making a cut down copper sheet further than hacksaw can reach
 

what the topic says... i need to cut into a copper sheet... (very thin, say 0.7mm or less)
the part that holds the hacksaw blade would get in the way...

i dont have a jigsaw, so im going to have to buy a tool to do it and id like to buy the best tool for the job... (cutting into metal from above, jig saw style)

i used to have a jig saw, never used it for metal, it seems like it would make a mess of the metal and probably bend the shit out of it.

while we're at it, ive got another problem... i need to be able to solder a copper pipe onto a copper sheet, over where a hole has been cut. due to the nature of the design i cant make the hole bigger and put the pipe slightly into the hole.
the pipe's edge is going to be 45 degrees, so its not going to be perpendicular to the sheet.

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(the dots are empty space)

any suggestions on how to "clamp" the pipe to she sheet while i solder it?

You make no mention on how long the cut is overall. Just guessing, I would try something like a dremel tool, using an abrasive cut off wheel. Great little tool, but you may want to practice on a piece of scrap or something to get a feel for it. As fac as t fixture to hole your copper plate at the correct angle to the tube, why not cut a small block of wood with a hole bored through it at the same angle and diamter of the pipe you are using? Then, starting at the top position, clamp below the block and solder your first fin above the block. The lower the wood block to the next position and solder another one..................

the cuts need to be about 30-40cm long.

for the soldering the pipe to the plate thing, i reckon some wooden contraption needs to be made, with a spring or something... :drool:

I've used a cutter to score 0.5mm aluminium - bend it & it breaks off easily. Copper wouldnt behave the same way I guess.
Heavy duty scissors?
:shrug:

Well the obvious is tin snips or even better a nibbler (no distorsion)

For the pipe just cut the end to the correct angle and prop it up with something

slater..

http://www.contacteast.com/product/g...parent_id=1271
Nibbler


Jigsaw will work fine, just use a very fine toothed blade. If it'll cut steel cleanly, it'll cut copper cleanly.

that nibbler looks like a nice cheap tool to have...
i guess im gonna have to buy another jig saw again :/
need to make some sub boxes for my car too at some point.

Be sure to get one with a reciprocating blade. It makes mdf/fibre/chip board work extremely fast compared to non-recip models.

For the cut, tinsnips (e.g. "aviation snips") of course. These are churned out by Chinese factories and sell cheap anyplace on Earth. If the material isn't very heavy ordinary scissors work fine too, go figure.

This tool, guided by a straightedge, will make very accurate cuts and doesn't warp material or leave burred and serrated edges like snips do. It's mainly for scoring brittle plastics for snapping, but can also be used to scratch through soft metals in several passes.

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A pipe-to-plate butt joint will be crazy fragile. Is it possible to punch an undersized hole out so it looks like a crater? Then you can jam the pipe through (tight), solder to fill, and cut off the excess. I know you said it can't be done on account of the angle, but why not just bend the copper pipe, or even bend both pipe and plate (locally) after the joint's made?