P1 Puma RIB racing-scratch building

Dim L · 28 jan 2022

Update #10
I would like to show you some progress with the rib.
1. Cutting the ribs to shape,
2. Sculpturing the nose,
3. Laminating the inner of the hull with cf and
4. Building slowly the other half of the tubes.

The tubes have become very strong with the cf and also the hull.
Still, a lot of work - building - sanding is needed, but it starts to look like the 3d plans

.

Plus a bonus photo from the latest snowfall in Southern Greece.

Tamiya1970 · 28 jan 2022

Wow looks great Dim.
The boat is really coming thogeter now.
Wow that snow [emoji849]

Unusual RC · 28 jan 2022

Really great to see the Fusion virtual boat come to life!

Tamiya1970 zei:
Wow that snow [emoji849]

Great fun with an airboat

Dim L · 28 jan 2022

Thank you Alex

!!
Yes it starts to look like a Rib progressively :thumbsup:

!
The snow was great, really.

Dim L · 28 jan 2022

Thank you Unusual. I remember your usefull tips when I was drawing the boat

!
Hmm airboat on snow that would be great.
For the time being, my sons enjoyed their traxxas rustler on snow!

Dirk Jan · 28 jan 2022

Nice work Dim! The Shape is getting visible more and more. How long and how wide is the hull?

By the way, big snow in Greece! I guess it is quite rare in the South?

Dim L · 28 jan 2022

Thank you Jan! Yes I am getting closer to the desired result.
The length of the hull is 76.5 cm and it's width is 23 cm while the max diameter of the tubes is 4 cm. It is approximately 1/10 scale of a 7,5 m Rib.
My goal for the weight of the hull (plus the cowl) is under 800 gr (500 gr until now).

Fortunately in my region (30 km north of Athens) it snows 2 or 3 times every year due to the altimeter (400 m above sea level) and its position which is valneruble to cold northeast winds :yes:

.

Dim L · 29 jan 2022

Good morning guys. I d like to show you how I sand the tubes cylindrically using my diy sander

.

Unusual RC · 29 jan 2022

For such tooling I use the 3D printer now, while I used to make such tools from wood too!
Call it lazy

I was about to print a complete hull, which I would laminate with glassfibre fabric and epoxy.

Looks good!
Such a project creates a lot of sanding dust and muscle pain!
All part of the job!

Dim L · 29 jan 2022

Lazy but accurate @Unusual RC

!
What happened to that project with the whole 3d hull, still in your plans?

Unusual RC · 29 jan 2022

Dim L zei:
Lazy but accurate @Unusual RC !
What happened to that project with the whole 3d hull, still in your plans?

Quite a remarkable story actually.
I have been developing a RC scale waterjet-drive, which everybody can download for free and 3D print. Started in 2017 on RCG with an American rc boater.

A few are running around the world in impeller-size 35mm and 45mm (not comparable with prop-size propulsion!)

Now I am developing a new version, which is more efficient.

Promised one copy of the new pump to a Belgium model boater. In return he send me a hand-crafted wood/glassfibre hull without letting me know

Exactly the type of hull I was creating in my 3D CAD

He knew from our email chat.

So for now I parked the hull project. I will focus fully on creating a better version of the current pump.
This boat is a great platform to fit all my sensors, cameras and finally 6S batteries (and more, however the Esc. become really expensive above 6S).
I can even mount a GoPro on the rear to study the drive at work!

Nevertheless 3D printing a hull is doable I think. I have seen an English boater create the ribs with his 3D printer, but build the boat in wood as you are doing making use of those plastic printed ribs.

Sincethen I believe in hybrid modeling: combining 3D printing with conventional construction methods.

I have seen fully 3D printed boats. They are not that large, or much too heavy.

RC airplanes are printed nowadays making use of special lightweight plastic and shapes impossible to create with conventional production methods, to make them strong and light. If that is possible a boat could be made too this way.

Nevertheless I think some glass fabric reinforcement of the wet part of the hull will be necessary, especially for a jet-boat.

Dim L · 29 jan 2022

Impressive story and information @Unusual RC !!!!
I am not familiar with the plastic material used in 3d printing but abs hulls have a limited lifespan since they tend to be very fragile after some (>10) years.
Why not making a nice mold using 3d printing

.

Unusual RC · 29 jan 2022

Indeed to form a plug is also an option.
ABS is pretty hard to print on a 3D printer. PLA is the most used material (made from korn, so biological)
However PETG same material as plastic bottles for example) is a type of printable polyester, which is stronger and more durable than ABS and PLA.
The Recoil I have is ABS too, vacuum formed. Indeed for very high speeds not suitable.
PETG binds with epoxy, so easy to reinforce or use as a plug!

Look at Lex Verkuijl his hydrofoil. Conventional wood building combined with plastic sheets and 3D printable parts and ribs. Hybrid-construction!

Dim L · 30 jan 2022

Searching for some theory for the spray rails, I came across this interesting discussion about the role of spay rails in the calculation of the effective deadrise angle.
I thought it would be nice to share it with you:
https://www.boatdesign.net/threads/does-deadrise-planing-degree.12121/

Dim L · 31 jan 2022

Along with the hull I am trying to build my diy outboard.
Today I received a 8mm brass tube and I made a try to construct hastily the tube system where the flex shaft is based.
I thought that you might be interested to see all my triew and not just the final product.
The most important thing that I d like to examine is whether standard soldering is strong enough ro use it with brass tubes. The result was very good since the two tubes were soldered together very well.

Below you see a flex shaft 3.17 mm, 2 ball bearings with outer diameter of 7mm and inner diameter of 4mm, bended 5mm brass tube and an 8 mm brass tube.

Next, the brass tubes will be fitted to the aluminum piece after being properly milled.

A view of the ball bearing that fits perfectly to the 8mm tube. The flex shaft also fits very well to the ball bearing with minimal play.

Dirk Jan · 31 jan 2022

Nice work on the outboard! Working on that chunk of aluminium must be challenging with hand tools.
The angle on the flex shaft seems quite small? Good for the flex shaft life [emoji123].

I would like to make a diy outboard someday as well. Units sold are quite expensive and often still have their flaws.

Dim L · 31 jan 2022

Thanks Jan!
Indeed, prices have increased considerably especially for the small tfl.
You are right, the angle is small on purpose to reduce friction (plus the ball bearings) and expand life span.

Tamiya1970 · 31 jan 2022

Very nice Dim,looks solid and smooth.
Look also here Dim for building an outboard.

https://www.modelbouwforum.nl/threads/152vo-dasilva-dubbelbouw.268178/

152VO DaSilva, dubbelbouw

Dim L · 1 feb 2022

Tamiya1970 zei:
Very nice Dim,looks solid and smooth.
Look also here Dim for building an outboard.

https://www.modelbouwforum.nl/threads/152vo-dasilva-dubbelbouw.268178/

152VO DaSilva, double construction

Thank you so much Alex :thumbsup:

!
I have googled a lot before starting to get ideas and I ve seen almost everything (in terms of of a Google search of course) including that one which is a piece of art.

If I am not wrong Alex, you have also a short video on your YouTube channel of an excellent (free) 3D printed outboard. What happened to this project, it looked really cool

!

Dim L · 1 feb 2022

Dirk Jan zei:
Working on that chunk of aluminum must be challenging with hand tools.

Indeed, Jan. As I have mentioned before I used my table power drill shown below

so as to mill slowly the aluminum.
A very useful tip when you work with metals is to use WD-40 spray the whole time of processing the metal. It serves as cooling system and as greasing material. Even drilling a simple hole becomes so much easier.