Looking for a Suitable Tool

[Prof]

I have an MDF timber box (describing it simply) that has a 200mm. hole cut out the bottom..The bottom panel thickness is 25mm.

I want to increase the hole to 250mm. in diam. The internal box base is approx. 300x300.The depth of the box is 150mm..

Normally a simple enough job, but in this instance I can only reach the hole by going into the box because it's a part of a larger construction..

There's not enough room inside the box to use a router or jigsaw, so any ideas what sort of cutting tool I can use..

[Brad]

Coping saw is the first thing that comes to mind.
Mostly used with holes drilled around the shape you want cut out, then cut between the holes and clean up the cog shaped hole it leaves with a file or a power burr.

[Prof]

Sorry..one thing I forgot to mention..There is another solid panel directly below the cut out, and the space between the panel that has the 200mm. hole and the solid panel is only 50mm.. so there's no room to fit a coping saw..
It can only be cut from inside the box like you would normally use a router or jigsaw..

[Jason]

In addition to @Brad, some of our other keen woodworkers on Workshop include @darylhewston, @AndrewJones, @Wayne, @She_Skills and @Rusty-Saw. 

Hopefully they will have some suggestions for you @Prof.

Jason

[darylhewston]

@Prof

What about a reciprocating saw or multi-tool with a timber attachment?  Otherwise you could try a handsaw cutting multiple cuts from the 200 to the 250 mark and knocking out with a hammer.  Tidy the larger hole with sandpaper.

Cheers

Daryl

[AndrewJones]

Can you provide a photo? Might help with how to approach the problem.

[Prof]

Thanks Daryl..
A reciprocating saw might be the answer if I can get a blade that's less than 50mm. long..
Don't those multi-tool devices only have broad flat cutter? would it cut through 25mm. thick MDF?

[Prof]

This is the unit in question..The dark angle brackets are only there for support during construction..

[Wayne]

I think looking at your drawings the only option would be a Mutli-tool, different width blades are available and it would chew through MDF like butter. Not really designed to travel but a series of individual cuts will conquer the task quickly.

[Brad]

https://www.bunnings.com.au/dremel-multipurpose-cutting-kit_p6373718

Should fit in with room to spare, from memory it is painfuly slow though.