Skybolt installation

sahrens · #1 02-13-2016, 08:01 PM

For those of you that have installed Skybolt fasteners along the firewall I have a question. The instructions tell you to drill the through the cowling in alignment with the installed skybolt flanges to 15/32". I am shortened the instructions but if you have done it you know what I am talking about.

To my question. You can cleco the cowling in place but as you drilll more and more openings for the Skybolts fasteners the clecos need to be removed. So....did you stop and install retainers and Skybolt fasteners periodically, then resume making drilling openings.

I am concerned about keeping the cowling from moving as I work from the top down both sides. What am I missing from the instructions or the process?

Thanks for you assistance.

stamper · #2 02-13-2016, 08:10 PM

I ran into this problem myself when I did mine not so long ago. the mistake I made was that I did the skybolts across the top first before I did the piano hinge along the side. I had the gaps perfect, better then perfect and if I would of done the piano hinge on the sides first then nothing would of moved.
so doing it again I would of done the sides first and then the top. That way nothing would of moved as I did the skybolts on top.

sahrens · #3 02-13-2016, 08:21 PM

Did you clamp the upper and lower in place with a strap like a cargo strap? Or did you just rely on clecos to hold the upper and lower in place?

I had been waiting to make that cut along the lower cowling until I had installed the firewall Skylocks.

Thanks for you advice.

bret · #4 02-13-2016, 08:22 PM

after I mounted the flanges, I drilled through the cowl and into the skybolt flange and clecoed . I will have a couple holes in the flanges but I did not want it moving....at all.

longline · #5 02-13-2016, 08:22 PM

installation can be simple, I think. Once you have the receptacle support (either sheet metal or the available sky bolt nesting supports) installed you can find an area that is not "busy" and install a couple of clecos. They never change positions, so you can take the cowl on and off several (hundred) times and it returns to the same position.

My only caution is to make sure that your receptacle spacing allows clearance between the upper engine mount and the nearest skybolt receptacle. I would make sure that the skybolt spacing puts those two receptacles far enough away from the upper engine mount to allow the full depth of the receptacle to be used. There are ways around this issue, but it is best to avoid it to begin with.

Seriously, good luck, it was fun for me...

BillL · #6 02-13-2016, 08:52 PM

I have some posts you can find on this very subject. I don't know how you can do the sides first but like a lot of things, it depends.

Meanwhile, Yes you can certainly drill for a cleco through the "adapter" then move to the next one. In my opinion, it is hard to cinch down the cowl tight without deforming it and causing other issues. So - i drilled, installed a cleco top center and alternated outward. I found it hard to hit the holes exactly, but had a workaround to fix them before drilling. Lots more special tools, but very happy with a precise fit. I suggest having a cleco in each position for the full fitting. Maybe your cowl is more rigid, but mine was not, so they all were used.

Here is how I did it : http://www.vansairforce.com/communit...d.php?t=114861

DaAV8R · #7 02-13-2016, 11:40 PM

The answer to your question is yes.

I installed the Skybolts as I went to prevent movement of the cowl. I started by doing every third or fourth hole. I also had a steel weldment attached to the front two cylinders so the cowl inlets were positioned exactly the same each time the cowl went on and off.

I did not have any perceptible movement during the install of the Skybolts but doing it this way is a fairly slow process.

DonFromTX · #8 02-14-2016, 09:08 AM

I am jumping in here to get some information from those that have been there and done that.
My problem is that the fairly thin cowling is being depressed in the area of the skybolt. I think this will really look bad after shiny paint is applied. I have experimented with raising the under cowling portion of the skybolt, does not seem to work very well. It appears that maybe a washer between the two parts might be in order, or perhaps actually putting some fiberglass on the inside part of the cowling to thicken and strengthen that portion. None of my ideas really seem like good ones, what have others used to solve this problem?

sahrens · #9 02-14-2016, 05:18 PM

Quote:

Originally Posted by DaAV8R

The answer to your question is yes.

I installed the Skybolts as I went to prevent movement of the cowl. I started by doing every third or fourth hole. I also had a steel weldment attached to the front two cylinders so the cowl inlets were positioned exactly the same each time the cowl went on and off.

I did not have any perceptible movement during the install of the Skybolts but doing it this way is a fairly slow process.

I would rather be slow and have the results that I want. I will use your technique.

Thanks

sblack · #10 10-28-2016, 10:39 AM

Quote:

Originally Posted by longline

My only caution is to make sure that your receptacle spacing allows clearance between the upper engine mount and the nearest skybolt receptacle. I would make sure that the skybolt spacing puts those two receptacles far enough away from the upper engine mount to allow the full depth of the receptacle to be used. There are ways around this issue, but it is best to avoid it to begin with.

Seriously, good luck, it was fun for me...

I installed the tabs for the skybolt fasteners (homemade) before I had the engine mount on. And guess what - I don't have enough clearance with it on. So I need 2 low profile recepticals to clear the top engine mounting pads, one on each side. If you know ways around this issue I would very much appreciate any wisdom on the subject. I am currently looking for a low profile camlock receptical.