R

ron sterba

Well Known Member
Ok I spent much of the day with the upper hinge and the .090" pin. What a Pistol. OK there is still time to look into Skybolt fasteners for the replacement of the firewall top hinge and still use the other hinges by Vans for the sides and the the two halves. Would like you all to weigh in on your pro's and con's. I like the look of a internal hinge but what a pain to get it in. Opinions much appreciated. Thanks

Ron in Oregon
 
You can't go wrong with Dzus fasteners along the top cowl..at 4" spacing and also on the lower cowl bottom...three per side.

Best,
 
Went with Skybolts (upper cowl only - used #10 SS screws with recessed washers on bottom and on each side at intersection of top & bottom aft of prop - really hard to tell the difference). What Pierre said for spacing. They have worked well for me.

Another -9 owner I know switched from hinges to skybolts when the hinge eyes started cracking.

Dan
 
Shephen I tried today for a couple of hours bending and tapering that .125 SS pin. Couldn't get the .125 to go but did get the .090 and it went in but the hinge is sloppy because the eyelets are for the .125". I think I'll abandon ship here. Thanks
Ron
 
Pierre. Looked up those Dzus fasteners. Look good. Do you recommend a size of 7/16". How would you build the the top firewall plate? .050" Aluminum strip out 3/4" from firewall flange? What about the cowling side? A full strip of say 1" by .050" full length of rear top cowl with fasteners every 4" as suggested? Thanks, Ron in Oregon
 
Terry thanks for the heads up on Milspec fasteners. Did your order the self sealing screws or which one did you order and how did you install them? Ron in Oregon
 
Dan thats a lot of weight you carry with that thought of the Skybolt fasteners. Especially the Conversion done by your friend. Dan do you know off hand which of the Dzus.Milspec or Skybolt fasteners are the easiest. They all look great to remove when the upper cowling comes off. Thanks Dan
Ron in Oregon RV9A
 
Skybolts

Ron,

I've done Skybolts around the firewall and hinges on the sides. Come by the hangar and take a look. Skybolt has a great FWF kit that includes the flanges. It is all very slick.

Kai
 
Milspec ...

I ordered the Milspec firewall kit; it includes 30 complete fasteners and both the tools you need to install and/or adjust. I used the MS4000 style, Phillips head, 1/4 turn fasteners. Don't know if they're "self-sealing" or not. The flanges that rivet to the firewall can be done in either .050" or .063" Al.
 
ron sterba said:
Ok I spent much of the day with the upper hinge and the .090" pin. What a Pistol. OK there is still time to look into Skybolt fasteners for the replacement of the firewall top hinge and still use the other hinges by Vans for the sides and the the two halves. Would like you all to weigh in on your pro's and con's. I like the look of a internal hinge but what a pain to get it in. Opinions much appreciated. Thanks

Ron in Oregon
Click to expand...

Bend the two upper hinge pins to the shape of the cowl and round the tips so they will be easier to insert into the hinges. A little lube and they go right in. It takes a little bit of effort to get them tweaked just right and minor bending adjustments at the very tip will help. Mine go right in with minimal effort (less than 10 seconds). I really like the standard Vans hinges. Good luck.
 
Ok guys hinges gone on top of firewall/cowling. Fasteners are on their WAY! TWO hand tools too! Thanks everybody! WILL stick with hinges on sides and the two halves. Bit cheaper that way. And A whole bunch easier on top! I checked out Kai 's beautiful job! And I got lessons too! Really like those fasteners!

Ron in Oregon
 
mikehoover said:
Bend the two upper hinge pins to the shape of the cowl and round the tips so they will be easier to insert into the hinges. A little lube and they go right in. It takes a little bit of effort to get them tweaked just right and minor bending adjustments at the very tip will help. Mine go right in with minimal effort (less than 10 seconds). I really like the standard Vans hinges. Good luck.
Click to expand...

+1 on the hinges. Once you get it right, they are in and out in seconds. Very slick, no tools required.
 
Ron - sorry you had trouble to the point, and beyond, of frustration. I am not really sure why some struggle with the installation of the pins and others seem to move on happily forever after with them.
Both systems work well when properly done. (I am a happily forever after pin guy for what it is worth.)
The important thing is you are keeping your build moving along....
 
Stephen,Jon Michael, Thanks Liked the video, You know after speaking with you. I got the the pin to slide right in that night by opening the eyelets more with the dremel tiny grinding ball. That went well, and seemed to be no problem. Here's the other item I didn't like and it may not have been a problem once all was fastened in. When I put that .090" pin all the way, I found the corner hinge snug and that was fine. What I didn't like was the SLOP of of the the first 12" of hinge that was made for a .125" pin. I could lift cowling side of the hinge up and down .030". This was the slop I wasn't sure about. Didn't know if It would be a factor. I love the hinge look as it makes the lines look clean, but as I spoke to a few more season owners they would welcome those quarter turn fasteners on the top rear cowling. I guess this is a 50/50 debate. Course I did put out $140 dollars plus shipping for the 13 fasteners and mounting plates. The mounting plates you can either make your own or buy theirs. Sorta getting tired of the build process and anxious to get it up flying! If you know what I mean. Thanks for all your ideas and direction,all quite helpful.

Ron in Oregon 9A
 
Well I was at a fly-in this past week end and talked with a few guys on the 7 & 9's about the cowling. Here are some of the suggestions. That gap between the spinner and cowling. Go on the larger gap to grab the cowling putting it on and off,it avoids the chipping of the paint. Go with 1/4 turn fasteners on the bottom. Stay with hinges on sides and between the two halves. I made a statement about the .090" hinge pin in the center section where the eyelets are .125" and that I didn't like the slop. Yes you'll see a little lifting in the cowl edge in flight but you maybe able to use your rivet squeezer on those eyelets to close the gap a little to reduce that lifting. So there you have it! FLY-INS are all about friends and sharing! Just doesn't get much better than that other than Doug Reeves RV Discussions forums.
 
ron sterba said:
I made a statement about the .090" hinge pin in the center section where the eyelets are .125" and that I didn't like the slop. Yes you'll see a little lifting in the cowl edge in flight but you maybe able to use your rivet squeezer on those eyelets to close the gap a little to reduce that lifting.
Click to expand...

Chuck a .125 hinge pin up in a drill motor, start up your disk or belt sander and taper the part of the hinge that has to make the bend. My neighbor did this on his 8 and it worked perfectly. Someday I am going to get off my rear end and do the same thing.
 
idealy

JonJay said:
Chuck a .125 hinge pin up in a drill motor, start up your disk or belt sander and taper the part of the hinge that has to make the bend. My neighbor did this on his 8 and it worked perfectly. Someday I am going to get off my rear end and do the same thing.
Click to expand...

Jon Jay, idealy would find a pin manufacturing company to make exactly as you mentioned.It's fascinating that one was fashioned! How cool. Great thinking. Ron
 
Pierre, Got the Mil Spec fasteners, I assume they are like the DZUS fasteners. Just the other day two RVs showed up for lunch at the restaurant and both builders switched to the 1/4 fasteners too! Thanks to all you guys for your encouragement. I'm really liking how they installed and pulled the cowling down with ease. Ron in Oregon EAA 292
 
Flange Strip

I was curious where one might purchase a .050 strip an inch or so wide (if that is the proper width) long enough to wrap around the firewall for the use of fasteners? I have looked on ACS, but perhaps I am missing something.

Thanks,
 
robertb328 said:
I was curious where one might purchase a .050 strip an inch or so wide (if that is the proper width) long enough to wrap around the firewall for the use of fasteners? I have looked on ACS, but perhaps I am missing something.

Thanks,
Click to expand...
You might try Vans, but I don't think they use much .050. They have remnants from their normal operations they do sell.
 
Spruce

I got my .050" strips (by about 3" wide and 3' long) from Spruce. That was around 3 yrs ago; I haven't looked in the A/S catalog recently. They were kinduv buried in the catalog I recall.
 
I dug out the Spruce part number ...

... and it came up empty on a search at A/S. It was called a "Mount Strip KIt" and the part # was 04-01993. Looks like they dropped it. Bummer ...that took some pain out the mounting strip process. :(
 
This is what I would recommend now that I consider myself a somewhat expert in the 1/4 fasteners. Contact Jeromy at MIL-SPEC FASTENERS. He has the kits for the RVs on line. Don't worry about one long strip across the top. He doesn't sell the strips but does sell the individual mounting plates for his receptacles at I think $2 bucks apiece. Consider this. If you were bending a strip to go around a corner like the top cowling I FEEL you would be liking the individual strips better to round the corner. There about 4" long and it is VERY EASY to bend one at a time and keep going right around the bend. Spacing is at 3.5 to 4.25" that is recommended. It works great too when near the engine mount bolts because you can shift the mounting plates to suit easy access if needed to those bolts or anything you mount up near the firewall flange. I made my bottom mounting strips from 2024 aluminum sheet .063" and they work GREAT. I took 3 mounting plates and placed them in the order that I needed them for spacing. Then I traced around them to make one long strip for 3 fasteners. Then I went to my table scroll saw and cut out the strips. A little sanding here to clean up your cuts. They fasten very nicely to the bottom firewall flange underneath. You'll make two, one for each side. You'll also have drilled the holes in the strips for the receptacles because next you'll put a work-light inside the cowling pointing down. Now that you strapped the lower cowl on its time to mark to holes to be drilled for the 1/4 screw fasteners. The shadow of the hole in the mounting strip under the cowl is very clear and is easily marked at this time. Jeremy is a very helpful business guy, he treats all of his customers with care. You'll like him. Another RV9A builder saw my cowling and abandon his upper hinge for the 1/4 turn fasteners. I installed the hinges on the sides and across the two haves. Clean look. Now I'm considering a second oil door/acess on the other side by the GUY REALLY REALLY. Using cam locs on my oil door too! Cam locs $10 bucks each at B&B Aircraft Supplies in Kansas. Great people too!

Hope it all helps.
Ron in Oregon RV9A
 
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One more vote for 1/4 turns = SAFETY

I used Skybolt hardware for the firewall to eliminate any hesitation ( excuse) not to remove the cowl. My experience with tube and fabric antiques that use cumbersome cowl attachment schemes encouraged me to spend the money and make it EASY to pull the cowl and investigate WHEN YOU SHOULD.
 
Ron,

Thanks for the information. I have a firewall fastener kit that I bought some time ago from Milspec and will check with them about the mounting plates.

Thanks
 
pics Ron?

Hi Ron - I'm in the same boat as Robert. I bought the Milspec kit years ago with no mounting plates. I'll certainly contact Jeremy. Do you have any pics of your install that you could post? It would really help. Thanks!
 
Dave,

I suppose you bought yours in the group buy as I did some time ago. I just looked on the Milspec website, and they do have some pictures that are in the installation instructions that might help. Hopefully, Ron or others can post some as well. I didn't see the mounting plates that Ron alluded to, but I suppose Jeremy will be getting at least two phone calls.

Robert
 
Yes Robert - I was one of the group buy ages ago. My build is taking longer than I thought... but I can begin to see the light at the end of the tunnel. In fact I'm hoping to get the wings/tail mounted and up on her gear this summer. The cowl will be right after that. I have an engine (in pieces) so my plan was to build up at least the bottom end so I can locate the prop flange for the cowl install.

I saw the Milspec instructions but they are for making your own mounting strip. If I have to go that way I will. I'll sure be glad to get these done. I left the firewall rivets out for these strips so they are the only clecos left in the project.

If you hear anything from Jeremy, post to this thread.
 
I emailed Jeremy at Milspec. They do indeed have the individual mounting tabs, but not mounting strips. They are $2.00 each.
 
Ok guys got something GREAT for you, A idea from Kai a RV8A builder who is just ahead of me on the mounting strips and fasteners. He asked if I had the grommet/screws/insert always falling out when you are taking on/ off the cowling (Permanent snap rings go on when the paint job is finished) and I replied WHAT A PAIN IN THE BUTT! Kai said he had the answer and you should go up to the ACE hardware store and get rubber "O" rings and just slip them over the collar of the grommet/insert to keep them from falling out. WHAT A GREAT IDEA KAI!! 20 minutes later I had the "O" rings in hand at .27 cents each or you could use baby rubber bands from a office supply house. HEY, cost of gas, just go to ACE,its the place!

Hey Robert I made my mounting strips for the bottom by buying those $2 plates and configuring them on top of a .063" sheet of 2024 aluminum. ( the seperation of the recepticale holes for the distance at the bottom cowling) then I traced around them cut out the outline on the table scroll saw. I would recommend buying from Mil-Spec the two templates for the EXACT locations of holes,templates ARE a must. When your done I would keep extra mounting plate in a drawer because no matter what, they can be used for fasteners on motorcycles,trucks bins, motor-home access doors, the list is end less! I have two pictures of the O rings as applied but have never been able to post pictures to the forums pages. If somebody wants to post them for me I will sent them the pictures on a email to them. Thanks guys.

Ron in Oregon RV9A
 
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Great idea ...

...wish I had heard it 2 yrs ago. :( My cowl is as-yet unpainted, and the snap rings are in place. Oh well.
 
Terry Good News, I used a small screw driver (straight blade) maybe a 1/8" wide and stuck it in between the slot in the snap ring and twisted. Able to get a edge up for a piece of safety wire to slide under and then wiggled screw driver blade to remove steel snap ring. Tricky!

Ron in OregonRV9A
 
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Things learned after 250 hours....

The next one will have solid strips down the sides....no scallops. They're unnecessary for fit, and they catch the upper rear corners of the lower cowl when you're lifting it into place. I've already chipped the paint on one cowl corner.

1z3tmi0.jpg


The strips at the lower edge of the firewall see a lot of stress, just like the hinges on the stock installation. However, they're stronger than hinges. Instead of the common hinge breakage problem, it appears possible to overstress the skin and firewall flange to which they attach. I started noticing paint cracks on the belly skin at each end of the attach strips, so I installed buttress reinforcements extending from each fastener to the -8's hard point at the floor line. You can clearly see one of them here. Its neighbor is behind the coil of wire:

2vv9g75.jpg


Caveat; I've pumped up lower cowl pressure as part of the effort to increase cooling exit velocity, and that would concentrate a lot of pressure at the ends of those strips. Still, given the not uncommon hinge breakage on other models with stock cowls it may be worth watching.
 
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