Cone Mandrel Plans

On 3/2911 I wrote about how I made my first cone mandrel.  This is an update with a SketchUp version of the plans.

http://sketchup.google.com/3dwarehouse/details?mid=4d2f349eb80ef784ee323db343c418a&prevstart=0

The concrete filled base was originally designed to fit a purchased mini cone mandrel.  Subsequently, I’ve used it to hold several other mini cones, a ring roller and just about anything with a tang of appropriate size.

The cone drawn to fit my original mini mandrel.

All components except for a couple of bags of concrete mix.

Cone Mandrel Sharp Cap

My favorite cone mandrel is an old heavy cast type positioned in my acorn table work area.  However, it has a blunt tip and the smallest ring I can form on it has a diameter of about 1.5”.  Often, I want to form a tighter radius, so, I made a work-around tool to permit that work.

I made a symmetrical trapezoidal pattern 7.5” across the base, 5.75” tall and 4.5” across the top. I rolled a cone from 10 gauge sheet scrap and MIG welded the seam.  Then I hot fitted the hollow form cone sleeve to the tip of the cone mandrel.

Next I forged a piece of 1.25” round to a taper a couple of inches long which closely matched the line of the cone sleeve.  That solid tip was welded to the cone sleeve and blended for a smooth transition of the surfaces.  

Finally, I welded a large punch drop to the base perimeter to serve as a knock-off flange in case the tool got tightly jammed onto the mandrel.

This tool works really well.  It’s simple.  Probably, it is not original, but I’ve never seen another.  It can be made in less than a half hour from scrap and it has saved me a lot of time and frustration.  My nickname is “the witch hat.”

Offered for what ever it is worth.

http://www.persimmonforge.com/

Cone Mandrel Model

I’m continuing to work at modeling projects in Sketchup so that blacksmithing might have more a a presence in the 3D Warehouse.  There was already a cone mandril (sp) at http://sketchup.google.com/3dwarehouse/details?mid=558c840370f0b1c0ba50ac9405bdcf2a&prevstart=0

So, I decided to add a version with a tong slot.  Check it out at

http://sketchup.google.com/3dwarehouse/details?mid=a8bad6fa0ec94062c17e7f250c5222bd&prevstart=0

That reminded me that the Saltfork Craftsmen group is offering a new mandrel at what seems to me to be a reasonable price.  I haven’t used one and I’m not sure how heavy they are.  More information at

http://www.saltforkcraftsmen.org/cone.shtml

Very heavy snow kept me from getting to the shop for several days so I used that time for blacksmithing related computer work.  Usually I’m not delighted by snow storms but we are nearly desperate for water in any form to relieve the drought.

http://www.persimmonforge.com/

A Fabricated Cone Mandrel

In 1997 I fabricated a cone mandrel that is still in use. At the time I hadn't come across a real cone mandrel yet but latter found two good ones. I did have two small cone mandrels. One was long and skinny and the other squat and wide. Both seemed awkward to use in the anvil hardy holes. I wanted a better base, taller and stable and something I could cobble together in a week.

I drew up some plans and took them to a fabrication shop which cut and bumped the halves of the frustrum on their break. I MIG welded them and placed and welded a centered square tube which fitted the mandrel tangs. A circular 4.5" end plate was welded with the center square cut out. This made a watertight hollow form which, when turned upside down, could be filled with concrete. A piece of rebar was place in the central opening and driven into the ground to hold the vertical position. I used Sakrete High Strength Concrete Mix and don't recall the exact amount but I think it just a bit more than one 80 pound bag. The entire volume was concrete filled. The finished base was left in place outdoors for about a week while the concrete set and dried.

The project was finished by welding a circular base plate which aids the smoothness and rapidity of travel when the cone is tipped and rolled into position. I painted it black and put it to work.

This has been one of the most satisfactory tools I have constructed. It has served its' primary purpose as a base for the mini mandrels and the base was used to form larger radius elements until the real cone mandrels were acquired. It cost less than $100 and was quite simple to make. It might not hold up to heavy use especially if it was used for cold work.

This experience led directly to making concrete filled bases for other shop equipment. I'll describe some of those applications in the next post.

http://www.persimmonforge.com/