Cutting Holes In MDF

[bitingmidge]

I am about to embark on the next great blast gate adventure which of course will mean cutting a lot of holes in 6-18mm MDF with diameters mostly 150 or thereabouts but going down to 75mm.

I really should conduct a poll on this one, but....I plan to set up a jig and use a router on a trammel, with tolerances close enough to get a push-fit on pvc ducting.

Question: Is there a better way?

Other options as I see it are:-

1) Purchase hole saw/s to precisely the right size (say $50.00 each)

2) Buy a wing/fly/roof/circle cutter - one of those gizmos with a sliding bar and blade at one or two ends for use in a drill press. Prices range from about $30.00 (FHP) to $180.00 (presumably for a better quality tool from Glenfords.

3) Jig saw- (I don't think I can get tolerances close enough?)

4) Any other?


Any advice appreciated as always!
Cheers,,
P

[rodm]

IMHO go the router and circle cutting jig or make a circular template.
Hole saws at 150mm will need a lot of grunt to drive them and the fly cutters are dangerous weapons. Also both of these methods will likely jam while you are cutting.

[Bob Willson]

I think that if I were going to cut a lot of 6" dia holes in 18mm MDF then I would use a router with a template.

Also, if possible I would cut the holes while the sheet was in one long piece and cut the holes off afterwards

[soundman]

I am in two minds.
I have a fly cutter and it does a very nice job and fast. mine is the type with the perspex bowl for safety. and removable tool steel bit.

A template looks good also particularly if you make up a jig & a vacume box.
I know its a good way to bang out a lot of speaker fronts in a hurry.

the hole saw is a rough ride & the above will make a nicer job id done right.

ps
a good fly cutter will cost you between $100 & $150.