Newbie from Canada

[Karl]

Hello everyone. New to the forum and trying to get some insight into metal spinning. Run a machine shop in Barrie Ontario and by necessity need to learn to spin simple end caps in stainless. Have done a few but having some difficulty with getting 90 degree bends. Always has a slight taper and not sure how to overcome this. I'm hoping someone might have some suggestions. Have not tried annealing as we are trying to keep the material from obvious heat discoloration. Doing these in 304 SS x .035" thick. Flat diameters range from 4" to 6" with 1/2" long skirt.

[Peter Tommasini]

Hi Karl welcome to the forum
Peter

[cliffrod]

Welcome to the forum, Karl.

[neilb]

hi karl, welcome to the forum.

i have no idea about metal spinning but love the process, have you tried to create a slightly wider angle on your die, so you can go past 90 deg? i ask as just sitting thinking about the process the centrifugal force is going to want to pull that edge back out from the centre line.

just a guess and maybe something to try?

[Karl]

Thanks for the welcomes.

Going to try and add some photos of what I am doing. The taper I am getting is at the open end so my 4" cap is 4.020" at the opening. To compensate for the size we turned the aluminum mandrel smaller by .020". The open end comes out to 4.00" but it has this taper, which I don't care for. Being a bit of a perfectionist I would like to, if possible, totally eliminate or reduce this taper considerably.

Here's the setup I have. Tried spinning at 312, 558 & 765 rpm but didn't find much difference in the performance, not that I noticed anyway.


The 3 sizes I'm working on at present are 4.00", 6.00" & 8.00" O.D. all with a 1/2" long skirt.

[neilb]

[QUOTE=Karl;147722]Thanks for the welcomes.

Going to try and add some photos of what I am doing. The taper I am getting is at the open end so my 4" cap is 4.020" at the opening. To compensate for the size we turned the aluminum mandrel smaller by .020". The open end comes out to 4.00" but it has this taper, which I don't care for. Being a bit of a perfectionist I would like to, if possible, totally eliminate or reduce this taper considerably.

Here's the setup I have. Tried spinning at 312, 558 & 765 rpm but didn't find much difference in the performance, not that I noticed anyway.[QUOTE]

does the die you are working on have a side face 90 deg to the main face?

[neilb]

Originally Posted by Karl

Thanks for the welcomes.

Going to try and add some photos of what I am doing. The taper I am getting is at the open end so my 4" cap is 4.020" at the opening. To compensate for the size we turned the aluminum mandrel smaller by .020". The open end comes out to 4.00" but it has this taper, which I don't care for. Being a bit of a perfectionist I would like to, if possible, totally eliminate or reduce this taper considerably.

Here's the setup I have. Tried spinning at 312, 558 & 765 rpm but didn't find much difference in the performance, not that I noticed anyway.

does the die you are working on have a side face 90 deg to the main face?