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  • Upper vs lower diameter ratio?

    probably a Peter question but hopefully will be another means to understand the specifics about wheeling machine function.

    The upper wheel is usually much larger in diameter than the lower anvil. Why is this? Does it provide a greater mechanical advantage (leverage) to smooth and shape the metal being worked? Does it provide better clearance for the walnuts in a blocked piece to enter between the upper wheel and lower die? Is it a combination of multiple things?

    One reason I ask relates to the kidney wheel lower I ordered via Peter & Hoosier when ordering my anvils. It's approx twice the diameter of a normal lower anvil and I need to make some adaptations to use it in earnest on my HandBuilt frame. The lower adjustment needs to be spaced to allow enough clearance to install and it would be safer to use it with a deeper cradle than the original one on the frame. It looks like it has a lot of potential.

    With much better clarity regarding full radius vs flats, I would also like to better understand the function of diameter ratios between upper wheel and lower anvils.

  • #2
    Well damn Cliff now you have me curious as to what you use a kidney shaped lower anvil for????
    Always wanting to learn, or at least try to
    David Bradbury

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    • #3
      Hi,

      I have heard of this kidney shaped wheel, I would like to see it as well.

      My opinion on wheel diameter ratios. If both wheels were 1:1 the panel would not curve much fore and aft when viewed from the operator. Hense the reasoning behind the large dia lower in the other post. The larger the ratio the more effective it is in creating shape. The upper wheel has a larger diameter which creates a flatter arc than the smaller wheel below. Which in turn pushes the material over the lower. If you flipped the machine upside down, the panel would curve up, do to this action. Or the same as a body hammer or slapper on a round bench dolly.

      Bill

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      • #4
        the larger upper wheel would be for inertia, i would imagine
        thanks neil

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        • #5
          Cliff
          The kidney lower anvil is ONLY used to get in to returns when you working the return up side down and it's to high and touching the cradle , it's also used to stretch narrow shapes (example ) to stretch the front of the Ferrari nose prior to turn it over, sometime it's also used to BRAKE THE RETURN PRIOR TO STRETCH IT .
          unless Hossier got it wrong ? the kidney lower anvil should fit the handbuilt machine ...here how you do it..... Lower the shaft all the way down, have the two cradle adjusters also all the way down, then lift back up the shaft to suit or re adjust the cradle adjusters
          The reason why the top wheel is larger in diameter it's to do with inertia and finishing off ..simply because if the two wheels where the same in diameter it would be too hard to control and achieve a good finish
          Peter T.
          Last edited by Peter Tommasini; 09-13-2019, 11:13 AM.

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          • #6
            Originally posted by Peter Tommasini View Post
            Cliff
            The kidney lower anvil is ONLY used to get in to returns when you working the return up side down and it's to high and touching the cradle , it's also used to stretch narrow shapes (example ) to stretch the front of the Ferrari nose prior to turn it over, sometime it's also used to BRAKE THE RETURN PRIOR TO STRETCH IT .
            unless Hossier got it wrong ? the kidney lower anvil should fit the handbuilt machine ...here how you do it..... Lower the shaft all the way down, have the two cradle adjusters also all the way down, then lift back up the shaft to suit or re adjust the cradle adjusters
            Peter T.
            Thanks, Peter. I wasn't sure if the added diameter was a benefit for reaching into areas that are generally inaccessible or ?

            Basically, the diameter of this kidney wheel IS the distance between the upper wheel and the cradle floor at the lowest original position. There's contact at top & bottom with no room to install metal between upper & lower. It will fit if I lower the threaded bronze (?) lower adjuster in the frame (loosen four bolts, install suitable spacers and relighted bolts) and the raise lower anvil axle cradle adjusters higher to compensate. Maybe this is not a big issue, but this arrangement seems precarious so Ive only done it a couple of times until I can address it. I was going to make some 1/8" or 3/16" spacers to lower the threaded receiver and have thought about making a taller/deeper lower cradle to clear the kidney wheel with a quick release to use for regular lowers.

            heres a pic and some background for others here- When I took Peter's class at Will's shortly before my HandBuilt English wheel arrived, there were numerous times when he mentioned (probably muttered is a more accurate description) while trying to educate us novices that "if I had.."/"Wish I had.."/"my kidney wheel and I could just fix this.." shaping issue we were working on. He was the Master and I was listening to the Master.

            So I pestered him about more information and about purchasing one. Peter generously accommodated me. All was coordinated with Hoosier when I ordered the rest of my parts.

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            • #7
              Cliff another way to fix the problem with the kidney wheel space between it and the top wheel would be to take the shaft out and lengthen the machined slot where the key is situated, you would only need to lengthen it by about 8/10 mm on the top which it would allow the shaft to slide down further.
              PS on the pics ..looks like the pins on the cradle are not all the way down ?
              Peter T.

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              • #8
                Bill Tromblay lengthened the key way slot in Jim's HandBuilt frame like that at the Redenck Roundup, so that is another option. When I first discovered the issue, it was easier to just loosen the four boots, drop the entire threaded receiver and install a couple of trimmed washers as temporary shims.

                The cradle sides are too short for the kidney wheel to fit & clear or turn. I must raise the adjusters to raise the axle so the kidney wheel will not rest upon the floor of the cradle. That's my concern. The pic shows the fit I have without dropping the threaded adjuster. The dimension between the floor of the cradle and the bottom of the upper wheel is the diameter of the kidney wheel.

                When I drop the threaded adjuster lower in the frame, I have to raise the cradle adjusters even higher. The entire axle then is placed above the cradle & slots. The lower axle is then simply resting on top of the adjusters with no additional support or protection. Not cool. It makes me think I might accidentally knock the entire kidney wheel off of those adjuster posts when working and I don't want it to bounce on my floor....

                the cradle adjuster bolts also bottom out against the frame when trying to lower the cradle that much. I haven't installed shorter axle adjuster bolts yet as a workaround. That may help, but the kidney wheel still need to be raised a lot to clear the cradle floor and that places the axle very high if not above the axle slots in the cradle.

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                • #9
                  Hi,

                  Can someone post picture of the kidney wheel? I'm curious of the shape. Thanks

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                  • #10
                    Originally posted by Bill Tromblay View Post
                    Hi,

                    Can someone post picture of the kidney wheel? I'm curious of the shape. Thanks
                    Bill,

                    Hope this helps- this is the same pic I posted above of the one I have, made by Hoosier from Peter's drawings & propriery design. It's basically a normal width but larger diameter lower anvil with a very small full radius so it is very round in cross-section. The combination of small radius & extra diameter allows for greater reach into restricted areas as Peter described above.

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                    • #11
                      not sure if this is the anvil but i took a few pics while up at peter's last year i think

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                      thanks neil

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                      • #12
                        That looks like mine, Neil & looks like how I need to run my adjusters up so it will work with my cradle. If this is normal, maybe I'm overthinking it..?

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                        • #13
                          Originally posted by cliffrod View Post
                          That looks like mine, Neil & looks like how I need to run my adjusters up so it will work with my cradle. If this is normal, maybe I'm overthinking it..?
                          not sure cliffy, i was taking some pictures last year i think, i took some of the hammer set up too if i remember correctly.
                          thanks neil

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