TF 1/5 Scale P-51 ARF Assembly (1ST MISHAP!!!)
05-09-2016, 11:16 AM
#3876
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With the webbing mod complete, and the electric Robart gear in place, I am ready to glue the wing together. I noticed some light between the two wing halves, and will need to correct this with some sanding maybe tomorrow evening. After that, Hysol will be used to glue the halves together. I tried the epoxy and just love it. Has anyone glassed the top section of the wing where they join? I have not read further in the manual, so I wasn't sure this was or was not recommended.....any thoughts?
Jeff
Jeff
05-09-2016, 12:45 PM
#3878
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I think the main reason is, pilots come to high and too fast, or way too slow and low. There is a sweet spot in between, too many pilots get impatient and try to drop them in, and then they start to bounce. Once you bounce, you better hit the gas and go around. If you bounce twice you will bend the gear, on the third bounce you are libel to break a wing or tail. I have seen a lot poor mustang landings. It took my several years to get it down pat.
05-09-2016, 03:57 PM
#3879
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No one ever said you had to do the mod. If you read all the TF P51 Mustang treads, they are full of complaints had how lousy and hard it is to land this plane. I personally don't have any issues. I have flown with un-moded wing and with. The change in dihedral wings settle and landed with more stability and and lower speeds then the unmoded wing. How ever, if you don't open and fix the shear webs, you WILL have a wing in pieces before long.
You mentioned-- However, if you don't open and fix the shear webs, you WILL have a wing in pieces before long.
Is this more of a landing gear issue on how weak the design is, in holding the retracts in place.?
05-09-2016, 04:47 PM
#3880
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No,Because the webs are weak, when the stress ( even from a normal landing) is transferred from the gear blocks to spar box with the weak shear webs. You can enforce the gear block all you want, the stress still goes to the spar box. Therefore it is the weak spar box that can't handle the stress, not the gear blocks.
05-09-2016, 05:19 PM
#3881
rampage-1, Take a look at post 3741 on page 150 (and a few post after that) to see what I feel is necessary mod to the spar box. I learned the hard way. Much, much easier to do the mod to the spar box now than to repair the spar box area after a couple poor landings. Everyone I know of flying a TOP Flight 1/5 Scale P-51 Arf has knocked the gear out if they don't mod the spar box area.
Ralph
Ralph
Last edited by Ralph White; 05-09-2016 at 05:23 PM.
05-09-2016, 09:22 PM
#3882
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Yes, DO THE WING REINFORCE NOW or rebuild the wing and reinforce after you rip the gear out on a less than perfect landing. Much easier to do it now. Ask me how I know. Also you will find a lot of joints missing glue.
I actually cut the ribs on each side of the spars to allow the new plywood shear webs to be continuous. And USE 1/8" 5-PLY PLYWOOD FOR THE NEW SHEAR WEBS.
Install the plywood shear webs on both the front and back of the spars. I used a sonic saw to cut the ribs (the vibrating kind)
I run the 1/8 plywood shear webs only 1 rib bay past the gear mounts on the other wing. I had to run the shear webs further out on this wing because the spars were broke further out when the gear came out.
I actually cut the ribs on each side of the spars to allow the new plywood shear webs to be continuous. And USE 1/8" 5-PLY PLYWOOD FOR THE NEW SHEAR WEBS.
Install the plywood shear webs on both the front and back of the spars. I used a sonic saw to cut the ribs (the vibrating kind)
I run the 1/8 plywood shear webs only 1 rib bay past the gear mounts on the other wing. I had to run the shear webs further out on this wing because the spars were broke further out when the gear came out.
Thanks for the info. I guess I should have purchased the Hangar9 P-51 or Aeroworks P-51.
I might as well rip the crap covering off and glass and paint it like I use to on other models. I am getting tired of ironing the wrinkles out and I am not even done building it.
I am surprised for a model that has been around for this long of time.
I JUST NOTICED THAT THIS THREAD WAS STARTED BACK IN 2003. Let me think , that has only giving 13 years for TOP FLITE to correct their problems.
I have built TP kits before without any problems and this being my first ARF from them will probably be my last.
Last edited by rampage-1; 05-09-2016 at 10:21 PM.
05-10-2016, 01:03 AM
#3883
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Rampage,
There is a big difference between TF and Hangar 9-Aeroworks. TF is highly scaleable. You can make it into a A,B or C Model with a small amount of effort. You can strip it. glass it and paint it. Bottom line, I quess, if you want to "model" a particular Mustang, TF is the way to go. If you want an arf like a 100 other people buy Hangar 9 or Aeroworks. Now I am not saying you can't "scale up" the other arfs, but it is more difficult.
There is a big difference between TF and Hangar 9-Aeroworks. TF is highly scaleable. You can make it into a A,B or C Model with a small amount of effort. You can strip it. glass it and paint it. Bottom line, I quess, if you want to "model" a particular Mustang, TF is the way to go. If you want an arf like a 100 other people buy Hangar 9 or Aeroworks. Now I am not saying you can't "scale up" the other arfs, but it is more difficult.
05-10-2016, 04:45 AM
#3884
As the old saying goes be careful what you wish for. The new H9 60cc Mustang and the Aeroworks P-51 have issues also! The H9 I viewed at the LHS was not fit for display; the covering was not stretched while installed at the factory, there was wave after wave of loose covering hanging from the fuselage. The canopy was warped out of shape as if it had been sitting in the hot sun etc. If you follow the H9 Mustang posts you will see there are also issues with horizontal and wing alignment issues etc. Since it is fairly new and with few flights reported so far, there maybe structural issues that have not shown up yet.
The Aeroworks P-51 has issues too, weak firewall, wing dowels coming loose, sloppy landing gear etc. There was lots of hype when the P-51 was released but owners began to find out that the price they paid for the P-51 was not worth the hype. If you follow the thread, customers were very disappointed with Aeroworks customer service when it came to warranty claims etc. Maybe that's the reason why so many Aeroworks P-51 Mustangs were put up for sale over the past few years.
The Aeroworks P-51 has issues too, weak firewall, wing dowels coming loose, sloppy landing gear etc. There was lots of hype when the P-51 was released but owners began to find out that the price they paid for the P-51 was not worth the hype. If you follow the thread, customers were very disappointed with Aeroworks customer service when it came to warranty claims etc. Maybe that's the reason why so many Aeroworks P-51 Mustangs were put up for sale over the past few years.
05-10-2016, 05:25 AM
#3886
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Rampage,
There is a big difference between TF and Hangar 9-Aeroworks. TF is highly scaleable. You can make it into a A,B or C Model with a small amount of effort. You can strip it. glass it and paint it. Bottom line, I guess, if you want to "model" a particular Mustang, TF is the way to go. If you want an arf like a 100 other people buy Hangar 9 or Aeroworks. Now I am not saying you can't "scale up" the other arfs, but it is more difficult.
There is a big difference between TF and Hangar 9-Aeroworks. TF is highly scaleable. You can make it into a A,B or C Model with a small amount of effort. You can strip it. glass it and paint it. Bottom line, I guess, if you want to "model" a particular Mustang, TF is the way to go. If you want an arf like a 100 other people buy Hangar 9 or Aeroworks. Now I am not saying you can't "scale up" the other arfs, but it is more difficult.
I agree, many years ago I would do a super scale but in the last 20 years, I just build ARF's and fly. I usually never keep a plane more then 25 flights. If the plane has not met it's expiration date, I usually sell it and start the next project. After this P-51 my sights are set for a 110 in Spitfire with a 4 stroke Kolm engine.I was thinking about the Bill Hempel 46% Pawnee PA-25 but the wings are to long for me to transport. I really enjoy flying my 33% Hangar9 Pawnee but it is a dual purpose plane, enjoy flying it and use it to towing gliders.This plane,Pawnee, I will probably keep until it meets it's expiration date.
I guess I'll go hack on a couple wings today and do the retrack mod. Oh, I did do your mod of 10 degrees, I almost changed my mind. Funny when I first open the box on this plane, I posted here or on RCGroup that it was well built,BUT the poorest grade wood that I have ever seen used in a plane. Must be grade #4 wood or worst. For example the firewall that holds your gas motor is not plywood. It is like layers of soft bass wood with a few layers of balsa wood. You can poke a screw driver thru it.With that said the wood blocks they give you to mount your servos to, must be made out of Iron wood. Drilling pilot holes for the screws was interesting how hard the wood was..
Last edited by rampage-1; 05-10-2016 at 05:34 AM.
05-10-2016, 05:37 AM
#3887
Funny when I first open the box on this plane, I posted here or on RCGroup that it was well built,BUT the poorest grade wood that I have ever seen used in a plane. Must be grade #4 wood or worst. For example the firewall that holds your gas motor is not plywood. It is like layers of soft bass wood with a few layers of balsa wood. You can poke a screw driver thru it.With that said the wood blocks they give you to mount your servos to, must be made out of Iron wood. Drilling pilot holes for the screws was interesting how hard the wood was..
05-10-2016, 10:31 AM
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As the old saying goes be careful what you wish for. The new H9 60cc Mustang and the Aeroworks P-51 have issues also! The H9 I viewed at the LHS was not fit for display; the covering was not stretched while installed at the factory, there was wave after wave of loose covering hanging from the fuselage. The canopy was warped out of shape as if it had been sitting in the hot sun etc. If you follow the H9 Mustang posts you will see there are also issues with horizontal and wing alignment issues etc. Since it is fairly new and with few flights reported so far, there maybe structural issues that have not shown up yet.
The Aeroworks P-51 has issues too, weak firewall, wing dowels coming loose, sloppy landing gear etc. There was lots of hype when the P-51 was released but owners began to find out that the price they paid for the P-51 was not worth the hype. If you follow the thread, customers were very disappointed with Aeroworks customer service when it came to warranty claims etc. Maybe that's the reason why so many Aeroworks P-51 Mustangs were put up for sale over the past few years.
The Aeroworks P-51 has issues too, weak firewall, wing dowels coming loose, sloppy landing gear etc. There was lots of hype when the P-51 was released but owners began to find out that the price they paid for the P-51 was not worth the hype. If you follow the thread, customers were very disappointed with Aeroworks customer service when it came to warranty claims etc. Maybe that's the reason why so many Aeroworks P-51 Mustangs were put up for sale over the past few years.
Last edited by rampage-1; 05-10-2016 at 04:52 PM.
05-10-2016, 04:50 PM
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05-12-2016, 03:54 PM
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First of all, all my wings have be fixed to the correct dihedral of 10 degs. The arf dihedral is 5-6 degs. I like my warbirds a little nose heavy. I just finish a new Mustang with a DLE 55 rear exhaust. I needed to put 8oz in the nose to balance it. Manuel say 4" 9/16. I have used that number for ever. I also reinforce the top of the nose of the arf from the inside.
I like to put my tanks where I can get at them and I only use Roto Flow tanks.
I always balance with an empty tank, gear up. When I put the plane on the balancer and get it dead level. Than I add just enough to get it to start tipping nose heavy and I stop. Because of the dihedral my Mustangs land and settle easily. 
Most other fliers think I'm nuts. But it all works for me.
I like to put my tanks where I can get at them and I only use Roto Flow tanks.
Most other fliers think I'm nuts. But it all works for me.
Hi Chris
FWIW-Today I doubled checked the dihedral on the wings of the TF P51 ARF not a kit. The angle was at 4 1/2 degrees from the factory . The pictures below shows the wing joiner with the 4 1/2 degrees . So with the real P-51 having a 6 degree dihedral and you mention that you made yours a 10 degree dihedral. I decided to change the factory setting of 4 1/2 degrees to a 6 degree dihedral. You mentioned that you take a 1/4in off at a tapper to the middle, at 6 degrees it was like .186in. The piece that I cut off I glued to the top as a shim.
Last edited by rampage-1; 05-12-2016 at 07:57 PM.
05-12-2016, 05:06 PM
#3893
05-12-2016, 06:32 PM
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I went over to my neighbors and his Real Mustang has 6 degrees of dihedral, that's where I came up with the real one.I don't understand how I could be substantially short if you are saying the real Mustang is 5 degrees and I have it set at 6 degrees????
05-12-2016, 08:05 PM
#3896
Check the wing dihedral of these two WWII fighters flying in tight formation, they are almost identical when viewed from the front and rear during air show flight. The Spitfire has 6 degrees of dihedral per wing half and the Mustang has 5 degrees per wing half.
https://www.youtube.com/watch?v=elnbvQ4GSxk
https://www.youtube.com/watch?v=elnbvQ4GSxk
05-12-2016, 09:12 PM
#3897
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You appear to be measuring your six degrees as compared to the opposite wing panel, as if you laid one panel flat on the building board and blocked up the other panel six degrees. See my second diagram. If you are measuring it in this manner then you have essentially cut the dihedral angle in half.
Hopefully I've not just muddied the waters further!
05-13-2016, 12:58 AM
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Check the wing dihedral of these two WWII fighters flying in tight formation, they are almost identical when viewed from the front and rear during air show flight. The Spitfire has 6 degrees of dihedral per wing half and the Mustang has 5 degrees per wing half.
https://www.youtube.com/watch?v=elnbvQ4GSxk
https://www.youtube.com/watch?v=elnbvQ4GSxk
Nice video
05-13-2016, 02:46 PM
#3899
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Dihedral is generally measured along the center line of the leading edge rather than against the bottom surface of the wing. Based on that the listed dihedral for the Mustang in all of my resources is 5 degrees per panel. If you are measuring against the bottom wing skin then you will get a higher number due to the taper of the wing. These are as measured against a reference line parallel to the ground as in my first diagram below.
You appear to be measuring your six degrees as compared to the opposite wing panel, as if you laid one panel flat on the building board and blocked up the other panel six degrees. See my second diagram. If you are measuring it in this manner then you have essentially cut the dihedral angle in half.
Hopefully I've not just muddied the waters further!
You appear to be measuring your six degrees as compared to the opposite wing panel, as if you laid one panel flat on the building board and blocked up the other panel six degrees. See my second diagram. If you are measuring it in this manner then you have essentially cut the dihedral angle in half.
Hopefully I've not just muddied the waters further!
6 degrees on each wing
