Community
Inventor Forum
Welcome to Autodesk’s Inventor Forums. Share your knowledge, ask questions, and explore popular Inventor topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Molding this part - possible?

16 REPLIES 16
SOLVED
Reply
Message 1 of 17
WHolzwarth
633 Views, 16 Replies

Molding this part - possible?

That's what I'm thinking about. I'm in doubt.

Smiley Wink But perhaps there's a way that I didn't think of.

 

Walter

Walter Holzwarth

EESignature

16 REPLIES 16
Message 2 of 17
LT.Rusty
in reply to: WHolzwarth

Anything's moldable, if you're willing to spend enough money on a mold.  This would require an extremely expensive series of collapsing cores to mold. 

 

You might wish to mold it in two pieces - front and back - and have snap-fits to put them together.  You might also then be able to have a fully-enclosed ring around the outside, rather than having it open on the back.

 

Edit: looking at it further you might be able to get away with using a fairly complicated series of lifters and actions.  Still, it'd be a really expensive mold.

 

 

Rusty

EESignature

Message 3 of 17
WHolzwarth
in reply to: LT.Rusty

Hmm. I know, it's no easy task.

But could you really solve it?

Walter Holzwarth

EESignature

Message 4 of 17
LT.Rusty
in reply to: WHolzwarth

I think I could, yes. But not for free. 🙂

Rusty

EESignature

Message 5 of 17
rdyson
in reply to: WHolzwarth

It might be doable where the inner half of the toriodial core is part of the ejector side and the outer half made up of some number of pieces that are hand striped after the part is ejected. I'm seeing these hand striped pieces being dovetailed to the inner toriod half.



PDSU 2016
Message 6 of 17
WHolzwarth
in reply to: LT.Rusty

Well, I 'm not willing to pay for this. It's just a follow-up of this thread:

http://forums.autodesk.com/t5/Inventor-General/shell-2mm-underside-of-5-spokes/td-p/4965310

 

Smiley Wink If anyone can provide a solution, that can be looked at, then ..

Walter Holzwarth

EESignature

Message 7 of 17
LT.Rusty
in reply to: rdyson


@rdyson wrote:

It might be doable where the inner half of the toriodial core is part of the ejector side and the outer half made up of some number of pieces that are hand striped after the part is ejected. I'm seeing these hand striped pieces being dovetailed to the inner toriod half.


 

That's probably the easiest way to do it, but I think it could probably be done automatically, if someone had a really massive attack of the clevers.  I think - not positive, and I don't have time right now to fully model up the concept - that if the inner part is pulled straight out, and dovetails into each section of the outer part ... you could have the first stage of the action be to hinge alternate sections of the outer ring inwards from the bottom, then pull them clear.  After that, the second stage hinges the remaining segments inwards from the top, then pulls them clear.  I see in my head how it would work, but I'm not sure how to explain it short of modeling it, and ... no time to do it right now.  😛

 

Rusty

EESignature

Message 8 of 17
WHolzwarth
in reply to: LT.Rusty

I'm still thinking, that it's impossible.

But splitting into 2 parts would make life easy again.

 

Walter Holzwarth

EESignature

Message 9 of 17
WHolzwarth
in reply to: WHolzwarth

Because the original part is 2013 IPT, here an additional STEP

Walter Holzwarth

EESignature

Message 10 of 17
mcgyvr
in reply to: WHolzwarth

As is thats not moldable (economically) at all... 

And as none of us know the design intent/application,etc.. you won't really get a "proper" answer.. "The devil is in the details".. and we don't know any of them

 

Why does the tire portion even have to curve back in again? or why does it even need to be round. Whats wrong with a "flat" tire surface? (google "pinewood derby wheels" 

 

Slight "bump offs" can be done as the plastic is still hot/moldable right after its been injected but thats not slight at all. And like others have said collapsible cores,etc.. are NOT cheap in both tooling cost and labor. 

 

 



-------------------------------------------------------------------------------------------
Inventor 2023 - Dell Precision 5570

Did you find this reply helpful ? If so please use the Accept Solution button below.
Maybe buy me a beer through Venmo @mcgyvr1269
Message 11 of 17
WHolzwarth
in reply to: mcgyvr

Well, mcgyvr, you've seen the part in the original thread, mentioned above. I didn't create it, but I added a possible solution for the initial question, nearly the same as JD Mather's version.

After doing this, I thought about injection molding of this part. My conclusion: No way for the initial shape.

Devil's in details? Sure, and I'm knowing as much of them as most people here. I'm in doubt, if the creator even did think of molding so far.

 

Result: If I'd need it, I'd create this of two separate parts. This can be done.

 

Smiley WinkBut I can't believe in a mold solution for the initial part. If agreed, than ok. If not, then I'd like to see this way.

 

Walter

Walter Holzwarth

EESignature

Message 12 of 17
LT.Rusty
in reply to: WHolzwarth

This is little more than a quick scribble.  There's obviously some interference issues just with the parts shown here.  Each of these segments would have to cover probably no more than 10° of the wheel.  Further, you'd have to develop things a little further with regard to the adjacent segments - if they all rotate at the same time they will bind on each other.  You'll have to rotate half of them - alternatinge segments - at once, then pull them out of the way, then rotate the remaining half.

 

Not economical in the slightest, but doable.

 

 

 

Capture.JPG

Rusty

EESignature

Message 13 of 17
WHolzwarth
in reply to: LT.Rusty

Hmm. You're looking at a section. It's strange enough.

Smiley Wink But how'd you do that all around 360 degrees?

Walter Holzwarth

EESignature

Message 14 of 17
LT.Rusty
in reply to: WHolzwarth

Do that in several places around the circumfrence, with the ends of each segment parallel to the other end of the sasme segment.  That way the rotating parts will not bind.  Once you've rotated them out of the way, they'll pull out like the inner core did.  This leave the remaining segments free to rotate.  Since their ends will not be parallel to each other, they would bind up if you rotated them before the first stage.  You'll probably need to keep each first-stage rotating section no more than 2" in length, and each second stage rotating section no more than 10° of arc, or the rotating bits may deform the plastic.

Rusty

EESignature

Message 15 of 17
WHolzwarth
in reply to: LT.Rusty

I'll bet, you'll never could do that in a real 3D model for this part.

Walter Holzwarth

EESignature

Message 16 of 17
Zac-C
in reply to: WHolzwarth

The original part was just a metal hand wheel for opening/closing a valve.....

Message 17 of 17
WHolzwarth
in reply to: Zac-C

Ok, that's a new point of view. But not really simple, too.

 

Was it a cast part? I'm in doubt, because of only 2mm wall thickness.

Was it pressed? I think so, but still special forming (roll forming perhaps) needs to be done for the wheel geometry.

 

 

Walter Holzwarth

EESignature

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report