Hydraulically operated mini Table Top Shearing Machines 1

[structure59]

Hi,
I have a table top model of Din Rail Cutter which is just a miniature hand operated shearing machine operating with a 1 mtr. long lever. It cuts m.s.channels of 1.6 mm thick in U and J shape easily. There is one fix and one moving die plate with slots to allow the U and J channel to be inserted.The total cross section of the m.s.channels is approximately 240 sq.mm.
Now I want to incorporate the feature of punching 10 mm dia holes in 10 mm thick copper flat bar by modifying the die plate to have a hole punch at the bottom.How much force will be required and what should be the length of the lever ?

Alternatively can somebody suggest suitable hydraulic mechanism for this operation ?
Thanks in advance.
Regards

 

[3DDave]

It depends on the shear strength of the copper, but multiplying the circumferential area of the hole by the shear strength should get an initial estimate of the force required. So 10mm x 31mm = 310 square mm is the area. I'd guess that mild steel has higher shear strength, so this should be similar. Copper is stickier than iron/steel - much more malleable, so the effort might still be just as high even if the strength is lower.

 

[EngineerTex]

If you go to your favorite search engine, search for a punch press tonnage calculator.

As far as distance the punch has to travel, there is no need for the face of the punch to enter the hole in the die.

Regarding the length of the lever, you can go with one inch. Wait - how hard can you push?

Engineering is not the science behind building. It is the science behind not building.

 

[itsmoked]

You may also be able to use the typical shear method of making the die progressive so only a leading edge is cutting, rather like scissors.

Hydraulic wise there are lots of punch/shears out there. They are just complex enough as to you'd not want to make your own. They typically come with a nearby hydraulic power-pack which is a small reservoir and a vertically mounted motor running a hydraulic pump that's suspended below in the oil.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[structure59]

Thanks itsmoked and keith for valuable inputs.