I am interested to find out people’s opinions/ideas on how you would modify the round holes in a PA28 panel to allow a pair of Garmin G5’s to be flushed in? As diagram below:-
I am not keen on any method that could create swarf or filings as I don’t want metal bits ending up in various looms. I was thinking a square Q.max punch might do the trick. They are hideously expensive for large ones but perhaps punching out each corner and using a punch like this to “nibble” away and join up the corners. A sacrificial plate could be put in each time to allow the punch to cut cleanly & square. A plastic cover bezel will go over the top so if the “sub-panel” cut out was not perfect it would not matter.
What are the tricks of the trade? – BTW an installer will do it but I like to plan in advance and I get the feeling that not many people have flushed G5’s in certified Aircraft to date as the flush kit is relatively new.
Also any ideas where to get Q.max punches at a reasonable price?
If you don’t want swarf in the aircraft then take out the panel and do the work on the bench. Unfortunately on a PA28 you do have to drill out the lower row of rivets for this behind the control yoke plastic trim, so no getting away from at least some drilling residue.
You could always do a full flat-panel like this 1975 Warrior we did for Reborn Aviation:
A flush install requires nice edges. I think I would either mount them un-flush, or take out the panel and redo/re-paint the whole thing while at it.
Thanks Wigglyamp and LeSving
My plan was to mount the G5’s semi-flush. Perhaps sink them in about 6-8 mm but not sure the exact depth yet.
Then (after getting it scanned) throw away the Piper plastic bezel and get a computer laser cut piece of painted Aluminium with screen printed decals. The replacement outer bezel will be perfect and will be mounted on spacers to replicate the gap that the Piper plastic stands out so the (rubbish) Piper lighting can work.
Would a replacement Piper bezel be allowed without lots of EASA paperwork I wonder?
In my opinion, non-flush mounted G5’s look like something out of a 1960’s Nuclear Power Station!
The swarf & filings are a problem but wrapping the looms in kitchen foil and having a second person holding a vacuum cleaner very near to the cutting will keep the work area clean.
The hole cutter in post #1 still needs the centre hole drilled so you still get contamination.
Having had a pile of metal filings left behind the panel by a “top uk 145 shop” (not the one which did the TAS605; this is another one) I well understand the problem
I would do what A&C suggests and put in some protection while somebody holds a hoover in place. A hoover is necessary for even a small hole drilled because you never know where the stuff will go.
If I got a Q.max punch a reasonable size then the centre hole would be in the original round instrument hole and hence in the “sacrificial/temporary” plate that I’d bolt in each time. Hence the centre holes could be pre-drilled on the bench. (Even if it was 4 x operations per G5). I’ve found Q.max punches half the price of my original post on Ebay.
I must admit that I had not thought about the 6 small mounting holes! I had thought about a hoover as I’ve often used them for example drilling a plaster ceiling inside a house to put a light fitting up. Perhaps a 4 mm plywood box could be stuck to the back with Blue Tac (U.S. translation = Poster Tack). All the rubbish would fall in the box and could be hoovered out?
Any other tricks of the trade out there or perhaps I’m making this too complicated? – A hoover should do a pretty good job I suppose. (As this is Aviation I’m surprised that Garmin don’t sell a super expensive punch for $ 2,000 and insist dealers use it as part of the STC………….better not give them ideas!!)
The punch will make a hole with bad edges which will need filling.
Thanks for the feedback all – the Garmin plate is better for me as it allows the exact depth of recess that will work best for me.
How would you make the hole? I am guessing most people would use a hacksaw blade, tidy up with a file and hoover? A bespoke 4mm ply box on the inside stuck with Blue Tack would stop all of the swarf falling inside would help.