Cutting 57mm holes in the instrument panel.....how to?

[John Bojack]

Here in the states I find it impossible to find metric hole saws.....so,
what have others done when cutting new panels for 57mm instruments?

Thanks!

J4

[Guy Byars]

I simply bought an adjustable hole saw. I measured it out to
precisely 57mm and cut several holes in scrap material to check and
make sure the saw was set to the right size. As long as I cut soft
material (aluminum, wood, fiberglass... etc) it worked perfectly.

[sisu1a]

> Here in the states I find it impossible to find metric hole saws.....so,
> what have others done when cutting new panels for 57mm instruments?

2 -1/4" holesaw for 57mm, 3-1/8" for 80mm... I have a set I only use
for cutting instrument holes so they stay nice.

-Paul

[Eric Greenwell]

Or just use a 2.25" standard USA hole saw. It's only 0.006" bigger than
57 mm, and you'll never notice the difference.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm http://tinyurl.com/yb3xywl
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what you need to know tinyurl.com/yfs7tnz

[Richard]

John,

Go to

http://www.craggyaero.com/ultimate.htm

Download the 2.25" and 3.25 Instrument hole templates at the bottom of
the page and follow the directions.

A 2.25" hole saw will work fine mark the center hole as in the
directions and us small pilot drills for starter holes then the 2.25"
hole saw then the instrument screw holes.

Make sure and use a punch to get the starter holes exact.

Richard
www.craggyaero.com

[cfinn]

One of the best ways is to use a hole punch. You need a 1 1/4 inch
size. Aircraft Spruce carries them. Here's a link:
http://www.aircraftspruce.com/catalog/topages/knockout2.php.

Charlie

[Dave Nadler]

On Nov 11, 7:09 pm, "John Bojack" <jboj...@charter.net> wrote:

http://www.blotorches.com/

[Canav8]

Charlie, I think you meant to type a 2 1/4 inch hole. 57MM equals 2.24
inches. Doug

[Alia Kuykendall]

On Nov 11, 4:09 pm, "John Bojack" <jboj...@charter.net> wrote:
> ...what have others done when cutting new panels for 57mm
> instruments?

Sawzall.

Much neater than the chainsaw, but not as cool as a loop of det cord.

Thanks, Bob K.

[Bob Kuykendall]

On Nov 11, 9:39 pm, Alia Kuykendall <alia.kuykend...@gmail.com>

> Sawzall.
>
> Much neater than the chainsaw, but not as cool as a loop of det cord.
>
> Thanks, Bob K.

Oops, that was my post.

Thanks, Bob K.

[Craig]

We just figured your daughter was picking up the torch. Put a sawzall
in their hands when they're three and they'll never look back.

Craig

[Peter Purdie]

The suggestion to use 2-1/4" or 3-1/8" hole saws is absolutely correct.
Those were the original standard instrument sizes (and you will find that
the P.C.D. of the fixing holes is also a neat measurement in inches.

Over here in metricland where they don't understand inches, it was
converted to the nearest integer millimetre.

And a hole saw (used on a panel clamped down to a good rigid drill press
bed for accuracy) is a damn sight less costly than a hole punch.

Although Bob's idea of a piece of det cord looks interesting, I must try
it. On someone else's panel...............

[Derek C]

Surely you can order metric hole saws by the internet? The hard work
way of doing it is to scribe the correct size hole onto the panel,
drill out a series of adjacent holes just inside the scribe mark,
knock out the centre, and them finish to size with a half round file.

Derek C

[Craig]

On Nov 11, 9:42 pm, Bob Kuykendall <b...@hpaircraft.com> wrote:

New aluminum panels can be cut out pretty effectively by waterjet or
laser using a local fabricator. I think I paid $80 the last time
(aluminum included) and just had to give them the drawing file.

Craig

[Dave Nadler]

Aluminum panels are quite dangerous in an accident;
edge removed leg of a friend in a crash.

Please use fiberglass panel with a integral rounded
flange as do all modern manufacturers. If you have
an older glider with an aluminum panel consider
upgrading it (good opportunity to add an SN10).

No kidding here.
Best Regards, Dave

[cfinn]

> > One of the best ways is to use a hole punch. You need a 1 1/4 inch
> > size. Aircraft Spruce carries them. Here's a link:http://www.aircraftspruce.com/catalog/topages/knockout2.php.
>
> > Charlie
>
> Charlie, I think you meant to type a 2 1/4 inch hole. 57MM equals 2.24
> inches. Doug

Thanks for the correction. Fingers on the wrong key. I need to edit
better before punching the send button! At least the link was correct.

[Craig]

I've had similar concerns about the aluminum panel and will probably
change to a fiberglass tilt up panel this winter. In the meantime,
I've set up the panel so that the upper bolts go through a vertical
slot that opens toward the bottom and the lower bolts are nylon that
will shear in an impact. I still have the sharp edge of the panel and
its weight to overcome, but at least it's free to break away from the
fuselage structure.

Thanks,
Craig

[Craig]

P.S. If anyone's looking to sell their SN10, please contact me via
email.

Thanks,
Craig

[bildan]

Unless the older glider used the instrument panel as a load bearing
bulkhead.

[Ralph Jones]

>Thanks, Bob K.

But this is just the right size...

http://www.rt66.com/~korteng/SmallArms/57m18.htm

rj

[Dave Nadler]

True: Some may use the panel to help prevent the
rails below the canopy from spreading on impact.
But actually, most gliders of a vintage that uses
aluminum panel have no effective crash-worthiness
anyway. Contact the manufacturer for specific
recommendations if panel bolts to sidewalls,
for pedestal-style just replace the dangerous bit.

Best Regards, Dave