From: Marc J. Zeitlin Subject: COZY: Nicopress sleeve question Date: Thu, 3 Apr 97 14:28:56 EST People; I've got a question regarding the strength of the nicopress sleeves used to clamp the 1/16" cables all over the place on our birds. While playing with my landing brake lever, my friend Claude let the lever slam down due to the overcenter nature of the beast and the strong springs. This popped the cable out of the nicopress sleeve in the rear mechanism. I've been using a small hand nicopress tool that I bought 15 years ago from Wicks (listed in the catalog still, I believe) that I mount in a vise and squeeze by turning a bolt with a wrench. I thought it was working fine on all my cables, but now I'm not so sure. How strong should these joints be? How does one tell if you're at full strength? Do I really need to spend the big bucks on the mother of all nicopress sleeve squeezers? Should I be worried about all of my rudder/trim cables? All the rest of the cables have thimbles (or the equivalent) in them, so the sleeve isn't in direct tension - this sleeve in the brake system is the only one I can think of that's in direct tension. On a related issue (after this slamming of the lever) I decided to put a hydraulic damper on the landing brake lever. I was able to find a small one with 2" of stroke in the McMaster-Carr catalog. I have not installed it yet, but will post a full report of it's workings when I do. If it works, it was only about $23. (Well, I guess it was $23 if it works or not - but YOU won't have to spend the money if it doesn't :-) ). aTdHvAaNnKcSe -- Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-8 #16063) with SMTP id <01IH9P6DHV88005N3F@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Thu, 3 Apr 1997 12:41:15 PST Date: Thu, 03 Apr 1997 12:43:43 -0800 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Nicopress sleeve question Marc J. Zeitlin wrote: >People; > >I've got a question regarding the strength of the nicopress sleeves used >to clamp the 1/16" cables all over the place on our birds. While playing >with my landing brake lever, my friend Claude let the lever slam down due >to the overcenter nature of the beast and the strong springs. This >popped the cable out of the nicopress sleeve in the rear mechanism. I've >been using a small hand nicopress tool that I bought 15 years ago from >Wicks (listed in the catalog still, I believe) that I mount in a vise and >squeeze by turning a bolt with a wrench. > >I thought it was working fine on all my cables, but now I'm not so sure. >How strong should these joints be? Simple answer: the cable should part before pulling out of the sleeve. >How does one tell if you're at full >strength? Do I really need to spend the big bucks on the mother of all >nicopress sleeve squeezers? Marc, I see no reason to spend big bucks, here. Perhaps your squeezer is suspect. there is a relatively cheap way to find out. Nicopress makes a "go, no-go" gage to measure the OD of the squeezed portion of the sleeves. They should be squeezed in accordance with the instructions in AC 4313-1A (the A&P's bible--you DO have one, don't you?) Basically, squeeze the center first, then the ends. >Should I be worried about all of my >rudder/trim cables? could be. Check 'em with the gage. >All the rest of the cables have thimbles (or the >equivalent) in them, so the sleeve isn't in direct tension - this sleeve >in the brake system is the only one I can think of that's in direct >tension. shoudn't matter >On a related issue (after this slamming of the lever) I decided to put a >hydraulic damper on the landing brake lever. I was able to find a small >one with 2" of stroke in the McMaster-Carr catalog. I have not installed >it yet, but will post a full report of it's workings when I do. If it >works, it was only about $23. (Well, I guess it was $23 if it works or >not - but YOU won't have to spend the money if it doesn't :-) ). This is a great idea. I had thought of it myself, but hadn't drawn up anything yet. If it works out, I would be very grateful for details of your solution. Howard Rogers, A&P 2005148 Date: Thu, 3 Apr 1997 16:55:50 -0500 (EST) From: AlWick@aol.com Subject: Re: COZY: Nicropress sleeve question In a message dated 97-04-03 15:46:05 EST, you write: << I've got a question regarding the strength of the nicopress sleeves used >to clamp the 1/16" cables all over the place on our birds. While playing >with my landing brake lever, my friend Claude let the lever slam down due >to the overcenter nature of the beast and the strong springs. This >popped the cable out of the nicopress sleeve in the rear mechanism. I've >been using a small hand nicopress tool that I bought 15 years ago from >Wicks (listed in the catalog still, I believe) that I mount in a vise and >squeeze by turning a bolt with a wrench. > >> I used to work for a company that routinely swaged wire rope. We found it important to allow the end of the wire rope to extend past the sleeve. The end should extend behond the sleeve by appx. 1/8". A sure winner also was to put two of the sleeves on the wire rope. We used to test winches using wire rope. Didn't take too long to learn these two techniques. Lot of energy when it broke! fwiw -al Date: Fri, 4 Apr 1997 00:47:13 -0500 From: INFINITY Aerospace Subject: Re: COZY: Nicopress sleeve question Hi Marc, Howard, Al and All, You all may know the following, but here goes: Put shrink tube over your cable and shrink it on over where you want to cut it - the shrink helps keep the cable from fraying when cut. Put a larger piece of shrink tube over the cable that will fit over the Nicropress Sleeve. Put TWO (2) Nicropress Sleeves properly (see Al's post) on your cable and thimble (use the gage - see Howard's post) butted together. Shrink the shrink tubing on over the 2 sleeves and down the cable about .5". Now I may be getting myself into a mess, and I'm probably going to hear about it from Patty, but I have a near new Kearney Swager and I will swage anyones fittings onto their cables - no charge. Just provide the cable(s), fitting(s), instructions, return postage and packaging. I've been swaging aircraft cables since my first Soap Box Derby car - but no guarantees of course. Infinity's Forever, JD Date: Fri, 04 Apr 1997 14:19:28 +0200 From: Rego Burger Subject: COZY: Nicopress sleeve question -Reply Hello Marc, I'm in the habit of testing things, did this one two. My first few attempts at cable tieing ALL FAILED with the little cheap hand crimper. As it's job is to crimp the lug to the go-no go gauge I "trimmed" my handtool. It required about 4-5 strokes on a flat surface with some flatting paper facing upward. What I in fact had done was just remove the plating. Simple test is to get a 50lb weight to hang on the end , the cable should pull tight without the sleeve moving, just get your feet out the way in case. Normal breaking strain is about 200lb, but I feel it would get about 50lb load in flight max ...??? ( thumb suck figure!) Let us know if you find this an improvement, the next best is to go out and buy a $ 100-00 nico-press. P.S. Just make sure you used the right lugs, stainless steel cables must have a special lug. Best of Luck! Rego P.E. RSA Cozy #139 ( canopy going on slowly ) Date: Wed, 18 Jun 1997 18:07:18 -0400 (EDT) From: Gunrider@aol.com Subject: COZY: Torque What sort of ft.lbs. inch lbs. or yard pounds are we supposed to be putting on these nuts? Especially the axles where attached to struts. Hugh Farrior From: "Steve Campbell" Subject: COZY: Hardware Date: Tue, 24 Jun 1997 08:25:12 Dear Fellow Builders It happened to me again last night. I had just gotten the package from Wick's containing 6 AN bolts slightly longer than called out in the plans. $1.50 for the hardware and $3.78 for shipping. I installed them and they fit perfectly. I went on to the next step and found that another bolt was just a bit too short to get 2 threads above the nut. If Mark is an oaf (actually I suspect he is a wizard in training), then I am surely only an apprentice oaf, hoping to someday make full fledged oafdom. While many of the hardware pieces fit as per plans, I would estimate that 20% are either just a bit too long or too short, due, no doubt, to my less than perfect efforts. How do you people handle this problem? - Does all of your hardware fit as per plans?, Do you mail away to you favorite supply house?, Do you keep a selection of AN hardware in stock at your house?, or have you found local suppliers? If it is the latter, how did you find them? Thanks Steve **************************************** Stephen A. Campbell Associate Professor, ECE University of Minnesota ***************************************** Date: Tue, 24 Jun 1997 19:02:58 -0400 From: Jim Hocut Subject: Re: COZY: Hardware I don't know about others, but I usually by about 50% excess of every "common" (i.e. not too expensive) piece of hardware as I go, realizing that threads will sometimes get cross threaded etc. For the times when I need one size shorter or smaller and don't have it in my stockpile I temporarily use whatever is close and make a notation on my "to-do" sheet I stapled on the front of my plans so that I won't forget about it later. I'll also make a note on my shopping list that's taped to the door of my workshop (so that I'm forced to look at it every time I leave - stuff eventually gets purchased that way). > > How do you people handle this problem? - Does all of your hardware fit as > per plans?, Do you mail away to you favorite supply house?, Do you keep a > selection of AN hardware in stock at your house?, or have you found local > suppliers? If it is the latter, how did you find them? -- Jim Hocut jhocut@mindspring.com Date: Sun, 29 Jun 1997 21:27:46 -0400 (EDT) From: DFinn7971@aol.com Subject: Re: COZY: Hardware Steve, I've had problems with short sizes on bolts too. To counter this, I order more bolts and bolt sizes then I need. If something doesn't fit, I just go to the parts cabinet and pull out the next size. Given the insane prices for shipping I found I can send in a single order and specify a complete selection (more then needed) and still come out ahead. Dick Finn From: Marc J. Zeitlin Subject: Re: COZY: Hardware (fwd) Date: Mon, 30 Jun 97 13:44:50 EDT Steve Campbell wrote: > ...... Does all of your hardware fit as >per plans? Ho, ho ho. That's a good one :-). >....... Do you mail away to you favorite supply house?, Do you keep a >selection of AN hardware in stock at your house? Yes, and yes. Dick Finn replied; >.... I order >more bolts and bolt sizes then I need. If something doesn't fit, I just go >to the parts cabinet and pull out the next size. Ditto. The next time you order anything, get 20 of every size that's remotely near anything used in the plans (two sizes up and two sizes down). Get one of those little parts cabinets, and start your own stockroom. It'll cost you $100, and you won't have to worry about this nonsense ever again. Plus, you'll have a lot of extra hardware for all the stuff that you do that isn't even IN the plans, or that's been forgotten. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 30 Jun 1997 14:53:40 -0400 (EDT) From: SWrightFLY@aol.com Subject: Re: COZY: Hardware (fwd) In the fly market at Oshkosh or Sun & Fun you will find bags of AN hardware for a dime on the dollar. I have bought bags of AN-3 and AN-4 assorted which will give you all the sizes you need in addition to the "kit AN hardware" Make sure you know how to spot grade 8 bolts as a few are still in the AN system. Steve Wright Stagger-EZE Date: Wed, 2 Jul 1997 09:47:51 -0400 (EDT) From: Gunrider@aol.com Subject: COZY: Overtorquing I never got a response to torquing the nuts on our airplanes. When necessary, what is the max ft. lbs. to use? Hugh Farrior Date: Wed, 2 Jul 1997 10:20:06 -0400 From: wilhelmson@scra.org Subject: Re: COZY: Overtorquing There are tables published for aircraft hardware in the aircraft maintenance bible. (This publication's official name escapes me, maybe someone else can provide it. If not I will look at mine and tell you tomorrow). Jack Wilhelmson N711CZ Date: Wed, 02 Jul 1997 10:24:22 -0500 From: Darren DeLoach Subject: Re: COZY: Overtorquing At 09:47 AM 7/2/97 -0400, you wrote: >I never got a response to torquing the nuts on our airplanes. When >necessary, what is the max ft. lbs. to use? >Hugh Farrior > > The tables are in AC 43.13; we offered a reprint of this book to this group a few weeks back for $15 plus shipping. I _think_ Jeanne still has one copy left from the ones we bought for the mailing list; email her at ddeloach@msn.com if you want it. (We don't normally keep these laying around in stock, so if she doesn't have the one left we can still get it for you but the shipping will be a little higher, though no more than $3). -- Darren DeLoach Sales & Software http://www.deloach.com From: Epplin John A Subject: RE: COZY: Overtorquing Date: Wed, 2 Jul 1997 11:25:36 -0500 I see several responses but will add an extra .02 worth Ac 43.13 has tables for recommended torque for standard hardware. As I recall this is with lightly lubricated threads. This does make a difference. What you ultimately want is max clamping force. This occurs at the yield point of the fastener. Using a torque wrench to do this does not take into account variables such as lubrication and thread condition. Tests we have run at Deere show that after several uses the clamping force will fall by a significant amount because of thread galling even with lightly lubricated threads. Engine oil is an acceptable lubricant. Obviously there are applications that should not be tightened to the values that produce the max clamping force. Think about the bolts in the control tubes, you may deform the tubing before you get to that point. My usual practice is to use a torque wrench any time there is a critical application such as engine connecting rods and case through bolts as well as wheel through bolts to mention a couple. This will eventually give you a good feel that is usually adequate for routine applications without using a torque wrench every time. Apply a lot of good common sense and you wont get into trouble. John Epplin Mk4 #467 > -----Original Message----- > From: Gunrider@aol.com [SMTP:Gunrider@aol.com] > Sent: Wednesday, July 02, 1997 8:48 AM > To: Cozy_builders@hpwarhw.an.hp.com > Subject: COZY: Overtorquing > > I never got a response to torquing the nuts on our airplanes. When > necessary, what is the max ft. lbs. to use? > Hugh Farrior Date: Sat, 02 Aug 1997 21:44:26 -0400 From: Neil Clayton Subject: COZY: AN Bolt specs Anyone know where I can see AN specs online (eg; diameters, lengths, etc) by AN#?? Thx Neil