help needed with copying a breadmaker tin

[Checkmate]

Hi, i am trying to copy a breadmaker tin and i need some help! firstly i have just assumed that it has been made from sheet metal which i think is probably correct but not entirely sure, if this is correct then it would be helpful to have some guidance about how i would go about creating it in sheetmetal.

this is the tin, admitedly its a little dirty as i haven't washed it since i cooked bread the other day sorry!
View attachment 2843

it seems to have just been pressed into shape with a mould and then the top lip been rolled back. there are also two indents on two of the sides. all the corners on the sides and on the bottom are all rounded. and there are three holes in the bottom where rivets sit flush with the base, the thing in the bottom is the kneeding paddle which i forgot to take out and can be ignored. and so can the handle be ignored for now.

here are another three angles..

the thing on the bottom can be ignored its just the mount.

View attachment 2844
as you can see the rolled back lip goes all the way around the corner.

this is the rivet flush in its hole, please ignore the kneading paddle.

thanks in advance for any direction on this as i am not sure how to do it at all
thanks,
checkmate

 

[vlad1979]

Hey,


I think with a punch you can create the main geometry.


insert/shape/form/punch/reference

 

[looslib]

Most CAD system sheetmetal packages ASSUME that you are going to be bending the parts to obtain the final shape. The bread pan is made be drawing process which, even the companies that do it, admit it is somewhat of a black art, trial-and-error approach to get the final product design shaped successfully.

 

[AHA-D]

You could use the "punch" tool to get to the geometry, but you might just as well use any other tool you're comfortable with to model the part since there won't be any advantage in starting in sheet metal. Trying to unbend won't get you anywhere or provide any usefull information. Using the punch tool in ProE just adds the geometry of the die to the sheetmetal part but does this with sheet thickness. If you are only basicly familiar with deepdrawing metal you know that this can't be done since any deformation of this kind "eats" material. Ending up with 1 mm thicknesscan demand a 2 mm sheet to start with.


There is also a limit to the depth of a drawn feature, related to the whidth. Deep pans are fabricated with a set of dies, where you start out with a wide and shallow pan that you deform to a narrow deep pan in a number of steps. Trying to do otherwise will tear the metal apart due to lack of material.


Alex

 

[echokilo3]

I believe the indents are for ejector pins after the carrier stock is trimmed away and the edge is mushed,similar to injection molding. This formalso strengthensthe pan, or it could be for easier bread removal. I imagine this part made in a series of draw dies, sameas AHA-D. I would not be surprised if all the rivet holes and paddle holeare added in a secondary operation.I want to follow this post because I am new on pro-e and have an interest in sheetmetal and have much to learn.

 

[AHA-D]

Although this IS sheetmetal, it is out of bounds for any mainstream CAD-system. Not that you can't model the thing (not necessarily in sheetmetal-interface), but there is no really usefull fabrication information that can be gathered from the model. Wall thickness is not constant on deepdrawn objects so the weight (strength, ...) in CAD will only be an estimate of the real thing. 3D-deformation featuresare "added" to sheetmetal, not formed out of the material present at the chosen location.


I've come around some studies, when searching the web, and attempts to master computer-aided deep drawing, but it's still a job of skill and experience and not a standard solution.

 

[Michaelser]

Hello there,


Your bread tin is obtained through a deep draw process. Actually, the initial material is a is a flat piece of Aluminum ( I believe) that has excellent malleability properties . The drawing process is done in a few steps and the shape of the initial part changes. It is possible that intermediary heat treatment of the material is necessary for re -growth of the material grain and re-gaining malleability properties. Also for each step in the process is necessary to lubricate the semi- fabricate part.


Yes, the wall of the tinis not constant since the flow of the material is different in corners vs. the flat portions of the part.


In Sheetmetal you create a form (the negative of the inside of the tin) and then you place it on the sheetmetal which becomes your part. You can contour the seed surface and the parting plane as such that all you need after is hem around the edge to obtain the final shape of the tin.


If you need more details contact me.

 

[arroyopr]

Hey,


I think with a punch you can create the main geometry.

I second the motion. I consulted with a co-worker that has a Man. B.S. and he told me, it's looks like is a die that punches the sheet through a hole and then they roll the edges one part and flange the other top part,
Edited by: arroyopr

 

[Checkmate]

thanks to everyone for all the info, i will read up more on deep drawing.

also i attempted using the punch in sheetmetal but it failed saying "could not intersect part with reference" right at the end after i had constrained the punch and everything.

if anyone has any ideas that would be useful

thanks,
checkmate

 

[Checkmate]

does anyone even know what 'can not intersect part with feature' means or where i can find out more about this failure?

thanks,

 

[AHA-D]

Have only rarely used the punch tool in ProE, but one of the reasons it failed on me was because of the reference plane that is asked on the tool. This face should NOT be a face of the needed geometry on the punch. In other words : create a block,create the punch on top of this block and then reference the bottom of the block.

 

[Checkmate]

yes that was it, thank you