Piano Key switch grommets

How to keep the Cessna 170 flying and airworthy.

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dstates
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Re: Piano Key switch grommets

Post by dstates »

bagarre wrote:OK. Quick shot of the short cut.
This is a GREAT idea,...so long as you don't mind two tiny little holes in your plexi panel.
I got a picture of his panel and thought I would share it here for the next person interested.
12202F2F-5330-4602-B9AC-E40B6465B94A.jpeg
N1235D - 1951 170A - SN: 20118
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oldtrucksrule
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Re: Piano Key switch grommets

Post by oldtrucksrule »

dstates wrote:
bagarre wrote:OK. Quick shot of the short cut.
This is a GREAT idea,...so long as you don't mind two tiny little holes in your plexi panel.
I got a picture of his panel and thought I would share it here for the next person interested.
12202F2F-5330-4602-B9AC-E40B6465B94A.jpeg
dstates, So, I may follow your process. I have a couple follow on questions.

How did you find the exact locations to drill?

How many screws must be removed to remove the switch / fuse panel?

Thanks, Cory
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dstates
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Re: Piano Key switch grommets

Post by dstates »

oldtrucksrule wrote:
dstates wrote:
bagarre wrote:OK. Quick shot of the short cut.
This is a GREAT idea,...so long as you don't mind two tiny little holes in your plexi panel.
I got a picture of his panel and thought I would share it here for the next person interested.
The attachment 12202F2F-5330-4602-B9AC-E40B6465B94A.jpeg is no longer available
dstates, So, I may follow your process. I have a couple follow on questions.

How did you find the exact locations to drill?

How many screws must be removed to remove the switch / fuse panel?

Thanks, Cory
Cory,

You only have to drill through the plexiglass in two spots if you want to remove the piano keys without removing the controls. I believe there are eight total screws holding on the piano key assembly. Here is a picture of mine after I made my change to circuit breakers. Unfortunately I had some bad luck and actually broke my panel drilling the second hole after drilling the first one perfectly. I’ve since learned there are bits especially for drilling plexiglass. I used a standard drill bit and it caught for a second and broke my plexiglass. I’ll eventually end up replacing it, but I’ll wait till I’m ready to address control replacement. But it isn’t too noticeable unless you look at it from the view the picture was taken from.

The best way to locate the two hidden screws is to know that they are directly above the ones below the center “key” and in line horizontally with the top corner screws.

It has been beneficial having access to those screws as I had to replace a master switch last winter and I was able to remove the piano key assembly. I would totally do it again, just with the correct drill bit next time.

Hope this helps.
Doug
247E9352-C775-4F97-975F-04405A757AEE.jpeg
N1235D - 1951 170A - SN: 20118
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GAHorn
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Re: Piano Key switch grommets

Post by GAHorn »

To drill thru plexiglas without cracking it out… take an ordinary bit and grind the end flat …. to remove the “rake” or point.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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oldtrucksrule
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Re: Piano Key switch grommets

Post by oldtrucksrule »

Great information!! This is definitely going to benefit me going forward. I'll try to get some pictures to share also.

Thanks!!
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lowNslow
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Re: Piano Key switch grommets

Post by lowNslow »

Step drills also work well on plastic and composite materials.
Karl
'53 170B N3158B SN:25400
ASW-20BL
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GAHorn
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Re: Piano Key switch grommets

Post by GAHorn »

Doug, looking at the crack in your overlay…. it appears that your overlay is clear…and not painted on it’s back surface.. Is that correct?
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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dstates
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Re: Piano Key switch grommets

Post by dstates »

GAHorn wrote:Doug, looking at the crack in your overlay…. it appears that your overlay is clear…and not painted on it’s back surface.. Is that correct?
George, I believe it was painted. I used double sided tape to re-install the cracked piece.

Doug
N1235D - 1951 170A - SN: 20118
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