CapeBuild Build Journal

[tony.latham]

So I'll go with a 2 piece flexible urethane mold. The part I printed will be the pattern.

So are the fixtures in the photos the mold or the final product?

Tony

[Capebuild]

Beautiful work! Outstanding! Thank you for documenting both your build and your thought processes. I am thinking about a second build - don’t tell my wife - and your build gives me inspiration,

Hi Tom, thanks so much for your comment. That's very nice of you to say. There's plenty I'd do a different way, I've made plenty of mistakes and mis-steps.... but, knock on wood, nothing fatal yet (that I know of). I don't think I ever responded your post on one of my inquiries looking for help with sheathing the hatch. The photos you posted were very good for me to see and a great help. You did a great job there with your's and I'm glad to have seen those photos, so thanks for sharing them. Your hatch door is beautifully rounded at the bottom. Really nice. If you do another build, good luck with it. You're a brave man.

So are the fixtures in the photos the mold or the final product?

Tony, the white parts you see in that previous picture were built on my printer. The bezel that will hold the Grote light fixture (the exterior part) is what I'd call the pattern.... or the "model". That part gets sanded, primed and kind of all fine tuned so it looks "good". The part then gets anchored in a box I'll build from styrene, and get's clayed up to the parting line (where the 2 mold halves separate), in this case the rounded flange that will lie on the aluminum. The urethane mold material then gets poured into the box, covering up the model. When it cures, 16 hours later, the box sides are removed, the clay is removed but the model stays in the urethane mold (part A). The whole shebang is turned 180° so now the bottom side is facing up. So what you'll see is half your model sticking up out from the urethane (which is the part that was enveloped by the clay). Some small diameter rods are glued to top of the model surface (at the highest points) and these will be vents (the urethane flows around these rods and when urethane of the second pour cures and rods removed, little openings are left) so when the mold is filled with whatever material you're using to create the final part the air is able to escape (you don't want air bubble holes in your final part, at least I don't). The surfaces get mold release, keys are cut into the mold (so the mold halves mate correctly), the box sides are reinstalled and you pour the other half of the mold. Cures for 16 hours. The 2 mold halves are separated, the model is removed (now there's a cavity created in the mold halves and this is a negative or your model), the top and bottom mold halves are cleaned ( there's now a cavity from where the model was) and now you're ready to pour in the material you're going to use to create your final part (in my case for this particular part, it will be a hard rubber like urethane which will get a UV protective additive and is colored black). That's the long and short of it. When I get to actually doing it I'll document it which will hopefully make all this clear. It is kind of cool process. I also have a pressure tank I usually put the mold into while the casting material is curing and put in maybe 10 pounds of air to further help drive out any air bubbles.

A bit long winded.... but hope that helps.

John

[Capebuild]

December 21, 2021

Been finishing up the interior components on the hatch. Got the latch installed. Turned some delrin pieces to insert where the latch locking rods exit the hatch to give it kind of finished look. Also helps to keep the rods centered to mate more easily with the receiving holes in the galley side wall. I'll probably need to notch the aluminum molding to fit around the delrin.

rod.jpg (270.61 KiB) Viewed 552 times

I didn't see a hole in the rod that is connected to the T handle. It occurred to me that if some bad person removed the screws from the exterior bezel the T handle could easily be removed and a piece of square bar stock could be inserted and retract the locking rods. So drilled a hole in the T handle rod and put a cotter pin through it to make it a bit more difficult to remove the T handle.

latch.jpg (148.98 KiB) Viewed 552 times

Added blocking for the license plate and the third brake light so they'd have some meat to hold the mounting screws. Varnished the interior surfaces. Will run the wiring next and then insulate. I'm kind of stuck after that point until I can get the exterior aluminum skin installed as the interior ply sheathing can't be installed until after the exterior aluminum is installed. If I get a warm day I'll try and do the aluminum. I'll also need to mold up all the models and make final castings mentioned previously.

Thanks for looking.

John

[tony.latham]

When I get to actually doing it I'll document it...

That helps a lot... but now your build journal is turning into something like a good mystery/thriller.

My eyes are wide open.

Tony

[gudmund]

will be watching for the "CapeBuild Build Journal/book on Amazon when it goes into print..................

[Capebuild]

will be watching for the "CapeBuild Build Journal/book on Amazon when it goes into print

hmmmm... actually, you know what would be really interesting, if there were a compilation of say 6 builds. Each build was a chapter in the book (kind of like a book of short stories).
Everyone has their own tricks, techniques and ways of building these things. It would be great for someone contemplating building a teardrop to have a variety of directions to contemplate as they prepare for "their" build.
Any experienced writers/publishers here who want to take the lead on this?

John

[tony.latham]

Any experienced writers/publishers here who want to take the lead on this?

A book is a lotta work... maybe 3x that of building a teardrop. It would be especially challenging to pull several builders together on something like this.

I've got two books in the mill at the moment –-one true crime and another nonfiction-- so I'll step aside on this idea.



But it is a good idea.

Tony

[Tom&Shelly]

will be watching for the "CapeBuild Build Journal/book on Amazon when it goes into print

hmmmm... actually, you know what would be really interesting, if there were a compilation of say 6 builds. Each build was a chapter in the book (kind of like a book of short stories).
Everyone has their own tricks, techniques and ways of building these things. It would be great for someone contemplating building a teardrop to have a variety of directions to contemplate as they prepare for "their" build.
Any experienced writers/publishers here who want to take the lead on this?

John

I do have ambitions to write a fiction story someday, but I'll call it a text book because there is more money in that! (It would be about the analysis of laser communications systems. I've explored the idea enough to realize to some extent how much work is involved just to get the content correct and consistent. Probably a whole lot I haven't seen yet regarding dealing with editors and such.)

Anyway, I wouldn't be qualified to lead any sort of effort such as you describe, John, though I agree with Tony that it would be a good idea. I would probably be qualified to contribute a chapter on mistakes.

Tony, can't wait to read your new books! Will the fiction be another Charlie Cove story? Can you give us a hint on the subject of the non-fiction book? (Just among us friends on the forum!)

Tom

[MickinOz]

I've been published. Two articles for a self sufficiency magazine.
A half page article about a homemade hoe that netted me $45, and a full pager about how not to kill yourself on your hobby farm tractor that got me $90.
I was so proud of myself I copied and framed one of the cheques.

[Capebuild]

Where you been Mick?
I’ve noticed your absence.
Hope all is well.

John

[Capebuild]

12.30.21

Most of the hatch has been wired up. Tested the 2 puck lights using the toggle switch on the control panel to make sure all works. Next up will be to insulate the hatch (and figure out how to install the foam boards around all the wiring). Those Wago connectors turned out to be really great. I included a close up photo although you really can't see the connector since I put a swatch of gorilla tape over the tabs, but I'd recommend the Wagos for connecting 3 or more wires. They worked out great.

John

[Capebuild]

12.31.21

I'll probably start molding up some parts soon (the parts primed in gray). Shown here are the tail light bezel, 2 piece hinge for the 2 side windows and the long 3rd brake light mounting fixture and a small mounting fixture for the "T" handle which locks the hatch. These were parts built on my 3-D printer.... sanded, patched and primed. The other items (painted black) are printed fixtures that hold the 2 puck lights located on the interior of the galley hatch and a box with cover which will get embedded in the hatch door which will hold the 8 pin connector (male and female) so I have a way of disconnecting the wiring if I want to remove the hatch from the trailer.

Happy New Year!!

John

[halfdome, Danny]

Those look great John.
When I mount the 3rd LED tail light I use a piece of aluminum angle and cut one leg so the light is horizontal, since they view best straight on.
Can't tell from your photo if you've made allowances for that.
Danny

[Capebuild]

Thanks for your comments, Danny. Yes. When I worked out the design the brake light fixture was positioned on the hatch in the CAD so when the light is mounted to it, the light is facing straight out (not downward or upward). Also the advantage of having the geometry of the hatch and the curve it generated, the light fixture housing can be made to mate with that curve. After I built the part in the printer I put it on the hatch exterior ply just to make sure it fit well picking up the curve of the hatch. Turned out well. Also molding the final fixture in a rubber material will allow it to be mounted on the hatch in such a way that when the screws are tightened, it will pull up tight against the aluminum, the rubber flexing to the aluminum shape if there are any minor high or low spots.

[swoody126]

John, i sure have been/am enjoying sitting out in the peanut gallery watching your talents come together to create your little trailer

very little is impossible when one puts his/her mind to IT ... whatever IT is

KEEP ON KEEPIN' ON

sw