multibend half cylinder

[TWingate1986]

Hey all,  

I am trying to "bump brake" a cylinder.  The shop wants to make a 24" i.d. tube, so we will plasma cut 2 halves and bump brake it and weld them together.  I have tried a few different sheet metal methods, however I only get 1 bend line in flat pattern view.  We want the bends in .500 or .75 spacing.  I could probably figure out the degree of bend and do a ton of flanges, but I was trying to get it done in one command.

Thanks all

Regards,

[mcgyvr · Accepted solution]

Use a polygon as your sketch (with an opening/rip in it) then use contour flange to create the tube..

That will unflatten with multiple bend lines..

Adjust the number of sides to achieve your desired bend line spacing in the flat..

[TWingate1986]

THANKS!

Exactly what I needed.  I had to do it a few times to get the spacing where I wanted, but flat pattern came out just fine.

Thanks a bunch.

Regards,

[CCarreiras · Accepted solution]

Hi!

My way...

[mcgyvr]

^^ yep.. lofted flange works great too and allows easier control of the distance between the bend lines..

[TWingate1986]

which out of the two ways do you guys think is more accurate on on flat blank?  I get a .055 difference on the flat blank. 

[CCarreiras]

Depends how you are doing it... theoretically speaking, it must have the same value for both cases.

By the way.... a 0,055 is a big difference for you??

[TWingate1986]

no its not a big difference in this case.

I just wanted your opinions.

Thanks for the help

[CCarreiras]

If you have both files, post it here and we check that...

[mcgyvr]

There shouldn't be any difference in the blank assuming the models are the same.. You should essentially get the exact same output from either process..

And really is best to model it up.. Then actually make the part and take your measurements.. If its off adjust the kfactor used in Inventor to achieve the needed blank dimensions..

I had to bend up all the different sizes of material here and actually press brake them then calculate for the kfactor for each material thickness/die radius,etc.. for our specific machine..

I will never supply a blank drawing to any outside vendor,etc.. unless I have confirmed the proper k factor for their specific machine/process..