Rick Spriggle (Rspriggle)
|Posted on Wednesday, January 16, 2002 - 07:17 pm: |
This one is more for the builders of the older models. Just tonight I looked into the outboard fuel filler of my closed left wing and found the rubber Adel clamps that were to be added in SB009 for extra fuel line support. Unfortunately, the next page in my manual is SB045, which states the Adel clamps shouldn't be used because of the unknown long term effect of fuel on the rubber. It then goes on to describe procedures for opening holes in the skins, replacing the clamps, etc...
Any opinions on the fuel handling capabilities of the rubber in these clamps? My EAA advisor didn't think they would be a problem with the mildness of 100LL but came up with some good points of what might happen over the years if they do deteriorate.
Dang - and I had decided to use the four tank configuration so I didn't have to cut open a perfectly good closed wing!
Jim Ward (Jehward)
|Posted on Thursday, January 17, 2002 - 04:30 pm: |
My manuals are at the airport, so I do not know which P/N the clamps are, but I checked the web, and found this info. Maybe you can identify the P/N and suitability from this info from Bob Nuckolls. Seems the question has been raised before.
Everything you ever wanted to know but were afraid to ask
by Bob Nuckolls
I've seen some conversation recently concerning "Adel" clamps and their suitability for use around fuel, high temps, etc. I've pulled the specs and will excerpt some of their contents as follows:
The "Adel" clamp is more properly called an MS21919 aircraft clamp. The company named Adel built a goodly portion of the MS21919 clamps back in the 60's (and may still). The term sort of stuck on these devices in spite of the fact that they are now made by dozens of companies.
The full description for these clamps follows the convention MS21919WXXZZ where:
W = "wedge" feature in cushion that helps prevent escape of small wires out of cushion. Virtually all new production of MS21919 clamps below size 50 have the wedge feature...
XX characters have the following significance:
DE = Aluminum band, Ethylene Propylene Cushion (212F)
DF = Aluminum band, Nitrile Cushion (212F)
DG = Aluminum band, Chloroprene Cushion (212F)
CE = Corrosion Resistant Steel band, Ethylene Propylene Cushion (275F)
CF = Corrosion Resistant Steel band, Nitrile Propylene Cushion (200F)
CH = Corrosion Resistant Steel band, Silicone Cushion (400F)
CG = Corrosion Resistant Steel band, Chloroprene Cushion (212F)
CJ = Corrosion Resistant Steel band, Fluorosilicone Cushion (450F)
F = Low Carbon Steel Band, Nitrile Cushion (212F)
G = Low Carbon Steel Band, Chloroprene Cushion (212F)
H = Low Carbon Steel Band, Silicon Cushion (400F)
CAUTION - Clamps with low carbon steel bands are not recommended for new design and most were purged from stocks back in early 80's, however, you never know what might show up in the Fly-Market at OSH so I've included the "heads up" here.
Cushion Application and Color Information:
Ethylene Propylene - for use in areas contaminated with phosphate- ester hydraulic fluid and other synthetic fluids. Excellent ozone resistance., Not resistant to petroleum based fluids. Color shall be solid purple.
Nitrile - for use primarily in fuel immersion and fuel vapors. Good ozone resistance. Not resistant to phosphate-ester based fluids. Not for use on titanium tubing. Color shall be solid yellow.
Chloroprene - for general purpose use in areas contaminated with petroleum based hydraulic fluids and occasional fuel splash. Excellent ozone resistant. Not resistant to phosphate-ester based fluids. Not for use on titanium tubing. Color shall be black with a blue identifier patch.
Silicone - for elevated temperature usage in phosphate-ester based fluid and other synthetic fluid contaminated areas. Unaffected by ozone. Not resistant to petroleum based fluids. Color shall be natural white.
Fluorosilicone - for elevated temperature usage in petroleum based fluid contaminated areas. Unaffected by ozone. Not resistant to phosphate-ester based fluids. Color shall be solid blue.
Silicone - RED now obsolete and used only on the low carbon Steel
The last characters (ZZ) are digits describing the internal diameter of the closed clamp in 1/16ths of an inch. E.G. an MS21219WDG4 is aluminum strap inside a chloroprene cushion and sized to support 1/4" diameter bundle of wires, tubing, etc.
I note that the spec does not speak to the "red" cushions currently being discussed. I recall seeing a number of clamps with red cushions over the years but quite frankly, I don't know if they were MS21919 or perhaps some other part number.
UPDATE: All of the "reds" have been purged from Raytheon's stocks, couldn't even find one in the junk boxes that I had access to. Mr. Sobek says the one he found does carry the part number MS21919H** which tells us it is indeed the obsolete, low carbon steel version and silicon rubber (not recommended for use where "wet" with hydrocarbons.
Rick Spriggle (Rspriggle)
|Posted on Thursday, January 17, 2002 - 06:22 pm: |
Jim - thanks for the info. My service bulletins are right next to the computer and of course the adel clamps listed are a Wheeler P/N, not an MS number. To take my bad luck one step further, I went down to the basement with a mini-mag and the clamps are stamped with the Wheeler P/N's.
If it means anything, the P/N's are:
LOUIE LACY (Llacy)
|Posted on Sunday, January 20, 2002 - 06:37 pm: |
Does anyone have a diagram of the nose wheel spindle. I had a shimmy upon landing today and I think I have the washers and spacers in the wrong order.Also what is the torque on the castle nut holding the nose wheel on.
Rick Spriggle (Rspriggle)
|Posted on Friday, January 25, 2002 - 04:11 am: |
For those using the fiber bushings for the aileron torque tubes, is there any kind of lubricant that gets put on there before assembly? I've searched both versions of my manuals and found nothing except for petroleum jelly while glassing the bushings in place. I remember a discussion on this list about fiber vs. bearings but can't find that either!
|Posted on Friday, January 25, 2002 - 09:08 am: |
Hi Rick (and builders),
The bushings were intended to be used dry as they are teflon lined which is the lubrication---But----that didn't work for me. I used a spray material called "Tri-Flow" which has worked great. It is available in stores that sell to commercial people, machine shops, etc. Made by Sherwin Williams. It is a lubrication that contains Teflon and penetrates very well after assembly. In fact, I use it on all my latches and anything else that moves and that can be lubricated.
The other problem with the bushings is the possibility of tightening the bolt that goes through the tubes too much and the bearing area becomes miss-shapen (oblong). There are 2 places where this easily happens. One at the elevator bell crank in the front area (under the seat) and the other where the aileron torque tube goes through the wing spar. In both cases the bolt is very near the bushing. I solved the problem by adding another bolt at 90 degrees and tightening them carefully to eliminate the problem. It worked and freed them up. My controls are very free. There probably are other ideas so hope others respond. Cheers, Jerry
By the way, it turns out that Louie (above) never did get the Bellvue washer that is part of the nose spindle assembly and has that coming from Express Aircraft Ltd. Should solve his problem. I did send him a lengthly email to explain the assembly. If anyone else wants that information, I have posted it on my web site. www.sierratel.com/jerico
Rick Spriggle (Rspriggle)
|Posted on Friday, January 25, 2002 - 10:11 am: |
I've used Tri-Flow quite often back in my go kart racing days for chains and bearings. I didn't think assembling them dry was the right thing to do.
|Posted on Monday, April 15, 2002 - 08:00 pm: |
How is everyone limiting the throws on their rudder and elevators?
|Posted on Monday, April 15, 2002 - 09:26 pm: |
You need to let us know what empenage you have. CT or the newer larger lower one. Is your's an EDI unit, a Wheeler CT, or one from Larry?
Jerry Sjostrand (CT owner)
|Posted on Tuesday, April 16, 2002 - 03:25 pm: |
It's a Original CT.