 ArtMetalsocial networking for the metal arts |
|
Flared or Trunicated Cones for Elevated Water Tanks. Specifically Sphere and Water Spheroids
hjnwt -
Sunday, November 15, 2009 - 10:05pm
Fabrication cones | flared | trunicated Hello All. I am new to the group. I am looking for help in die design. My work involves fabricating elevated water tanks. We press or dish our elliptical heads involving segemented pie shaped plates. We use the typical male over female die configuration checking both raduis with radius boards as the piece is pressed. Now to the problem. We have a Water Spheroid to fabricate that includes a flared or trunicated cone between the top of the cylinderical stem (support shaft)and the bottom of the spheroid tank itself. The cone will be 10' diameter at its bottom and 15' diameter at it's top. The height of the cone will be 5'. The material is Mild Carbon A-36 and is 1.25" thick. I just can't seem to get a three way die in my mind. I have used compound (two way) for decades. I have thought about rolling the pieces (blanks) to a larger than required radius and then press the curved pieces with a male die on bottom that would be retangular in shape and a female die on top to press the required radius at the bottom and opening the limit switch on the press to allow the die to form the curve to a larger diameter as I go. I am hoping someone will reply and tell me what I am missing. I am not very confident in my idea. I appreciate any thoughts anyone has or any reference books for forming flared or trunicated cones. Thanks,  cone
Stephen Fitz-Gerald -
Monday, November 16, 2009 - 5:17am
Stephen Fitz-Gerald  Double Curved Cone
tankguy -
Saturday, May 7, 2011 - 9:02pm
Stephen, Two years ago you responded to a post from me. Here is the update since then. I am having trouble uploading a working drawing with diminsions. Do you have an email I could send it to. Here is my new post. We use these in elevated water tanks for municipalities for their drinking water supply. The cone is a smooth or flared transition between the stem of the tank and the sphere. The tank is similar to a golf ball on a tee. It is known as a water sphere type tank. The flared cone goes between the shaft or stem of the tank and the sphere on top. I have attached a drawing of the development of the double curved cone. The thickness runs between .5 and 1.5 inches. The drawing has the dimensions. We have been rolling the exterior radius (usually around 50 degrees) and using a rectangular male/female die with the parallel portion of the die forming the inside The parallel radius is equal to the lower or tightest radius of the cone. We loosen the While this has proven successful, it is time consuming and does not make each piece 100% identical. This requires additional fit up time to make the finished product within tolerance. We would like to make a die that would press the entire piece in one press. Our largest press is 750 Ton. I would appreciate any ideas you may have. Thank you in advance for your time and thoughts. Double Curved Cone
tankguy -
Saturday, May 7, 2011 - 9:00pm
Rich, Two years ago you were kind enough to respond to a post. Here is the latest on my project. We use these in elevated water tanks for municipalities for their drinking water supply. The cone is a smooth or flared transition between the stem of the tank and the sphere. The tank is similar to a golf ball on a tee. It is known as a water sphere type tank. The flared cone goes between the shaft or stem of the tank and the sphere on top. I have attached a drawing of the development of the double curved cone. The thickness runs between .5 and 1.5 inches. The drawing has the dimensions. We have been rolling the exterior radius (usually around 50 degrees) and using a rectangular male/female die with the parallel portion of the die forming the inside The parallel radius is equal to the lower or tightest radius of the cone. We loosen the While this has proven successful, it is time consuming and does not make each piece 100% identical. This requires additional fit up time to make the finished product within tolerance. We would like to make a die that would press the entire piece in one press. Our largest press is 750 Ton. I can't seem to get the drawing to load. Do you have an email address I could send it to ? I would appreciate any ideas you may have. Thank you in advance for your time and thoughts. So as I interpret it you are
bigfootnampa -
Monday, November 16, 2009 - 10:40am
So as I interpret it you are basically creating the top portion of a gigantic golf tee? Visualizing this on such a scale I can see where extreme accuracy would be pretty important! Assume that you make these parts in 15 sections... you'd have pieces which would be slightly over 2 feet wide at the narrow end and just over 3 feet wide at the large end. As a ragged guess maybe about 6 feet long before forming (depending on the amount of flare). Since these will be made in 1.25" thick material any large inaccuracies would result in a real nightmare for your welders! My guess is that you'll want to keep the amount of flare small as that will give more triangularity and greater strength. That leaves you with a shallower radius at the top (large end) of the segments and a slight back bend lengthwise. If it were me, (I assume you have HUGE presses to work with) I would form a single die set based on many cross sections cut at 90 degrees to the length and assemble them to also model the lengthwise curve, then I'd hot bend the sections in one (or two) pressings. I might consider profiling the edges with a double chamfer before bending to get a head start on the welding prep. It seems to me as if a free hand approach such as you are thinking of might be inaccurate enough to create the threat of mutiny among my welding crews! I'd spend more on the forming and hopefully save a bit on the welding process. flared cone
hjnwt -
Monday, November 16, 2009 - 11:18pm
Thanks for the comments from all. I am thinking the bottom die (male) might be rectangular with a length wise radius to accommodate the longitudal radius and another radius (left to right)with a radius equal to the smaller end radius of the cone. The top die (female) would be an upside down horse shoe with the radius of the smaller end. I am thinking this would allow the pressing (750 Ton) would accomplish the outside radius up and down the cone while pressing the proper radius as I progress up the piece from the small end to the big end. I would appreciate any thoughts anyone has regarding my thought process. I may be way out there with this idea. Thanks, Herman Flared Cone
Stephen Fitz-Gerald -
Tuesday, November 17, 2009 - 1:07am
Stephen Fitz-Gerald Flared Cone
hjnwt -
Tuesday, November 17, 2009 - 8:03pm
Steve, I am not familiar with Anticlastic shape. This will be a cone with a small diameter on the bottom and a larger one on top. It has to be dished for the proper radius but at the same time the back has to break and flare out creating a smooth transition. The real difficulty for me is going from a compound curve (typical Sphere, elliptical, etc. head) to a three deminsional die. I think the dies will end up perpindicular to one another. The bottom die will be two or three feet wide and two feet long. It will have the smalles radius from left to right and a radius for the longitudial curve running from the top to bottom of the longitudial or length. The top die will be concave and horse shoe in shape. The width of the shoe will be sufficeint to go around the large end and get a tighter radius as it goes up. Thus to decrese the radius the die can just be allowed to lengthen it's stroke. The die will also have a curve the other way (90 degrees) to insure the longitudial curve of the exterior of the taper of the exterior of the flare. I would appreciate your or anyone's elses help with this plan. It's the best I have come up with thus far. Not even sure if it will work. Thanks  Do you have any pictures or
T Bourke -
Tuesday, November 17, 2009 - 9:17pm
Do you have any pictures or diagrams? Flared Cone for Water Sphere Tank
hjnwt -
Wednesday, November 18, 2009 - 11:43pm
I have been thinking of using a rectangular bottom die (male) with 3 to 4 foot radius l to r and a longitudial radius equal to the exterior flared radius. The top die would be female and perpendicular to the bottom die. It would be 3 to 4 foot radius l to r with a longitudial radius equal to the bottom die. I would appreciate and thought, comments, etc. Thanks, Herma Flared Cones - Seeking Comments
visitor -
Sunday, March 20, 2011 - 2:53pm
Thank to all for comments. We ended up doing a 1/4 scale model. We rolled the 50 degree radius with plate rolls and then bumped the piece on an old C Punch Frame. We used our CNC cutting table for to obtain the left to right radius and hand ground the opposing radius. We pressed the entire lenth of the piece with a die that would move up and down to accomadate the radius we were seeking. While not perfect (yet), we pressed the piece to a very tight and acceptable radius. Next step is to make a fixture for our 750 Ton press to install a flat blank and press what we want in one pass. Would appreciate any comments. Double Curved Cone
tankguy -
Saturday, May 7, 2011 - 9:04pm
Mr. Bourke, Two years ago I made a post hear regarding a double curved cone. Here is an update on the project. I can't seem to get the file to upload. Do you have an email I can send it to ? We use these in elevated water tanks for municipalities for their drinking water supply. The cone is a smooth or flared transition between the stem of the tank and the sphere. The tank is similar to a golf ball on a tee. It is known as a water sphere type tank. The flared cone goes between the shaft or stem of the tank and the sphere on top. I have attached a drawing of the development of the double curved cone. The thickness runs between .5 and 1.5 inches. The drawing has the dimensions. We have been rolling the exterior radius (usually around 50 degrees) and using a rectangular male/female die with the parallel portion of the die forming the inside The parallel radius is equal to the lower or tightest radius of the cone. We loosen the While this has proven successful, it is time consuming and does not make each piece 100% identical. This requires additional fit up time to make the finished product within tolerance. We would like to make a die that would press the entire piece in one press. Our largest press is 750 Ton. I would appreciate any ideas you may have. Thank you in advance for your time and thoughts. anticlastic shape
Stephen Fitz-Gerald -
Sunday, May 8, 2011 - 11:15pm
Stephen Fitz-Gerald My email is stephenfitzgeraldfineart@yahoo.com  explosive forming?
ScottTheSculptor -
Sunday, April 3, 2011 - 2:13pm
Have you considered explosive forming over a cnc milled form? I worked on a proposal a few years back and was amazed at what the top in the indusry can do with it. Scott, Two years ago you
tankguy -
Saturday, May 7, 2011 - 9:06pm
Scott, Two years ago you replied to a post I made. Here is the latest. I can't seem to upload my drawing with diminsions. Do you have an email I could send it to ? Here is my new post. We use these in elevated water tanks for municipalities for their drinking water supply. The cone is a smooth or flared transition between the stem of the tank and the sphere. The tank is similar to a golf ball on a tee. It is known as a water sphere type tank. The flared cone goes between the shaft or stem of the tank and the sphere on top. I have attached a drawing of the development of the double curved cone. The thickness runs between .5 and 1.5 inches. The drawing has the dimensions. We have been rolling the exterior radius (usually around 50 degrees) and using a rectangular male/female die with the parallel portion of the die forming the inside The parallel radius is equal to the lower or tightest radius of the cone. We loosen the While this has proven successful, it is time consuming and does not make each piece 100% identical. This requires additional fit up time to make the finished product within tolerance. We would like to make a die that would press the entire piece in one press. Our largest press is 750 Ton. I would appreciate any ideas you may have. Thank you in advance for your time and thoughts. double curved cones
tankguy -
Saturday, May 7, 2011 - 8:55pm
Two years ago I posted an inquiry for ideas about how best to form a double curved cone. We use these in elevated water tanks for municipalities for their drinking water supply. The cone is a smooth or flared transition between the stem of the tank and the sphere. The tank is similar to a golf ball on a tee. It is known as a water sphere type tank. The flared cone goes between the shaft or stem of the tank and the sphere on top. I have attached a drawing of the development of the double curved cone. The thickness runs between .5 and 1.5 inches. The drawing has the dimensions. We have been rolling the exterior radius (usually around 50 degrees) and using a rectangular male/female die with the parallel portion of the die forming the inside The parallel radius is equal to the lower or tightest radius of the cone. We loosen the While this has proven successful, it is time consuming and does not make each piece 100% identical. This requires additional fit up time to make the finished product within tolerance. We would like to make a die that would press the entire piece in one press. Our largest press is 750 Ton. I would appreciate any ideas you may have. Thank you in advance for your time and thoughts. |
|
ArtMetal
Herman, I think you're going
Herman,
I think you're going to need to do that forming in one pass, rather than two. If you try to do the rolling and then press the rolled segment into a flare, you're going to get buckling at the edges. Are you pressing these pieces cold or hot?
An alternative to pressing the compound curves is to do a compound rolling operation using shaped rolls and a programmable follower roll to control depth of engagement into the shaped rolls. I've done this with smaller non-ferrous pieces, but doing it on the scale you're discussing is out of my league by several orders of magnitude. So I'm just tossing out ideas here in the hope that they spark an insight on your part. :-)
Rich