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dgrayent

Active Member
...Probably been hashed over before, but I'm a newby.

I saw at Snu-n-Fun '05 a couple of 7s with Cam Locks spaced about 4" apart in place of the piano hinge at the top and upper sides of the cowl/firewall, but wouldn't you know I was too excited to take pics or get the N number! :eek:

They looked very neat and will avoid the problem of cracked piano hinges...

Your opinions please, pros & cons, photos, sizes of Cam Locs, construction hints, etc, before I begin that phase.

Thanks in advance,

Don Gray
Cortland, OH
N17QB
 
Skybolt fasteners

I went the Skybolt fasteners on my 7. I used the hinge for sides of the lower cowl. There are no curves on this portion. Regarding spacing, I have flown in a couple that had 4" spacing and could see the cowl bulge between the fasteners at high speed. I went with 3.5" and haven't had the problems.

I my opinion, this type of fastener is the way to go. They are relatively easy to install and make cowl removal quick and easy.

Darwin N. Barrie
Chandler AZ
RV-7 N717EE
 
Camlocs

I have had no trouble with mine and love them. I used them everywhere no hinges anywhere. Would I do it again?....absolutely. Was it worth the money...yes. I think hinges would work just as well on the sides. I just kinda liked the machined look of the camlocs.
f2og.jpg
 
I would replace all my hinges with extruded hinge.
Stronger and longer lasting.
I still think hinges cannot be beat for overall strength.
 
Don,

I installed camlocs on the top cowl-to-firewall joint, and will do it again. I've never actually tried opening/installing a cowl with hinges on that line, so can't comment; never actually tried shooting myself in the head, either. The bottom cowl is held by hinges on the side, and, on the bottom, five #8 screws through aluminum reinforcements on each side of the exhaust into platenuts. Hinges join the cowls.

It all works quite well for easy manipulation. No signs of stress after 150 hours. The toughest part is moving the lower cowl past the spinner, gear legs, and air box intake on a carbed engine.

A slight ripple exists in flight between camlocs. So what. I think you can see my installation in "RV of the Week" pix about July last year.

John Siebold
 
John (and others),

Thanks for your replies -- VERY informative for me. I LOVE THIS PLACE!

John, what spacing between the Camlocs on top (that allow a slight bulge in flight)?

The way I see it, Milspec fasteners are not adjustable for depth (thickness) of cowling, etc. except by ordering the appropriate length of stud. The Skybolt's fasteners are adjustable depth, thus the added $80 or so for the complete 7A kit (about $500 + or - a few $ for slot or phillips on their website this morning). 'Kinda pay your money and takes your choice." For the fussy person who insists on the best possible fit of studs, Skybolt fasteners could all be exactly right height, but Milspec's might vary 1/32 or so. Right? Still a little :confused:

Don
Cortland, OH
 
Friend of mine used Camlocs on his 6, had the cowl lifting problem so went the plenum way, replacing the silicone baffle material. now the cooling air puts pressure on the plenum, not the cowl - problem solved. The plenum was a glass epoxy layup over foam on the engine, get it nice and snug, lay the glass, saran wrap over as release, then fit the top cowl, fits where it touches, stays close everywhere else. When set, trim, fix, fly !

Having seen his, we will be using locks on our 7.

If you are using #8 screws in places, here is a tip from our Eagle rebuild. Countersink where the hole is and epoxy a stainless tinnerman washer in the hole. Once set, lay some deck cloth or thin glass over the area, once set, touch the hole with a countersink to clear the glass and hey presto, a wide bearing surface, recessed stailness receptacle - will never wear out.
 
dgrayent said:
The way I see it, Milspec fasteners are not adjustable for depth (thickness) of cowling, etc. except by ordering the appropriate length of stud.
Don
Cortland, OH
Click to expand...
Did you call and talk to them? I'm fairly certain the ones that come in the kits are adjustable.

PJ
 
Cam Locks

Don,

I could have been one of the 7's you saw at Sun n Fun. I used the cam locks on the top cowl to firewall joint. If I had it to do again I might consider using them everywhere. They work great and are adjustable so you get a perfect fit on each one. I have some pictures on my web site but no detail. If you go this route I would recomend reinforcing the cowl with a couple of layups where the locks go to avoid pucker in the cowl.

Pete DeCraene
N526PD
http://www.ews.uiuc.edu/~decraene/index.htm
 
I used skybolt fasteners all round. A couple of comments:

* The skybolt instructions recommend .063" for the bits that extend out from the firewall. They said .040" is too thin and cracks. Other folks told me they had no problem with .040", so I went with .050" just to be safe. Still quite bendable for the curves (with appropriate relief holes for flexibilty/weight reduction).

* For the upper part of the cowl it seemed easily thick enough to just use 'as-is' for the camlock ring. However, now that I've been flying for a while a couple of spots have bent up about 1/16" due to the heat. For my next RV I'll be adding a few layers of bid to this spot prior to drilling the holes.

Kevin
 
dgrayent said:
John (and others),

Thanks for your replies -- VERY informative for me. I LOVE THIS PLACE!

John, what spacing between the Camlocs on top (that allow a slight bulge in flight)?

The way I see it, Milspec fasteners are not adjustable for depth (thickness) of cowling, etc. except by ordering the appropriate length of stud. The Skybolt's fasteners are adjustable depth, thus the added $80 or so for the complete 7A kit (about $500 + or - a few $ for slot or phillips on their website this morning). 'Kinda pay your money and takes your choice." For the fussy person who insists on the best possible fit of studs, Skybolt fasteners could all be exactly right height, but Milspec's might vary 1/32 or so. Right? Still a little :confused:

Don
Cortland, OH
Click to expand...


Please search and find the group buy info. The milspecs are exactly the same as the skybolts and are adjustable. Make sure you go to Scotts website for specifics including a sample and pictures.

Alan
 
Further info

Skybolts are 100% adjustable. I wouldn't use anything that isn't. I used used a 3.5 inch spacing, .063 mounting strips and the slotted version.

I don't see a need to spend the extra on the Phillips, the Skybolt slotted is recessed so the screw driver will not slip. Additionally, when the pin is pulled they slots all line up perfectly.

This is an area where the additional cost is money well spent!!!

Darwin N. Barrie
Chandler AZ
RV-7 N717EE
 
More Info

Don,

You asked, so...

Spacing is something over 4", maybe 4.38. I don't remember exactly. Spacing does affect the pucker factor, but mine (and it is there on the ground, too) is, at worst, .04 proud of the top skin. The fiberglass cowl in its off-the-airplane state has larger radiuses than the firewall, so it wants to pucker a bit when confined. Right at the camloc it's even, so adjustability wouldn't have helped in my case.

This touches on the shim-or-not issue (Van's says stick a .020 shim between hinge and fiberglass). The material thicknesses suggest that installing the shim would have edges even. That's how the math works out, but real world the hinges and plate for the camloc receptacles sit a tad deeper once install to somewhat mimic the effect of a shim, and the fiberglass thickness could be locally thin. A shim is likely to set the cowl below the fuse, which I say is real ugly because the fuselage presents an edge to the slipstream. If the cowl is slightly proud of the fuse it looks o.k. since it is streamlined, except you see a bit of cowl edge from the cockpit. Crucial to visuals is an even gap between surfaces: consistant, uniform, unwavering... yada, yada. The actual gap width is more dependant on function, ease of fabrication, and allowing for paint build-up, having little bearing on how it looks unless way too big or troublesomely teeny-tiny. But if you have uneven gap widths, particularly on the same line, it's going to look like hell even if there's nary a pucker. This holds for oil doors, wheel pants, anywhere there's a parting line.

Also, I used plus-flush (I think that what Camloc calls 'em) receptacles. For them you simply bore a hole; flush receptacles require a tapered edge, tough to do in that diameter while keeping the hole on center, and weaker support from the fiberglass. You have to get close and squint real tight at my cowl to detect that the receptacles are not flush.

John Siebold
 
MilSpec Camlocs

Don,

The Milspecs are adjustable...ask the 80+ people on this list that are in the group buy. Quality is comparable (if not a little better) to the Skybolt. As has been mentioned, you can get a 30% discount still till 2/10/06. See below for additional details.

http://www.scottsrv7a.com/camloc.htm

I'm in no way affiliated with Milspec...just a happy (bargain) customer. I believe everyone else who has recently purchased has been very happy as well.

Just my $.02...
 
Camlock spacing problem

When Scott set out the deal for the group Camlock purchase he said on his website that the Milspec kits for the RV7(A) allowed for a 3" spacing. I felt that this was a reasonable dimension given reports from other builders that larger spacing had resulted in "pillowing" of the cowl between camlocks in flight. However on later reading in their instalation instructions that Milspec advocate a spacing of 3.5" to 4.0" I emailed them and asked them exactly what spacing their RV7 firewall kit would provide. They wouldn't tell me (or they didn't know). They simply responded by saying that the firewall kit had 26 camlocks and if I wanted more I could buy them.

My calculation is that 26 camlocks will provide a spacing of approx 4.3" (this is now going way beyond the 3" spacing that we were originally told) and that is not an acceptable spacing to me. So I have ordered an additional 4 camlocks to reduce the spacing to a more reasonable distance (closer to 3.5").

Others in the group buy might like to consider this situation.
 
Adjustable!? That's why they are so darn expensive. at $400.00 per set I should make up kits and sell all the ones I have in the basement and buy a nice radio. stack$$$$$ :D All you have to do is order the conventional camlock and order the correct stud! Sure is alot cheaper. I don't get it . some spend pennies for screws at home depot and pay $400.00 for camlocks :confused:
 
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Don't know about everybody else, but the thickness of my cowl varies quite a bit. And the firewall only kit is closer to $200.

That's not good news about the number of fasteners. I'll have to measure things out this weekend and maybe add a few more to my order.

A question about installing camlocs. How wide does the backing strip need to be? I noticed that Van's sells some long 1-1/2 .063 strips, but I'm not sure that's wide enough.
 
2" will satisfy.

You need 5/8 of material around the receptacle. I used 2"x 0.63 which gave slightly more than 5/8".
I had Vans cut it to order.

Pete.
 
Pete and Others,

Pete, yes, perhaps yours IS the one I saw at S-n-F. I DO rember that it was red and b-e-a-u-t-i-f-u-l-l-l! That may be why I didn't get a photo -- too enamored! :eek:

Anyhow, for the rest of you great guys, I now feel fully infomed enough to make a decision for the the fasteners.I think I'll go for them.

Again, thanks for all your inputs!

Don Gray
Cortland, OH
 
To All,

O.K.! O.K.!

After hearing from a few of the builders regarding this fastener spacing / bulging / pillowing issue, I have decided to change all of the kits to include an additional 4 fasteners. This should give everyone enough to complete their cowling regardless of the style of support structure or spacing they choose to use on their particular airplane. You may even end up with a couple of extras to play with. This will bump the price of the kits sold after the Feb 10, 2006 deadline a little but, for those of you already involved in the group buy, just call me and I will send the extras out at the 30% discount and I will even pick up the ground shipping cost. That would make the cost for stainless Phillips head $5.71ea ($22.84 for 4ea). Slotted heads would be a few pennies less. Fair enough?

Thanks to everyone for using MilSpec Products on your aircraft.

Best regards,
Jeremy Summers
MilSpec Products, Inc.
31537 Long Acres Dr.
Sorrento FL 32776
Tel. 352-735-0065
Fax 352-735-0504
[email protected]
www.milspecproducts.com
 
Are you guys using the low profile of the flush camlocks? I'm thinking of purchasing a set myself, but being that wings aren't started and my fuselage isn't on order yet, I'm not sure what would work.
 
Thatchman said:
I have decided to change all of the kits to include an additional 4 fasteners.
Click to expand...
Jeremy,

Just curious how many are currently included in the kit, and what is the recommended spacing between them?
 
Camloc Pictures

For those debating how many Camlocs to use and how to fit them, see my post with Pictures under Camloc Group Buy.
Pete.
 
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