Mass Production of a pin with a tapered double radius ends

dlinnik · May 9, 2016

Hello all, I've been given the task of researching a concept of mass production (possibly tons per year) of the pin that has double radius on tapered ends. The initial though was to use a couple of angled grinding wheels and some rocking motion as pins are fed thru but the more I think about it, it make less and less sense to me. So I thought, what if someone out there encountered something similar in their career and can share with me an idea or give me some clues or insights. Anything would be greatly appreciated. I attached a screenshot of a pin, it's a little over inch long and I exaggerated the radiuses to make them visible. On the real pin they're much bigger and look like flat surfaces. Thanks!

michiganbuck · May 9, 2016

No way of knowing with this information but a grinder can have a radius (form) dressed into the wheel and with feeding parts can make size, surface finish and length in one hit. looks like cut the angle and then make the form..

this might be over kill for a simple part
Form Grinder | ITM – International Tool Machines

Yes you would not need a programable machine for one simple part.

Richard King · May 9, 2016

If it is flat and not a round taper pin, how about a punch press and then a deburing tumbler. There is a place in Minneapolis called Bookers who make washers. Maybe they could help.
Boker’s, Inc. | Stamping and Washer Specialists

Milland · May 9, 2016

We need to know material grade/hardness, accuracy required, surface finish needed, etc. If not at "bearing" levels of precision, I could see these stamped to rough shape, then finishing the ends with EDM'd hammer dies (hardened tool steel or carbide). Some sort of inspection for form/finish, maybe stages if one-shot hammering doesn't give the needed result.

michiganbuck · May 9, 2016

shaving mills used to be used to make simple saw cutters.. with a parts feeder one would make quick work of that job.
They had one form as a cutter blade and would come in at an arc off a cam and make a two way form.
think they were also used on a lathe. Might have been called a shave head.

Finegrain · May 9, 2016

Don't know the specific geometry or the order of magnitude of the radii, but one crazy idea if the radii are <12" or so would be to make a QR fixture plate that holds a bunch of them out at the periphery and cut the shape with a lathe. If the radii are in the 12" range, each fixture could hold 100's of blanks.Would take only seconds to cut the shape at each end for each batch, but loading/unloading would be slow. Might could imagine some automation around the loading.

Regards.

Mike

michiganbuck · May 9, 2016

Finegrain said:
Don't know the specific geometry or the order of magnitude of the radii, but one crazy idea if the radii are <12" or so would be to make a QR fixture plate that holds a bunch of them out at the periphery and cut the shape with a lathe. If the radii are in the 12" range, each fixture could hold 100's of blanks.Would take only seconds to cut the shape at each end for each batch, but loading/unloading would be slow. Might could imagine some automation around the loading.

Regards.

Mike

or the same on a grinder with one radius on the wheel and the other in tha diameter of the swing..
Good idea Mike.

D Nelson · May 9, 2016

Couldn't that whole piece just be cold headed cheap and fast

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dgfoster · May 9, 2016

As Buck suggested above, but if the radius is "large" it may require a trunnion arrangement that guides the part through the specified long arc as it could be awkward using a long pivoting arm to do this for tons of pins per year. It sounds like this part is nearly flat and therefore has a very long arc radius both ways. The trunnion should flip about a pivot point to allow a single loading of a blank to grind one end then flip and grind the other end to reduce handling. More specifics on the actual radii could allow more specifics on design. It would be nice to use air actuated work holding too.

Denis

dlinnik · May 11, 2016

I appreciate all the comments and suggestions. Sorry I couldn't be more specific (confidentiality, competitor issues). Some of the suggestions actually crossed my mind too. Now I have to boil it down to something that we can use. Thanks again!

RJT · May 11, 2016

If the radius on each end have the same center, a 2 jaw chuck (or custom fixture) in a CNC lathe would be my choice.

bpm9 · Feb 15, 2021

Considering the mass production, sliding head bar feeder cnc lathe will be a best solution.

michiganbuck · Feb 15, 2021

It could/might be done with a special fixture with conventional machines but the ballpark size and hardness would need to be known. Tons per year might suggest a special machine. but so little information.

Are you starting from soft, what tolerances needed?

From here it looks like a part only .060 x a little over an inch long.

Richard Winn · Feb 15, 2021

shear/ coining progressive die

prior to heat treat

powdered metal die

tdmidget · Feb 15, 2021

michiganbuck said:
It could/might be done with a special fixture with conventional machines but the ballpark size and hardness would need to be known. Tons per year might suggest a special machine. but so little information.

Are you starting from soft, what tolerances needed?

From here it looks like a part only .060 x a little over an inch long.

As Buck says. What are your tolerances and finish requirements? In other words, is this even a grind job?

michiganbuck · Feb 15, 2021

Wow, who wood-ah thought .060 o1 bar stock could cost this much.

Error 400 (Bad Request)!!1

Milland · Feb 15, 2021

Guys, it's a five year old thread, and the OP's not been back...

Chip Chester · Feb 19, 2021

Given the elapsed time, now the task is to find the final product out in the marketplace. If you're bored, and all that...

Mass Production of a pin with a tapered double radius ends

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