Ziroli 92" p-47 build thread
05-26-2017, 03:43 AM
#101
Calil,
thanks.
==================
Wing LE.
Ripped some large stock balsa into a LE for the wing.
I actually thought I could drill out the holes, perfectly spaced, and place the LE over the guns: That delusion was quickly dispelled and I just cut each LE piece for each gun and glued it in place. Will be much easier to fill in LE cuts versus enlarged gun holes. After removing the screwed in guns, started to plane down the LE to conform to the wing.
Some local neighborhood kids came over to 'help'.
thanks.
==================
Wing LE.
Ripped some large stock balsa into a LE for the wing.
I actually thought I could drill out the holes, perfectly spaced, and place the LE over the guns: That delusion was quickly dispelled and I just cut each LE piece for each gun and glued it in place. Will be much easier to fill in LE cuts versus enlarged gun holes. After removing the screwed in guns, started to plane down the LE to conform to the wing.
Some local neighborhood kids came over to 'help'.
05-26-2017, 07:00 AM
#102
Wing LE (cont)
The balsa used for the LE was extremely hard so I switched from a small modeling hand planer to my woodworking power planers and a Fein oscillating sander: It still took about 3 hours to get the LE close to where it should be.
Some masking tape laid along the wing's sheeting to protect it in case I get careless when sanding the LE.
Some 100 grit wrapped around a paint stick finished the last sanding.
I found it much easier to drill/tap the wing to the fuse before adding the LE: there was a 1/4" to 7/16" gap up front for 'wiggle room' while attaching the wing. I then knew how much of the LE had to be trimmed after gluing the LE to the wing.
The balsa used for the LE was extremely hard so I switched from a small modeling hand planer to my woodworking power planers and a Fein oscillating sander: It still took about 3 hours to get the LE close to where it should be.
Some masking tape laid along the wing's sheeting to protect it in case I get careless when sanding the LE.
Some 100 grit wrapped around a paint stick finished the last sanding.
I found it much easier to drill/tap the wing to the fuse before adding the LE: there was a 1/4" to 7/16" gap up front for 'wiggle room' while attaching the wing. I then knew how much of the LE had to be trimmed after gluing the LE to the wing.
05-26-2017, 01:54 PM
#103
Wing tips.
Cut my last remaining balsa block stock from WW II surplus for the wing tips.
Another couple hours sanding them down to the correct profile: it must of been a lot of work building those old kits that gave you lots of blocks to carve and shape!
Finally looking like a P-47 wing.
Cut my last remaining balsa block stock from WW II surplus for the wing tips.
Another couple hours sanding them down to the correct profile: it must of been a lot of work building those old kits that gave you lots of blocks to carve and shape!
Finally looking like a P-47 wing.
05-28-2017, 09:26 AM
#104
Moving surface gaps.
Used G-10 to fill in flap and aileron to wing TE gaps. Still have to do the elevators.
Had to change the blade allot for multiple cuts through the G-10.
220 grit sandpaper to rough up the sides and some CA to secure it.
Defects fill in:
Used easy sand two part auto body filler to fill in defects before glassing.
Used G-10 to fill in flap and aileron to wing TE gaps. Still have to do the elevators.
Had to change the blade allot for multiple cuts through the G-10.
220 grit sandpaper to rough up the sides and some CA to secure it.
Defects fill in:
Used easy sand two part auto body filler to fill in defects before glassing.
05-30-2017, 01:59 PM
#106
Thanks, ragtop,
===========
Hinging tail surfaces:
The LE of the elevators and rudder were rounded over.
Used robarts large pin and pocket hinges on the elevators and rudder. Everything is modular for ease of glassing, painting, maintenance.
===========
Hinging tail surfaces:
The LE of the elevators and rudder were rounded over.
Used robarts large pin and pocket hinges on the elevators and rudder. Everything is modular for ease of glassing, painting, maintenance.
06-15-2017, 01:36 PM
#107
Horizontal stab (cont)
Cut some 1/64" thick by 5/8" wide ply to cover the gap to the elevators.
Initially, was going with an 85 engine but probably will get the DLE-120 so I can swing a 4 blade prop. It may be a little wide by a 1/4" so either some 'bubbles' an the cowl or cut the cowl in half and widen it.
With flyins and PM, time can be a premium on building.
Cut some 1/64" thick by 5/8" wide ply to cover the gap to the elevators.
Initially, was going with an 85 engine but probably will get the DLE-120 so I can swing a 4 blade prop. It may be a little wide by a 1/4" so either some 'bubbles' an the cowl or cut the cowl in half and widen it.
With flyins and PM, time can be a premium on building.
06-16-2017, 09:57 AM
#108
Glassing.
First picture shows the 'tools of the trade'.
I'm using Ziroli's 1 0z FG cloth on the wings.
Normally, I would do the whole wing with one piece of cloth but, with only 1 roll left in my stock, I went the economy way and cut enough to do the out wing section with the 3' wide FG cloth.
A bondo applicator works well for me in getting a thin layer of resin over the cloth.
After the resin dried, the excess cloth around the bottom edges were sanded off.
I put some masking tape over the gun threads to keep stray finishing resin from getting on them.
Next, the center section was covered.
Fuse:
Some more 'easy sand' around the base of the vertical fin.
Vertical fin:
CA'ed some 1/64" thick ply along the trailing edge of the fin.
I'm using the ply over the G-10 as the ply is more flexible covering the rounded edges of the tips of the fin and stab.
First picture shows the 'tools of the trade'.
I'm using Ziroli's 1 0z FG cloth on the wings.
Normally, I would do the whole wing with one piece of cloth but, with only 1 roll left in my stock, I went the economy way and cut enough to do the out wing section with the 3' wide FG cloth.
A bondo applicator works well for me in getting a thin layer of resin over the cloth.
After the resin dried, the excess cloth around the bottom edges were sanded off.
I put some masking tape over the gun threads to keep stray finishing resin from getting on them.
Next, the center section was covered.
Fuse:
Some more 'easy sand' around the base of the vertical fin.
Vertical fin:
CA'ed some 1/64" thick ply along the trailing edge of the fin.
I'm using the ply over the G-10 as the ply is more flexible covering the rounded edges of the tips of the fin and stab.
06-16-2017, 02:35 PM
#109
Main wing fillet.
The plans have a 1/32" ply for the bottom of the fillet that contacts the wing. I've always had trouble getting the ply to lay flat on the wing due to stress from the fuse pushing on the ply. This time, I cut some 1/64" thick ply by 1/2" wide and stuck it under the original ply and taped it to the wing: There is no stress on the 1/64" thick ply so it lays nice and flat along the wing.
I used some thick CA to secure the 1/64" thick ply to the 1/32" thick ply. Some thick CA was also applied along the fuse sheeting where it contacts the 1/32" thick ply.
Some triangle stock was then thick CA'ed to the inside corner of the fuse to ply fillet.
Finally, some easy sand was applied to smooth over the fillet.
Some more work needs to be done but this gave a nice smooth transition from the fillet to the wing without any large gaps.
The plans have a 1/32" ply for the bottom of the fillet that contacts the wing. I've always had trouble getting the ply to lay flat on the wing due to stress from the fuse pushing on the ply. This time, I cut some 1/64" thick ply by 1/2" wide and stuck it under the original ply and taped it to the wing: There is no stress on the 1/64" thick ply so it lays nice and flat along the wing.
I used some thick CA to secure the 1/64" thick ply to the 1/32" thick ply. Some thick CA was also applied along the fuse sheeting where it contacts the 1/32" thick ply.
Some triangle stock was then thick CA'ed to the inside corner of the fuse to ply fillet.
Finally, some easy sand was applied to smooth over the fillet.
Some more work needs to be done but this gave a nice smooth transition from the fillet to the wing without any large gaps.
06-19-2017, 06:37 AM
#110
Glassing (cont)
Glassed the bottom of the wing.
Nav lights.
Some scrap plastic from existing canopies to make the covers with the help of a heat gun.
Main wing fillet (cont)
Put the flaps on the wing to finish up the back part of the wing fillet.
A small ply former cut and glued in to hold the ply flat against the flap, some triangle balsa to fill in the space and, finally, easy sand to fill in the fillet shape.
Nice doing the sanding, outside.
Glassed the bottom of the wing.
Nav lights.
Some scrap plastic from existing canopies to make the covers with the help of a heat gun.
Main wing fillet (cont)
Put the flaps on the wing to finish up the back part of the wing fillet.
A small ply former cut and glued in to hold the ply flat against the flap, some triangle balsa to fill in the space and, finally, easy sand to fill in the fillet shape.
Nice doing the sanding, outside.
Last edited by samparfitt; 06-19-2017 at 06:43 AM.
06-19-2017, 04:09 PM
#111
Glassing (cont)
Using only the 3' width of the FG cloth, it's taking longer to glass parts but, in the warm weather, the resin is dry enough after about 2 hours, to add more cloth to the parts. Only the other side of the fin and part of the front side of the fuse is left. The bondo applicator works well in distributing and removing excess resin.
Stab and all moving surfaces still must be done.
Using only the 3' width of the FG cloth, it's taking longer to glass parts but, in the warm weather, the resin is dry enough after about 2 hours, to add more cloth to the parts. Only the other side of the fin and part of the front side of the fuse is left. The bondo applicator works well in distributing and removing excess resin.
Stab and all moving surfaces still must be done.
07-06-2017, 06:37 AM
#112
Glassing (cont)
Got some time again and glassed the elevators, rudder, tail doors and belly pan. Used 1/2 oz on all but the belly pan with 1 oz. Only did one side.
Old fashion wax paper good non-stick surface to do glassing.
Still have to do the flaps and ailerons.
Got some time again and glassed the elevators, rudder, tail doors and belly pan. Used 1/2 oz on all but the belly pan with 1 oz. Only did one side.
Old fashion wax paper good non-stick surface to do glassing.
Still have to do the flaps and ailerons.
Last edited by samparfitt; 07-06-2017 at 11:28 AM.
07-06-2017, 11:32 AM
#113
Glassing 2 (cont)
Got the top layer of 1/2 oz on the flaps and ailerons and bottom layer on the elevator, stab and rudder.
Old age: after almost finishing a layer on the stab, I realized, Hey moron, you're doing the top again. Fortunately, the cloth came off easily and lots of alcohol removed the excess resin.
Got the top layer of 1/2 oz on the flaps and ailerons and bottom layer on the elevator, stab and rudder.
Old age: after almost finishing a layer on the stab, I realized, Hey moron, you're doing the top again. Fortunately, the cloth came off easily and lots of alcohol removed the excess resin.
07-11-2017, 12:33 PM
#114
glassing 2 (cont)
Sand now or sand later!
Kept sanding the resin until entire surface is dull. It looks smooth but when I put on the primer, it will show all the imperfections. Rarely need more than 2 coats of primer though, which includes panel lines.
Finished glassing the bottoms of the flaps and ailerons.
Sand now or sand later!
Kept sanding the resin until entire surface is dull. It looks smooth but when I put on the primer, it will show all the imperfections. Rarely need more than 2 coats of primer though, which includes panel lines.
Finished glassing the bottoms of the flaps and ailerons.
07-19-2017, 01:03 PM
#115
Tail feathers:
Forgot to put hard points in for the control horns for the elevators. Some 1/8" aircraft ply was glued in.
Stab is glued in last as I find it easier to prep the stab not attached to the fuse.
Prep for 1st coat of primer.
I forgot how much work it is to prep a FG plane. You couldn't pay me enough to do this for someone else. Used 100 grit sandpaper to smooth out the resin in the FG cloth. All done outside with a mask and gloves on.
I use a 2 part epoxy primer from my local auto store. The primer is extremely tough as of all my planes that I've built, I only know of one spot on one plane that bubbled on me.
Everything done under the trees in the shade and outside as this primer is very toxic.
Forgot to put hard points in for the control horns for the elevators. Some 1/8" aircraft ply was glued in.
Stab is glued in last as I find it easier to prep the stab not attached to the fuse.
Prep for 1st coat of primer.
I forgot how much work it is to prep a FG plane. You couldn't pay me enough to do this for someone else. Used 100 grit sandpaper to smooth out the resin in the FG cloth. All done outside with a mask and gloves on.
I use a 2 part epoxy primer from my local auto store. The primer is extremely tough as of all my planes that I've built, I only know of one spot on one plane that bubbled on me.
Everything done under the trees in the shade and outside as this primer is very toxic.
07-20-2017, 01:38 AM
#116
Sam,
I'm going to go back to post 14 and ask you a couple of questions.
When you started installing the stringers, you said you were using basswood, cut part way through, to keep the framing stronger as well as add "usable" weight.
So my questions area as follows:
1) By cutting the stringers part way through, aren't you sacrificing a considerable amount of strength? My thought is that you now have only half the strength the stringer would have had
2) Have you considered using two basswood strips, laminated together in the appropriate shape or, conversely, cutting the stringer out of appropriately sized plywood, to get a stronger stringer?
I'm going to go back to post 14 and ask you a couple of questions.
When you started installing the stringers, you said you were using basswood, cut part way through, to keep the framing stronger as well as add "usable" weight.
So my questions area as follows:
1) By cutting the stringers part way through, aren't you sacrificing a considerable amount of strength? My thought is that you now have only half the strength the stringer would have had
2) Have you considered using two basswood strips, laminated together in the appropriate shape or, conversely, cutting the stringer out of appropriately sized plywood, to get a stronger stringer?
07-20-2017, 04:09 AM
#118
Was just a thought since I have tried the slotted stringer technique before in a boat build and found it to be too weak while both of the other options I asked about seemed to hold up better.
07-20-2017, 01:15 PM
#121
BEFORE/AFTER
The primer always reveals all the defects: recesses and not enough resin added to fill in some spots of FG cloth. The primer along with some bondo red glazing putty from walbox fills in all the imperfections.
Some wet/dry 220 hand sanding removes the bulk of the defects.
The result is a nice, smooth, hard surface.
Messy job using water so old cloths and, again, done under the tree on the grass.
The primer always reveals all the defects: recesses and not enough resin added to fill in some spots of FG cloth. The primer along with some bondo red glazing putty from walbox fills in all the imperfections.
Some wet/dry 220 hand sanding removes the bulk of the defects.
The result is a nice, smooth, hard surface.
Messy job using water so old cloths and, again, done under the tree on the grass.
08-07-2017, 07:40 PM
#122
Engine, firewall and cowl build.
I'm a big fan of removable firewalls and I'm using my old P-47 firewall as a guide for the new plane. All ignition, throttle/choke servos and fuel tank will be mounted on the firewall for ease of install and maintenance.
I cut some 1/4" thick lite ply that will be glued/screwed along the LE of the cowl flaps: this will give a base to secure the dubro hinges to while making the cowl flaps functional.
With the engine metal standoffs, I needed a engine box 2" wide. Some 1/2" multiply cabinet grade ply from Rockler's woodworking store was the source for the ply. Beside the 1/2" thick front ply, a 3/8" thick aluminum plate is also used for the front of the engine box. From the front, the top right corner is even, the bottom right and top left corners are in 1/8" and the bottom left is in 1/4" to give down and right thrust. I find moving the engine over and up 1/4" puts the end of the prop shaft back into the center of the firewall.
The flat metal surface gives a perfect plane insuring no racking of the engine's metal mounts.
Some carbon tipped forstner bits were used to drill out the metal plate and sub-ply for throttle/choke servo control rods. For safety, the plate was clamped down in case the bit bound in the metal plate.
Some 2" long 1" diameter dowels were cut to hold the cowl in the proper location; the 1/4" thick ply for the cowl flaps has 4 nodes along the edge to rest on the wooden dowels. Four bolts will be used to secure the cowl to the dowels.
Part of the 1/4" thick ply had to be cut as well as the back of the cowl for muffler pipe clearance.
I'm a big fan of removable firewalls and I'm using my old P-47 firewall as a guide for the new plane. All ignition, throttle/choke servos and fuel tank will be mounted on the firewall for ease of install and maintenance.
I cut some 1/4" thick lite ply that will be glued/screwed along the LE of the cowl flaps: this will give a base to secure the dubro hinges to while making the cowl flaps functional.
With the engine metal standoffs, I needed a engine box 2" wide. Some 1/2" multiply cabinet grade ply from Rockler's woodworking store was the source for the ply. Beside the 1/2" thick front ply, a 3/8" thick aluminum plate is also used for the front of the engine box. From the front, the top right corner is even, the bottom right and top left corners are in 1/8" and the bottom left is in 1/4" to give down and right thrust. I find moving the engine over and up 1/4" puts the end of the prop shaft back into the center of the firewall.
The flat metal surface gives a perfect plane insuring no racking of the engine's metal mounts.
Some carbon tipped forstner bits were used to drill out the metal plate and sub-ply for throttle/choke servo control rods. For safety, the plate was clamped down in case the bit bound in the metal plate.
Some 2" long 1" diameter dowels were cut to hold the cowl in the proper location; the 1/4" thick ply for the cowl flaps has 4 nodes along the edge to rest on the wooden dowels. Four bolts will be used to secure the cowl to the dowels.
Part of the 1/4" thick ply had to be cut as well as the back of the cowl for muffler pipe clearance.
Last edited by samparfitt; 08-08-2017 at 05:06 AM.
08-09-2017, 04:06 PM
#123
Functioning cowl flaps.
Two holes cut for the cowl flap servos.
Hysol and screws used to secure 1/4" thick ply to cowl, just at the cowl flap hinge line. The servo screws will be replaced by button head.
Some sullivan golden rod epoxied and FG clothed to the cowl flaps.
Two holes cut for the cowl flap servos.
Hysol and screws used to secure 1/4" thick ply to cowl, just at the cowl flap hinge line. The servo screws will be replaced by button head.
Some sullivan golden rod epoxied and FG clothed to the cowl flaps.
08-10-2017, 07:31 AM
#125
ragtop,
Thanks for the comments. You'll have to talk to the monitor for that.
===============
Cowl flaps (cont)
Prefer hitec 645's but not enough room with the muffler pipes so had to use 225's. Due to space, the lower two cowl flaps were not made functional. A servo reverser was needed and will be tied in with the choke servo.
The usual procedure for flaps: cut hinge side first, install hinge and then cut remaining two sides. Some flat head #1X3/16" screws used. Unlike installing a functioning canopy, functioning cowl flaps is a very simple process with the added plus of keeping the engine from over heating.
Thanks for the comments. You'll have to talk to the monitor for that.
===============
Cowl flaps (cont)
Prefer hitec 645's but not enough room with the muffler pipes so had to use 225's. Due to space, the lower two cowl flaps were not made functional. A servo reverser was needed and will be tied in with the choke servo.
The usual procedure for flaps: cut hinge side first, install hinge and then cut remaining two sides. Some flat head #1X3/16" screws used. Unlike installing a functioning canopy, functioning cowl flaps is a very simple process with the added plus of keeping the engine from over heating.
Last edited by samparfitt; 08-10-2017 at 07:50 AM.