Sea Turtle - 3D carve

[jtclose (Jim Close)]

My grand daughters birthday is next week and I had asked her what I could make for her.
She said a Sea Turtle … Uh oh …

So I found a 3D model of a sea turtle. I decide to cut the top first, make a mold that would fit the top, then cut the bottom. Right …
I added a “stand” so the little critter would lay flat on a table.

The issue is how to hold the part in the mold in order to cut the bottom.

I came up with the following “caul” process ( I learned that word this week, I had to use it ) where I cut one side then the next.

I would rather find a way to temporarily glue the part into the mold.
That would eliminate some tool changes at least.

The part is will be made from pine, at least until I get a successful cut.

[CrookedWoodTex (Tex)]

I’ve had a similar problem with a ball. I decided to make the fixture a vacuum fixture. Shouldn’t take too much vacuum in a well-fitting fixture.

[jtclose (Jim Close)]

Never thought of that ! Thanks.
Another rabbit hole

[jtclose (Jim Close)]

Did you use a single inlet to the mold cavity or multiple holes from a manifold ?

[TonyMurray]

Understand this is a different concept, however I know how important birthdays are so thought I would share this idea I seen in case you run out of time and need a backup plan!

https://www.etsy.com/listing/1071300973/turtle-shaped-jewelry-box-files-for-cnc

[jtclose (Jim Close)]

Oh that is pretty. Your product ?

[jtclose (Jim Close)]

If is used MDF for the mold and seal all surfaces with shellac, then cut the negative out along with a vacuum hole, do you think it will hold ?

I have read that people suck vacuum through MDF.

[TonyMurray]

This is not my product however I have had success from buying files from this seller.

-Tony

[jtclose (Jim Close)]

I will try the vacuum concept tomorrow with this.
1.25 hole for the nozzle and .5 hole to the negative.

I will use the strap concept is that fails. All good.

I am a bit worried about plugging the vacuum ( pre Stealthsonic Dewalt ) , so I may put some sort of air bleed valve or hole somewhere in the line.

[Tod1d (Tod (with 1 'd'))]

If you cut the bottom first, then you have a flat base to cut the top.

Cut your bottom. Mount the cross braces you show and square them using the machine.
Or screw a rectangle into the base & machine it square at a known dimension.
Now flip the part & use the temporary base to square it up.

[jtclose (Jim Close)]

@Tod1d thank you.

I think I missed the Forest because the trees were in the way.

The vacuum concept will have to wait.

[Redlander (Tim Jones)]

Out of all the “cauls” I’ve seen used this week…. Yours is the best Jim!!

[CrookedWoodTex (Tex)]

My design has an “X” shape, because the ball is so smoothly round.

[jtclose (Jim Close)]

I am going to try the vacuum idea soon, but today I made firewood . Oops

[jtclose (Jim Close)]

Using @Tod1d suggestions I am starting the second side. Already made one piece of firewood, hopefully not another one.

The back fins are very thin so I am not sure if this is going to work.

[jtclose (Jim Close)]

Still alive

[jtclose (Jim Close)]

I am done for tonight before I break something.

The cross section is very thin on the front fin and it is vibrating.
I am cutting 0.1 step over .125 DOC and 100 ipm using a Jenny.
That is tooooooo much. I tried slowing it down , but the step over is too big.

So I know what the Z height I need to restart at, so I will make up another path and run it tomorrow.

[jtclose (Jim Close)]

Here is the STL file if anyone wants to play around.
seaTurtle.stl (335.8 KB)

[Redlander (Tim Jones)]

Fantastic start Jim, lots of possibilities with this method.

[jtclose (Jim Close)]

I’m hind sight I could have cut a sacrificial mold to support the fins.