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All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Share Your Simple Home Projects (TRICKS-N-TIPS) => Topic started by: Ronno6 on February 21, 2021, 11:38:31 AM
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Daisy has been out of seal kits for 880's for some time, and it'll be a while before they get some in.
I have U-cup seals and the correct O-rings, but that pesky foam oil ring is not so simple.
I sell these parts in kits for resealing new and old 880 platform riffles.
I have sheet foam if the correct (I think) material.
I have 3/8" I.D. and 3/4" O.D. punches for the correct ring size.
I made am aluminum button to place in the ID in order to concentrically locate the OD
Punching by hand doesn't always produce a concentric donut, even with the tools I am using.
And I struggle with getting square edges.............
I have tried depressing the punches to compress the foam; I have tried barely resting the punches on the surface and letting the hammer blow do all the work. Nothing seems to reliably produce the desired result....it is "Hit or miss" pun intended but accurate.
Any suggestions or guidance would be appreciated.
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Try wetting the foam and freeze it. It may hold its shape that way.
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Try wetting the foam and freeze it. It may hold its shape that way.
I'll try that...thanks!
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Try wetting the foam and freeze it. It may hold its shape that way.
I'll try that...thanks!
Do you have any kind of arbor or hydraulic press? I struggle ALL THE TIME to get perfect rubber washer donuts with the hammer punches. Usually 4/5 are usable but 3 of those are "ugly" ones. Pretty much 1/5 is always WAY OFF concentric (trash). The few times I was able to use a PRESS instead of a hammer they all came out MUCH BETTER.
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I have a 20 ton hyd. press....it is laboriously slow, bit I may try it.
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A two lip punch with the leading edge of the inner diameter lip being .008 “ shorter than the outer diameter. Using a rubber pad to rest material on.
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Can the punch be chucked and spun on a drill press ?
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Could the hole be punched first then place it on a jig with a correct sized pin in the punched hole Do the outside diameter last
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Could the hole be punched first then place it on a jig with a correct sized pin in the punched hole Do the outside diameter last
Precisely the way I do it.........I love having a metal lathe....
I punch the 3/8" center hole and drop an aluminum button w/3/3" projection and 3/4" O.D. over
which I use the 3/4" punch.
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Can the punch be chucked and spun on a drill press ?
The O.D. punch body is probably 1" or so....larger than my DP chuck.......
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Can the punch be chucked and spun on a drill press ?
The O.D. punch body is probably 1" or so....larger than my DP chuck.......
In that case, perhaps the proper sized hole saw would work, just grind off the teeth to a razor edge ???
https://www.amazon.com/MonkeyKingBar-Wood-Full-Mandrels-Install-Drilling/dp/B07XDTLLJM/ref=asc_df_B07XDTLLJM/? (https://www.amazon.com/MonkeyKingBar-Wood-Full-Mandrels-Install-Drilling/dp/B07XDTLLJM/ref=asc_df_B07XDTLLJM/?)
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Compress the foam before punching it out, you will get square shoulders this way.
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In many of the HOBBY activities using Foams there cut via HOT WIRE method
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Compress the foam before punching it out, you will get square shoulders this way.
Yessir.
That's one of the techniques I have tried.........not tremendously successful.
I haven't learned how to hold my mouth right.....
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In many of the HOBBY activities using Foams there cut via HOT WIRE method
Hmmmmmmmm
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Some reason to not make it as a strip and melt/glue the ends together?
Al
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Some reason to not make it as a strip and melt/glue the ends together?
Al
Dunno........
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Most hobby stores will have thin wall brass tubing. I have used it to punch out holes in thin foam and rubber for gaskets. You have the option of filing the ends to a sharp edge either on the OD or the ID. The smaller hole can be done with the ID sharpened and the larger hole can be done with the OD sharpened piece. Depending on how tough the material is, you can just press through softer material or just spin by hand with light pressure to cut heavier materials. This hopefully will work for your application.
pv