VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics



Go Back   VAF Forums > Model Specific > RV-6/6A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-15-2012, 12:25 PM
MNellis MNellis is offline
 
Join Date: Jan 2005
Location: Georgtown, TX
Posts: 84
Default AN - MS Cross Reference chart

I'm trying to cross reference a part on my plans to an MS number, with little success. I've seen this link http://www.bonaero.com/CrossReference.htm#ANORDER but it doesn't show the part I'm looking for.

I need to order the clamp that holds the teflon rudder cable guide to the fuselage. It shows on the plans as AN742-6c but in the Vans web site they only show clamps using MS numbers.
Reply With Quote
  #2  
Old 01-15-2012, 12:31 PM
Mike S's Avatar
Mike S Mike S is offline
Senior Curmudgeon
 
Join Date: Sep 2005
Location: Cameron Park Ca "o61"
Posts: 10,357
Default

Go the GAHCO site.

Better still, get his book of products, there is a ton of helpful info, and cross reference charts in it.

http://www.gen-aircraft-hardware.com/site_tips.asp

Good guy, and an RV builder also.
__________________
Mike Starkey
Rv-10, N210LM.
VAF 909
EAA 512


Flying as of 12/4/2010

Phase 1 done, 2/4/2011

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
Reply With Quote
  #3  
Old 01-15-2012, 01:24 PM
Bob Axsom Bob Axsom is offline
 
Join Date: Mar 2005
Posts: 5,685
Default Just a little background on specs

Before the Clinton Administration elected to stop maintaining them as a way to cut cost in the reinventing of government (just a fact not a criticism) there were tightly controlled specifications with hard qualification requirements, non conformance penalties and Qualified Product Lists (called QPLs). AN Standards were earlier and then came Military Standards. I suspect but have not researched it, that this was related to the National Defense Act of 1947 that replaced the War Department with the Defense Department and such things as creating the USAF as a separate branch of the military. The Army Navy Standards and the Military Standards are independent and you should carefully check the requirements which are still available but not maintained (updated, etc.) before automatically assuming they are substitutable. I think the individual standards are available on line. Military Standards have a related Military Specification with the same numeric part preceded by MIL-(a letter which is the first letter of the thing being specified - like "C" for clamp) and a dash between the letter. For example Military Standard MS21919 clamps may be covered by Military Specification MIL-C-21919. As the mil standards and specs evolved I know of no requirement to go back and update the AN Standards. There were also Federal Standards by the way. Several years back I needed a replacement O-ring for one that was damaged in manufacture of a master cylinder by Cleveland. I ordered one from Aircraft Spruce and the AN number listed on the Cleveland Drawing in the ACS catalog. They substituted a MS number part and it leaked. When I checked with Cleveland customer support they said the MS part is not an acceptable substitute and in fact the drawings show a slightly different thickness. Van's still had the old AN parts so I got a few from them and fixed the problem. Now all three call out the MS part so I guess they are compatible. For a clamp I would just check the construction, the materials and the ID of the closed clamp and select the one that will work.

Bob Axsom

Last edited by Bob Axsom : 01-15-2012 at 01:31 PM.
Reply With Quote
  #4  
Old 01-15-2012, 01:40 PM
MNellis MNellis is offline
 
Join Date: Jan 2005
Location: Georgtown, TX
Posts: 84
Default

Thanks for the lesson Bob, it's interesting. The GAHCO site that Mike mentioned does not show a "cushioned" clamp only an uncushioned version. The part number for the uncushioned version did show it as a 3/8" like I suspected. I then looked up clamps on vans site and found a 3/8" cushioned clamp and the correct MS number.

As you mentioned, there might some small differences with MS and AN parts, for the purposes of this clamp I don't anticipate a problem unless the screw hole is different or something like that.
Reply With Quote
  #5  
Old 01-15-2012, 01:51 PM
az_gila's Avatar
az_gila az_gila is online now
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 6,581
Thumbs up

Go to www.everyspec.com and search.

Interestingly the MS number is this case is superceded by the AN number, instead of the other way around

http://www.everyspec.com/MS+Specs/MS...OTICE-1_15059/

MS21103 is the equivalent....

The AN-742 spec. is here for download -

http://www.everyspec.com/AN+SPECS/AN...2_REV-12_8713/

The web site will list obsolete specifications.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
RV-6A VSB (Very Slow Build)
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 01-15-2012 at 01:53 PM.
Reply With Quote
  #6  
Old 01-15-2012, 02:56 PM
MNellis MNellis is offline
 
Join Date: Jan 2005
Location: Georgtown, TX
Posts: 84
Default

Thanks Gil, that's a good reference site as well. Even with this site it does not show the AN742-6C which denotes the "cushioned" clamp.

It was interesting to see the mechanical drawing for the the part too.
Reply With Quote
  #7  
Old 01-15-2012, 08:16 PM
az_gila's Avatar
az_gila az_gila is online now
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 6,581
Smile

Quote:
Originally Posted by MNellis View Post
Thanks Gil, that's a good reference site as well. Even with this site it does not show the AN742-6C which denotes the "cushioned" clamp.

It was interesting to see the mechanical drawing for the the part too.
Sorry, but your original part number with a "C" on the end was incorrect...

Check the title of the AN742 part

AIR FORCE-NAVY AERONAUTICAL STANDARD, CLAMP, LOOP, PLAIN, SUPPORT, AIRCRAFT

I believe the "PLAIN" bit says the the specification is NOT for a cushioned part. Note that the MS21919 title is

MILITARY STANDARD: CLAMP, LOOP TYPE, CUSHIONED, SUPPORT

Vans part numbers on the plans are not always perfect....

Since the tubing is called out on my -6 plans as 3/8 polyethelene tubing, then the -6 would be the correct size for a non-cushioned clamp.
The "C" at the end is incorrect and does not mean cushioned for an AN742. A cushioned clamp is not even really needed for this location.

Why did you think "C" meant cushioned?
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
RV-6A VSB (Very Slow Build)
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 01-15-2012 at 08:19 PM.
Reply With Quote
  #8  
Old 01-15-2012, 08:37 PM
MNellis MNellis is offline
 
Join Date: Jan 2005
Location: Georgtown, TX
Posts: 84
Default

Quote:
Originally Posted by az_gila View Post
Sorry, but your original part number with a "C" on the end was incorrect...

Check the title of the AN742 part

AIR FORCE-NAVY AERONAUTICAL STANDARD, CLAMP, LOOP, PLAIN, SUPPORT, AIRCRAFT

I believe the "PLAIN" bit says the the specification is NOT for a cushioned part. Note that the MS21919 title is

MILITARY STANDARD: CLAMP, LOOP TYPE, CUSHIONED, SUPPORT

Vans part numbers on the plans are not always perfect....

Since the tubing is called out on my -6 plans as 3/8 polyethelene tubing, then the -6 would be the correct size for a non-cushioned clamp.
The "C" at the end is incorrect and does not mean cushioned for an AN742. A cushioned clamp is not even really needed for this location.

Why did you think "C" meant cushioned?
I "assumed" the "C" meant cushioned since that plans called for an AN742-6C and the small drawing depicted on plans page 34 looks to me like a cushioned part. Additionally, I have one of the clamps but couldn't find another in my little storage bins but that's not surprising since those bins have been sitting around gettin bumped and jostled for the past 5 or 6 years. All the references I've seen have showed the AN742-6 and indicated it was NOT a cushioned part so, again, I assumed the -C designation meant cushioned. The rubber cushioning would probably add to the clamps ability to hold the tubing but I'm sure the clamp would work fine without it.

As you say, there are a lot of areas where the plans need some interperation. I'm out of practice since I haven't worked on the plane much in the past 5 years and it's going to take some relearning. For example, there is little mention of the F-639 and F640 in the construction manual other than a dimensional drawing.

The plans/manual have been weak in some areas in the past and that's OK, I just have to do what makes sense sometimes. I sometimes envy the isometric drawings the -7, -10 and -12 builders get to use though.
Reply With Quote
  #9  
Old 01-15-2012, 10:17 PM
az_gila's Avatar
az_gila az_gila is online now
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 6,581
Smile

Quote:
Originally Posted by MNellis View Post
I "assumed" the "C" meant cushioned since that plans called for an AN742-6C and the small drawing depicted on plans page 34 looks to me like a cushioned part. Additionally, I have one of the clamps but couldn't find another in my little storage bins but that's not surprising since those bins have been sitting around gettin bumped and jostled for the past 5 or 6 years. All the references I've seen have showed the AN742-6 and indicated it was NOT a cushioned part so, again, I assumed the -C designation meant cushioned. The rubber cushioning would probably add to the clamps ability to hold the tubing but I'm sure the clamp would work fine without it.

As you say, there are a lot of areas where the plans need some interperation. I'm out of practice since I haven't worked on the plane much in the past 5 years and it's going to take some relearning. For example, there is little mention of the F-639 and F640 in the construction manual other than a dimensional drawing.

The plans/manual have been weak in some areas in the past and that's OK, I just have to do what makes sense sometimes. I sometimes envy the isometric drawings the -7, -10 and -12 builders get to use though.
Yep - it is confusing...

It's interesting since I bet most folks use a cushioned clamp there, simply because they are easy to find.

But when I look closely at the little drawing on sheet 34 I see it as a plain clamp.

I'm not sure about cushioning actually being better in this location - a plain clamp might actually grip better on the 'slippy' tubing.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
RV-6A VSB (Very Slow Build)
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #10  
Old 02-08-2012, 08:43 PM
GAHco's Avatar
GAHco GAHco is offline
 
Join Date: Dec 2006
Location: Paso Robles, CA
Posts: 1,164
Smile Please look at the whole document, they are there.

Quote:
Originally Posted by MNellis View Post
Thanks for the lesson Bob, it's interesting. The GAHCO site that Mike mentioned does not show a "cushioned" clamp only an uncushioned version. The part number for the uncushioned version did show it as a 3/8" like I suspected. I then looked up clamps on vans site and found a 3/8" cushioned clamp and the correct MS number.

As you mentioned, there might some small differences with MS and AN parts, for the purposes of this clamp I don't anticipate a problem unless the screw hole is different or something like that.
Both are visible in the PDF right on the website, there are 8 pages of loop clamps. I hope this helps!

http://www.gen-aircraft-hardware.com...LoopClamps.pdf
__________________
Get em in the Sky!
Tom Brink Pres.
GENUINE AIRCRAFT HARDWARE Company
www.gen-aircraft-hardware.com

www.gen-aircraft-hardware.com/site_tips.asp


28th Anniversary of GAHco March, 2012
Thanks for being part of our success
Dues Paid November 2012
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 04:54 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.