Skip to main content

3D Printed Lead Ballast Molds

I'm in the process of thinking, yes... just thinking, about making my own ballast for both the Sun Wind Hf and for the upcoming Wampum III, both Vintage Marblehead sailboats, but using two different styles of lead ballast.

The Sun Wind HF takes a torpedo style bulb. I 3D modeled one in Sketchup Pro 2017, and from there exported an STL file that I used in one of our 3D printers at school (I'm a teacher and the CTE teacher actually printed it for me). Here is what we ended up with... two identical male molds:

Vintage Marblehead lead bulb mold

Here is what the bottom of one of them looks like:

Vintage Marblehead lead bulb mold

3D prints are a bit rough, and if I used them straight they might stick to the cement too well. So I'm coating them with thickened epoxy and will then sand them down. I'll then wax them before using them.

The idea is that I will sink these into a container of refractory cement and let it harden, will remove the molds, and then let it cure for a long time (weeks). The concrete will probably also take a turn in a low oven for several hours at some point.

Then I'll attempt to pour the lead. Should work fine... fingers crossed!

As designed, they should create a bulb that weighs just over 9 lbs. That would be just over 4.5 lbs each half. Then they would then be cleaned up and attached to either side of the fin inner core as I did on the new Sun Wind HF Vintage Marblehead sailboat. Its bulb was 11 lbs and a bit too heavy for this design. I think that 9 lbs would be better suited.

I'll do the same thing with the Wampum ballast, but it will take some time to make the male molds for it. They can't easily be 3D printed, and will instead need to be made from laminated plywood layers and then shaped and filled in with thickened epoxy, and then shaped again. Will update later when I make those.


Peace!



Comments

Popular posts from this blog

IOM Alignment and Measuring Jig (UPDATED)

I need to start to consider how I'll mount the fin and bulb, and get it all straight, so I made a 3D modeled alignment jig:



Ian Dundas in Scottland sent me pictures of his setup. I just bought a laser level too! He does amazing work and has been a great help in this project so far.




There is also another jig featured on page 14 of the winter 2008 Canadian Radio Yacht Association (CRYA) newsletter that features one. It's by Lawire Neish. Read it here.

I took both those designs and made my own version that features sliding cradles for the hull, a fixed waterline sight, proper depth to cradles for the bulb, etc... Most of the parts can be laser cut, and the two end pieces and the base can easily be cut on a tablesaw.

It has fixed waterline sights that are 420mm above the top edges of the bulb sliders in the base. The fore and aft cradles can be slid up and down to adjust the waterline of the hull. You'll see that the overall interior length is 1003mm to accommodate the aft…

IOM Rig Box (IOM Sail Box) plans

So all the cool IOM kids seem to have nice wooden boxes to store their rigs in. This might be my next quick project then, so that I can pretend to be cool too. :-P

The rig box images that I've seen online are mostly similar, and would work well, but David Jensen from Bellevue, WA, USA (The same guy who designed a fantastic IOM boat stand I posted about earlier) has a really nice design that he shared on RC Groups. Or if that link doesn't work, the go here and search for "IOM sail box" or "IOM rig box".

It holds three sets of rigs for the A, B, and C rigs.


He also has a nifty way to attach his IOM boat stand, with a boat on it, to the rig box. His rig box has wheels attached, so once everything is loaded up he just wheels it to the launch spot. Very nice!



There are other sources online. They show different variations of the same type of sail box.

Here's a nice looking one.

Here's a YouTube video of a really nice one.

Will post more if I actually end…

IOM Sailboat Stand

I made an IOM boat stand!



The plans are from David Jensen in Bellevue, WA, USA. I found the plans through someone else's blog here, and a model sailboat club from Australia here.

It was pretty straightforward to build. My only contribution to the design is that I laser cut the cradle out of 1/8" Lite Ply. I made eight copies, and then epoxy laminated two sets of four each. Turned out really well.



If you wish to laser cut your own set, here is my DWG file. You'll have to have your own laser cutter, or send the job to a laser cutting company like National Balsa. Here are the original plans, and here are the original plans for just the cradle. Thanks to David Jensen!!

Note that in the picture below, my boat is not finished! Yikes.


You can't see it in this image, but there's a small chuck of self-stick foam behind the bulb to protect the bulb. I'll eventually incorporate some Velcro or a strap of some sort to hold the bulb in place so that I can use the carry-han…

Rip Tide RC Sailboat

Well I just hit the R/C Sailboat jackpot! Rod Carr, of Carr Sails in Redmond, WA, and the second ever member of the AMYA, just gifted me a Marblehead "Rip Tide" hull and many of the parts and templates to finish it! Thank you Rod!

I'm not sure when I'll be able to work on this, but hopefully it will turn into a fantastic vintage Marblehead. The gentleman who started it did a fantastic job. He was a true artist and I will do my best to get as close as I can to his workmanship but it will be a challenge.

Here are some pictures...


He even cast his own bulb and the mold came with the hull! I could probably start making my own fleet of Rip Tides as he also gave me many of the templates and such. I will only need to pin and epoxy the bulb to the fin and fair it smooth. It will be easy to do.


The frames look and feel like he hand cut them on a scroll saw, but they are very close to perfect. He used thicker plywood than I may have but they are very sturdy. The bow is very s…