Draw, or taper on castings

[Anonymous]

A pattern for sand casting needs to have draw, or taper to allow it to be withdrawn from the sand without damaging the mould ( I believe that is 'mold' to Americans.

Can a draw angle of, say, 3 degrees be easily added to a model?

Brian

[MRWakefield]

Yes, you'll find 'Draft' in the Modify menu.

[g-andresen]

Hi,

please share your design to take a look at.

günther

[Anonymous]

Many thanks for the reply Gunther. I've added a design before but things seem to have changed. Please can you advise how to make the design viewable?

Kind regards, Brian

[g-andresen]

Hi,

try this:

günther

[Anonymous]

Again, many thanks Gunther, I'll give that a try.

Kind regards,

Brian

[Anonymous]

Link to my model. The other side is plain i.e. no ribs or boss, just the rim and the hole.

https://a360.co/2RfRv5S

[MRWakefield · Accepted solution]

Is this what you're after? I had to guess where you want to split the mould but it's easy enough to change that if you want it somewhere else. I've had to move some of the fillets to the end of the timeline to get it to draft but apart from that it was very simple to do. You might want to thicken up some areas as obviously the webs etc. are now thinner than they were. Also, the OD and the bore for the crank pin (I presume that's what it's for) has a double taper and will require machining so you might also want to add some material there before applying the draft.

Here's the link to the modded file: https://a360.co/3aDXPfh

Hope this helps.

Edit: I'm no casting expert but I expect you'll want to split the body so you've got two halves (one for the drag and one for the cope). In which case you'll probably want to reposition the neutral plane midway through the inner 'disc'.

[whittakerdw]

Did you happen to try the suggestion of adding draft. I don't know if draft is an American term but draft is what will add the taper for sand castings to allow them to be able to be withdrawn easily without messing up the sand around the pattern.

[MRWakefield · Accepted solution]

Here's an updated one with the neutral plane moved as per my suggestion in my previous post: https://a360.co/30IYqYp

[Anonymous]

Many thanks for working on my model. I will need to thicken up some areas and also add some metal in places for machining. What angles have you added to produce the draft?

Again, many thanks, Brian

[MRWakefield]

You're welcome. I added 3° as per your original post. This is easily changed by editing the Draft feature.