ZIROLI 120" B-25 MITCHELL
05-14-2015, 12:41 PM
#501
Hey, I'm used to throwing around a lot of #$@%^
=============
Not a good move!
I've been supporting the fuse by placing the plane support just in front of the stab. Sometimes I put pretty good pressure on the wing when putting in bolts, etc.
I now think it's best to put the plane support just behind the TE of the wing, that's where the full 1/8" thick aircraft ply runs along both sides of the fuse up past the nose gear mounts (don't need to be cracking a fuse in half: enough to make a grown man cry!).
=============
Not a good move!
I've been supporting the fuse by placing the plane support just in front of the stab. Sometimes I put pretty good pressure on the wing when putting in bolts, etc.
I now think it's best to put the plane support just behind the TE of the wing, that's where the full 1/8" thick aircraft ply runs along both sides of the fuse up past the nose gear mounts (don't need to be cracking a fuse in half: enough to make a grown man cry!).
05-14-2015, 04:01 PM
#502
Main gear small doors.
The UP 4 air valve has 4 outlet nipples, 2 for open and 2 for close.
I already used 2 for the small nose door.
I routed air lines from the other 2 nipples to T's at the wing and routed the 2 lines to each main gear.
I had to remove the fire wall and tank to route the air lines.
That's it for today.
That makes 7 air lines to each main gear: gear gets 2, each main door gets 2, the small door gets 2 and the brakes get 1.
If I knew now at the beginning of the air install, I think I would have left the small doors off. That's a lot of work and expense for 3 small doors that no one will even notice, unless I point it out! As I mentioned, previously, if I hadn't added the two extra wire wing tubes, in addition to the original one, I wouldn't have had room to route all these wires and air lines.
The UP 4 air valve has 4 outlet nipples, 2 for open and 2 for close.
I already used 2 for the small nose door.
I routed air lines from the other 2 nipples to T's at the wing and routed the 2 lines to each main gear.
I had to remove the fire wall and tank to route the air lines.
That's it for today.
That makes 7 air lines to each main gear: gear gets 2, each main door gets 2, the small door gets 2 and the brakes get 1.
If I knew now at the beginning of the air install, I think I would have left the small doors off. That's a lot of work and expense for 3 small doors that no one will even notice, unless I point it out! As I mentioned, previously, if I hadn't added the two extra wire wing tubes, in addition to the original one, I wouldn't have had room to route all these wires and air lines.
Last edited by samparfitt; 05-14-2015 at 04:06 PM.
05-15-2015, 12:53 AM
#503
Join Date: May 2003
Location: Ikast, DENMARK
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Hello
Looking great Sam, you are almost there, if you should run out of motivation to finish the model I have this Little video and a couple of Photos from yesterday
, I got 4 flights and I am still very very happy with the B-25,it flies like a big Trainer.
https://www.youtube.com/watch?v=zryhPiLBjII
Looking great Sam, you are almost there, if you should run out of motivation to finish the model I have this Little video and a couple of Photos from yesterday
, I got 4 flights and I am still very very happy with the B-25,it flies like a big Trainer.https://www.youtube.com/watch?v=zryhPiLBjII
05-15-2015, 07:43 AM
#504
Henrik,
Thanks for posting your pics and video: she looks great.
=============
Small doors on main gear:
Initially, I thought I could use some robart 1" throw air cylinders but the two nipples stick out 90 degrees to the air cylinder and, either, interfered with the outside wall in one direction or the gear supports in the other direction.
I pulled out some BVM air cylinders and modified them.
Fortunately, the swivel base is only held on with a C clip. After removing the metal base, I made a new one that allows the mounting to be done vertically instead of horizontally (as in the original base). Not sure why they make the base where the screws have to be put in at a 90 degree angle to the cylinder as there's usually not a lot of room to use a screw driver at that angle inside a fuse.
Some brass was used for the new mounts.
In the picture: the new mount is on the left and the old mount is on the right.
Rotating the air cylinder 90 degrees, the bottom nipple now is parallel to the fuse so no interference with gear or side walls.
The thin UP air cylinders would have worked but I'm awaiting some from Darrell. I have two but without mounts.
A resistance soldering was used to secure the two pieces of brass needed to make the new mount.
The resistance soldering takes about 2 seconds, if that, to heat the area to flow the solder.
The usual control horn and ball link on the door end.
A 1"X1.25" piece of ply was epoxied along a stringer and nacelle ply: fortunately, the stringer is spruce and the nacelle ply was aligned with the stringer for an easy fit. Not tested, yet, but it should work OK as the cylinder and door moves the needed dimensions.
Thanks for posting your pics and video: she looks great.
=============
Small doors on main gear:
Initially, I thought I could use some robart 1" throw air cylinders but the two nipples stick out 90 degrees to the air cylinder and, either, interfered with the outside wall in one direction or the gear supports in the other direction.
I pulled out some BVM air cylinders and modified them.
Fortunately, the swivel base is only held on with a C clip. After removing the metal base, I made a new one that allows the mounting to be done vertically instead of horizontally (as in the original base). Not sure why they make the base where the screws have to be put in at a 90 degree angle to the cylinder as there's usually not a lot of room to use a screw driver at that angle inside a fuse.
Some brass was used for the new mounts.
In the picture: the new mount is on the left and the old mount is on the right.
Rotating the air cylinder 90 degrees, the bottom nipple now is parallel to the fuse so no interference with gear or side walls.
The thin UP air cylinders would have worked but I'm awaiting some from Darrell. I have two but without mounts.
A resistance soldering was used to secure the two pieces of brass needed to make the new mount.
The resistance soldering takes about 2 seconds, if that, to heat the area to flow the solder.
The usual control horn and ball link on the door end.
A 1"X1.25" piece of ply was epoxied along a stringer and nacelle ply: fortunately, the stringer is spruce and the nacelle ply was aligned with the stringer for an easy fit. Not tested, yet, but it should work OK as the cylinder and door moves the needed dimensions.
Last edited by samparfitt; 05-15-2015 at 07:52 AM.
05-15-2015, 08:13 AM
#505
Small doors (cont)
Just tested them and all three are working.
The last item is installing the 2 air cylinders for the remaining main gear doors.
I think it took all week to get all the doors installed and operating!
With all those air lines and cylinders, I've been lucky that no air leaks have occurred. Each part of the air system gets some BVM oil before assembly. Some of those parts can sit around a long time before being used.
Just tested them and all three are working.
The last item is installing the 2 air cylinders for the remaining main gear doors.
I think it took all week to get all the doors installed and operating!
With all those air lines and cylinders, I've been lucky that no air leaks have occurred. Each part of the air system gets some BVM oil before assembly. Some of those parts can sit around a long time before being used.
Last edited by samparfitt; 05-15-2015 at 08:17 AM.
05-15-2015, 01:19 PM
#506
Main gear doors:
The air cylinders for the left large doors were installed.
All is working well. There's a lot of door movement when 5 of the doors close after the gear comes down!
Doing a pressure test with the gear down and then will do the important one: with the gear up for an hour!
Got my UP 6 valve from Darrell: good service: emailed him Wed and got it Friday
The wheels and disk brakes are Darrell's.
With all functions done, I did a re-bind.
Tomorrow, put the engines back on and do an engine test.
The air cylinders for the left large doors were installed.
All is working well. There's a lot of door movement when 5 of the doors close after the gear comes down!
Doing a pressure test with the gear down and then will do the important one: with the gear up for an hour!
Got my UP 6 valve from Darrell: good service: emailed him Wed and got it Friday
The wheels and disk brakes are Darrell's.
With all functions done, I did a re-bind.
Tomorrow, put the engines back on and do an engine test.
Last edited by samparfitt; 05-15-2015 at 01:23 PM.
05-15-2015, 05:31 PM
#507
Engine test:
Two DA-50's using TBM's variable pitch 3 blade, 20" CF props.
Having the removable fire wall with the servos attached to the back of the fire wall made it pretty easy to get ball park adjustments before starting the engines.
I started out at 12 pitch and only got 1600/4500 rpm's.
I then went to 10 pitch and got 6100 rpm's.
Adjusted to about 9 3/4 pitch and got 2100/6800 rpm's.
I love variable blade props: allows one to get the optimum RPM's without having to buy 3-4 different blades.
There are 3 ticks marks on the blades and one on the hub.
DA-50 engine test video:
https://www.youtube.com/watch?v=FU6s...ature=youtu.be
Two DA-50's using TBM's variable pitch 3 blade, 20" CF props.
Having the removable fire wall with the servos attached to the back of the fire wall made it pretty easy to get ball park adjustments before starting the engines.
I started out at 12 pitch and only got 1600/4500 rpm's.
I then went to 10 pitch and got 6100 rpm's.
Adjusted to about 9 3/4 pitch and got 2100/6800 rpm's.
I love variable blade props: allows one to get the optimum RPM's without having to buy 3-4 different blades.
There are 3 ticks marks on the blades and one on the hub.
DA-50 engine test video:
https://www.youtube.com/watch?v=FU6s...ature=youtu.be
Last edited by samparfitt; 05-15-2015 at 05:38 PM.
06-04-2015, 06:58 AM
#510
My Feedback: (43)
I have landed the 101" version without flaps and it is not advised. The flaps allow you to fly slower, ie more lift at slow speeds, and also adds drag. This will allow you to raise the nose for the flare and touch down flat or better yet, nose high. Without flaps, it is hard to slow it down predictably, and since it is moving faster, flaring only results in a ballon affect which rapidly bleeds off speed, but at altitude--not good. If you don't touch down flat or nose high, the nose gear will pogo you back into the air, normally too slow to fly out of.
06-04-2015, 08:29 AM
#511
My Feedback: (13)
I have landed the 101" version without flaps and it is not advised. The flaps allow you to fly slower, ie more lift at slow speeds, and also adds drag. This will allow you to raise the nose for the flare and touch down flat or better yet, nose high. Without flaps, it is hard to slow it down predictably, and since it is moving faster, flaring only results in a ballon affect which rapidly bleeds off speed, but at altitude--not good. If you don't touch down flat or nose high, the nose gear will pogo you back into the air, normally too slow to fly out of.
06-08-2015, 10:14 AM
#513
Final touch ups before the maiden.
Top fuse/wing cover:
Cleaned off the aluminum tape, drilled some holes in 1/4" thick ply and wing for tooth for the epoxy and used some button head screws to hold it on.
Tail feathers:
Some 1/64" thick ply for covers over the rudder servos.
Some 1/4" wide tape put into the corners between the stab and fins.
Double checked the engines: 1800/6800 rpm's.
Brakes:
Set up the brakes to use:
1. down elevator for brakes.
2. A top right toggle to engage brakes while starting the plane.
3. A top right toggle for 'mix' so I can disengage the brakes on the down elevator while flying the plane.
Aux 5 slaved to the elevator. The 'D' got input to move the Aux 5 channel (brakes). Also had to add input to the OFFSET to get full brake movement (took awhile to figure that out: kept trying things until they moved!).
Mix added to save on air so brakes aren't working while in the air.
Leaving tomorrow for Mac Hodges warbirds over Georgia for the maiden: 1400' long and 400' wide (even I should be able to land there!). Will put stars-n-stripes and nose decal on when I get back.
Top fuse/wing cover:
Cleaned off the aluminum tape, drilled some holes in 1/4" thick ply and wing for tooth for the epoxy and used some button head screws to hold it on.
Tail feathers:
Some 1/64" thick ply for covers over the rudder servos.
Some 1/4" wide tape put into the corners between the stab and fins.
Double checked the engines: 1800/6800 rpm's.
Brakes:
Set up the brakes to use:
1. down elevator for brakes.
2. A top right toggle to engage brakes while starting the plane.
3. A top right toggle for 'mix' so I can disengage the brakes on the down elevator while flying the plane.
Aux 5 slaved to the elevator. The 'D' got input to move the Aux 5 channel (brakes). Also had to add input to the OFFSET to get full brake movement (took awhile to figure that out: kept trying things until they moved!).
Mix added to save on air so brakes aren't working while in the air.
Leaving tomorrow for Mac Hodges warbirds over Georgia for the maiden: 1400' long and 400' wide (even I should be able to land there!). Will put stars-n-stripes and nose decal on when I get back.
Last edited by samparfitt; 06-08-2015 at 10:26 AM.
06-14-2015, 05:34 PM
#518
Maiden:
Had 12-15 flights at Warbirds over Georgia.
Engine start up:
It took about 5 flights (cowls off) to get the left engine lean enough to run without 'popping' in flight.
The DA-50's are starting extremely easy. After the first start of the morning with the chokes on, all remaining starts are without choke and only takes 2-3 flips. 6800 rpm's
https://www.youtube.com/watch?v=x98e...m-upload_owner
Taxi, take off:
After the maiden, I started using about 10 degrees of flaps on take offs. It seems to help for a nice scale takeoff.
https://www.youtube.com/watch?v=w6av...m-upload_owner
Landing:
On the down lap, I put in 10 degrees flap, on the turn and final, the throttle is reduced to about 20 percent and full flaps are put in (45-50 degrees of flap)
https://www.youtube.com/watch?v=8_0CNRzdhYo
Had 12-15 flights at Warbirds over Georgia.
Engine start up:
It took about 5 flights (cowls off) to get the left engine lean enough to run without 'popping' in flight.
The DA-50's are starting extremely easy. After the first start of the morning with the chokes on, all remaining starts are without choke and only takes 2-3 flips. 6800 rpm's
https://www.youtube.com/watch?v=x98e...m-upload_owner
Taxi, take off:
After the maiden, I started using about 10 degrees of flaps on take offs. It seems to help for a nice scale takeoff.
https://www.youtube.com/watch?v=w6av...m-upload_owner
Landing:
On the down lap, I put in 10 degrees flap, on the turn and final, the throttle is reduced to about 20 percent and full flaps are put in (45-50 degrees of flap)
https://www.youtube.com/watch?v=8_0CNRzdhYo
Last edited by samparfitt; 06-14-2015 at 06:26 PM.
06-19-2015, 11:37 AM
#523
Thanks, guys.
Appreciate all the comments.
I think that gull wing helps on her flying.
Got some PM to do: if it stops raining (shop's full and I can only work on her outside).
Got a slow air leak that I've traced to the left gear doors.
The ball links to the doors have also been popping off. Will try to replace with some nylon clevises.
The top hatch over the fuse keeps popping the ply studs from the wing: I'm suspecting that the back of the fuse is flexing some as a couple of my 15 landings weren't always smooth. Also, the four bolts holding the wing to the fuse were loose.
After about 5 flights, I noticed some stress marks on the aluminum tape between the outer and inner wing.
I put extra long wing tubes in so I'm puzzled by it: Removing the wings, I find the aluminum dowels used for anti wing rotation were almost completely inside one wing. Never had this happen before with aluminum dowels, especially since it is a shear force and not a longitudinal force. I was able to use pliers to pull them back into place and then thin and thick CA'ed them and they haven't moved since the fix. Another flight and it could have looked like an osprey aircraft! Had she crashed, I probably have never figured out the cause as I build sturdy planes. If they crash, it's usually do to 'dumb thumbs'. After the first flight, I did the usual PM, removing servo hatches, check gear bolts, etc to make sure nothing came loose: didn't think about removing the wings!.
The CG at 6" seems to be perfect where I needed 4 lbs of lead in the nose (gear up).
ps: I was able to view the landing video. Perhaps youtube was having problems.
Appreciate all the comments.
I think that gull wing helps on her flying.
Got some PM to do: if it stops raining (shop's full and I can only work on her outside).
Got a slow air leak that I've traced to the left gear doors.
The ball links to the doors have also been popping off. Will try to replace with some nylon clevises.
The top hatch over the fuse keeps popping the ply studs from the wing: I'm suspecting that the back of the fuse is flexing some as a couple of my 15 landings weren't always smooth. Also, the four bolts holding the wing to the fuse were loose.
After about 5 flights, I noticed some stress marks on the aluminum tape between the outer and inner wing.
I put extra long wing tubes in so I'm puzzled by it: Removing the wings, I find the aluminum dowels used for anti wing rotation were almost completely inside one wing. Never had this happen before with aluminum dowels, especially since it is a shear force and not a longitudinal force. I was able to use pliers to pull them back into place and then thin and thick CA'ed them and they haven't moved since the fix. Another flight and it could have looked like an osprey aircraft! Had she crashed, I probably have never figured out the cause as I build sturdy planes. If they crash, it's usually do to 'dumb thumbs'. After the first flight, I did the usual PM, removing servo hatches, check gear bolts, etc to make sure nothing came loose: didn't think about removing the wings!.
The CG at 6" seems to be perfect where I needed 4 lbs of lead in the nose (gear up).
ps: I was able to view the landing video. Perhaps youtube was having problems.
Last edited by samparfitt; 06-20-2015 at 10:54 AM.
06-20-2015, 09:04 AM
#524
Thanks, guys.
Appreciate all the comments.
I think that gull wing helps on her flying.
Got some PM to do: if it stops raining (shop's full and I can only work on her outside).
Got a slow air leak that I've traced to the left gear doors.
The ball links to the doors have also been popping off. Will try to replace with some nylon clevises.
The top hatch over the fuse keeps popping the ply studs from the wing: I'm suspecting that the back of the fuse is flexing some as a couple of my 15 landings weren't always smooth. Also, the four bolts holding the wing to the fuse were loose.
After about 5 flights, I noticed some stress marks on the aluminum tape between the outer and inner wing.
I put extra long wing tubes in so I'm puzzled by it: Removing the wings, I find the aluminum dowels used for anti wing rotation were almost completely inside one wing. Never had this happen before with aluminum dowels, especially since it is a shear force and not a longitudinal force. I was able to use pliers to pull them back into place and then thin and thick CA'ed them and they haven't moved since the fix. Another flight and it could have looked like an osprey aircraft! Had she crashed, I probably have never figured out the cause as I build sturdy planes. If they crash, it's usually do to 'dumb thumbs'. After the first flight, I did the usual PM, removing servo hatches, check gear bolts, etc to make sure nothing came loose: didn't think about removing the wings!.
The CG at 6" seems to be perfect where I needed 4 lbs of lead in the nose (gear up).
Appreciate all the comments.
I think that gull wing helps on her flying.
Got some PM to do: if it stops raining (shop's full and I can only work on her outside).
Got a slow air leak that I've traced to the left gear doors.
The ball links to the doors have also been popping off. Will try to replace with some nylon clevises.
The top hatch over the fuse keeps popping the ply studs from the wing: I'm suspecting that the back of the fuse is flexing some as a couple of my 15 landings weren't always smooth. Also, the four bolts holding the wing to the fuse were loose.
After about 5 flights, I noticed some stress marks on the aluminum tape between the outer and inner wing.
I put extra long wing tubes in so I'm puzzled by it: Removing the wings, I find the aluminum dowels used for anti wing rotation were almost completely inside one wing. Never had this happen before with aluminum dowels, especially since it is a shear force and not a longitudinal force. I was able to use pliers to pull them back into place and then thin and thick CA'ed them and they haven't moved since the fix. Another flight and it could have looked like an osprey aircraft! Had she crashed, I probably have never figured out the cause as I build sturdy planes. If they crash, it's usually do to 'dumb thumbs'. After the first flight, I did the usual PM, removing servo hatches, check gear bolts, etc to make sure nothing came loose: didn't think about removing the wings!.
The CG at 6" seems to be perfect where I needed 4 lbs of lead in the nose (gear up).
06-21-2015, 09:01 AM
#525
thanks, Gary.
=========
Graphics:
Thanks to Henrik's generosity in sending me the Panchito graphics, I have some very nice nose art. They are from avery graphics.
http://averygraphics.com/cms/avery/p...ml?p_name=Home
Being vinyl I, first, cut a 1/3 of the backing off and using the graphics still with the paper backing, I can align and lay down the paper back part, to get the graphics aligned on the plane, and then the sticky part can be laid onto the fuse.
I then cut another 1/3 of the paper backing off and laid that down and, finally, pulled off the last 1/3 backing to finish up the nose art.
The stars-n-bars and numbers are water slide decals from major decal.
http://majordecals.com/
The decals are soaked in water until they slide off but not come off the paper (may dilute the glue).
After positioning the decal, I hold one end and pull off the paper backing.
It takes several minutes to remove all the water and bubbles under the decal. Initially, I use a wet folded paper towel and then a dry one to pat and 'pull' any bubbles to the edge of the decal.
The 2" numbers go much faster.
After the decal is free of all bubbles, I used a new xacto blade to cut where it lays on the bottom servo hatches and lay down the edges while the glue is still wet.
The water slide decals are extremely thin and show all rivet details.
=========
Graphics:
Thanks to Henrik's generosity in sending me the Panchito graphics, I have some very nice nose art. They are from avery graphics.
http://averygraphics.com/cms/avery/p...ml?p_name=Home
Being vinyl I, first, cut a 1/3 of the backing off and using the graphics still with the paper backing, I can align and lay down the paper back part, to get the graphics aligned on the plane, and then the sticky part can be laid onto the fuse.
I then cut another 1/3 of the paper backing off and laid that down and, finally, pulled off the last 1/3 backing to finish up the nose art.
The stars-n-bars and numbers are water slide decals from major decal.
http://majordecals.com/
The decals are soaked in water until they slide off but not come off the paper (may dilute the glue).
After positioning the decal, I hold one end and pull off the paper backing.
It takes several minutes to remove all the water and bubbles under the decal. Initially, I use a wet folded paper towel and then a dry one to pat and 'pull' any bubbles to the edge of the decal.
The 2" numbers go much faster.
After the decal is free of all bubbles, I used a new xacto blade to cut where it lays on the bottom servo hatches and lay down the edges while the glue is still wet.
The water slide decals are extremely thin and show all rivet details.
Last edited by samparfitt; 06-21-2015 at 09:14 AM.