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It's got to be an improvement on inefficiant immobile motorways.
Horseless carriage of the sky's, care feed stable vet and dont take liberties. |
Not sure yet !
Keep forgetting to put the upload into the log !! I'm expecting an improvement overall but I don't think it's going to be that substancial.;) |
R44 Blade debonding AD
A new AD has come out from the CASA website.
Click Here Although it is not specified on the AD, rumour has it that an R44 may have suffered M/R blade skin debonding (near the tips) in flight. 1. Has anyone else noticed this occurung on R44 blades? 2. If debonding happened in flight with skin peeling back to the extent of causing moderate to severe vibration, would a "power off" autorotation be a safe option? |
Sorry Sprocket.........
But an Auto in any "R" Series is not a safe option.....:confused:
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Robbo bashing OMR ?
Hardly the wittiest or most original move; can't you come up with something a bit more imaginative ? |
oh dear, old man rotor strikes again!
i dont mean to moan about any other rotary pilots but the quote 'an auto in any R heli'.......isnt safe , what utter tosh! from previous posts i assume you are an ' old bold pilot' on large twins, well news for you, not everyone wants or can afford to fly twins- twice the trouble and as the pilot of G-SAEW found out having 2 donkeys on top doesnt stop you having an accident(no disrespect to the guy, i think he did an exellent job in the circumstances, just using it as an illustration) also as most are filled with fuel from the same filler neck, get bad fuel and both engines stop-how many eols have you performed recently in your flashy twin? yes the r22 can be difficult to get it right but any problems are mostly down to pilot inexperience or lack of currency than a bad design, and as for the r44 it autos almost exactly like a 206-regarded by most as the safest single engine helo if people in the industry can be so blinkered how are we to beat the likes of the mirror in thier latest campaign? |
Old Man R
Oh dear...oh dear! Do you also believe no-one out of uniform should be allowed near a helicopter? Shame on you. Now, come and play nicely.:p |
Blade debonding.
Debonding of the blade skin may be a manufacturing anomaly or it could be caused by the use of unapproved cleaning or protective materials. Check the Robinson forum on Vertical Reference under “Corrosion”. It is apparent that Robinson operators and by extension all operators are using unapproved materials to protect their helicopters from corrosion. One Robinson pilot from Australia indicated that they used a product called Nutcreaker, which he said far out performs WD-40 which most certainly would result in debonding. Check it out.
:eek: |
Hope I'm not out of line...
Just wanted to get back to the original topic, I personnaly don't think entering an auto would help the matter, since the NR would likely remain the same, or higher at some stages. The debonding of the Blades would cause vibrations, and if I experienced severe low-frequency vibrations I would land ASAP no matter what machine I was in.
ABout the Robbo and auto's, they glide a lot better than the "greased anvil" i currently fly, my only gripe is that you have to be a bit more on the ball should the donkey decide to go on strike Well, those words were my opinion anyways...:cool: |
I have heard that the Robbos can be tricky in auto, more so the R22, and good training is important.
Winnie: I was thinking that if the blade skins debonded in flight, then the disturbance in the airflow would act a bit like a speed brake in a wing, particularly if some of the skin were protruding outwards. Entering an auto with reduced or no power (IMHO), could allow the rotor RPM to slow down below the minimum limit. All opinions are welcome! Lu: Yes I agree that unapproved materials being used for these sorts of things happens a lot. WD40 has a lot of competition in the commercial market and operators will generally use what they consider a cheap alternative if WD40 is scarce. I’ve also heard that the scrim used in bonding can act as a wick, which draws moisture and chemicals into the bond line when the sealing surfaces erode . Are there alternatives to the use of scrim? |
Huh?
Not sure what scrim is? If it is a sealant then yes petroleum and caustic detergent materials can wick into the bonding material and cause the fracture or deterioration of the bond. We washed our Sikorsky blades with castile soap and DI water or bottled water, which had minimal mineral content. We used to wax our helicopters because we spent a lot of time aboard ship. I tried the wax on the blades and the mineral spirits in the wax caused a debond on the blade pockets. That stopped very soon thereafter.
I can't say this LOUD enough. Don't use WD-40 for anything on an aircraft unless the manufacturer of the aircraft for that particular function approves it. I believe Allison approves it for long term storage of an engine on aircraft and the WD-40 is not used as a preservative. WD in WD-40 stands for Water Dispersant. Also the fumes from WD-40 can cause some serious medical problems if it is ingested into the lungs or into the stomach for whatever reason. Read the label. I assume that other similar products can cause the same problems. :( |
Scrim
It is the word I use for the gauze/fabric that is used in between two bonded surfaces (sometimes).
I think it maintains a constant thickness between joints and helps retain the adhesive while it is still curing during the bonding process. |
The recent debonding event happened about 20 miles from here and was one of my friends machines. The scenario was the pilot was on approach to the airport, felt vibrations and lost rotor RPM.
Entered an auto, but found still had some power and did a low powered "auto". Bad news was that the clear spot he picked short of the airfield was actually a nest of power lines (The airport is right next to major electricity sub station with both high tension and 240 volt lines every where. Not a bright place for them but the airport was there first;) Anyway, clipped a lone wire just above the ground and probably took out the tail rotor. At some point the aircraft started rotating and settled on the skids while rotating and proceded to thrash itself to bits. Both pilot and passenger walked away, though the pilot had some squashed vertebrae, I'm told. As for the use of WD 40 etc. It's use is ubiquitous here. Mostly its used on the leading of blades to prevent corrosion because of the high salt content and very high humidity in the air. If you use nothing the blades rapidly develop corrosion on the D Spar or on the skin where the paint has worn off. Now whether or not the operator used WD 40, one has to bear in mind that there are at least 6 R44s (and several have been through rebuilds so are on second or third sets of blades)operating in this area and several R22s. Most use WD 40 (so do the local Bell operators as well) and of the 10,000s of hours the local sets of blades have had up on them over the last say ten years there has been one blade debond here (I don't know where the other blade mentioned in the CASA report was) That blade was getting close to its 2200 hours I think. They were put new on that machine only about two years ago so they have seen plenty of use in a short time. I would have to say that with all due respect to Mr. Zuckerman, recalling events that happened in 1952 and using them as evidence for or against current practice is a bit of a long bow to draw. The bonding agents were probably not even invented then. Similarly putting your ideas on one forum and then quoting that forum as a source of evidence against a practice is also a pretty rude trick. Your negative comments on the Vertical Reference forum merely echo your statements here and yours were the only ones backing your statements. I'm not trying to be smart or nasty just trying to keep an even keel on the debate. You may after all be right. But your evidence is not yet that convincing. Anyway, the obvious answer is to contact Robinson and get their word on it. I have written to them and will post the answer when they write back. |
Yeah but....
To: RobboRider
I made a point about what can happen and used a personal experience to illustrate the point. Granted it happened in 1952 but you seemed to have missed the point. What I suggested was that WD-40 is not a preservative. Its' sole purpose is to displace water. WD-40 was developed to protect the stainless steel skin of the Atlas Missile and it was not called WD-40 at that time. WD-40 like liquid Wrench and other similar products is capable of weeping into very tiny crevasses on metal surfaces and in the process it displaces water where Liquid wrench penetrates rusted surfaces. All of these products contain petroleum distillates that can react with the bonding material. My second point is that you can not use a product in the maintenance and servicing of an aircraft if that product is not approved for that function. The aircraft manufacturer will run tests or they will have the product manufacturer submit the product to an approved laboratory for testing for the intended function. If the product is not in the approved materials list in the maintenance handbook then it can't be used. Also, if WD-40 is approved you must only use it for the approved purpose. Also, if you use WD-40 on the blades as a preservative the film of WD-40 will attract sand and other entrained particles and upset the delicate aerodynamics of the blades. I have worked as a Reliability, Maintainability and Systems Safety Consultant since 1968 and problems like this are constantly being raised. |
WD40 as a preservative:eek:
No, don't do that. Most any light oil is a better preservative than WD40. |
I spoke to the LAME who looks after the R44 that debonded the blade and he told me categorically that those blades have not been treated with WD 40. As I trust him implicitly (he does my machine as well, I am prepared to say "That answers the question" - in relation to the blade which did debond. They wash them with standard detergent and that's it. Unauthorised cleaning agents had nothing to do with it.
Also found out the blades had 700 hours to run and were 4 years old (not the two I thought - time flies. I remember when they were installed and didn't realise it was that long ago. :O No wonder I'm feeling old. Time is speeding up!) I also got back a reply from Robinson which despite a specific question about WD 40 was only a very general answer. They advise using automotive wax. I'll post their reply on my website (If it fails try again later It might take me a while to get around to it.) Go to http://helipics.homestead.com |
Sensitive New Age Folk.....
Perhaps I should add the R22 in my Profile.........as I do have instructional time on them............:p
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R44 Helipods
Any of you out there use or have used the Helipod for the R44?
Are they worth the investment, in terms of ease of use and functionality? How do they affect the aircraft's performance, and what, if any, drawbacks are there? Can they hold for example, a standard airline-allowed rollaboard case? Thx in advance..... |
RobboRider
would the lame know if WD40 had been used by the pilot?
i wonder if the debonding happend on the top or bottom of the blade first (i think i should buy a ladder) and i wonder if flying in the rain after the paint at the tips has been worn off, has anything to do with it? just thinking out loud.:confused: |
What goes around comes around.
I also got back a reply from Robinson which despite a specific question about WD 40 was only a very general answer. They advise using automotive wax. It was stated that their operator used plain household detergent to clean the blades. Detergents in some countries can contain Sodium Meta silicate penta hydrate, which is highly alkaline or possibly monobutyl ether, which is a solvent. I would suggest that you return to the dark ages of 1952 and use Castile soap and deionized water to wash the blades and go back to Robinson and ask them which car wax and detergent they recommend. That way, you are protected if you experience debonding or any other problem and it is traced to the use of the recommended products. . Run Henney Penney the sky is falling or, is it Wolf, Wolf! :eek: |
Oh yeah, I forgot
Alkaline detergents come in two forms. Ionic and non-ionic. Ionic detergents contain free Hydroxyl (free Hydrogen) ions and Non ionic detergents do not have free Hydrogen. 99.5% or thereabouts alkaline detergents are ionic.
The free hydrogen can be absorbed by heat treated steel. The entrained hydrogen will migrate to the point of highest stress causing the item to fracture under high stress. This is called Hydrogen Embrittlement. Alkaline detergents can also cause stress fracture on parts made of PolyCarbonate plastic. These alkaline detergents are wicked so, choose wisely. That is why the US Military has banned them from use on aircraft. Has the sky fallen yet? Better yet, have you seen any wolves? :eek: |
Robinson and WD-40.
This is aimed at the use of WD-40 on Robinson helicopters as well as the maintenance of the helicopters painted surfaces.
Robinson does not approve WD-40 however Corrosion X aircraft grade is approved for corrosion protection. It is available in spray cans and in bulk. You can purchase an application kit and several gallons of Corrosion X for several hundred dollars. The US Army used corrosion X in a test. Two companies of UH-60s were sent to Somalia. One group of UH-60s was aggressively treated with Corrosion X and the other group had no protection. When the two groups of helicopters were returned they were put into refurbishment. The maintenance cost on the treated helicopters was $192,000 less than the untreated ships. Robinson also approved another Corrosion X product. The name of the product is REJEX which is used to protect the painted surfaces that get contaminated by engine exhaust and bugs. Check out their website WWW.corrosionx.com or call them at 1-800-638-7361 Here is a partial lis of those aviation organizations using corrosion X The Ages Group AMR Combs Eurocopter (Aerospatiale) Chalks International Airways Comair Air Academy Confederate Air Force Erickson Air Crane Co. Gulfstream Aerospace Technologies Learjet Corp. McDonnell Douglas Helicopters NOAA Aircraft Operations Northrop Grumman Aircraft Petroleum Helicopters Raytheon Aircraft Rockwell Collins Saberliner Corp. Textron Flight Service :cool: |
Wow, quite a post Lu, thanks.
Anybody familiar with CarbonX? We use it (diluted) at our flight school to clean the aircraft. Corrosion is not really a problem, and the blades are just cleaned with water. Im pretty sure this stuff is made for aircraft, it would seem that this stuff is made by the same company but I didnt see anything on the website. Just want to make sure nobody has had bad experiences caused by CarbonX. |
Let me make myself clear on that point.
That should have read $192,000 per helicopter.
:cool: |
R 44 Helipods
I have fitted a set of helipods to a 44, they are not particularly user friendly as they don't just clip on/off. The load is useful but won't accept anything as large as a roll on case, more like a weekend bag. It does effect cruise speed but I don't remember the exact figures.
The build quality of the pods wasn't great, they were literally just a spray tank converted with a cut-out door, but it does give you a bit more flexibility for small bags or boxes. Check out www.helipod.co.nz |
Could I ask the same questions as asked in the first post - but for R22's.
I've been thinking of buying a set for my 22. My specific questions are: 1. How much calculating, weighing of baggage etc do you have to do to check your C of G when they are loaded. 2. From the web site they look like they might interfere with using the ground handling wheels. Do they or is it just the angle of the photos? 3. Do they decrease your cruise speed or increase your fuel usage to compensate and if so by how much. 4. Anyone know any names or phone numbers of users I could talk to about the above questions before I outlay the $$? Thanks:D |
Vorticey
I didn't ask about which surface was debonded, I'll ask the owner when I see him on Friday. I do know that I'm buying a longer ladder so I can check the top surface as well. The problem occurred in R44s and the AD was only for the 44 series but I think it would be prudent to be vigilant with R22 blades as well. The blades are different though (apart from their size) The R22 has alloy D spar and the R44 stainless. I don't know if they use different bonding agent but the fact that one side of the bond is different metal might make a difference. I couldn't be that lucky though ;) The owner keeps all the local machines at his rural property (he has a fleet of them) and he is fastidious about his machines and does most of the cleaning, washing etc himself. He's the chief pilot so he's with them all the time and the LAME is doing something with one of the machines pretty frequently. Beyond that who could say. As far as is known they don't use it. I hope having bare metal leading edges isn't the cause because every Robbo I've seen with over about 500 hours on the blades has no paint on the outer leading edges. Again I think it would be a case of, if that were the cause every blade here would have delaminated. Mr. Zuckerman Unfortunately as I said Robinson gave a very general answer to a specific question. Their reply was a page from a manual which just said automotive wax. No type or quality specified. Not much help. Where did you get the information that Robinson do not approve the use of WD-40? I haven't been able to find that sort of specific information but if its available, officially, I would like to get it. Though they didn't say so, I got the impression from their brief reply and attachment that they weren't too keen to actually name names. Maybe again for fear that an apparent endorsment might prove to run against them if a problem ensued. But they also did't say what you could NOT use either. My LAME rang around operators and distributors here in OZ and came up with carnuba automotive wax. If I recall carnuba is some sort of organic oi l /wax from a tree or plant (though I am delving back into the dark recesses of my memory there. CorrosionX doesn't seem to be available here in this part of OZ. Now, Mr. Zuckerman, you wouldn't be trying to baffle and impress us with lots of big words would you? ;) Something something Meta Silicate penta hydrate - sounds a bit glassy to me. Alkaline agents having free hydrogen :confused: Don't you mean acids have free hydrogens and alkalines accept hydrogens. Free hydroxyl (Free Hydrogen) ;) MonoButyl Ether in a detergent (mmm, maybe, though the ether linkage would would render it very insoluble in ionic solution like detergent and probably defeat its purpose. If one end of the chain were a butyl what's on the opposite end of the ether bond? :O Whoops, just remembered you are right...some of the short chain aromates are included in engine degreaser types to help dispersion into water when you wash off the stuff. I take that bit back. Ah well doesn't matter its all one up-manship isn't it. Some of us Robbie drivers have more letters after our names than in them:) Now with regard the falling sky. I do recall - I checked the posts -and that it was your good self who first saw the waxy shadow of debonding and cried that it proved the sky was falling on all users of such evil unauthorised stuff. And it was your own post which revelled in the call that WD-40 in sheeps clothing caused the problems (of course - self protected by the little insertion at the start it could be a "manufacturing anomoly" but.......) If I recall I mentioned a few lines indicating perhaps there might be more to it, as lots of blades gets lots of WD 40 and lots of blades (in fact all except 2) don't debond every time they turn. Now I DO agree with you that if the manufacturer doesn't endorse then we shouldn't use it. I have written back to Robinson for a more specific answer and again I'll post it when I get an answer. Till then I'm off to buy a bigger ladder and some maybe some carnuba wax :rolleyes: |
Apparently they do affect the ground handling wheels, but if its as easy as advertised - 30 seconds whip on and off.............
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Yeah but....
The bit about the sky is falling and crying wolf was placed there for you the reader to exclaim and at the same time saying to yourself, ”Oh no, not again”.
The lesson in detergent chemistry was included because if I said don’t use detergents or car wax on your helicopter or on the blades you might wonder why not. As for the helicopter manufacturer endorsing one product over another that is not the case. It is required that both military and civil airframe manufacturers test or have tested every product that is to be used on or in their respective aircraft. If it happens that two different manufacturers submit competing products and both pass the test procedures then both products can be used. In any case the manufacturer is required to include the names and / or specs of the products and publish these product names in the maintenance manual or the parts catalog for the helicopter or aircraft. In some cases the manufacturer will assign their own spec number for a given product and not identify the product by name forcing the operator to purchase the product from them more than likely at an inflated price. :O |
RobboRider: Corrosion X has been available through Aviall, in spray paks or 5 litre containers.
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My LAME rang around operators and distributors here in OZ and came up with carnuba automotive wax. You can get the real carnuba wax, but you have to look for it. Best bet would probably be an outfit that sells to the high-end collector or detailer. |
Sprocket
I'll go to Aviall myself tomorrow then. I ran them one morning this week but the guy I spoke to said he hadn't heard of it. But you get plenty of times where you strike the wrong guy who hasn't heard of something but if you'd got one of the others the answer would have been more favourable. He tried to tell me Innox was the bee's knees but I've used that on a boat motor and I reckon it never lasted as long as the WD 40. Speaking of answers; Try this [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[ Dear Mr. Martin: RHC is not aware of any debonding problems associated with any waxes or corrosion inhibitors. With respect to waxes, use a carnuba-type wax if you ever intend to repaint your blades. Silicon-type waxes, while not prohibited, have an annoying tendency to cause "fish-eyeing" in subsequent paint applications. I do not know if the same holds true for the "modern polymeric substances" you mentioned. Also, to preclude the possibility of frictional heat buildup, do not use power tools on blades. Regarding corrosion inhibitors, we have for may years recommended either ACF-50 or Corrosion-X, mainly because of their superior corrosion protection properties over the omnipresent WD-40. We have no objection to your continued use of WD-40, but do not spray it on Teflon-based hinges such as MR hub hinges, rod ends, tail rotor drive shaft damper pivots, governor or carb heat assist friction clutches, etc, or any rubber belts. We are aware of debonding problems due to excessive heat from either direct (flame, or heat gun) or indirect (power tools) sources, which is why our Maintenance Manuals (MM) contain warnings to avoid heating blades above 175 degrees F. We also prohibit the use of chemical paint strippers on blades. Presently, there is no published list of specifically approved corrosion inhibitors for our aircraft; we will incorporate such a list in a future MM revision. I am not familiar with RP-7; is the CRC product you refer to actually CRC-3.36? Sincerely, Patrick Cox RHC Tech Support ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]] Direct from the horses mouth.:rolleyes: Cheers |
Pat Cox speaks.
Pat stated that they recommended that the blades never be exposed to temperatures over 175-degrees F. When I worked in Iran we had air temperatures of 113-degrees F and the ground temperature was 168-degrees F and inside the helicopters it was over 180-degrees F and it fried most of the avionics. Solar radiation is a killer and mechanical devices can soak the heat up so the local temperature (of the mechanical item) was far in excess of the local air temperature. I would assume that the two Oz Robinson’s that exhibited debonding operated in similar temperature extremes.
Lord the manufacturer of elastomeric elements on helicopters stated that if an elastomeric element were exposed to temperatures of 160-degrees F for a total period of one hour in the parts lifetime the part life expectancy (MTBF) would be cut in half. If solar radiation was the cause of the debonding then the killer has claimed two lives (blades) :eek: |
We regularly put temperature sensing tape on bearings, does this mean putting them on the blades would be a good idea???
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It never gets that hot here.
We get the occasional 40 - 42 degree day (by this I mean once or twice on a bad year. ) Further west they get lots of 40 - 44 degree days in summer but never get any air temps as high as those which Lu experienced in Iran. That machine spent a lot of its time operating along the coast and closer areas so I doubt the temps it was exposed to were very high or high for very long. The blades are out in the sun - so on those bad days the actual temp on the blades probably is very high - as high as 175 degrees? I don't know. Maybe, but as far as I know no one has measured it and published the data. Maybe thats a good little project for some engineering student. I suppose putting telatemp strips on the blades would be the easiest way find out. But I'd be worried about one coming off in flight and unbalancing the blades. I suspect the high temps would only apply to blades not in flight so you could probably get by without even leaving them on permanently - and having to do track and balances when they were put on. Just have to remember to take them off before starting up. I guess again the case is - why only two blades suffering - and especially why the blade on a machine that spent most of its time at far lower temperatures down here along the coast. Why not the dozens of machines that permanently live and work in the hot climate? I still haven't had a chance to ask the owner about which surface debonded. He didn't turn up at the aero club last night. I'll ask him when I see him. |
How hot is hot?
To: Shawn Coyle
I don’t believe it would stick. However there are handheld infra red sensors similar to what a doctor sticks in your ear to take your temperature that could be used for this purpose. My intro reads How hot is hot and here is an example. We landed our aircraft at Corey Field an outlying field at Pensacola during the summer. Our aircraft was on the ground for about five minutes when I was approached. I was told that the base order was that on a three blade prop one blade must be up and the other two down. I climbed up and onto the wing and the skin was already over 160-degrees F and getting hotter. My feet and skin were burning and in trying to hand move the prop a gas pocket caused the prop to rotate. I almost fell off the wing and by the time I got down my butt, my feet and my hands were burnt. I told the guy to screw the base order or to do it himself. Anyone that has pulled maintenance under similar conditions will know what I am talking about.. :rolleyes: |
robborider
what are you going to carrie in them, foam?
i wonder do the skids need reinforcing, the manual states nothing can be attached to them.:confused: |
The distributer told me they are approved for 46 lbs if you are using one or 100 lbs each if you are using both.
I think their actual attachment point is on the bottom frame rather than the skid, but I may be wrong there cos I haven't actually seen a set in the flesh. Obviously that weight is part of your all up max weight so it is just redistributing what you are going to carry. But then I do a lot of trips where: me plus son plus camping gear is below max weight but above the volume that is comfortable in the cabin. But if the Vne is dropped I'm not that keen cos on our Secret Mens Business (see http://secretmensbusiness.homestead.com )trips I'm trying to keep up with a squadron of fixed wingers who are TAS-ing about 100 - 105 kts. While I'm TAS-ing at 90 the separation is good but if it dropped me down to say 80 kts it starts making me too far behind. |
i have heard from a reliable source that both the blades had
delaminated, how bizarre is that. one blade was a very small section but the blade that failed the most had delaminated from the tip and in one metre. the laminate had peeled back. it is not known yet where the delamination started. the main delamination occured at the spar in front of the trim tab. i also heard that the pilot had full throttle with the collective fully down and only just maintaining rpm because of the drag. i am sure that the pilot would not have been able to see properly with the huge ammount of vibration present. he was extremely lucky to get it near the ground but unfortunately they hit a wire. the pilot suffered minor spinal injuries but is ok and the passenger is back at work. the blades have gone back to the usa, to franks. :eek: :rolleyes: |
Imabell: It sounds like these guys were lucky to survive. I did hear last week that the wire may have slowed their descent but that was probably only rumour.
Obviously a full auto was out of the question. RobboRider: Corrosion X (MIL-C-81309E) part number for aerosol cans is 80102 and 84004 for gallon container. Sometimes you get a better response from the suppliers when you give them a part number. :) |
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