N

N787TR

Active Member
I'm looking for suggestions to help make it easier to install the lower cowl on a 7A. My problem is every time I install it (it has been trimmed to fit), either the firewall hinges get caught up in themselves or it binds between the spinner and fly wheel. The baffle seals certainly don't help much either. Needless to say things are getting a bit banged up. Since it isn't painted yet not a big deal but very annoying. However, I certainly want to improve the installation process while everything is still in the cleco stage and definitely before any paint is applied. My current set up has the standard Vans hinges along the firewall sides and bottom but I have extended the nose wheel cut by a few inches. The longer cut helped some but there is still plenty of room for improvement.

Any suggestions on either technique or cowl modification would be greatly appreciated.

-Todd
 
I thought that fitting the lower cowl my RV6 was a pain too until I helped fit the lower cowl on one our club C172s at the weekend. It uses camlocs which can be a difficult to line up and engage while supporting it's weight, and it also got caught between the baffles and spinner. The basic Van's set up is actually pretty good in comparison. The trick is to trim for decent fit and access but not too much as to be untidy.
Jim Sharkey
 
I had the same problem...

...until I sprang for a hydraulic lift table from Harbour Freight. I think it was about $120. The table has rollers, a foot operated jack and release.

I used some lengths of 1x6 wood material, and attached it to the lift table. I contoured the far end of the wood to match the contour of the lower cowling. The wood is long enough that the cowling completely overhangs the table...cantilevered like.

The end result is that I can place the lower cowling on the lift and jack it into position a little at a time as I roll the lift table /cowling into position. Works for me...
 
I feel your pain. Im sure I must own the record for the most cowl installations/removals - at least from a frequency standpoint. The 'good' part is that I now have an intimate understanding of every binding point and anticipate them before the bind occurs. Lots of practice does make it much easier and faster, and also with much less potential for dings and scrapes.

My tips are simple and short:

(1) when installing the lower cowl, sit yourself down in a low, rolling seat - something like this one:
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_19648_19648

Then you can be more relaxed, resting the cowl on your knees while you get it into position. You can also quickly roll around to the other side when needed without ever standing up, and while still keeping one hand on the cowling if needed.

(2) Take your time, be patient, and when you feel it bind up, stop until you understand exactly where, how and why it is binding. You probably wont be able to ever completely eliminate the binding, but you will get to the point where you know exactly where it wants to bind and what to do about it before anything ugly happens.

(3) I commonly get offers from others to 'help' with the cowl installation when they see me doing it. I always thank them but refuse. For this particular task, its really something I prefer to do alone, as there are a lot of little subtle things about it that I cannot fully communicate to others at the required instant. Bottom line - less chance of damage when I do it myself, and if something does get scratched or dinged, I would much rather just have myself to blame

Your technique will improve - dont paint until it does!

erich
 
I was going to suggest lengthening the slot for the nose gear leg but you said you have already done that. I'll still suggest that. I used Fairings Etc upper fairings on my plane and their nose fairing allows you to extend the gear slot quite a ways forward. I had trouble getting my lower cowl on and off untill I finally extended the slot as far as I could using the Fairings Etc. fairing to cover up the extended slot. It helped quite a bit and prevents me from getting the cowl hung up on the spinner back plate. Wish I had extended the slot BEFORE painting, would have saved me a few nicks and scratches.

Also, once your airplane is painted, be sure to put a strip of 2" wide masking tape down the front edge of your nose gear leg fairing before taking off or putting on the lower cowl, saves it from getting scratched and nicked.
 
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Something else that saves the nose gear leg paint...

...are the plastic cover sleeves that fit around a shower rod (bath tub stuff). One sleeve, cut in half, gives two useful covers. I like them better than tape...when the fiberglass gear cutout hit them, they just spin and allow the cowling edges to slip past. The tape method just allowed the fiberglass edge to cut through and scratch the paint.
 
Todd,

In addition to the above tips to prevent the cowl contacting the rear of the spinner whilst installing, I use a ~.050" teflon type cutting board from my local foodmart. They are available over here (AUSTRALIA) in coloured sets of four and are approximately 1.5 feet long by 1 foot wide. I cut a profile in the middle of one to set it over the cranckshaft/case on the rear of the spinner and then held in place by some tape. This then allows you to butt the front of the cowl up to the rear of the spinner whilst slotting the cowl into position without fear of scratching, chipping etc either the front of the cowl or the rear of your spinner. All you have to do then is concentrate on the firwall area and the nose leg (if you have one). Works for me and many other local builders too. Not home at the moment though could get a picture if you need one in a week.

Health, wealth and happiness,

Greg
 
Great Feedback

Thanks for the feedback... the helpful hints are terrific and it is really nice to know I'm not the only one inventing a new vocabulary every time I install the cowl!

-Todd
 
cowl woes

Tod,
I take my cowl off way too much, and I'd LIKE to do it as a part of every pre-flight ....but don't, because it's such a pain.!
Thus, it has become a safety issue!
I can only suggest in addition to the other tips provided, that you take a long hard look at the various types of air box gaskets/seals that builders have come up with. THis is a major sticking point for me, when I think I've got it on nicely, I see it has to come off again 'cause I missed getting the cowl fit to the throat of the airbox properly!!!! :-( rack'um sac..krm stiflin-scrumb-lerazzn'sp etc.)
 
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