Clever ways to mount a round cowl?
01-09-2015, 03:39 AM
#1
Thread Starter
Clever ways to mount a round cowl?
I'd like to mount a cowl onto the firewall so that it can be removed using an allen wrench from the front. I've seen people do this, but would appreciate any photos of this type of setup.
01-09-2015, 04:35 AM
#2
This is what I am doing on my Lockheed Vega.
The cowl ring idea may work for you.
Mine mounts to blind nuts in the firewall.
The cowl ring idea may work for you.
Mine mounts to blind nuts in the firewall.
Last edited by TomCrump; 01-09-2015 at 04:42 AM.
01-09-2015, 06:49 AM
#4
Thread Starter
Tom, this may be a dumb question, but how to you attach the cowl to the cowl ring? (Incidentally, your Vega is going to be a beauty!)
As for a dummy engine...well, I don't need one!
As for a dummy engine...well, I don't need one!
01-09-2015, 07:07 AM
#5
I didn't take pics, but I tacked the ring to the cowl, using CA. I then ran a small bead of Gorrilla Glue around the seem. I didn't spray it with water. I just let the ambient humidity do it's thing.
The next day, that ring and cowl were firmly joined !
Thanks for the compliment on the Vega. It's a model that I've wanted to build for a long time. This one is from an old IKON N'west kit.
The next day, that ring and cowl were firmly joined !
Thanks for the compliment on the Vega. It's a model that I've wanted to build for a long time. This one is from an old IKON N'west kit.
01-09-2015, 07:15 AM
#6
Thread Starter
You trust the Gorilla Glue? I hate working with the stuff myself and threw away the bottle I brought back from the states a few years ago. Maybe I just don't know how to use it properly. Anyway, the idea of "gluing" on the cowl (a metal cowl) makes me nervous.
01-09-2015, 08:10 AM
#8
I also mount many cowling like Tom has done, I bond the cowl ring to the cowling with CA, then I layup a ply of glass cloth and epoxy resin on the inside of the cowling to the cowl ring. Then I just use a long ball driver to pull and install the cap head screws into T-nuts installed on the firewall side. Mine are not round but the same principal applies.
Bob
Bob
01-09-2015, 08:14 AM
#9
If you are going to glue a ring of wood in the back of the cowl...
Once you get the wood ring ready to glue to the cowl position it on your firewall.
Drill 4 3/16 holes around the ring every 90 degrees thru the ring and the firewall.
Now remove the ring, glue 3/16 dowels into the ring so they exit the back of it ...and will now perfectly align in the firewall.
Then you could go halfway between the mounting pins, drill holes for STRONG round magnets. Put magnets in both the ring and the firewall .Making sure they attract, and don't repel !!!
Now glue the cowl onto your ring,and it will line up and click on with authority.
Once you get the wood ring ready to glue to the cowl position it on your firewall.
Drill 4 3/16 holes around the ring every 90 degrees thru the ring and the firewall.
Now remove the ring, glue 3/16 dowels into the ring so they exit the back of it ...and will now perfectly align in the firewall.
Then you could go halfway between the mounting pins, drill holes for STRONG round magnets. Put magnets in both the ring and the firewall .Making sure they attract, and don't repel !!!
Now glue the cowl onto your ring,and it will line up and click on with authority.
Last edited by foodstick; 01-09-2015 at 08:23 AM.
01-09-2015, 05:23 PM
#13
Thread Starter
Foodstick, I like that dowel pin and magnet idea. One slight complication regarding the use of a ring is that on my model there are ridges on both sides of the firewall. Any brackets would have to clear the ridges.
I would trust glues to hold a ply ring to a fiberglass cowl. I don't know about ply to aluminum, however.
I would trust glues to hold a ply ring to a fiberglass cowl. I don't know about ply to aluminum, however.
Last edited by abufletcher; 01-09-2015 at 05:26 PM.
01-09-2015, 09:05 PM
#14
Foodstick, I like that dowel pin and magnet idea. One slight complication regarding the use of a ring is that on my model there are ridges on both sides of the firewall. Any brackets would have to clear the ridges.
I would trust glues to hold a ply ring to a fiberglass cowl. I don't know about ply to aluminum, however.
I would trust glues to hold a ply ring to a fiberglass cowl. I don't know about ply to aluminum, however.
Bob
01-10-2015, 02:18 PM
#17
My usual method for mounting a radial cowl is to run a horizontal ply plate
out from the firewall (also used to baffle off half the unused area in the cowl) .
The ply plate is supported at the front by being attached to the engine mount.
I then glue balsa triangle strips inside the cowl to slide along the ply plate like
a drawer, the cowl is secured by screws between the dummy cylinders.
Obviously you don't have dummy cylinders!
Can you make some supports from aluminium angle out from the firewall & just
bolt through the cowl? Sure, not as neat as some other methods, but your situation
is a little different to the norm. - John.
out from the firewall (also used to baffle off half the unused area in the cowl) .
The ply plate is supported at the front by being attached to the engine mount.
I then glue balsa triangle strips inside the cowl to slide along the ply plate like
a drawer, the cowl is secured by screws between the dummy cylinders.
Obviously you don't have dummy cylinders!
Can you make some supports from aluminium angle out from the firewall & just
bolt through the cowl? Sure, not as neat as some other methods, but your situation
is a little different to the norm. - John.
01-11-2015, 08:52 AM
#20
Thread Starter
Cut skeleton key 'keyhole' shapes in cowl ring. They will be oriented same direction. Put panhead screws in firewall with 'interference' fit to cowl ring, i.e. they are inserted at a slight angle from 'normal' to the firewall. All ya gotta do is remove one 'key' bolt inside (pun intended, lol) then rotate cowl to remove it! That's what I'm doing on my DH-5.
01-15-2015, 04:24 AM
#22
Thread Starter
The 26cm pot has been transformed into a cowl! It looks like brackets will be the best method of mounting it...attached to either the firewall or the engine mount. I'm thinking of painting the cowl a red to match the stripes on the fuselage. I need to do some paint/fuel testing.
01-15-2015, 03:00 PM
#25