panel rewire

[LBPilot82]

Greetings everyone. Well the time has come (sooner than I expected) after recently purchasing my 170 to replace my failing comm. Of course, as expected, this completely snowballed into totally redoing the panel with all new IFR ready radios, transponder, instruments and while I'm in there, rewiring the panel. Of course I have a thousand questions but I'll stick to some important ones.
First, I want to change my fuses out for circuit breakers. My IA recommended Klixon breakers. Has anyone used the 7277-2 breakers? Are these approved? The AC Spruce book says they are "designed for applications that do not require the tighter performance characteristics and approvals of our military circuit breakers."
Miles- I have read your posts on how you mounted your new breakers, did they all fit under the panel (main breakers AND avionics?) Have any pics?

Second, my cigar lighter was previously removed and I want to put one back in for a portable GPS unit. Is something like a $58.00 unit from Spruce the only (and I use this term very loosely) legal way to put one back in? I was thinking maybe getting one from an aircraft salvage yard.

Last, with replacing the instruments, I want to upgrade the old post lights. I have read some good reviews on the NULITE lights and am considering them. I was also recommended using the standard post lights with LED bulbs to replace the incondescents. I like both of these options as it can save a fair amount of current draw. George, I read your post on the interior light upgrade and I am also very impressed. Are the post lights on the B model the same and the A model?
Anyone use/like the NULITES?
Thanks all.
Richard

[hilltop170]

Richard-
The fuses can be replaced nicely with Klixon circuit breakers. The ones used were the pull to disconnect style, don't know the part number. Log book entry only as I recall. Some of the more tech-smart folks can verify that.

Two new panels were fab'd for the c/b's, one for the radio stuff and the other for all the rest of the electrical stuff.

I kept the old post light because I like them.

The cigar lighter was replaced with new and a separate fuse is required for it to be legal. Again, the tech-smart guys can verify that.

Good luck with your project, it's going to be interesting. The IFR stuff will be tight but it should all fit somewhere.

Click on picture to enlarge

[GAHorn]

The instrument light system is different on the A and B models, but LEDs are made which can replace the standard incandescents on an A model. (The B-model used directed-spot lamps, the A-model used lights incorporated into the panel itself.
The Nulites are good, but are not always compatible with some of the older AN style instruments. They are LED and provide similar electrical demands.

[dacker]

I installed the Nulites and think they are great! I was able to use mine with all of the 3 1/8" instruments including the old style DG. If I could figure out where to post pictures I would take some. When I installed mine several years ago I did not buy any for my smaller guages but used the stock lights instead. I soldered ground wires on the stock lights to eliminate the flicker I was getting from vibration causing them to lose their ground. I built a harness for all of the lights and used the old reostat. It all works great and provides a full range of lighting without the flicker I was getting from the stock lights. This was a nice little project that did not take too long.
David

[cessna170bdriver]

deleted by the author

[GAHorn]

Pictures may be posted whenever a message is being written or edited. You must LOOK DOWN (scroll down) below your screen to see the "upload attachment" TAB. click on it, and "browse" thru your computer to find the pic, then click on "add the file" . You can further influence exactly where in your message you wish to place the pic by clicking on "place inline" and it will put the pic wherever your cursor is located in your message.

[LBPilot82]

Hilltop170- love the picture. That is very much what I am looking to do. I tried to upload a picture of my current panel but got an "image invalid" massage (George?). Anyway, really like the 430, but couldn't find room on the panel without removing the glove box, which I would like to keep if possible. I see you removed the lower sub panels which I am also trying to keep. Of course this meens making a new one on the left side to accomidate a slightly smaller radio stack. I went with an all Garmin stack with the SL30, SL40, GMA 340 audio panel, and GTX 327 trans. Most of the old instruments are unusable as they are probably twice my age. Some can be refaced/overhauled.
Staying with the ventury system for vacuume but have concerns about being able to pull enough vacuume for modern gyros. My vac. indicator under normal cruise speeds/altitudes usually shows around 4". New gyros need at least 4.5. Anyone have any thoughts? Looking at replacing the old venturies with a couple of new ones (maybe the 9in. super venturies).

[bpaige]

I am working on my '52 170B panel also. I intend to replace my fuses with the W23-xx breakers. Do you guys just go shopping or have you found a particular store that beats the rest on price? I would also like to ream out the 4 instrument holes (located between the control tube sockets) to a full 2.25" and mount the instruments using standard instrument mounting screws (removing sub-panel #0412491). Have any of you guys done this?

[cessna170bdriver]

deleted by the author

[GAHorn]

Hilltop170- love the picture. That is very much what I am looking to do. I tried to upload a picture of my current panel but got an "image invalid" massage (George?). Anyway, really like the 430, but couldn't find room on the panel without removing the glove box, which I would like to keep if possible. I see you removed the lower sub panels which I am also trying to keep. Of course this meens making a new one on the left side to accomidate a slightly smaller radio stack. I went with an all Garmin stack with the SL30, SL40, GMA 340 audio panel, and GTX 327 trans. Most of the old instruments are unusable as they are probably twice my age. Some can be refaced/overhauled.
Staying with the ventury system for vacuume but have concerns about being able to pull enough vacuume for modern gyros. My vac. indicator under normal cruise speeds/altitudes usually shows around 4". New gyros need at least 4.5. Anyone have any thoughts? Looking at replacing the old venturies with a couple of new ones (maybe the 9in. super venturies).

Pics must be no wider than 800 pixels (you can edit yours and resubmit them) and they must be in jpg, jpeg, or gif format. To change your pic's format, simply re-save it in the appropriate format then re-upload it.

The "super" venturiis will run the modern gyros and not be noticeably different than the original standard venturiis. Expect to add a vacuum regulator if you don't already have one installed.

Circuit breakers do not have to be expensive, and I do not recommend using surplus or "salvage" CB's because as they age and/or are abused they lose calibration. (I've personally experienced avionic failures that wasted lots of money checking radios that were traced to nothing more than defective, old CBs.) CBs are a safety-device. Here's a link to check prices on the W23 and other types at Spruce, many of them less than $10 ea.:
http://www.aircraftspruce.com/catalog/e ... itbrkr.php


If space is a problem here are Klixon 7277's that are very small and reasonably priced:
http://www.aircraftspruce.com/catalog/e ... on7277.php

[LBPilot82]

Thanks George!

Well here is what I am working with. BPaige asked about reaming out the engine instrument holes. I was thinking I would do the same thing to fit EI instruments but it doesn't look like Hilltop170 had to.
I love the classic original look of my current panel but living in southern California, functionality and usability has to come before keeping it original. I'll post pics of the new panel when she's done.
Thanks for the input all.
Richard

[n2582d]

I would also like to ream out the 4 instrument holes (located between the control tube sockets) to a full 2.25" and mount the instruments using standard instrument mounting screws (removing sub-panel #0412491). Have any of you guys done this?

This panel is structural. Consider it a bulkhead like the others in the tailcone. By the look of many panels--mine included--many A&Ps and Avionic Techs don't know this. Reaming out these holes might be considered a major alteration--ask your A&P.

[bpaige]

Here is the stationary instrument panel assy for 170B serial numbers 20267 - 25372, which is what I have ...

and here is the panel for serial numbers 26039 - 26995...

It looks like Cessna removed alot more metal from that structure in the later years than I would by opening the (4 ea) 2" holes to 2.25". Maybe this will help pave the way.

[oz502man]

LBpilot82,

I have just about finished the rewire in my '51a. I used the Klixon 7277-2-xx CB's. The reason I went with these is that the Ayres Thrush aircraft I worked on during my days as an AME (the company I worked for was the Australian Agent/Importer and had a fleet of 14 of these when I was an apprentice) used these and they always proved reliable even in harsh environment of a crop sprayer. I not saying that the others are not as good, but I like to stick with what I know. I also like their compact form. While I didn't do anything as drastic as an IFR panel, I am pretty pleased with the results....



The original fuse holder holes are too big for the CB's so I cut a strip of alclad and drilled the holes in it, then put the CB through the original hole then the new hole. This means the CB's actually hold the strip in place. I made the strip long enough to go from the first fuse to the last covering the gap in the middle where the hand mic used to be. I could fit another three CB's in this gap. Also I used wire 'pigtailed' from CB to CB as a bus bar. I'm not a fan of solid copper or al bus bars.Theres too much exposed live power for my liking and it makes a much bigger job of swapping a CB as you have to undo the whole bus instead of just undoing one terminal. Not much fun when screwed up in a ball under the panel.




Of course I couldn't stop at a rewire, as you can see the panel has been painted which led to the trim pieces...



Which led to the flap handle...



which led to the door jamb...



when will it end???

[GAHorn]

.... Also I used wire 'pigtailed' from CB to CB as a bus bar. I'm not a fan of solid copper or al bus bars.Theres too much exposed live power for my liking and it makes a much bigger job of swapping a CB as you have to undo the whole bus instead of just undoing one terminal. Not much fun when screwed up in a ball under the panel. ...when will it end???

Ha! It NEVER ENDS!

Re: rewiring CB's: I agree. Short pigtails are much better than copper bus-bars for the reasons stated, although some reliability-risks may increase due to the "series" -effect . (If any single connection fails, all subsequent/downstream items will not receive power.)

Another solution is to make a "master" pigtail (a long pigtail with numerous short pigtails branching out) and feed all branch-circuits from that, in effect creating a flexible/serviceable bus. The "branches" should be soldered/heat-shrinked and the entire master securely attached to structure to prevent vibration and/or flexing from resulting in soldered-joint failure. (My own consists of the former system of short-pigtails,.... I was only offering a solution to any fears of series-effect.)