KP10A Landing Gear Sproket Bearings

jeffw

jeffw

New member
I found a supplier via the www for KP10A type bearings for the through-the-spar gear sprocket shaft - who sent me this quotation response:
________________________________
Emerson Bearing Co.
[GLOBALSPEC] Request for Quotation for Emerson Bearing Co.

Product Category: Ball Bearings
Part Description: KP-A Series -- KP10AX

We have plenty in stock - your cost is $ 10.80 each and the brand is IJK.
I must tell you that these bearings are not approved for aircraft usage, so
if that's your
Application then we cannot offer them to you. They are fine for any other
usage though.

Thanks
Mary Ann Quintal
Emerson bearing company
_________________________

Price appears to be relatively inexpensive. Can anyone comment on the brand "IJK" or the part # "KP10AX", or the "aircraft usage" note?

Jeff
 
Generally, if you can get these bearings for less than $25.00, don't feel screwed. There are many variations of the the KP10 series......different alloys and bearing seals. I have found all to work OK. My recollection is that at least 50% of the bearings removed are unsatisfactory. WARNING.......the little cast bearing retainers can be broken easily. Be careful when pressing the old bearings out! I have found some of the retainers that have an ID. slightly oversize. In that instance, press the new bearing with a piece of aluminum foil into the housing. I have been able to find KP10 series on Ebay, under the heading of "aircraft bearings." Dan
 
Many suppliers of hardware items have this prohibition on aircraft use. If questioned directly, I always mention that the application is for my vintage John Deere tractor! Dan
 
Dan, thanks for the advise. I found a local bearing shop that could get me the KP10A bearings for $43 ea (plus tax). They also made a huge deal out of the bearings being aircraft control bearings and they would not sell them to me if they were going in an airplane. The counter sales guy got all puffed up like he had an FAA enforcement badge, he started "quoting" FAA'ease jargon. They are afraid of liability claims and such. Such is life.

I told them they are for a homemade pin ball machine's flippers.

I went ahead a ordered the KP10AX ones from Emerson Bearing for $11 / ea. I looked at the IJK spec sheet on the 10AX bearings and everything is identical to the RBC 10A ones (axial loads, thrust loads, dimensions, etc), maybe some of the metal is different but for the amount of turning and the slow rotation that they are handling, i think i can feel safe. Sounds to me like the aircraft versions just have a lot of paperwork tagging along, kind of like kosher vs non-kosher.
 
I've had the same BS from various hardware suppliers. Many different manufacturers made bearings to the KP10A spec.....Fafnir, Torrington, Schatz, Etc. I'm sure what you get will as good or better than original. Be careful of those castings! Dan
 
I visited with a guy this summer who had worked at a place where they build voltage regulators and misc. other devices. He told me that they built "special ones" for aviation for two weeks a year. An FAA inspector would stop in from time to time during those two weeks, but they were building the exact things that they had been building all the rest of the year. But...these were the ones approved for aircraft. :D
Gary
 
Well, at least those regulators were made in the US. I've seen new regulators that were bad - out of the box - made in Mexico. Dan
 
I received another quote for KP10A bearings (not for aircraft use) from Impact Bearings >> $19.50/each.

Scott Barton
Sales Manager
Impact Bearing
949.361.5356 P
949.361.5314 F
scott@impactbearing.com
http://impactbearing.com/
 
I was looking for these last year. I have Fafnir KP10A now. I was told Fafnir no longer makes the KP10A and Timken sold the rights to that bearing to RBC when they bought Fafnir. E.B Atmus Co did find some NOS Fafnir for $36.43. I ended up just cleaning my old ones. I was afraid I would crack the casking removing them so I just removed the seals, soaked them and repacked them. Then put the seal back on.

Kevin
 
Kevin, with both your and Dan's cautions about removing the bearings from the castings, I am beginning to be fearful of trying to press out those bearings. I will bet those castings are impossible to find unless you came across a whole wing assembly or a cruisair being parted out.

Dan, can you give me any more specific advise or directions that I must follow if i do try to press them out, for example - I assume I need to find the appropriate bearing press die, make sure things are aligned perfectly, etc. What about soaking the casting and bearing assembly in liquid wrench before attempting to press them out or other procedures_??
 
Just support the housing around the perimeter. I think I used a socket, last time. Use another socket of the correct size and using an arbor press, push the old bearing out. Don't use a hammer and punch! You don't need anything fancy. A small arbor press is more than adequate. Dan
 
I pulled out the worm gear drive shaft bearing housings from the left wing last night and found that one of them has a pretty serious crack across the entire flange on one side of the housing close to the bearing housing rim; definitely not reusable. I better get the right wing side housings out and hope that they are in good shape.

It looks like the cracked one was at some time the victim of the thru wing spar bolt being tightened too much as the flange is bent slightly at the crack as the fulcrum and has left a corresponding impression in the wing spar. I guess i will need to shim or somehow fill in the dimple in the spar before putting another housing in place or that one will be subject to the same stresses and break another flange.

Are these bearing housings available anywhere, or a replacement, or is there a way to do a repair (cast aluminum)?
 
dan, thanks. i'll get the other wing's shaft and bearings out and see how those look. later.

jeff
 
Jeff,
I have a bunch of spares on the water coming to australia, they are due any day, I think I may have one of whose housings. If I have I will post it to you. Give me a week or so - if you can wait.
I have just removed these from my right wing and fortunately mine look good - How are your worm drive brass bits, mine are pretty worn with lots of play in them, it appears this is where most of my play in the undercart system is coming from. Has anyone got new ones kicking around?

regards
bernie
 
Bernie, Those are called "trunion nuts." By design, they don't fit tightly. I'm not a machinist; but, I'd say that new tolerances would be .010 loose fit. If there is a lot of visual "slop" at that location, then maybe you need a new pair. Bellanca originally had a little canvas "boot" that covered and protected the acme screw and trunion nut from dirt and the elements. Most of these are long gone during the past half century, leaving these parts exposed to dirt and water picked up by the tires. This is why I recommend a good cleaning with solvent and regreasing twice a year, especially in dusty environments. While the gear is off, inspect the cage and support tubes that hold the trunion nuts for cracks. The same for the rear spar bracket. BTW, I may have a new pair of those trunion nuts. Dan
 
Bernie,

Jim Greene in Atlanta, Georgia had made new trunion nuts five - six years ago. Not sure if he still has any, i think he did run out but indicated that he would be making more. I bought two back then and just now have my old ones out and tried the fit of the ones > they do fit and are a lot tighter. Interesting that for the first few turns on the trunion screw they are very tight but run on ok after a few turns, that must indicate the wear on the screw itself.

Jim's number is 1-770-446-6797. You can also e-mail him at mcgreene@earthlink.net > he is member #1574.

If you do have two of those bearing housings, I need two. I removed the other side's yesterday and the same one on the wheel well side of the rear spar was cracked just like the other side. Tell me what they're worth to you i'll send you a check. Something else i came across that I need is the landing gear down stop parts (15128-1, steel cap and the 15128-2, steel threaded rod), service bulletin #24, August 13, 1948. One gear leg had it and the other does not. I never noticed it before or maybe thought that only one side needed it.

my mailing address is >> 20 Debonair Way, Simpsonville, South Carolina 29681.
 
Jeff,
When my spares arrive I will check for them, but I seem to remember seeing a pair. Hope I'm right :oops:
I have been helped by so many of you good people I would be embarrassed to take anything for them. If I have them they are yours. I will also check for the gear down stop parts in my boxes of goodies.
I have a nice new overhauled set of legs on the way over as well.

Dan
Thanks for the information, I am checking the undercart very carefully, I may have some trunion nuts in the stuff I collected while in the State but if I haven't I am very interested in a purchase, or I will chase up Jim Greene. Mine are plus or minus about 0.05 at least!!!
Any idea what that canvas boot looked like, sounds like a great idea to protect the screw jacks. As we get pretty dusty out here. I was forever cleaning and regreasing mine.
 
I can only imagine what that canvas boot looked like.

There may have been a drawing of it > I scanned the list of Bellanca drawings that Cy is restoring and did not see anything that looked like it. If there was a drawing of the boot fabric pattern, it ought to be pretty easy to make one.

The main issue would be designing and making one that you could be sure would not get caught in the screw mechanism and cause a gear operation problem. Would ruin any good day if that happened.
 
Univair has AN201-K10A bearings for $3.66. They are the same bearing that is in the control mast on the Ercoupe. I received six of them. They are made by Schatz and appear to be NOS.

Kevin
 
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