ZIROLI 98" P-51B MUSTANG
12-23-2011, 01:54 PM
#1
ZIROLI 98" P-51B MUSTANG
I've got a short kit for the P-51 but I've also got a FG fuse that I built awhile ago as a B model.
Last summer, I saw the prototype FG P-51B for Ziroli, and, depending on how much work to strip my old FG fuse, I may buy a new FG fuse, or convert the wood kit to a B model.
The gear is Robarts and power is a Brison 5.8 or about 95cc's.
The plans come with an extra sheet for the FG fuse build.
The wing will be built as a 3-piece wing.
I'll probably have time during the summer so I will probably start on one of my three new projects when it's warm out and my present two projects are completed.
Last summer, I saw the prototype FG P-51B for Ziroli, and, depending on how much work to strip my old FG fuse, I may buy a new FG fuse, or convert the wood kit to a B model.
The gear is Robarts and power is a Brison 5.8 or about 95cc's.
The plans come with an extra sheet for the FG fuse build.
The wing will be built as a 3-piece wing.
I'll probably have time during the summer so I will probably start on one of my three new projects when it's warm out and my present two projects are completed.
12-23-2011, 11:20 PM
#2
RE: ZIROLI 98
We have a D model done with a precision Eagle 5.8. It's a strong motor. I got over 45 pounds thrust on the ground. Also noisy with scale exhaust. The cops came one evening when I was running it in the back yard. They said it was a cool plane but I really needed to take it out to the flying field for testing.
It's a fun plane to build. another one that looks like there is all kinds of room inside. but actually not much. Especially after you install your great interior!!!! ( compliment) the spinner is huge and care is needed to get it to run true and stay that way.
We have had trouble with the crankshaft on the 5.8. the prop adaptor has ripped the crank up twice and one other time the extension shaft broke off and luckly it didn't throw the whole thing off. I'm not sure if this is just a 5.8 problem or just the way PE mounted theirs. It's shaky anyway you look at it. You may need some baffles to help with cooling as the 5.8 takes up a lot of room. I've already burned up one cowl.
good luck on the build.
It's a fun plane to build. another one that looks like there is all kinds of room inside. but actually not much. Especially after you install your great interior!!!! ( compliment) the spinner is huge and care is needed to get it to run true and stay that way.
We have had trouble with the crankshaft on the 5.8. the prop adaptor has ripped the crank up twice and one other time the extension shaft broke off and luckly it didn't throw the whole thing off. I'm not sure if this is just a 5.8 problem or just the way PE mounted theirs. It's shaky anyway you look at it. You may need some baffles to help with cooling as the 5.8 takes up a lot of room. I've already burned up one cowl.
good luck on the build.
12-24-2011, 04:58 AM
#4
RE: ZIROLI 98
I forgot about the vent hole behind the motor too. It needs to be at least 2 1/2 to 3 times the area of the intake so try and fudge the intake as much as possible. The greater the ratio the better. It won't hurt to put the oil cooler holes in also.
Can't wait to see how this one comes out. Nothing like having the master builder do a Mustang.
Can't wait to see how this one comes out. Nothing like having the master builder do a Mustang.
12-24-2011, 01:50 PM
#6
RE: ZIROLI 98
I use the copper fittings, 3/4 in. They TIG weld very nicely as the copper is high quality. I use silicone -bronze to TIG braze to the steel flange. Works great. Not cheap however. Solder doesn't work on the copper as the melting point is 495 deg at best and the EGT is greater than that. Don't ask how I know. haha
07-16-2013, 02:53 PM
#7
RE: ZIROLI 98
Wings
I'm a fan of 3 piece wings so the P-51 wing will be modified just outside the gear at rib W-6 so the center section will stay attached to the fuse via bolts.
With extra strength needed for the wing tubes, many of the ribs are being re-cut using aircraft ply. The existing holes in the ribs for the wire guide tubes will be used for the wing tubes. I'm figuring they are already aligned so I just 'eye balled' the metal part of the tube over the present hole to enlarge it. Those inner wing ribs getting the tube support was done the same way.
The kit is from Lazer lizard from a few years ago and all the ribs were 'spot on' to the plans. Interesting in that you get the entire piece of ply/balsa sheet that the parts are cut from.
The two wing plans were carefully aligned with each other, taped down and then wax paper was taped over them.
I've spent all afternoon just cutting new ribs; still lots to cut/file yet as each notch is checked with like dimension lumber to insure all parts fit.
The gear is forward of the main spar and the ribs for the wheel well get pretty thin so aircraft ply is needed for the entire center wing. The outer wing will get aircraft ply on the inner rib (W-6) and the last rib to hold the wing tube. Those between these will be lite 3-ply that I used from left over material in the short kit.
Due to the thin ribs, the LE will have a spruce 1/4" square sub LE and 1/8" thick aircraft ply will replace the balsa that normally would cover the 1/4" square. The entire wheel well and mount area will also be fiberglass with auto body heavy duty cloth. I don't want any ground loops ripping out the mounts. I always prefer the gear to be the weak point.
The washout is pretty high at a 1/2" versus the 120" B-25 is at 1/4".
I'm a fan of 3 piece wings so the P-51 wing will be modified just outside the gear at rib W-6 so the center section will stay attached to the fuse via bolts.
With extra strength needed for the wing tubes, many of the ribs are being re-cut using aircraft ply. The existing holes in the ribs for the wire guide tubes will be used for the wing tubes. I'm figuring they are already aligned so I just 'eye balled' the metal part of the tube over the present hole to enlarge it. Those inner wing ribs getting the tube support was done the same way.
The kit is from Lazer lizard from a few years ago and all the ribs were 'spot on' to the plans. Interesting in that you get the entire piece of ply/balsa sheet that the parts are cut from.
The two wing plans were carefully aligned with each other, taped down and then wax paper was taped over them.
I've spent all afternoon just cutting new ribs; still lots to cut/file yet as each notch is checked with like dimension lumber to insure all parts fit.
The gear is forward of the main spar and the ribs for the wheel well get pretty thin so aircraft ply is needed for the entire center wing. The outer wing will get aircraft ply on the inner rib (W-6) and the last rib to hold the wing tube. Those between these will be lite 3-ply that I used from left over material in the short kit.
Due to the thin ribs, the LE will have a spruce 1/4" square sub LE and 1/8" thick aircraft ply will replace the balsa that normally would cover the 1/4" square. The entire wheel well and mount area will also be fiberglass with auto body heavy duty cloth. I don't want any ground loops ripping out the mounts. I always prefer the gear to be the weak point.
The washout is pretty high at a 1/2" versus the 120" B-25 is at 1/4".
07-17-2013, 08:04 AM
#8
RE: ZIROLI 98
wings (cont)
33 new ribs and 4 spars cut, which took about 12 hours. Center rib W-1 was epoxied to half ribs W-1A/B (left and right side) I left the slot off since I won't be using a center dowel to secure the wing. I didn't cut the haunch out of the front of W-1 either as I'm not, presently, sure what that is for!
The half ribs were also cut longer so they can be part of the wing tube's strength.
I plan on adding 1/8" thick G10 to the 1/4" thick ply gear mounting plate to strengthen this area so the ribs supporting the plate will need to be trimmed another 1/8".
A nice touch on the lazer lizards parts as lite burn lines are placed where parts are later to be cut: ie, flaps/ailerons from ribs. I partially cut through all ply ribs, leaving a 1/4" left uncut, to make later removal with a razor saw a lot easier.
33 new ribs and 4 spars cut, which took about 12 hours. Center rib W-1 was epoxied to half ribs W-1A/B (left and right side) I left the slot off since I won't be using a center dowel to secure the wing. I didn't cut the haunch out of the front of W-1 either as I'm not, presently, sure what that is for!
The half ribs were also cut longer so they can be part of the wing tube's strength.
I plan on adding 1/8" thick G10 to the 1/4" thick ply gear mounting plate to strengthen this area so the ribs supporting the plate will need to be trimmed another 1/8".
A nice touch on the lazer lizards parts as lite burn lines are placed where parts are later to be cut: ie, flaps/ailerons from ribs. I partially cut through all ply ribs, leaving a 1/4" left uncut, to make later removal with a razor saw a lot easier.
07-17-2013, 02:24 PM
#10
RE: ZIROLI 98
ducky22,
It's been awhile since I had a mustang so I'm all pumped up to build her.
===============
wings (cont)
Ribs W-1 were cut to fit the fuse so about 3/8" was cut off the back and about 5/8" off the front. The front was cut first relative to the plans and then the back so the wing will fit inside the fuse.
conversion to 3-piece wing (cont)
Wing tube:
Inner wing:
I'm using the existing paper wire tube guide holes as the location for the wing tube. Ideally, the wing tube should be next to the main spar but I think this location is 'good enough'.
Careful measuring and double checking was done to mark the drill holes for each rib. I used the main spar as the bench mark to locate each wing tube hole which was 1.5". I also measured the distance from the center of the hole to the bottom of the rib and it decreased by 1/16". I put the new paper wire tube out 4" from the spar and dropped the hole the same 1/16" per rib.
A piece of spar was put in the ribs (both rib sides done at once, ie W-2 (right and left wing rib) and clamped on each end and then a 1 1/4" forstner bit was used for the wing tube and 3/4" for the paper wire tube.
After two ribs were drilled (W-2/3) a piece of the aluminum tube was inserted in the two ribs, put in their respective locations on the plans and then rib W-3 was set against the end of the tube to insure exact alignment. This was done for each rib until the final inner wing rib W-6 was finally completed.
The top spars were then added and lots of fine tuning (ie sanding) of the tube hole to insure every rib was seated on the main spar as well as the washout riser. Any sanding done required very little to get all ribs aligned properly.
Once all ribs were aligned, next was to enlarge each hole to allow the paper outer tube to fit all ribs. A piece of scrap outer paper tube was used to outline the sanding which was done on an oscillating sander.
Again, everything was dry fitted to insure complete alignment of all ribs.
=====
Note:
I'm using a D model wing on a B model P-51. For me I don't notice it so I'm OK with it. Again, this plane is for me to enjoy and fly and not for contest purposes.
It's been awhile since I had a mustang so I'm all pumped up to build her.
===============
wings (cont)
Ribs W-1 were cut to fit the fuse so about 3/8" was cut off the back and about 5/8" off the front. The front was cut first relative to the plans and then the back so the wing will fit inside the fuse.
conversion to 3-piece wing (cont)
Wing tube:
Inner wing:
I'm using the existing paper wire tube guide holes as the location for the wing tube. Ideally, the wing tube should be next to the main spar but I think this location is 'good enough'.
Careful measuring and double checking was done to mark the drill holes for each rib. I used the main spar as the bench mark to locate each wing tube hole which was 1.5". I also measured the distance from the center of the hole to the bottom of the rib and it decreased by 1/16". I put the new paper wire tube out 4" from the spar and dropped the hole the same 1/16" per rib.
A piece of spar was put in the ribs (both rib sides done at once, ie W-2 (right and left wing rib) and clamped on each end and then a 1 1/4" forstner bit was used for the wing tube and 3/4" for the paper wire tube.
After two ribs were drilled (W-2/3) a piece of the aluminum tube was inserted in the two ribs, put in their respective locations on the plans and then rib W-3 was set against the end of the tube to insure exact alignment. This was done for each rib until the final inner wing rib W-6 was finally completed.
The top spars were then added and lots of fine tuning (ie sanding) of the tube hole to insure every rib was seated on the main spar as well as the washout riser. Any sanding done required very little to get all ribs aligned properly.
Once all ribs were aligned, next was to enlarge each hole to allow the paper outer tube to fit all ribs. A piece of scrap outer paper tube was used to outline the sanding which was done on an oscillating sander.
Again, everything was dry fitted to insure complete alignment of all ribs.
=====
Note:
I'm using a D model wing on a B model P-51. For me I don't notice it so I'm OK with it. Again, this plane is for me to enjoy and fly and not for contest purposes.
07-17-2013, 02:37 PM
#11
RE: ZIROLI 98
wings (cont)
conversion to a 3 piece wing (cont)
outer wing:
Continuing from the previous post, I used the same sequence to make the holes in the outer wing rigs.
With the outer paper tube in place on the inner wing, I telescoped the aluminum tube inside the inner wing and move it out each time to the next outer wing's rib to insure exact alignment. This was done for W-6 (mating rib for outer and inner wing) through W-9.
The paper wire guide tube was getting too close to the TE of the wing so I cut partially through the paper tube and bent it so it could finish to rib W-11 (where the aileron servo will be located).
Again, all parts were dry fitted to insure proper alignment.
One side done!
The outer wings rise 5 1/4" dihedral to when all ribs are glued, the center W-1 will be done last after the wings tips are raised.
conversion to a 3 piece wing (cont)
outer wing:
Continuing from the previous post, I used the same sequence to make the holes in the outer wing rigs.
With the outer paper tube in place on the inner wing, I telescoped the aluminum tube inside the inner wing and move it out each time to the next outer wing's rib to insure exact alignment. This was done for W-6 (mating rib for outer and inner wing) through W-9.
The paper wire guide tube was getting too close to the TE of the wing so I cut partially through the paper tube and bent it so it could finish to rib W-11 (where the aileron servo will be located).
Again, all parts were dry fitted to insure proper alignment.
One side done!
The outer wings rise 5 1/4" dihedral to when all ribs are glued, the center W-1 will be done last after the wings tips are raised.
07-17-2013, 06:06 PM
#12
RE: ZIROLI 98
wings (cont)
center wing (cont)
retract area:
(last thing for the night)
Traced the original 1/4" thick ply onto some 1/8" thick G10 and cut it with the band saw, dremel metal diamond saw for the corners (too lazy to change out the large 3/4" wide band saw blade) and sanded it with a dremel drum sander. Once, I tried cutting G10 with my scroll saw: the blade lasted about 5 seconds. I'm not sure what kind of damage it does to my 105" band saw but there's enough teeth to 'get the job done'.
Initially, I was going to epoxy the G10 to the 1/4" thick ply but the 1/4" thick ply is no longer 1/4" thick and it's only 3 ply so I just cut new 1/8" thick aircraft ply and epoxied the ply to the G10 to give me a true 1/4" thick gear mount. The plans are from 1990 and they show true 1/4" thick ply (back when it was sold in 'normal' dimensions) so it saves me time not having to trim any ribs as they are already cut for 1/4" thick ply.
The G10 has a pretty smooth surface so I roughed it up with some sandpaper and then cleaned it with alcohol.
(that should withstand some ground loops!)
center wing (cont)
retract area:
(last thing for the night)
Traced the original 1/4" thick ply onto some 1/8" thick G10 and cut it with the band saw, dremel metal diamond saw for the corners (too lazy to change out the large 3/4" wide band saw blade) and sanded it with a dremel drum sander. Once, I tried cutting G10 with my scroll saw: the blade lasted about 5 seconds. I'm not sure what kind of damage it does to my 105" band saw but there's enough teeth to 'get the job done'.
Initially, I was going to epoxy the G10 to the 1/4" thick ply but the 1/4" thick ply is no longer 1/4" thick and it's only 3 ply so I just cut new 1/8" thick aircraft ply and epoxied the ply to the G10 to give me a true 1/4" thick gear mount. The plans are from 1990 and they show true 1/4" thick ply (back when it was sold in 'normal' dimensions) so it saves me time not having to trim any ribs as they are already cut for 1/4" thick ply.
The G10 has a pretty smooth surface so I roughed it up with some sandpaper and then cleaned it with alcohol.
(that should withstand some ground loops!)
07-18-2013, 07:04 AM
#14
RE: ZIROLI 98
KM,
Here's the build thread: pretty old as it was back in 2006.
I built two P-51's in the thread: a B and a D.
http://www.rcuniverse.com/forum/m_51..._1/key_/tm.htm
=============
wings (cont)
Got my original stack of 3/32" thick 4"X4' balsa from my pile of wood. It's nice and hard balsa: perfect for sheeting the wings.
I got it from that place that had a fire; not sure if they are still in business.
Center wing (cont)
I epoxied and sistered sub ribs to W-4 and W-6: 1/4" thick aircraft ply ribs around the landing gear should work!
It took all morning setting up the right half of the center wing, getting it ready to epoxy. Some extra sanding was needed to get everything aligned: sanding is the easy part, getting the rib out from the middle is the time consuming part, and putting everything back together again
. Had to insure all ribs were on the washout riser, seated on the bottom main spar, etc. I put the landing gear mount in (dry fit only) to insure all ribs are properly aligned with it (more sanding). The sub LE 1/4" square is spruce to strengthen that week area around the wheel well. Top spars were added just for alignment.
Due to the complexity of the set up, I just used an acid brush to apply epoxy to the ribs at contact points at the bottom spar, wing tube, sub LE and paper wire tube, without disassembling anything.
I also moved W-5A over maybe an 1/8" as I thought it was a little close to where the gear is screwed in and I want some 'wiggle' room for mounting the gear. The G-10/ply gear mount won't be epoxied until after the center wing is done to insure the angles are correct for the landing gear. I also moved rib W-3 out about a 1/4" as it seemed a little too close to the wheel; again, some 'wiggle' room.
Here's the build thread: pretty old as it was back in 2006.
I built two P-51's in the thread: a B and a D.
http://www.rcuniverse.com/forum/m_51..._1/key_/tm.htm
=============
wings (cont)
Got my original stack of 3/32" thick 4"X4' balsa from my pile of wood. It's nice and hard balsa: perfect for sheeting the wings.
I got it from that place that had a fire; not sure if they are still in business.
Center wing (cont)
I epoxied and sistered sub ribs to W-4 and W-6: 1/4" thick aircraft ply ribs around the landing gear should work!
It took all morning setting up the right half of the center wing, getting it ready to epoxy. Some extra sanding was needed to get everything aligned: sanding is the easy part, getting the rib out from the middle is the time consuming part, and putting everything back together again
. Had to insure all ribs were on the washout riser, seated on the bottom main spar, etc. I put the landing gear mount in (dry fit only) to insure all ribs are properly aligned with it (more sanding). The sub LE 1/4" square is spruce to strengthen that week area around the wheel well. Top spars were added just for alignment. Due to the complexity of the set up, I just used an acid brush to apply epoxy to the ribs at contact points at the bottom spar, wing tube, sub LE and paper wire tube, without disassembling anything.
I also moved W-5A over maybe an 1/8" as I thought it was a little close to where the gear is screwed in and I want some 'wiggle' room for mounting the gear. The G-10/ply gear mount won't be epoxied until after the center wing is done to insure the angles are correct for the landing gear. I also moved rib W-3 out about a 1/4" as it seemed a little too close to the wheel; again, some 'wiggle' room.
07-18-2013, 11:59 AM
#15
RE: ZIROLI 98
wings (cont)
3 piece wing conversion (cont)
center wing (cont)
The left side of the center wing (W-2 through 6) done the same as the right side.
Those plastic cheese cups have about 8 lbs of buckshot in each one: three of those usually insures that all ribs are making contact with the main bottom spar and washout riser!
Used my last wing tube on the B-25. Ordered more on Tuesday and hoping they get here shortly so I can do the outside wings. I hate having to stop on a build due to parts shortage so I usually have a good inventory on hand and always order when an item is getting 'low' but I missed this one (and it's not like something you can just get locally).
3 piece wing conversion (cont)
center wing (cont)
The left side of the center wing (W-2 through 6) done the same as the right side.
Those plastic cheese cups have about 8 lbs of buckshot in each one: three of those usually insures that all ribs are making contact with the main bottom spar and washout riser!
Used my last wing tube on the B-25. Ordered more on Tuesday and hoping they get here shortly so I can do the outside wings. I hate having to stop on a build due to parts shortage so I usually have a good inventory on hand and always order when an item is getting 'low' but I missed this one (and it's not like something you can just get locally).
07-18-2013, 08:04 PM
#16
RE: ZIROLI 98
wings (cont)
3-piece wing conversion (cont)
center wing (cont)
Heat gun saves the day!
I just noticed that there are dihedral plates (W-1GF/R to set up the angles between the two wings. I should have remembered this as Nick's other planes uses the same technique. Anyway, rib W-2 is key to getting these plates at the correct angle, ie 90 degrees (perfectly vertical). Both of mine were not; so epoxy is very forgiving, once you apply a heat gun of 400 degrees! The heat softened the epoxy so I could re-align the two ribs, clamp them and re-epoxy them.
The dihedral plates are not the correct width due to multiple layers of ply on W-1/a/b. There's 3 plates, one for the front, middle and back. The center had the width increased by 1/8" and the two ends, shortened by 1/8". I re-cut the balsa plates with aircraft ply as I will be sheering the center main spar with ply. The front ply is especially needed since that is where the wheel well is located. The plates are made to rest on the plans and, after gluing, the waste above and below the ribs are to be sanded. Easy to do on balsa: since mine are ply, I made them the exact width of the ribs and sistered glued them to the original balsa plates.
The plates were first epoxied to rib W-2: the front of the rib was not quite 90 degrees to the plans so I used Archimedes lever rule to align it while the epoxy was 'cooking'.
Finally, rib W-1 was epoxied to the dihedral plates with lots of clamps.
While things were cooking, I got the stab/elevator parts out and placed them on the plans.
3-piece wing conversion (cont)
center wing (cont)
Heat gun saves the day!
I just noticed that there are dihedral plates (W-1GF/R to set up the angles between the two wings. I should have remembered this as Nick's other planes uses the same technique. Anyway, rib W-2 is key to getting these plates at the correct angle, ie 90 degrees (perfectly vertical). Both of mine were not; so epoxy is very forgiving, once you apply a heat gun of 400 degrees! The heat softened the epoxy so I could re-align the two ribs, clamp them and re-epoxy them.
The dihedral plates are not the correct width due to multiple layers of ply on W-1/a/b. There's 3 plates, one for the front, middle and back. The center had the width increased by 1/8" and the two ends, shortened by 1/8". I re-cut the balsa plates with aircraft ply as I will be sheering the center main spar with ply. The front ply is especially needed since that is where the wheel well is located. The plates are made to rest on the plans and, after gluing, the waste above and below the ribs are to be sanded. Easy to do on balsa: since mine are ply, I made them the exact width of the ribs and sistered glued them to the original balsa plates.
The plates were first epoxied to rib W-2: the front of the rib was not quite 90 degrees to the plans so I used Archimedes lever rule to align it while the epoxy was 'cooking'.
Finally, rib W-1 was epoxied to the dihedral plates with lots of clamps.
While things were cooking, I got the stab/elevator parts out and placed them on the plans.
07-19-2013, 06:34 PM
#17
RE: ZIROLI 98
wings (cont)
3-piece wing conversion (cont)
center wing (cont)
The 4' long rock hard 3/32" thick balsa sheeting gives the least waste covering the entire wing. I cut them to sheet the inner wing and outer wing separately. Wing sheeting is easily made with some masking tape and carpenters glue. All the spars are epoxied in. I sheeted the top from the main spar to the TE of the wing using weights to insure washout is maintained and carpenters glue.
Next the sub LE was cut from aircraft ply instead of balsa sheeting to give this retract area some strength. The first ply was epoxied from W3 to W6 and then the second ply was from W4 to just past W2: a third piece will be epoxied when the two halves of the center wing are jointed.
The sheeting from the main spar to the LE was then epoxied to the ribs. I used epoxy as this is the gear area and I figured all the sheeting may not contact some ribs due to the compound curve in that area.
After the epoxy 'cooked' I sanded all the edges smooth. The 4 connecting spars will not be epoxied until last, as I want to insure I have the proper 5 1/4" height on each wing tip.
There will be some delay on this as my ziroli order for wing tubes are on back order.
I tried to flex this part of the wing and it doesn't budge: should be good for handling ground loops or sharp turns.
3-piece wing conversion (cont)
center wing (cont)
The 4' long rock hard 3/32" thick balsa sheeting gives the least waste covering the entire wing. I cut them to sheet the inner wing and outer wing separately. Wing sheeting is easily made with some masking tape and carpenters glue. All the spars are epoxied in. I sheeted the top from the main spar to the TE of the wing using weights to insure washout is maintained and carpenters glue.
Next the sub LE was cut from aircraft ply instead of balsa sheeting to give this retract area some strength. The first ply was epoxied from W3 to W6 and then the second ply was from W4 to just past W2: a third piece will be epoxied when the two halves of the center wing are jointed.
The sheeting from the main spar to the LE was then epoxied to the ribs. I used epoxy as this is the gear area and I figured all the sheeting may not contact some ribs due to the compound curve in that area.
After the epoxy 'cooked' I sanded all the edges smooth. The 4 connecting spars will not be epoxied until last, as I want to insure I have the proper 5 1/4" height on each wing tip.
There will be some delay on this as my ziroli order for wing tubes are on back order.
I tried to flex this part of the wing and it doesn't budge: should be good for handling ground loops or sharp turns.
07-20-2013, 04:53 PM
#18
RE: ZIROLI 98
wing (cont)
center wing (cont)
retracts/mount.
Nothing's ever easy!
I cut out the two partial cut pieces of ply out of ribs W-2/3 so the wheel will fit.
I used the original wood gear mount as a template to see how the gear fits.
Since I had moved rib W-3 out a 1/4" from center for wheel clearance, I knew I'd have to enlarge the slot a little for the scissors part of the oleo. The slot in rib W-4 also had to be enlarged slightly. The oleo is at a slight angle to the gear (not parallel) in the up position: since I have two sets of retracts and they are both the same, I have to assume they are made that way. This slight angle does help as it moves the wheel back a little farther from the narrow LE.
Too late now but rib W-2 could have been moved toward the center about a 1/4" as the end of the oleo hit the rib. This area is only about a 1/4" wide and I didn't want to make it any thinner so I moved the oleo an 1/8" up in the retract trunion. I also had to put a notch into the wood mount for the oleo clearance since it is paste the end of the trunion.
I clamped the original wood mount onto my sistered ply/G-10 and drilled/tapped #6X32 holes/threads. A small notch also had to be sanded along the bottom of the mount so a bolt head would clear when inserting the gear into the mount.
With the pin locked into the up position, the bottom of the oleo touches the surface of the wing plus, with the wheel on, the front edge of the wheel hits the thin W-2 rib. Thus, I had to put a 1/8" thick piece of ply under one retract edge for clearance of the oleo and wheel in the wing well. I considered an alternative of cutting the sistered ribs W-5/6A but, already glued in place, it would be difficult to do a clean job. The 1/8" riser ply now gives the wheel and oleo sufficient clearance in the well so the locking pin easily engages.
I also checked the angle of the gear, being 85 degrees, so these are the proper gear for the plane.
Nothing will be glued until the 2 halves of the center wings are glued together to insure the gear are properly aligned to the ground in the down position.
center wing (cont)
retracts/mount.
Nothing's ever easy!
I cut out the two partial cut pieces of ply out of ribs W-2/3 so the wheel will fit.
I used the original wood gear mount as a template to see how the gear fits.
Since I had moved rib W-3 out a 1/4" from center for wheel clearance, I knew I'd have to enlarge the slot a little for the scissors part of the oleo. The slot in rib W-4 also had to be enlarged slightly. The oleo is at a slight angle to the gear (not parallel) in the up position: since I have two sets of retracts and they are both the same, I have to assume they are made that way. This slight angle does help as it moves the wheel back a little farther from the narrow LE.
Too late now but rib W-2 could have been moved toward the center about a 1/4" as the end of the oleo hit the rib. This area is only about a 1/4" wide and I didn't want to make it any thinner so I moved the oleo an 1/8" up in the retract trunion. I also had to put a notch into the wood mount for the oleo clearance since it is paste the end of the trunion.
I clamped the original wood mount onto my sistered ply/G-10 and drilled/tapped #6X32 holes/threads. A small notch also had to be sanded along the bottom of the mount so a bolt head would clear when inserting the gear into the mount.
With the pin locked into the up position, the bottom of the oleo touches the surface of the wing plus, with the wheel on, the front edge of the wheel hits the thin W-2 rib. Thus, I had to put a 1/8" thick piece of ply under one retract edge for clearance of the oleo and wheel in the wing well. I considered an alternative of cutting the sistered ribs W-5/6A but, already glued in place, it would be difficult to do a clean job. The 1/8" riser ply now gives the wheel and oleo sufficient clearance in the well so the locking pin easily engages.
I also checked the angle of the gear, being 85 degrees, so these are the proper gear for the plane.
Nothing will be glued until the 2 halves of the center wings are glued together to insure the gear are properly aligned to the ground in the down position.
07-20-2013, 05:03 PM
#19
RE: ZIROLI 98
previous post continuation
(not sure why but my previous post cannot be edited as it appears that the web site has modified how long you can edit your post: which now appears to only be about 60 seconds: hardly enough time to make spelling and poorly phrased statement and bad grammatical corrections).
One unusual item on my two sets of retracts is that one set of oleos are about a 1/4" longer than the other pair. Not much but critical when trying to miss rib W-2!
(not sure why but my previous post cannot be edited as it appears that the web site has modified how long you can edit your post: which now appears to only be about 60 seconds: hardly enough time to make spelling and poorly phrased statement and bad grammatical corrections).
One unusual item on my two sets of retracts is that one set of oleos are about a 1/4" longer than the other pair. Not much but critical when trying to miss rib W-2!
07-22-2013, 12:24 PM
#21
RE: ZIROLI 98
thanks, Bob.
==========
Wings (cont)
3-piece conversion (cont)
outer wing (cont)
A friend had an extra wing tube so I could do one side.
After aligning the center wing and the outer wing on the main bottom spar and the wing tube, the upper main spar and all the small spars were dry fitted. The duplicate rib W-6 was clamped to inner wings W-6. Due to the complexity of keeping all the ribs, etc in place, I used epoxy for the wing tube and bottom spar. All the others got carpenters glue as they were removable.
Inner wing (cont)
Sheer webbing was epoxied to the main spar using aircraft ply (I remembered the lightning holes, this time!).
Stab/elevator:
I started on the stab with gluing the TE made of 1/4" thick balsa and the center,mid and outer ribs, which have 'break off' risers on them.
==========
Wings (cont)
3-piece conversion (cont)
outer wing (cont)
A friend had an extra wing tube so I could do one side.
After aligning the center wing and the outer wing on the main bottom spar and the wing tube, the upper main spar and all the small spars were dry fitted. The duplicate rib W-6 was clamped to inner wings W-6. Due to the complexity of keeping all the ribs, etc in place, I used epoxy for the wing tube and bottom spar. All the others got carpenters glue as they were removable.
Inner wing (cont)
Sheer webbing was epoxied to the main spar using aircraft ply (I remembered the lightning holes, this time!).
Stab/elevator:
I started on the stab with gluing the TE made of 1/4" thick balsa and the center,mid and outer ribs, which have 'break off' risers on them.
07-22-2013, 04:47 PM
#22
RE: ZIROLI 98
wings (cont)
3-piece wing conversion (cont)
outer wing (cont)
The top 3/32" thick sheeting from the main spar back to the the TE of the wing was cut to shape and glued with carpenters glue. The TE along the flap was cut at a 45 degree angle to save doing that after sheeting installation.
The 1/8" thick balsa sheet was cut and glued to the sub-LE, then sanded to shape and then the remaining sheeting from the main spar to the LE was glued to the wing. Both 'sheetings' put on the plans and on the washout riser with lots of weight to insure proper washout.
stab/elevator (cont)
A spruce 1/8"X1/4" top spar was glued to the ribs with the risers on them. An aircraft ply was glued across the center section securing the top spars to the middle rib. After the carpenters glue dried, I flipped the stab over and glued in the remaining ribs to the main top spar and TE. I figure the spruce spar would give a little more support in case I ever flip the plan over.
I found some nice light weight 3/32" thick balsa to make sheeting for the stab.
I'll be sheering the spar with some 3/32" sheeting.
Also, I plan on putting in a servo in each side of the stab to control each half of the elevator.
3-piece wing conversion (cont)
outer wing (cont)
The top 3/32" thick sheeting from the main spar back to the the TE of the wing was cut to shape and glued with carpenters glue. The TE along the flap was cut at a 45 degree angle to save doing that after sheeting installation.
The 1/8" thick balsa sheet was cut and glued to the sub-LE, then sanded to shape and then the remaining sheeting from the main spar to the LE was glued to the wing. Both 'sheetings' put on the plans and on the washout riser with lots of weight to insure proper washout.
stab/elevator (cont)
A spruce 1/8"X1/4" top spar was glued to the ribs with the risers on them. An aircraft ply was glued across the center section securing the top spars to the middle rib. After the carpenters glue dried, I flipped the stab over and glued in the remaining ribs to the main top spar and TE. I figure the spruce spar would give a little more support in case I ever flip the plan over.
I found some nice light weight 3/32" thick balsa to make sheeting for the stab.
I'll be sheering the spar with some 3/32" sheeting.
Also, I plan on putting in a servo in each side of the stab to control each half of the elevator.
07-23-2013, 07:26 AM
#24
RE: ZIROLI 98
wings (cont)
Salvage old wing parts:
I cut off the air scoop and guns of the old foam wing that was melted in a fire. The rest goes in the trash.
Stab/elevator (cont)
Sheeting was glued to the top and weighted.
3-piece wing conversion (cont)
The aileron and flap for the right side was cut to size, 1/64" thick by 3/8" wide ply CA'ed to the TE and the sheeting was glued to the center/outer wing.
Salvage old wing parts:
I cut off the air scoop and guns of the old foam wing that was melted in a fire. The rest goes in the trash.
Stab/elevator (cont)
Sheeting was glued to the top and weighted.
3-piece wing conversion (cont)
The aileron and flap for the right side was cut to size, 1/64" thick by 3/8" wide ply CA'ed to the TE and the sheeting was glued to the center/outer wing.
07-23-2013, 12:18 PM
#25
RE: ZIROLI 98
stab/elevator (cont)
elevator:
It seemed best to build the elevators vertical. CA was used to get a fast set so each rib would stay vertical. Used one of my wood shop tools to get the proper angle on rib E-1. I added 4 extra ribs to bracket the trim tabs to give the sheeting support when the tabs are cut out.
Stab:
Bottom spruce spar glued in along with center stiffening spar.
Used 3/32" thick lite balsa to sheer web both sides of the spar to box it in: small weight gain, large strength gain.
outer wing (cont)
Also sheer webbed both sides of the outer wings main spar using, again, 3/32" balsa and carpenters glue.
elevator:
It seemed best to build the elevators vertical. CA was used to get a fast set so each rib would stay vertical. Used one of my wood shop tools to get the proper angle on rib E-1. I added 4 extra ribs to bracket the trim tabs to give the sheeting support when the tabs are cut out.
Stab:
Bottom spruce spar glued in along with center stiffening spar.
Used 3/32" thick lite balsa to sheer web both sides of the spar to box it in: small weight gain, large strength gain.
outer wing (cont)
Also sheer webbed both sides of the outer wings main spar using, again, 3/32" balsa and carpenters glue.