[Arctos]

Greetings,
Has anyone seen or used the Enhanced Circle Cutter attachment for a Rotozip cut out tool?  I just saw this yesterday at the local hardware store and am wondering how accurate it is.  It looks very easy to use (if you own a Rotozip, which I do) and claims it will cut circles from 1" to 20" in diameter.  These diameters should work for most driver, post cup and port tube holes.

Thanks,

RDS

[randytsuch]

Something like this?
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=365-255&DID=7

Its for routers, not sure about a rotozip

Randy

[Arctos]

Randy,
I am familar with the Jasper jigs and they are supposed to be pretty accurate, but you need 2 of them to cover the range of the one from Rotozip (the 2 jaspers will get you 1" to approx. 18", where the Rotozip claims 1" to 20").  The cost for the single Rotozip unit would be about half that of the Jaspers and it may be easier to handle due to the smaller size of the Rotozip tool compared to the average router.

http://www.rotozip.net/rotencircut.html

I would love to hear from someone that has used one of these.

Thanks for the reply,

RDS

[gonefishin]

Hi there.

  The circle jig for the roto-zip actually works pretty good.  In the pic below you can see a couple of the circles I used to cut with the roto-zip.  I used the roto-zip to cut the midrange and tweeter holes...The 15" woofer opening was large enough to just cut with a jigsaw.

   When cutting holes in wood with the roto-zip...remember to practice on a junk piece of wood first.  After your practice hole is cut...measure to make sure that it's the desired size.  

   Also, There are a few ways to cut the hole...but the method I find to work well is to lay a second "scrap piece" under the wood your cutting the hole in.  then set the depth to go just into the second piece of wood.  Set your center pin in the center of the circle...and go slow!.  Don't push the roto-zip...you'll be guaranteed to break every bit if you push to hard.  just go slow...position yourself (and the cord) so you can easily cut the hole in one turn.

   If you go nice and slow...keep the rotozip at a nice 90...and don't push...you should be able to cut the circle off without a "nub" at the very end of your cut.  What can happen is this.  If your cutting a circle with the board laying down...and you've got the "center pin" of the jig in the middle of the circle...all will go well with the cut.  But when you get to the very last second of the cut...and the circle is completely cut out...your middle position is then released.  the circle is cut out at this point and you don't have a stable center pin any more.  Here it has the ability to shift or move a bit.  Leaving with a very little nub (or a nubett).  If you find this happening...and you want to avoid it...you can try to go slower and keep yourself and the tool nice and steady.  If it still isn't working for you...you can change the center set pin to something that goes thru the entire thickness of the board your cutting and halfway into the bottom 'scrap" board.  This way...your center is set into a stable piece of wood...even after the circle is cut.
    Another way I have heard of people doing this is to cut the circle last.  Assemble your entire box...and once your completely done...find the true center...mark the center.  Then set the depth on the roto-zip (or router) just a fraction of a 1/8" short of going thru the board.  Then cut your circle.  The idea here is that you will find the true center of the assembled speaker...and by setting the depth just Short of going thru...you never "release" the circle...so you keep your stable center point.  After the circle is cut...you can finish the cut with an exacto knife...releasing the circle.


    If you don't have a roto-zip...I'd just get a jasper jig...if you have a roto-zip...I'd get the circle jig for that.

[Arctos]

Thanks for the info!!
I have a router and a Rotozip.  I actually made a custom hole jig for the router and it works pretty well, but I didn't design it to work for sizes smaller than 3" and larger than about 14".  I think I will pick up the Rotozip model based on your info.

Thanks again,

RDS