Fusion360 for free (hobbiest license), but you would probably have to spend 20-40 hours learning how to use it.

There are lots of YouTube videos showing how to design a propeller in Fusion360. Based on that, you may be able to complete the design in 8 hours.

Here is a good one:

 

[Northern Spy]

Pretty sure the Volvo Penta QL line of thrusters are just rebranded Sleipner Motors.

Known as Sidepower here in North America. Look at a EB series Sidepower manual and see if it is the same. Can get them on the Imtra or sidepower website.

In my experience, Imtra answers inquiries quickly and accurately, and can probably sell you a prop.

PS: doubt the prop is ABS. Probably Delrin.

 

[Xsbank]

Try looking at British Seagull props, they are 4 blade cast aluminum.

 

[Arc]

It is probably easier to find an aluminum prop do similar size then have the hub welded closed and machined to fit.

 

[Chrisjs]

But, build your own prop sure sounds like a fun Winter project!!

 

[DDW]

I doubt very much that a 3D printed prop in ABS will be strong enough to last long, if it survives the first use. Even carbon filled. There is one printer (MarkForged) that will print with continuous carbon filament reinforcement, and that would definitely be strong enough (about the same as aluminum) but it uses nylon, a bad choice for underwater. There are a number of metal 3D printers that could print one of whatever you wanted - SS, titanium, inconel, etc. - but you will find the price prohibitive, several thousand dollars at a service bureau (or buy a printer for around $0.5M).

I'd think far easier to find something the right size (can always be made smaller) and adapt.

 

[Xsbank]

Looks like Woodstock lost interest.

 

[Northern Spy]

Hopefully they just buy a new one from sidepower...

 

[Woodstock]

Didn't loose interest, just evaluating alternatives. Your responses have been extremely helpful!!
Many said it probably wasn't ABS and that's correct. It's some sort of fiberglass reinforced composite.
I thought I just sheared a drive pin but when the diver went to remove it there was no prop there anymore. Seems the threaded mounting bolt came off so there was nothing left to make a duplicate of. 10 years old and had never been removed so don't know why it suddenly unscrewed itself
Northern Spy, your suggestion about looking at a Sidepower EB series prop was right on. And Chrisjs, Getaprop.com helped find a replacement prop for the Sidepower EB90 which turns out to be identical to my Volvo QL CT900. The people at getaprop (Olympic Propeller) are great to work with!
Got it put on today and it works perfectly again
Thanks Trawler Forum

 

[Northern Spy]

Happy ending! Excellent.