Author Topic: Punch for Cardboard/Gasket  (Read 1843 times)

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1405
  • North Eastern Pennsylvania USA
    • YouTube Channel
Punch for Cardboard/Gasket
« on: February 20, 2017, 09:11:51 PM »
This came about from a need for a school project for my daughter and I realized that it could apply to our hobby for gasket making.

This punch can be used at any location on a sheet of cardboard.  It was "whipped up" in around five minutes from scrap "off the top of my head".  No formal dimensions, just "that looks about right". 

The cone in the center is for picking up punch marks for locational purposes.  The punch is used by simply laying the cardboard on block of wood and stricking the punch with a hammer. 

It has a .020 wall thickness with a slight internal chamfer on the id.  It was quickly deburred/honed with a stone while still in the lathe.

The cardboard in the picture is .020 thick.  Being, "whipped up", the punch is not perfect. The punched slug has to be picked out with an Exacto knife. With some refinements I believe that it could be developed into a useful tool.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13491
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: Punch for Cardboard/Gasket
« Reply #1 on: February 20, 2017, 09:29:48 PM »
Nice Bob and obviously worked well too. What did you use under the cardboard to keep the edge from dulling? Also you could drill a small hole through it off center and use a rod to push the slug out if you wanted to get fancy :)

Bill

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1405
  • North Eastern Pennsylvania USA
    • YouTube Channel
Re: Punch for Cardboard/Gasket
« Reply #2 on: February 20, 2017, 10:17:16 PM »
Thanks Bill. 

I just used a scrap piece of wood under the cardboard.  That's part of the trick of how it works. The wood provides enough resistance for the punch to cut, but "gives" enough so that the cutting edge doesn't  get damaged.

I like the off center/hole idea.  It's nice and simple.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline wheeltapper

  • Full Member
  • ****
  • Posts: 61
Re: Punch for Cardboard/Gasket
« Reply #3 on: February 20, 2017, 11:07:16 PM »
when I use a punch like that I find it works better using the end grain of the wood.

Roy.
I used to be confused, now I just don't know.

Offline Thor

  • Full Member
  • ****
  • Posts: 140
Re: Punch for Cardboard/Gasket
« Reply #4 on: February 21, 2017, 05:12:52 AM »
 Nice work Bob, simple but effective.

Thor

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1405
  • North Eastern Pennsylvania USA
    • YouTube Channel
Re: Punch for Cardboard/Gasket
« Reply #5 on: February 21, 2017, 10:53:09 AM »
Thanks Roy.  I actually used the end of 2x4 clamped in the vice for my daughter's project.  I put a slot with radiused corners on the end of a cereal box for her.

Thanks Thor.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline ART

  • Full Member
  • ****
  • Posts: 26
Re: Punch for Cardboard/Gasket
« Reply #6 on: February 21, 2017, 01:22:29 PM »
Hey Bob, Nice work on the punch. The suggestion for using the end grain in wood  works well. I have also used lead. I got several of the old wheel weights, melted them and poured the melted lead into a cat food can so the total thickness was about .500, and cut the can away. This left a smooth surface which would not dull the brass tubing I was using as the punch. Once the lead got full of punch marks I just would re-melt it in the same type of can and make another one. Art

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1405
  • North Eastern Pennsylvania USA
    • YouTube Channel
Re: Punch for Cardboard/Gasket
« Reply #7 on: February 21, 2017, 02:24:31 PM »
Thanks Earl.  I like the lead idea.  Lead should work much better than wood.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline wheeltapper

  • Full Member
  • ****
  • Posts: 61
Re: Punch for Cardboard/Gasket
« Reply #8 on: February 21, 2017, 07:42:32 PM »
Lead sounds a much better idea.




now where can I get some lead? :thinking:

Roy.
I used to be confused, now I just don't know.

Offline Lew Hartswick

  • Full Member
  • ****
  • Posts: 232
  • Albuquerque, New Mexico, USA
Re: Punch for Cardboard/Gasket
« Reply #9 on: February 21, 2017, 09:36:30 PM »
No formal dimensions, just "that looks about right".

-Bob
:-)  TLAR .  That is what one of instructors told me to use when turning from down-wind to base leg on landing in sail-planes. :-)
I think it's a very useful "measuring" technique.
   ...lew...