The dumb ideas I get sometimes

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John Hasler
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Location: Elmwood, Wisconsin

Re: The dumb ideas I get sometimes

Post by John Hasler »

No taper. Tilt the rotary table and use a radius endmill. No need for a sine table either. For a non-critical 2 degree angle shims will do.
stephenc
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Joined: Sat Jul 05, 2014 6:13 pm
Location: youngstown ohio

Re: The dumb ideas I get sometimes

Post by stephenc »

I had a similar thought to that , then my ocd kicked in on the line it leaves in the surface finish of the model . is it a problem for the flywheel itself . nope it sure isn't .

It comes down to being a mental and visual issue for me . and not for reasons a sane person would have
I get obsessed with little tiny details . I don't actually care if the flywheel comes out of the mold perfect . but my ocd wants the mold itself to be as perfect as I can get it .

Fortunately my common sense kicks in and I know when to cry uncle when my wallet becomes involved .
I don't want or need a mold bad enough to invest $100-$125 in tools and materials .
This was a bit of a lark to see if i could make it work without spending cash
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tornitore45
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Location: USA Texas, Austin

Re: The dumb ideas I get sometimes

Post by tornitore45 »

To create draft you can angle the rotary table with a spacer and use a regular end mill.
I do not quite understand the concern about creating fillet IF they are the type where metal can be removed later on the lathe.
Yes draft is mandatory.
Mauro Gaetano
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rmac
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Re: The dumb ideas I get sometimes

Post by rmac »

stephenc wrote: Thu May 27, 2021 10:20 pm I don't want or need a mold bad enough to invest $100-$125 in tools and materials .
Others have suggested ways to proceed without buying any new tools. If all you're worried about now is the price of a new chunk of aluminum, why not just modify your CAD model to add some draft to the existing mold?

-- Russell Mac
stephenc
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Joined: Sat Jul 05, 2014 6:13 pm
Location: youngstown ohio

Re: The dumb ideas I get sometimes

Post by stephenc »

Well I do have to apologize for one thing that I thought was obvious , I am using cnc mill not manual , so there's no rotary table to tilt .

And I could very easily edit and do it all with a ball mill , but like I mentioned it makes for a long run time .
I'm only willing to invest so much time , effort and cash into what amounts to a useless project . Useless is a rather harsh term I shouldn't use though .
In the time it would take to surface the mold I could just machine a stack of flywheels.

I've also mostly satisfied the urge to have a flywheel mold which was the stronger urge then the flywheels it was supposed to make . it not working doesn't take away that satisfaction one tiny bit '
I'm sure a few others out there can understand the bright shiny and different aspect of it .

Edit ... I've forgotten if I mentioned that this mold was just a practice piece that fit inside some scrap . I'd have to buy new stock to make the size I'd want .
jscarmozza
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Joined: Mon Mar 03, 2014 5:09 pm

Re: The dumb ideas I get sometimes

Post by jscarmozza »

I had similar issues with a permanent mold that I had made, it was very thin so I didn't think draft was that important...it was. You may also want to relocate your pouring sprue or at least make it longer to get more liquid head to help fill the mold and act as a source of feed metal during cooling. Still, a nice piece of work.
stephenc
Posts: 311
Joined: Sat Jul 05, 2014 6:13 pm
Location: youngstown ohio

Re: The dumb ideas I get sometimes

Post by stephenc »

Thanks :)
If I didn't know from the start it didn't have much chance of working I might be disappointed .
It filled out perfectly once the mold got up to temperature , to perfectly it turns out .

I am very happy , forgetting the bad engineering the mold itself meets all my expectations. As a hobby machinist that pleases me to no end .
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