What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Washers for Stall Warning Switch???

MartySantic

Well Known Member
Bag 2618 is supposed to contain 16 AN-960-4 and 12 AN-960-4L washers. Looking at the 28 washers supplied they appear alike. All are 0.0225" to 0.024" thick. These are the small washers used to assemble the stall warning microswitch.

Specifications from Internet:
AN960-4 - #4 .125 x .312 x .032"
AN960-4L - #4 .125 x .312 x .016"

Anyone notice this issue with the supplied washers???
Do you think it makes any difference if I use the washers supplied???
 
16 AN-960-4

I had the same challenge. Could not find a difference between the washers as called out in the plans. The bag did not contain any 16 AN-960-4 as it turned out. Vans scratched their heads too, until they figured out that they had no AN-960-4 washers in inventory. The answer for my washer dilema was to double up the AN-960-4L until I got the clearance right. A call to Vans might help.

You can see more on my blog: http://slane-rv-12.blogspot.com/2008_08_01_archive.html

Slane
 
Thanks for the information. I assume the washers only serve to center the vane in the wing skin slot??

Nice blog!!
 
Different washers since revision

At 23/02/2009 there was a revision of page 16-02.
Step 4 now calls for NAS1149FN432P and NAS1149FN416P. I assume the 432P are he thick ones, but they were stored together in one bag and I can't find the specs of these washers.
Figure 1 says to use 432P at 14 places but 16 are drawn. Does anyone still remember what he used?
The second picture is from Tony. Total washers are hard to tell due to the shiny aluminum (please prime it next time Tony;))
I guess it's not critical but if someone remembers it will save some time.

Thanks, Joeri.

Schermafbeelding2009-09-22om235544.png


Schermafbeelding2009-09-22om235522.png
 
Update

432P=32/1000 of an inch, 416P=16/1000 of an inch. Simple but I didn't know that.
Besides that I was confused by the drawing showing 16 432P washers and the text saying to use 14 washers. In Slane's blog there is a picture of the stall warning with the "old" page before the revision. In the revision one washer is added without updating the text. Not really important but I mailed Van's.
Below a picture of both versions. The white insert is the last revision (four washers instead of three between the micro switch and the alu plate).

StallWarning.png
 
Last edited:
This update must be very new. I received my kit in June and has the old drawing. Without the additional washer you can not tighten the nuts for the vane won't move. Indeed it is very hard to separate those washers. I use a caliper to separte the thick and the thin ones.

(I did not realize this is a RV12 thread. I am building a 10 and from the drawing the stall warning system looks the same.)
 
Last edited:
Built my RV-12 stall warner today and for a little job it took at long time about 4 hours in total including researching the plans confusion with the washers required. I also took about 3 attempts to get the micro switch to work with the skins fitted and pleased to report it does now.

I decided to take plenty of photos for future builders that will hopefully help and they start here on my website.
 
Thanks all

Jason, the pictures are very nice to have - thanks for them. Did you have to change anything when you put the skins on? If so, please tell what changes you had to make. Thanks again for the pictures.
 
I had to bend the micro switch a little when test fitting the middle skin to get it to work. I will double check it still activates and make any adjustments when I fit the skins properly as I suspect despite the access panel you'd need rather flexible small hands to actually remove / refit the switch so it's gotta be right from day one.
 
Is this right?

Reviving a very old post...couldn't find any other info. I know a lot of RV12is wing kits shipped this summer so hopefully several are past this stage.

I figured out the different meaning of the washers and how to identify, but when I put things together there is quite a bit of room for the stall warning arm (on right) to move- I'm guessing that so it doesn't bind and/or so it can account for slight differences in the skins.

Does this look right? Or am I using the wrong washers even tho I think I'm being really smart about it. Haha.

Thanks!
 

Attachments

  • thumbnail_IMG_2373.jpg
    thumbnail_IMG_2373.jpg
    152.9 KB · Views: 59
Back
Top