Autism puzzle piece help.

[Lupe Duncan]

Hi Folk,
I am needing to make a puzzle piece about 1 1/4 square(puzzle profile) by about 6-8 inches in length.

I will need to make a mold so the "puzzle piece rod" would probably need to be made out of UHDP or machinable wax or something that silicone wont stick to. I thought about using a router but I dont have one. I would like a "professional" profile with nice clean sides.

I contacted some CNC guys here in town but have gotten any response. Im wondering if the jobs not worth the time(probably). Would this be a job for a cnc machine? What should this cost?


199988

This is the profile I would need. Is this a CNC application or some other sort of machining?

Thanks for the info. :D

[Steve knight]

it could be made out of mdf and you just seal the mdf and use release.

[Jim Underwood]

You say you want a eight inch length of this stuff with that cross section?

That looks to be a bit difficult to do on a CNC router.

If you wanted something that looked just like a puzzle piece but about 1/8" or 1/4" thick, then that would be easy-peasy...

[Chuck Stone]

couldn't do them in 1/4" .. make 32 of them and glue together? :p

[Lupe Duncan]

Things would be ALOT easier if I could do that Charlie.

Steve PMed me and said he had some PVC foam? Im not familiar with that foam, is that rigid enough for me to cast a verticle mold?

Jim, so the CNC isnt the optimal tool for the job? what would be better?

[Paul Johnstone]

Things would be ALOT easier if I could do that Charlie.

Steve PMed me and said he had some PVC foam? Im not familiar with that foam, is that rigid enough for me to cast a verticle mold?

Jim, so the CNC isnt the optimal tool for the job? what would be better?

The problem is that it's going to be a bear (if not impossible) to make that thing 6-8 inches deep.. Are you sure you can't glue maybe eight 1" layers together to make the mold? That would be doable.

[Steve knight]

oops I was thinking long. to get that depth it would have to be layers.
but it may be better to just cut material out that are the puzzle piece shape glue them together and then use that to make the mold. that would be the best bet over making a deep mold and getting smooth sides.

[Lupe Duncan]

Paul when I hear depth I think of a hole.

I need a rod the shape of the puzzle piece.

I was thinking starting out with a piece of 2x2x6 machinable wax and rout a grove on each side as the "indentions" or "female grooves" then knock off the top corners to expose the "male nub".

When I get to a real computer I'll try to draw this out, sorry for the confusion guys. But I do appreciate the help and education.

[Steve knight]

I think just cut the parts out of say mdf glue them in a stack sand smooth and use that to make a mold. you ca seal the mdf and make the surface hard. The problem with the groove is it is round with a smalle hole on top. then the top is undercut too. it can be done with a lot of work and ome practice.

[Jim Underwood]

Lupe,
You'll have to visuallize this...

You have a vertical cylindrical bit cutting out a flat sheet of parts. That's what a CNC router does best.

It can cut out any number of 2 dimensional pieces of any shape or size as long as it lies flat on the table, and is a reasonable thickness (1/8" - 3")

In order to cut what you're asking for, the bit would have to be 1/4 diameter x 8 inches long, and your material 8 inches thick, and your "rod" standing vertical. Not really possible...
The other scenario is even more impossible. You cut with the rod laying horizontal, and cut four sides, flipping the "rod" for each side. But on at least two sides the vertical bit would have to be able to undercut to get the shape right.
One other possible way to do this, would be to make the female sides symetrical so that you could put a specially shaped router bit in there and cut it in one pass... But that's a long shot too. The cost of getting custom made bits is pretty high.

You might get it to work with a five axis router. But if you're having trouble getting anyone interested on forums geared toward the smaller operator and hobbyist with a three axis machine, then you definitely won't get anyone interested that has a five axis machine. Those guys won't even think about turning on the machine until they have a paying customer with lot's of $$$$.

What's your budget on this project/part?
What's your final material going to be?

Maybe someone could cut some aluminum or copper on the router and you could extrude the rod?

[Gerry Grzadzinski]

You could cut it with a rotary axis, but you'd need to use a small enough bit to reach into the undercuts.

[Lupe Duncan]

Thanks for the schooling guys.

My nephew has autism and I wanted to try to help them raise some funds. I am donating part of my autism pens from my website to the autism foundation but I need something a little less pricey. So I wanted to make a mold in the shape of the autism awareness puzzle piece so I could pour some colored PR and make pendants. If the mold is long I can swirl the colors together and then slice the pendants out when cures.

I appreciate the help and I need to think of a different way to do this.

Extrude a rod?????

[Chuck Stone]

If you're going to cast silicone around this, then go with the 1/4" pieces. glue them together
into an 8" long piece. Then do a good CA finish with your sandpaper and micromesh. Cast it
in the silicone to make your mold.

Note: with those undercuts, you can't do a straight pour. Here's what you do:
Get a small paper cup and mix up a small batch of silicone. Thin up to 10%
with silicone oil.
Tape the two ends of the puzzle rod to give yourself a surface to cast against.
Put a little vaseline on the tape because silicone loves to stick to the tape.
Lay the puzzle rod down and pour the silicone into the undercut. Let it cure
and then turn the piece over, exposing the other undercut. Repeat the process.
then when you have a long puzzle rod partly filled with cured silicone, wash your
hands.. dry them and then wash again. With a clean rag and some denatured
alcohol, wipe down the silicone of your partial cast so that the new silicone
will stick to it. (any traces of release will cause the bond to fail)
Now you should be able to do a new pour and when it is cured you should have
a solid mold.

[Lupe Duncan]

Chuck,
Would the undercut be an issue if I were to cast a vertical mold?

I can get a better mix/swirl in the vertical molds.

[Jim Underwood]

To extrude you would need a "hole" the shape of the puzzle piece in the end of a cylinder in which you place your raw material. Then a piston or ram would force the material through the hole. Think of a play-doh press or a cookie press.

If you used polymer clay, you could get all kinds of colors.

[Jim Underwood]

You could cut it with a rotary axis, but you'd need to use a small enough bit to reach into the undercuts.

Y'know I think you're right. I didn't think so at first, but the more I look at the profile, I think this would be the way to do it. I bet you could do this with a rotary axis and a 1/8" tapered ballnose bit pretty easily.

Wish I had one, I'd do it just for the kicks...

[Chuck Stone]

Chuck,
Would the undercut be an issue if I were to cast a vertical mold?

I can get a better mix/swirl in the vertical molds.

WIth a vertical mold you'd have no issue of undercuts at all.
But you get better mix with a vertical mold?? That's backwards
from that I'd expect, but if it works for you, great!

[art baylor]

Plastic extrusion dies are not that expensive. Small plastics companies can make it from your design and do small runs of plastic rods or tubes. Probably even slice it if needed. Art

[Paul Grothouse]

I am not sure the volume you want to make, but a small plastic extruder will be able to make an aluminium die and extrude these for you for a small price tag. The die will be very easy to manufacture for this part. Check the internet for plastic extruder in your nearest large town.

This is a poor application for a mold. Even if you can get this mold made, you will need about 7 (or more) deg of draft to get it to release. It will look like a pyramid when you get done. Engineering class would tell me to make a two sided mold a put a parting line through the part, but your part will not work this way it will require a 3 or 4 parting lines. You could sand cast this in steel or aluminum, but that is different game and often requires post machining/polishing.

[Wes Grass]

A stick like this would be a piece of cake with wire EDM, but it'd have to be metal and might give you fits with casting silicone around it. Assuming you're casting the silicone as a flexible mold to cast resin in? And the resulting stick gets diced and polished?

So, I know nothing about this. Are mold releases effective enough to allow you to get the silicone off of a metal rod? Is the mold reusable or one shot and cut off the cast piece? Wondering if a slightly tapered mold wire cut in aluminum or steel would let you knock the resin piece out after curing?

As for milling it from a bar, you might be able to use a 'lolly-pop' cutter to mill the undercuts. And that could eliminate the need for a 5 axis system. Or if the shape isn't critical, eyeball to a scribed line good enough, a shaper (metal working shaper) and a hand ground tool could get this done without too much difficulty. But shapers are more or less only found in the hands of hobby machinists these days, which is probably as good a reason as any as to why local machine shops aren't interested. They don't have any of these old machines around anymore.

[Jim Underwood]

I still think extrusion would be the easiest and quickest way to do this...