Van's Air Force
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Service Bulletin 12-11-09 (Main Landing Gear Upgrade)
- Thread starter Tony_T
- Start date
skydiverlv
Well Known Member
I used this puller for the main gear channel Cherry rivets with no problems.
http://www.amazon.com/exec/obidos/ASIN/B0009XAQ8Y/ref=nosim/13422164-20?s=merchant&m=ATVPDKIKX0DER
Also used the Harbor Freight pneumatic puller for the skin Cherrys.
I did have to clean the grooves in the gripper dies on the HF puller to get it to work properly, but then that gun did all the rivets in the fuselage with no issues.
I think the swivel head puller at ACE hardware is a rebranded Stanley.
Should work also.
http://www.amazon.com/exec/obidos/ASIN/B0009XAQ8Y/ref=nosim/13422164-20?s=merchant&m=ATVPDKIKX0DER
Also used the Harbor Freight pneumatic puller for the skin Cherrys.
I did have to clean the grooves in the gripper dies on the HF puller to get it to work properly, but then that gun did all the rivets in the fuselage with no issues.
I think the swivel head puller at ACE hardware is a rebranded Stanley.
Should work also.
Overly stiff hose doesn't help, but the instructions suggest totally sealing the end of the hose with some duct tape (just stuffing a rag in the hose wont seal it well enough). This causes all suction to be directed though the small hose... if it gets anywhere near any loose material, it gets sucked up.
I would recommend that RV-12 (and any other RV builders using Cherrymax rivets) builders not deviate from the manufacturers installation process of the rivets. Cherrymax rivet domentation may be found HERE
These are highly engineered pieces of hardware. Just because it is refered to as an aircraft grade rivet, doesn't mean you can choose to use any installation technique that is used for any other rivet.
A lot of the shear strength of a Cherry rivet is developed by the steel stem being properly locked in place.
Please do not deviate from the standard installation process.
These are highly engineered pieces of hardware. Just because it is refered to as an aircraft grade rivet, doesn't mean you can choose to use any installation technique that is used for any other rivet.
A lot of the shear strength of a Cherry rivet is developed by the steel stem being properly locked in place.
Please do not deviate from the standard installation process.
yankee-flyer
Well Known Member
You gotta be kidding--1/2 inch bit
Just looked at prices for a 100 degree 1/2 inch "spotting bit" (is this the same as the 100 degree bit Van's wants?? You gotta be kidding me!!! Anybody want to sell/rent their's after completing the mod? I'm planning on doing this the last 2 weeks in Feb 2013.
Wayne 120241/143WM
Just looked at prices for a 100 degree 1/2 inch "spotting bit" (is this the same as the 100 degree bit Van's wants?? You gotta be kidding me!!! Anybody want to sell/rent their's after completing the mod? I'm planning on doing this the last 2 weeks in Feb 2013.
Wayne 120241/143WM
txaviator
Well Known Member
I just glanced at the SB plans, and it's a 100-degree countersink bit they call for. From what I just saw, they simply want you to put a 100-degree countersink in a 1/4" hole. These bits are relatively cheap! It wants the overall countersunk area to be 1/2" in diameter.
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yankee-flyer
Well Known Member
3/8 or 1/2??
Dave, what comes up in the tool link you posted says it's a 3/8 diameter bit. Is that right? Price certainlt is better than the $70 - $100 "centering bit" I was looking at.
Wayne 120241/143WM
Dave, what comes up in the tool link you posted says it's a 3/8 diameter bit. Is that right? Price certainlt is better than the $70 - $100 "centering bit" I was looking at.
Wayne 120241/143WM
Geico266
Well Known Member
Aircraft Spruce $13.00
Geico266
Well Known Member
You are gonna get a lot of chatter without the 1/4" center stub.
Good point. I'll need to get the 1/4" stub version.
That will work just fine (though there is no need to disassemble the cage).
The whole point of the process as described in the S.B., is that it allows you to use any 100 deg. countersink cutter (#40 pilot, #30 pilot, no pilot) as long as it is 1/2 inch diam (Many of them are only 3/8").
If you do it in a drill press at slow speed as described, it will not chatter.
An easier way would be to disassemble one of the hand deburring tools sold by Avery tools (and maybe Cleveland also). Use the threaded barrel in the Drill chuck and thread the cutter into the barrel.
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Sorry about that.
The S.B. tried to be specific in saying that any 100 deg countersink 1/2 in diam will work as long as it is done using the prescribed method (in a drill press). If someone was attempting to do it a different way (such as using just a hand drill) then it probably would chatter (totally different situation compared to it being restrained on a drill press table).
I guess that is one of the problems with forums such as this.
There are a lot of knowledgeable people with many different opinions, but not everyone is going to be right all the time (People at Van's or any body else)... but it would be nice if when people gave advice that directly contradicts something published by Van's, that they had actually tried to do a process exactly the way it is described, and then described what didn't work. Then if it isn't working for some people, it might be possible to change the process, or the way it was described to be done....
Ok, I feel better now......
Oh, don't feel too bad about it. I should know by now that I need to READ the instructions. Besides, you can never have too much `stuff'.
You can never have too much stuff indeed - especially when a local fellow builder will be begging to borrow the stuff
Thanks in advance, Rob!
Hmm... I suppose you'll want to borrow my new Cherrymax riveter as well Shirley?
Dgamble
Well Known Member
Noted. Shutting up now.
Dgamble
Well Known Member
Noted. Shutting up now.
Notes
Completed near-solo SB mod. Here are my notes for those who will be doing this with little or no help.
If you live in warm climate, now is a good time to get this over with; sweat in your eyes and dripping on the work will not add to the fun.
Step 7: actually, the fuel tank info is in Chapter 12, pps 4,5.
Step 8: the preferred rear sawhorse position is just fine; no need to balance the end of the bird where it is narrow.
Step 15: a 1/16 pin punch will bend easily if not struck carefully. Drive out the 8 mandrels in the center channel, then cut down the el cheapo pin punch purchased for this project with a Dremel to about 3/4". Then you can quickly drive out the other thousand mandrels with ease.
Step 32: mark all parts fore/aft on every side you may need to read from during installation. Stuff if going to drop in the belly and you don't need to be pulling it out to re-orient
Step 37: get your drill into position and check for clearance chuck to center channel sides and rear handle to lateral seat brace. Purchase or modify drill bits to fit. You must drill straight here and you don't want to discover the interference when you are all ready to go.
Step 45: stubby Phillips on a ViseGrip will hold the machine screw heads while you turn torque wrench on the nuts up top.
Step 46: if you have chosen not to drill out the small panels under each gear leg opening and you do not have very large hands, gear reinsertion can be facilitated by suspending the powder-coated steel yoke of the outboard attach point from an AN5 bolt approximately 1" longer than the hardware supplied. Once the gear leg is through the yoke and secured tire-to-floor, you can run the supplied AN5's one after another up through the yoke and into the nuts in the center channel.
Step 47: pay close attention to the diagrams with regard to hardware placement.
Step 52: that fuel tank material is page 12-5 in Maintenance Manual.
Be thankful if you have a willing helper but the job can be done by one person with help only with final torque-ing, wing handling and fuselage suspension.
Jim
#264
flying 130 hours
Completed near-solo SB mod. Here are my notes for those who will be doing this with little or no help.
If you live in warm climate, now is a good time to get this over with; sweat in your eyes and dripping on the work will not add to the fun.
Step 7: actually, the fuel tank info is in Chapter 12, pps 4,5.
Step 8: the preferred rear sawhorse position is just fine; no need to balance the end of the bird where it is narrow.
Step 15: a 1/16 pin punch will bend easily if not struck carefully. Drive out the 8 mandrels in the center channel, then cut down the el cheapo pin punch purchased for this project with a Dremel to about 3/4". Then you can quickly drive out the other thousand mandrels with ease.
Step 32: mark all parts fore/aft on every side you may need to read from during installation. Stuff if going to drop in the belly and you don't need to be pulling it out to re-orient
Step 37: get your drill into position and check for clearance chuck to center channel sides and rear handle to lateral seat brace. Purchase or modify drill bits to fit. You must drill straight here and you don't want to discover the interference when you are all ready to go.
Step 45: stubby Phillips on a ViseGrip will hold the machine screw heads while you turn torque wrench on the nuts up top.
Step 46: if you have chosen not to drill out the small panels under each gear leg opening and you do not have very large hands, gear reinsertion can be facilitated by suspending the powder-coated steel yoke of the outboard attach point from an AN5 bolt approximately 1" longer than the hardware supplied. Once the gear leg is through the yoke and secured tire-to-floor, you can run the supplied AN5's one after another up through the yoke and into the nuts in the center channel.
Step 47: pay close attention to the diagrams with regard to hardware placement.
Step 52: that fuel tank material is page 12-5 in Maintenance Manual.
Be thankful if you have a willing helper but the job can be done by one person with help only with final torque-ing, wing handling and fuselage suspension.
Jim
#264
flying 130 hours
E. D. Eliot
Well Known Member
Thanks
To all for the very helpful information.
To all for the very helpful information.
engineerofsorts
Well Known Member
My two cents worth of experience
I, too, have mostly completed all the landing gear mods (still have to put the gears back on).
My two cents worth of tricks:
1. The exterior cherry rivets were no problem pulling with the Avery pneumatic puller--worked about the same as the LP-4s and CS-4s.
2. The eight interior rivets going through the web were a bit more challenging, in that neitnher the pneumatic puller nor the close-quarters hand puller (from the Avery tookit collection) would grip. Curiously, the $10.00 or thereabouts Harbor Aerospace rivet puller seemed to work just fine. I was pleased to find that a one foot-length of 2x4 works wonders for driving the brass bushing out of the way.
3. I was concerned about my abilities to drill the four holes through the web nice and perpendicular, but, having some 3/4" thick acrylic sheet laying around, I cut a 2x2" piece and drilled #30 and 1/4" holes close to the edges, and used these as handy-dandy perpendicular drilling guides. The standard #30 drill was too short, and the 12" #30 drill was too long, so I ended up using a right-angle drilling attachment to the air drill.
4. All the countersinks in my countersink set were 1/2 wide, so countersinking the steel wear plates following Van's destructions was a non-event.
I, too, have mostly completed all the landing gear mods (still have to put the gears back on).
My two cents worth of tricks:
1. The exterior cherry rivets were no problem pulling with the Avery pneumatic puller--worked about the same as the LP-4s and CS-4s.
2. The eight interior rivets going through the web were a bit more challenging, in that neitnher the pneumatic puller nor the close-quarters hand puller (from the Avery tookit collection) would grip. Curiously, the $10.00 or thereabouts Harbor Aerospace rivet puller seemed to work just fine. I was pleased to find that a one foot-length of 2x4 works wonders for driving the brass bushing out of the way.
3. I was concerned about my abilities to drill the four holes through the web nice and perpendicular, but, having some 3/4" thick acrylic sheet laying around, I cut a 2x2" piece and drilled #30 and 1/4" holes close to the edges, and used these as handy-dandy perpendicular drilling guides. The standard #30 drill was too short, and the 12" #30 drill was too long, so I ended up using a right-angle drilling attachment to the air drill.
4. All the countersinks in my countersink set were 1/2 wide, so countersinking the steel wear plates following Van's destructions was a non-event.
Yes please Rob - and advice when you've done all the hard work. I don't ask for much, do I?
Friends! (...sigh). Sorry for the thread drift everyone...
Special Delivery
Well Known Member
SB/ Re:Cherry Rivet Puller
Short data point for those concerned about pulling those Cherry rivets.
Scott McDaniels says any hardware store puller should work... that's what they used.
Bob Avery tested his "Stanley" brand swivel head puller on the identical Cherry rivets furnished in the SB kit and it worked flawlessly.
Today, Eagle's Nest-3 used my 10+ year old hardware store "Arrow" brand economy puller, and it worked flawlessly.
I know the engineers at Van's have sent some of us in search for a metric crescent wrench that's called out in the RV-12 plans, but I personally don't see a need for the $125+ Cherry puller to complete the SB. BTW, it took me two weeks but I did finally locate a metric crescent wrench... $200 from a supplier in London... will sell for $100 if anyone is interested.
Aside:
I want to personally thank the Engineering team at Van's for their outstanding work in resolving the RV-12 landing gear issues and for the care and attention they devoted to developing an "out of the box" retrofit tailored for easy installation on both flying and under construction aircraft. Job well done, guys!
Van's Aircraft also deserves high praises for accepting 100% of the financial burden to produce and supply retrofit kits to over 300 builders. This was no small ticket item and it would have been reasonable, at least to me, to pay shipping costs. Thanks Van's for the OUTSTANDING customer service... you continue to exceed my every expectation!
Short data point for those concerned about pulling those Cherry rivets.
Scott McDaniels says any hardware store puller should work... that's what they used.
Bob Avery tested his "Stanley" brand swivel head puller on the identical Cherry rivets furnished in the SB kit and it worked flawlessly.
Today, Eagle's Nest-3 used my 10+ year old hardware store "Arrow" brand economy puller, and it worked flawlessly.
I know the engineers at Van's have sent some of us in search for a metric crescent wrench that's called out in the RV-12 plans, but I personally don't see a need for the $125+ Cherry puller to complete the SB. BTW, it took me two weeks but I did finally locate a metric crescent wrench... $200 from a supplier in London... will sell for $100 if anyone is interested.
Aside:
I want to personally thank the Engineering team at Van's for their outstanding work in resolving the RV-12 landing gear issues and for the care and attention they devoted to developing an "out of the box" retrofit tailored for easy installation on both flying and under construction aircraft. Job well done, guys!
Van's Aircraft also deserves high praises for accepting 100% of the financial burden to produce and supply retrofit kits to over 300 builders. This was no small ticket item and it would have been reasonable, at least to me, to pay shipping costs. Thanks Van's for the OUTSTANDING customer service... you continue to exceed my every expectation!
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woodsideraff
Well Known Member
Just a couple of notes on my Cherrymax experience.
I tried the G-27 puller and found that it offers only a marginal advantage over the other pullers that can grip the shorter mandrel.
What I found makes for a successful installation of the rivets is continuous force applied directly in line with the rivet. I pulled most of the rivets with the Avery pneumatic, set to 50 lbs of air pressure. Whenever I relaxed the pressure or was off line, the mandrel broke prematurely. This happened in only two rivets; the others installed flawlessly, as evident from the mandrel being almost flush with the manufactured head.
Those rivets in which the mandrel broke before being locked in place were easily removed. A couple of taps with a drift pin and the mandrel falls of the back. Shallow drilling with #30 drill and break the head. The rivet then is easily punched out. I found that the Cherrymax rivets, provided they are not set (mandrel locked), are easier to remove than the LP's. To remove them after fully set, however, is another story. One must first grind the head down to release the lock.
Oh, the learning curve!!
RL
I tried the G-27 puller and found that it offers only a marginal advantage over the other pullers that can grip the shorter mandrel.
What I found makes for a successful installation of the rivets is continuous force applied directly in line with the rivet. I pulled most of the rivets with the Avery pneumatic, set to 50 lbs of air pressure. Whenever I relaxed the pressure or was off line, the mandrel broke prematurely. This happened in only two rivets; the others installed flawlessly, as evident from the mandrel being almost flush with the manufactured head.
Those rivets in which the mandrel broke before being locked in place were easily removed. A couple of taps with a drift pin and the mandrel falls of the back. Shallow drilling with #30 drill and break the head. The rivet then is easily punched out. I found that the Cherrymax rivets, provided they are not set (mandrel locked), are easier to remove than the LP's. To remove them after fully set, however, is another story. One must first grind the head down to release the lock.
Oh, the learning curve!!
RL
engineerofsorts
Well Known Member
Make your own template
If I were in any rush, and didn't want to wait for the Van's Holiday time constant, I would simply fabricate my own drill template, in that you already have a model for it--take either the 1/4" stiffener or the steel wear plate, and match hole drill some aluminum sheet, and trim it up so that it fits where it needs to fit.
got the SB
Received the SB on Decamber 21. It included only the skin doublers since I don't have the finish kit. My understanding is that a new hole must be drilled in the channel (one not present before the SB). I'd really like to do this before buttoning everything up. Am I worrying needlessly?
Jerre
Received the SB on Decamber 21. It included only the skin doublers since I don't have the finish kit. My understanding is that a new hole must be drilled in the channel (one not present before the SB). I'd really like to do this before buttoning everything up. Am I worrying needlessly?
Jerre
DonFromTX
Well Known Member
Not at all. I just finished, and not having the rear window installed yet was a real help. You have to drill FOUR new holes in the center channel, and it would be infinitely easier if you did not have any of the surrounding stuff to contend with.
DonFromTX
Well Known Member
I had no help in installing the SB, proving it can be done by one person. Hardest part was reattaching the gear legs, I think that took as long as all the other steps together. If someone else is doing it by themselves, PM me and I will show you how I conquered the beast.
Walt Shipley
Active Member
Don, speaking of rear windows, I if you decide not to use the window supplied by Van's I still want yours.
Walt Shipley
DonFromTX
Well Known Member
?? But I thought you were already flying! Oh I get it, you are flying without a rear window.
I also have done it solo (on purpose to try and develop a process that could be done solo).
If people do what it says in Step 8 of the S.B. installation document (support the fuselage so that the tires are about 1 " off the floor), then the legs sit in just about the proper position during re-installation when they are resting on the fuselage skin (as long as they small skins haven't been removed). Because of the 1/4" in thick spacers that gets added above the gear legs, 3/4" thick boards are then just about the perfect thickness shims to use under the tires to get the legs just about perfectly aligned.
DonFromTX
Well Known Member
Yep, all that worked out as you said. My most perplexing problem was "threading" the gear leg back on that inner main bolt. No matter how much I tried, trying to get those two pieces and the leg on the bolt was not going to happen, the bolt kept pushing up thru the channel. I finally made me a fix, that got it done very nicely, here was my solution:
Even with that problem, my total time on the installation was far less than others have stated, but of course I had no wings to remove and had good access to that area and was in an air conditioned shop.
[/IMG]
Even with that problem, my total time on the installation was far less than others have stated, but of course I had no wings to remove and had good access to that area and was in an air conditioned shop.
txaviator
Well Known Member
Yep, all that worked out as you said. My most perplexing problem was "threading" the gear leg back on that inner main bolt. No matter how much I tried, trying to get those two pieces and the leg on the bolt was not going to happen, the bolt kept pushing up thru the channel. I finally made me a fix, that got it done very nicely, here was my solution:
Even with that problem, my total time on the installation was far less than others have stated, but of course I had no wings to remove and had good access to that area and was in an air conditioned shop.
[/IMG]
VERY good solution, Don! I am off until the 2nd of January, and I will soon embark on this upgrade myself. I think I will use your neat idea! Thanks.
Walt Shipley
Active Member
?? But I thought you were already flying! Oh I get it, you are flying without a rear window.
Nope, I'm flying with some seriously crazing in my rear window!
Walt
WingedFrog
Well Known Member
My Cherrymax experience
Working in a friend's well equipped shop, we started setting the Cherrymax rivets in the U channel as they are the most challenging ones. We used a manual pop riveter that had proved to work on Cherrymax rivets and which head had been ground to fit in tight corners. Out of the first three rivets that seemed to set correctly (i.e. no premature break of the shank) after consulting the Cherrymax rivet domentation recommended by Scott, 2 out of the three were no good (although they appeared good at first to an LP4-3trained eye). Given this aggravation, we decided to go with AN470 solid rivets as we had the equipment available in the shop. I just called VANs to get clearance to do so which I got readily. I would not be surprised that in future kits these rivets become solid squeezed rivets, set before the skins are installed. As for the rest of the Cherrymax rivets (the shorter ones), they all worked well on the skins, pulled with an HF pneumatic rivet puller.
To the fellow builders who want to stick with the Cherrymax rivets on the U channel, I cannot emphasize enough the importance of following the process described here:
http://www.cherryaerospace.com/files/pdf/catalog/CA-1015.pdf
Working in a friend's well equipped shop, we started setting the Cherrymax rivets in the U channel as they are the most challenging ones. We used a manual pop riveter that had proved to work on Cherrymax rivets and which head had been ground to fit in tight corners. Out of the first three rivets that seemed to set correctly (i.e. no premature break of the shank) after consulting the Cherrymax rivet domentation recommended by Scott, 2 out of the three were no good (although they appeared good at first to an LP4-3trained eye). Given this aggravation, we decided to go with AN470 solid rivets as we had the equipment available in the shop. I just called VANs to get clearance to do so which I got readily. I would not be surprised that in future kits these rivets become solid squeezed rivets, set before the skins are installed. As for the rest of the Cherrymax rivets (the shorter ones), they all worked well on the skins, pulled with an HF pneumatic rivet puller.
To the fellow builders who want to stick with the Cherrymax rivets on the U channel, I cannot emphasize enough the importance of following the process described here:
http://www.cherryaerospace.com/files/pdf/catalog/CA-1015.pdf
Gagarin737
Well Known Member
Nice solution Don but your U-1203C plate is upside down on the picture.
Geico266
Well Known Member
yankee-flyer
Well Known Member
Jean-Pierre, can you
describe what made 2 out of three of your rivets bad? It look like there are several things that can go wrong. I'm not sure that those of us with flying airplanes can use solid rivets.
Thanks
Wayne 120241
describe what made 2 out of three of your rivets bad? It look like there are several things that can go wrong. I'm not sure that those of us with flying airplanes can use solid rivets.
Thanks
Wayne 120241
