MadModder
Gallery, Projects and General => How do I?? => Topic started by: Mike K on October 27, 2021, 05:20:45 PM
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I'm making a pair of Kant Twist clamps. I'm not using threaded fasteners to hold the plates together; according to the plans I have, I've made pins and am peening the ends. The trouble is that the slop that I thought would go away hasn't. My pin shoulders wound up about 2-3 thou smaller than the holes, and they're about 102 thou long going into 16 gauge (62 thou) thick arm plates. After a few minutes of peening with a small ball pein hammer I have the pin staying in and not falling out, but the 2-3 thou slop is still there and the extra 40 thou that I thought was needed for peening hasn't reduced that much. So, there's slop in both directions.
I'm wondering if: 1) My hammer is too big?...it's 8 oz and on the scale of the 3/16" pins maybe the end is too flat? B) The extra 40 thou beyond the plate thickness is too much? The plans were calling for 60 thou, though. And iii) I just need to spend much more time hammering?
Any tips for peeing would be appreciated.
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You are peening round the edge of the pin not just hitting it square on aren’t you?
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Well, no...I was hitting it square, but with the round nose end of the hammer. I guess this is an obvious mistake.
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Actually, I was hitting every spot on the face, square on as well as the edge. I think I need a smaller nosed tool, like maybe a small drift with the nose rounded? The pin face is only 3/16".
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Rivet snaps are the tool to use , you can make them with a ball nosed end mill or buy them ready made .
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Mike
Far from your hammer being too big I'say that 8oz is much to small. Try a 2lb hammer.
Phil.
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My thinking for needing a smaller hammer is that the peen end will have a smaller radius. The peen of a larger hammer has a face that's nearly flat compared to what I'm peening. That would be like hitting it with a flat faced hammer, no?
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Maybe a beefy center punch?
Sent from my SM-G892A using Tapatalk
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Okay, I finished up one side of the pin and did another pin very quickly. First pin literally took about ten minutes. Second pin under a minute. Both pins are nice and tight. I changed up a few things. I was using the "drill block" directly on the vinyl floor (concrete slab underneath). I moved that onto a wood block that I use as a car jack stand. I also took bigger swings, I think. And I was angrier this time. :)
Thanks, guys. I've literally never done peening before. I think I should still get an anvil for future use.
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:mmr:
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Another question...
The elbow hole of that harm holds a pivot piece that the leadscrew fastens to...It'll turn as the clamp opens and closes. I have a rod of bearing bronze that I was thinking of using for it. Will that peen well? Or will it distort too much and leave me with a bad pivot? It's part #7 in the diagram.
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I made my pivot pins longer and when peening kept turning the pivot until it felt right .
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(http://)#7 and #4 are not peened on the real thing.
p.s. One of the #3's is not peened.
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(http://)#7 and #4 are not peened on the real thing.
p.s. One of the #3's is not peened.
Now that I think about it, it makes sense...the pivots don't need to be peened as the plates are already bound by the other pins that *are* peened. And that explains why there is a #3 so close to that pivot. Thanks.
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I made my pivot pins longer and when peening kept turning the pivot until it felt right .
I may do this if the 16 gauge plate winds up being too flexible. Thanks.