Vent window lock broken

Open for questions of visitors of DAN. Posts of our guests are on moderation queue.

Moderators: Rick, Lance Murray

User avatar
TwinStarScott
4 Diamonds Member
4 Diamonds Member
FIRST NAME: Scott
Aircraft: DA42
Registration: N189Y
Airport: WN53

Posts: 399
Joined: Mon May 18, 2015 3:13 am
Has thanked: 788 times
Been thanked: 192 times

Re: Vent window lock broken

Post by TwinStarScott »

The plastic ones I ordered were just installed and they worked perfectly right out of the box - huge improvement!
To add your aircraft to the G1000 petition (listed below) please send me a PM - thanks!

https://docs.google.com/spreadsheets/d/ ... sp=sharing
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Rich
Aircraft: DA40
Registration: N40XE
Airport: S39

Posts: 2576
Joined: Mon Aug 30, 2010 12:40 pm
Has thanked: 67 times
Been thanked: 407 times

Re: Vent window lock broken

Post by Rich »

I have the bronze ones. Herewith some details:

Bore through the new part is 5.77 mm dia.
Original bushing is ~6 mm. It won't fit in that bore.
The screw on which it pivots is 4 mm, so there is 1.77 mm of slop if one does not use some kind of bushing. That is a lot.

It's conceivable there has been some variation in manufacture of the latch over the years. But my additional problems have to do with inconsistency in the location of that block above each vent window. In my case each of the two presents a different problem.
2002 DA40: MT, PF, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210.
User avatar
Boatguy
4 Diamonds Member
4 Diamonds Member
FIRST NAME: Russ
Aircraft: DA40NG
Registration: N454M
Airport: O69

Posts: 407
Joined: Mon Jan 22, 2018 4:48 am
Has thanked: 162 times
Been thanked: 294 times

Re: Vent window lock broken

Post by Boatguy »

Rich wrote:
Tue May 05, 2020 11:33 pm
I have the bronze ones. Herewith some details:

Bore through the new part is 5.77 mm dia.
Original bushing is ~6 mm. It won't fit in that bore.
The screw on which it pivots is 4 mm, so there is 1.77 mm of slop if one does not use some kind of bushing. That is a lot.
Assuming the bushing is 6mm OD, I guess we could take a 6mm drill and open up some room for the sleeve. But does it affect a performance difference?

I can see the need for a metal sleeve to contain a metal screw in a plastic part. But this is a metal screw through a metal part. 1.77mm is .07" of slop on the shaft on which the latch rotates. If the latch shifts side to side by .035", it really doesn't make much difference as it's held in place by the friction between the latch tongue and the block into which it rotates. The tongue is probably .5" and .07" of lateral movement doesn't have any material effect. Maybe the SS screw will eventually wear on the softer bronze latch, but probably not in the next 5-10yrs.

I appreciate the measurements you've taken and that we'd never want that sort of play in a lot of other places in our airplanes. But this is a window latch. The bottom line is whether or not it reliably holds the window closed and is less likely to snap off than the original plastic.

I installed the bronze in my plane and they work fine. I'm ok with the .07" of slop and would like to thank Kai for posting the part.
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Rich
Aircraft: DA40
Registration: N40XE
Airport: S39

Posts: 2576
Joined: Mon Aug 30, 2010 12:40 pm
Has thanked: 67 times
Been thanked: 407 times

Re: Vent window lock broken

Post by Rich »

Ah, but you don't have a block that's excessively far from the vent window. That additional play means the latch won't stay in place. In any case, the nylon bushings I got takes it all out for the low, low price of $.25 each. And solves the base-washer thickness problem at the same time.
2002 DA40: MT, PF, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210.
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Rich
Aircraft: DA40
Registration: N40XE
Airport: S39

Posts: 2576
Joined: Mon Aug 30, 2010 12:40 pm
Has thanked: 67 times
Been thanked: 407 times

Re: Vent window lock broken

Post by Rich »

After tedious Dremeling of the latches I got the bronze latches installed. This is not a criticism of the design of the new latches. It is something that has been required of all the Diamond-supplied latches on my plane. I've confirmed a subsequent design change of the canopy-bonded blocks would make this Dremel work unnecessary, but my old bird requires it.

Here's the Diamond part on the left window, before replacement. Note the tenuous hold of this latch (it was #3 mounted there), that somehow has held up for over 15 years:
N40XE Original Left Vent Window Latch.jpg
Here's the Bronze one in place on the same window.:
N40XE Bronze Left Vent Window Latch.jpg
2002 DA40: MT, PF, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210.
User avatar
Charles K
3 Diamonds Member
3 Diamonds Member
FIRST NAME: Charles
Aircraft: DA40
Registration: N5WU
Airport: KCCR

Posts: 162
Joined: Mon Feb 21, 2011 7:46 pm
Has thanked: 6 times
Been thanked: 27 times

Re: Vent window lock broken

Post by Charles K »

Just ordered a set of Bronze - my 2004 latches have held up great and still perfect - but the metal is nicer - will keep you posted. Thanks!
Charles
KCCR Based
N5WU - 2004 G1000 DA40 40.400, GTX345R ADS-B
IFR and ME Rated - Advanced Ground Instructor Rated
User avatar
Kai
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Kai
Aircraft: DA40F
Registration: XXXX
Airport: VTCY

Posts: 1352
Joined: Tue Jun 15, 2010 6:14 pm
Has thanked: 122 times
Been thanked: 92 times

Re: Vent window lock broken

Post by Kai »

Rich wrote:
Fri May 08, 2020 12:29 am
After tedious Dremeling of the latches I got the bronze latches installed. This is not a criticism of the design of the new latches. It is something that has been required of all the Diamond-supplied latches on my plane. I've confirmed a subsequent design change of the canopy-bonded blocks would make this Dremel work unnecessary, but my old bird requires it.
Rich, if you send me your old latches (the broken ones), I can try to adapt the design for older models and add a second design option to shapeways.
DA40F - N405FP/HS-KAI (sold)
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Rich
Aircraft: DA40
Registration: N40XE
Airport: S39

Posts: 2576
Joined: Mon Aug 30, 2010 12:40 pm
Has thanked: 67 times
Been thanked: 407 times

Re: Vent window lock broken

Post by Rich »

Kai wrote:
Thu Aug 13, 2020 4:57 am
Rich wrote:
Fri May 08, 2020 12:29 am
After tedious Dremeling of the latches I got the bronze latches installed. This is not a criticism of the design of the new latches. It is something that has been required of all the Diamond-supplied latches on my plane. I've confirmed a subsequent design change of the canopy-bonded blocks would make this Dremel work unnecessary, but my old bird requires it.
Rich, if you send me your old latches (the broken ones), I can try to adapt the design for older models and add a second design option to shapeways.
The change wasn't to the latch, but that block bonded to the canopy into which the tab on the latch fits. I was sent a replacement block from Diamond years ago to try deal with the poor placement of my left-side block. I couldn't figure out a satisfactory way to remove the original one, so this was never done. But I still have that replacement block.

Recently I decided to compare the replacement with the original and discovered that the cutout for the newer one is deeper than the original. This allows a thicker tab to be used, as that inner surface is now further from the inner surface of the vent window. The difference in dimension is enough that I think it was an intentional design change.

The bronze tabs needed to be thinned on both sides to fit into these old blocks. They are also longer. This is a good thing for my left side, as I have more engagement of the tab in the block. But on the right side, where the block is very close to the vent panel, I actually had to shorten the tab so I could close it. Given the variations of these blocks in dimension and placement, I think the latches are just fine the way they are. They allow for adaptation to circumstances in the field.
2002 DA40: MT, PF, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210.
Post Reply