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  #41  
Old 03-18-2019, 06:12 PM
Peter Tommasini Peter Tommasini is offline
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Originally Posted by kjc View Post
Way back on the internet sites when the true radius vs flats debate was hot, it occurred to me that sets of true radius lowers were being made with the same general radius as the flat sets.

That is: a 12" radius wheel whether it had a flat or not was the lowest crown wheel generally supplied. With Peter's wheel sets specified by him and manufactured by Hoosier - the wheels go 36-24-12 at the low crown end.

I'm far from an expert, but it seems to me that comparing a 36" TR wheel to a 12" with flats, that the contact area for a given pressure is likely to be somewhat more similar than that between a 12" TR vs 12" flat as supplied in the earlier sets.

I wonder if the folks on the various internet sites earlier dislike for TR wheels came from the supplied sets having too high a crown?
For best results I always use the flatter anvil possible, open the panel to suit the flatter anvil , wheeled it, shaped it, then close the panel back up ,rather then use a sharper crown anvil ,

PS all will be shown on dvd N 11
Peter
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  #42  
Old 03-19-2019, 08:48 AM
toreadorxlt toreadorxlt is offline
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peter nailed it. most people who debate these sorts of things don't adhere to the golden rule of unfold the panel and use the die with the most contact at all times. I can get the same results with true radius and flats by using this rule alone.
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  #43  
Old 03-19-2019, 06:22 PM
Peter Tommasini Peter Tommasini is offline
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Originally Posted by toreadorxlt View Post
peter nailed it. most people who debate these sorts of things don't adhere to the golden rule of unfold the panel and use the die with the most contact at all times. I can get the same results with true radius and flats by using this rule alone.
I found that most beginners and others do not know, or where not taught about opening the panel and manipulating it while wheeling it technique ,there for when they shape tight radius panel they use a tight radius anvils with flats on them and they are wondering why they get lines, distortion,stop marks , lumps etc on the panel while wheeling, not only that but they also believe, or where told that PSI is the answer well... they could not be more wrong!
To make 95% of shapes you need manipulations of the panel on the machine to the shape needed, rhythm, and most important VISION of what you try to make . Trow LOAD OF PRESSURE out of the window , Panels do not like to be squeezed , but instead they like to be worked on slowly and patiently . in another words rather then do one heavy pass do 3 but lightly and wheel only where it's needed.
I do not like to make a contradiction with this (PLEASE USE ANY METHODS YOU LIKE OR ARE USED TO ) but I will show and prove the usages of flats and full radius anvils,+ pressure used and manipulation of any blanks on my N 11 dvd out soon ..... For example I will be wheeling a reasonably flat door skin with a much sharper anvil than needed, and demonstrate that with the right pressure and handling of the blank no lines or distortions of any kind on the finished skin
Peter
PS I am only trying to help so one can do the job properly, quickly and learn with out frustrations
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Last edited by Peter Tommasini; 03-20-2019 at 04:11 PM.
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  #44  
Old 03-21-2019, 01:51 PM
crystallographic crystallographic is offline
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Originally Posted by RockHillWill View Post
Recent inquiries regarding the use of full radius vs anvils with 'flats' on them, has left me wanting to know why the anvils with 'flats' are used in the first place. When viewing from the end position, it would seem that the anvils with flats are more likely to leave tracks than the full radius anvils used with judicial pressure. I am just curious. What are the flat anvils used for and who got that started?

I realize this might get heated, but I am only seeking useable information.

I use the full-flat anvils/lower rolls for erasing mischief in damage. I also use flat dies in my bead rollers for erasing mischief. Sometimes cold. Sometimes hot, but I like having an eraser handy. Leftover from school days.
Using the very low crown roll for a higher crowned part seems counter-intuitive, until you recognize "springback" and the harder the sheet is, the more springback you have.

And no marks at all - flats or no flats, when using the correct roll/anvil.

Marks schmarks. The panel that looks like a plowed field is obviously not the way to Wheel.

Geometry at work = radius of roll vs radius of shape vs hardness of material.
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  #45  
Old 03-21-2019, 06:54 PM
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neilb neilb is offline
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Quote:
Originally Posted by RockHillWill View Post
Recent inquiries regarding the use of full radius vs anvils with 'flats' on them, has left me wanting to know why the anvils with 'flats' are used in the first place. When viewing from the end position, it would seem that the anvils with flats are more likely to leave tracks than the full radius anvils used with judicial pressure. I am just curious. What are the flat anvils used for and who got that started?

I realize this might get heated, but I am only seeking useable information.

I had the same question, that's why I did some digging of my own. if you read the email I posted it says that he has a set of original Ranalah anvils, but only 1 has a flat in it. and that is the only 1 he has seen.

if anyone knows of someone that worked at rippon brothers in huddersfield or did their apprenticeship there it would be nice to ask the question!
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  #46  
Old 03-22-2019, 12:07 PM
crystallographic crystallographic is offline
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Originally Posted by bobadame View Post
There are 2 schools of thought, I have no idea which came first. "All the metal knows is PSI". These folks use anvils with flats and with these anvils, the technique is to bring the wheels together with enough force to squeeze the sheet metal a tiny amount. This thins the sheet along the path of the anvil flat. This thinning causes the sheet to extrude away from the contact zone and because metal is non- compressible, what it looses in thickness, it gains in area. Gravity causes the sheet to droop. Anvils with flats require the operator to track in a very precise pattern to achieve the desired 3D curve they are creating. These flat anvils must be held exactly parallel to the top wheel to prevent disaster. This leads the E-wheel frame builder down the path of stiff frame or some method of tilting the anvil to compensate for frame spread.

This method has worked well for many professionals for many years.

Then comes the true radius or full radius anvil folks. These people use a different technique to make a 3D curve in flat sheet. The wheels are brought together with much less force, (less compression). The sheet is formed by the operator physically bending the sheet over the anvil as he rolls it through. Cass calls this technique "Pumping". Imagine hand pumping water from a well. There is a downward force on the handle. With this technique the stiffness of the frame is a non issue and the tracking pattern is less critical and more intuitive.

This method has worked well for many professionals for many years.

The important thing to understand is that the technique needs to be the correct one for whichever style of anvil you use.

Or, I could be completely full of shit.

I think you summed it up perfectly, Bob.
Thank you!
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  #47  
Old 03-22-2019, 07:09 PM
Peter Tommasini Peter Tommasini is offline
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[QUOTE]

Originally Posted by bobadame View Post
There are 2 schools of thought, I have no idea which came first. "All the metal knows is PSI". These folks use anvils with flats and with these anvils, the technique is to bring the wheels together with enough force to squeeze the sheet metal a tiny amount. This thins the sheet along the path of the anvil flat. This thinning causes the sheet to extrude away from the contact zone and because metal is non- compressible, what it looses in thickness, it gains in area. Gravity causes the sheet to droop. Anvils with flats require the operator to track in a very precise pattern to achieve the desired 3D curve they are creating. These flat anvils must be held exactly parallel to the top wheel to prevent disaster. This leads the E-wheel frame builder down the path of stiff frame or some method of tilting the anvil to compensate for frame spread.

Bob
Not having used lower anvils with flats that often your statement above could work ?? But it seems a lot of work , care, and strategy and time is required to do a job .
What as not been mention is what the flat anvils does at a certain point of wheeling bulbous shapes and smoothing (with no pressure reverse curves,) is that they will slow you down on finishing off and finished result. I will show just this issue on my next DVD called ''learn how to use an English wheel''
I guess what I am saying is that...... is NOT THE WRONG THING to use flat anvils BUT!!! Wheeling with FULL radius anvils is A LOT QUICKER and better results faster. Whether a cast or fabricated frame is used

PS I have learned to use the full radius anvils and still do from 3 English tradesman which worked at Rolls Royce and Aston Martin for 40 Years before emigrating to Australia
Peter
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Metalshaping tools and dvds
www.handbuilt.net.au

Metalshaping clip on youtube
http://www.youtube.com/watch?v=WEAh91hodPg

Making Monaro Quarter panel:
http://www.youtube.com/watch?v=KIpOhz0uGRM
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