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  #1  
Old 05-18-2015, 08:05 PM
skelly24 skelly24 is offline
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Default true radius dies

what is a true radius die and what are the advantages?
what are the advantages of dies that are not true radius dies?

are there true radius dies for the pullmax?
how about the english wheel?
plannishing hammer?
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Old 05-18-2015, 08:16 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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what is a true radius die and what are the advantages?
what are the advantages of dies that are not true radius dies?

are there true radius dies for the pullmax?
how about the english wheel?
plannishing hammer?
Shane, any machine that has dies can have true radius tooling or contact flat tooling.

On ewheels, traditionalists seem to prefer TR anvils. Contact flat anvils are more of an American thing and, imo, are more forgiving and easier to learn and use than TR because the overlapping of tracks is much easier. Sometimes TR anvils actually have developed flats due to use against hardened uppers over the years.

Due to the smaller contact area, TR anvils are usually more aggressive and move metal a bit faster at the expense of leaving more tracks in the panel.

Of the 400+ ewheels we've sold I recall only ONE where the customer wanted to provide their own TR anvils. I'm sure there are folks who have both. Some folks will only use one or the other. I prefer contact flats but can use TR if I have to. Others are just the opposite. It's kind of what you get used to.

I'll let others talk about Phammers and dies for recip machines.
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Old 05-19-2015, 08:45 PM
skelly24 skelly24 is offline
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Thanks for the explanation...
I am making my own dies for plannishing and for my pullmmax, so I am trying to learn as much about dies and their differences as I can.
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Old 05-24-2015, 07:41 PM
John Buchtenkirch John Buchtenkirch is offline
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Shane, true radius dies which are just a constant radius are very hard to use to make a smooth panel with correct flow (they are just too aggressive) so that’s the reason for flat areas on the top of dies, which is also known as a hit point. The flat area has a 1/8” or so blend in area (a DA sander with a foam pad works great for this) so there’s no edge to grab the panel and restrict it’s movement thru the dies. The photos below are 5 of my CP planishing hammer dies with the hit points marked with a black Sharpie pen. It’s always a good idea to check your hit points with the blackest drain oil, after a while you will grow to know what the various hit points will do for you. ~ John Buchtenkirch
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!die.jpg

33081die1.JPG

33082die2.JPGfficeffice" />>>
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Old 06-28-2015, 07:39 AM
skelly24 skelly24 is offline
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that explanation was great... I understand now.

Should the dies on a hand held plannisher have flat hit points also? They are set up on a pivot, so would that create any problems?
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Old 06-28-2015, 09:53 AM
John Buchtenkirch John Buchtenkirch is offline
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that explanation was great... I understand now.

Should the dies on a hand held plannisher have flat hit points also? They are set up on a pivot, so would that create any problems?
The only time I use true radius dies is when I want to pre stretch an area significantly before performing another operation…… better than 98% of the time they just ARE NOT my go to dies. On any powered hammer (pneumatic or electric powered) they are just too aggressive for most use, other opinions may vary. ~ John Buchtenkirch
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Old 06-28-2015, 11:10 AM
KAD KAD is offline
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When making anvils and dies pay particular attention to what's called the "blend area" as this is where the lines in your panel will come from when using flats.

The work you do in the blending are will make them either hard or easy to get a good panel finish.
There will be a radius for this area that allows the metal to curve gently over without diving in until your at really high pressures which isn't going to be your finish passes.
It take time and experimentation to achieve these "sweet blended areas"

Even the "store bought" anvils most times need this area better blended to reduce marking at normal wheeling pressures.

The time you spend tuning up the blend areas of all dies will pay huge rewards in all the work you do with them.

That's my feeling
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Old 06-29-2015, 08:34 PM
skelly24 skelly24 is offline
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Thanks for the tips... that explains a lot of the results I have been getting.

Need to fine tune my entire set except my 12 inch radius die... it seems to work much better than the rest in every way.
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Old 06-30-2015, 12:36 AM
skintkarter skintkarter is offline
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Thanks also for this guys. Just starting to use my APH a little now and was struggling to get a nice finish. Shaped things no problem, but the final planish still left hammer marks no matter what I did to the gap or air pressure. Having a true radius die is now the suspect. I'll give them a doctoring before the next job.
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Old 07-01-2015, 10:54 AM
crystallographic crystallographic is offline
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Originally Posted by skintkarter View Post
Thanks also for this guys. Just starting to use my APH a little now and was struggling to get a nice finish. Shaped things no problem, but the final planish still left hammer marks no matter what I did to the gap or air pressure. Having a true radius die is now the suspect. I'll give them a doctoring before the next job.
For the APH -

I like using flats when shaping, and having different flats for one radius can be helpful. --
http://www.tinmantech.com/products/f...mer-dies.php#2

Sometimes for planishing I prefer a lack of flat, but not a "true" radius, or maybe what I would prefer to call a "constant" radius?

Constant radius dies have one radius all the way across. But there are times when I prefer a "multi" radius die for planishing - like a triple angle valve seat?

Having a slight crown in the center can be more helpful than having a flat there - for planishing.
Sometimes.
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