need advice enlarging hole for autopilot

[mjones 59]

I found a replacement controller for my autopilot but it's a newer model and the New unit has a

Larger center hub. On a new installation I would use the right hole saw, but I don't know the best

way to enlarge an existing hole. Due to the cabling it has to stay where it is.

 

                                                                        Thanks

[J&J]

Use 2 hole saws on one arbor put the larger one on first then the one that matches your existing hole the inner will guide.had the same problem installing a hyd helm last year.

[landingzone]

How much enlargement do you need?  If it is just a small amount (1/8" to 1/4" dia. increase) you may be able to use a rasp of some sort.  For more than that maybe a sabre saw would work w/o damaging the cables.

[John E Powell]

If you do not have the capability or equipment for the double hole saw described above, you can place a temporary cover over your existing hole and then drill a new hole using the cover to center the pilot hole for your existing hole. A piece of clear plastic is ideal so you can easily see the center of your existing hole. Then just drill through both the materials at the same time.

Edited July 1, 2013 by John E Powell

[Tall Tails]

Roto-zip will work perfect. Just trace your new line and cut it.

[sszoldra]

Or you can do what I did when I was in the same predicament  . I called Raymarine and they shipped out a surface mount adaptor  at no charge.

[Has Been]

 They sell a rotary rasp that fits on a drill in different stlyes. They work great , A few bucks a lowes . Tape /protect exist cable in case you slip.