#41
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Johnny, that looks pretty good to me. That's about what I would expect from three rounds in my Shopdog shrinker that works well in my limited experience. And you have very little marking. I don't think you have far to go at all.
John |
#42
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Is it one of these bolts that you broke:
quillholder236.jpg That would be an odd problem, since all those bolts have to do is lift the quill. Even at speed, the mass of the conrod shouldn't be enough to break a 1/4-20. It'll make a bit more noise (just a little clattering), but I would try putting a shim or two in to space apart the 2-pieces of the connecting rod. The only other thing I can think of is that there might be a bit of side-loading going on, but there shouldn't be. Tim D. |
#43
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Johnny, I agree with Richard and Tim. That bolt shouldn't be breaking, certainly not twice now. I wouldn't think that even grade 2 chinese crap bolts would fail.
If the quill/connecting rod is in a bind, it will increase the load and cause it to heat up and eventually fail as Richard said. One way to check this is to pull the quill, remove the gibs, reinstall the quill, and just let it hang down unobstructed. You can then measure at the top and bottom of the adjuster shell and see if anything is binding when you have the gibs in. You should also be able to spin the shaft by hand fairly easily.
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Kerry Pinkerton |
#44
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That is the bolt.
I think it was a combination of two problems.First I over tightened the connecting rod around the bearing,second I had the connecting rod lined up perfect in the beginning but then I adjusted the quill and the tool arm to line up for dies.My mistake was not re-aligning the bearing after the adjustments. Its just a small bug I will get it taken care of.
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Johnny Arial This forum is dedicated to Metal Shaping. Please stay on topic. |
#45
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I made a upper die tonight that I can do some grinding and experiment with.
I still have soften the edges and play with the sweet spot. test run 6 185.jpg test run 6 186.jpg
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Johnny Arial This forum is dedicated to Metal Shaping. Please stay on topic. |
#46
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The photos show Lorne Richards dies I use in my Pettingell hammer, they work really sweet with minimal metal marking. I think it’s because the tail of the raised thumbnail isn’t sharp, it just sort of fades away in a way that doesn’t mark the metal. Also on old man Red’s recommendation I spaced the hit point an extra 1/8” towards the front of the dies. And on Red’s recommendations the hit point starts and stops at the 4 o’clock and 8 o’clock positions --- see the ink pen marks on my dies. I don’t know if these ideas will work on Pullmax type dies but they sure do work great on my power hammer dies. ~ John Buchtenkirch
!1sd1.JPG !1sd2.JPG !1sd3.JPG |
#47
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Thank you John
I still have to do some grinding.I'm leaving this weekend for Branson but I get off the whole week of Christmas off.I am hoping to tie up some loose ends that week. I have a lot of stuff started but nothing finished
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Johnny Arial This forum is dedicated to Metal Shaping. Please stay on topic. |
#48
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I was really tired last night when I posted so I have a bit more to add. Lorne told me my dies were copies of Red’s dies, that is why I contacted him about the hit point. I think Red is 100% on by saying the hit point has to be spaced off the front edge of the male thumbnail a bit, if you think about it, if it’s touching every time it strikes it would be bending the metal like a press brake but instead of a straight bend it would be in a little half circle.
When I took Scott Knight’s class I watched him change dies in his hammers --- I never saw him change dies without checking the hit point with black drain oil, even though he had used those dies many many times. If I was making thumbnail dies I would constantly be checking my progress on the hit point with the blackest drain oil I could get my hands on. Machinist’s blue will somewhat work for the actual contact point but with thick black drain oil you can see the clearance fade a-ways . Put the drain oil on the die faces, let the dies hammer each other lightly for a while and then study your die faces, where it’s oil free & shinny is the actual contact, where you can see the die thru the oil has a little bit of clearance and where it’s black you have a lot of clearance. The black oil contrasts the shinny die nicely , new oil or grease just doesn’t work worth a darn . ~ John Buchtenkirch P.S. A cute story. I sent Red an exact drawing of the top of my lower die and asked him draw in the hit point. I also enclosed a few photos of my 2 hammers (which I told him he could keep) and a self addressed & stamped envelope plus a check for $20 for his time and expertise. He sent back the drawing with the hit point drawn in, a brief explanation of what to look for plus he returned my check ! He kept my photos but said he felt funny about keeping my check. Obviously he was from an era where people believed in earning their money . !1sd2.JPG Last edited by John Buchtenkirch; 12-11-2009 at 11:06 AM. |
#49
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Interesting series of photos and writeup John. Am I seeing things correctly when I think the top of the male die isn't flat? If so, that makes the smile area pretty small. Do you have to watch the speed at which you pull the metal out of the dies? I do with mine or I get some marking. I'd really like to correct that, but not sure how.
Bob |
#50
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John, who is this Red person you refer to? Do you have any history on thumbnail dies on power hammers? I know that a couple people are credited with first adapting them to Pullmax's, that is Terry Stegall and Clay Cook. Probably others also.
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Kerry Pinkerton |
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