best way to cut 175mm hole in mahogany

[lenseman]

hi there all woodies what’s the best way to cut a 175mm hole in 1 inch mahogany any ideas greatly appreacheated

Bring your timber up to HMS Victory in Portsmouth harbour and get the crew to load and fire off one of their 'tween deck cannons! That will do the trick for you.

Only one of my ideas, mind!

 

[forethought]

When running out of electric drill torque with a hole saw, use a long arm ratchet spanner to turn the saw. Nearly as slow/bad as 2 nails and a bit of wood technique.

Cut a hole in a steel fuel tank in about an hour for a Webasto heater fuel pickup with this method.

 

[Scotty_Tradewind]

I've come to this posting late and initially it wasn't clear as if the 175mm was circular or square.
If it had been square and you wanted accuracy and a very clean cut, I would have recommended the fein Multimaster.
It's an incredible piece of kit.
http://www.feinmultimaster.co.uk/
I have done some major works onboard with it in a fraction of the time it would have taken with conventional tools, with less mess and better results.
It can make DIY a lot easier in the home.
I have my own and had a job to get my hands on it as my bespoke stairmaking son kept on borrowing it..... so I had to get him one last Christmas.
Bosch do a far less expensive model but with fewer blades available and a little less speed control, but can also be exremely useful.