How many CA hinges to use ?
11-17-2014, 09:32 PM
#1
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How many CA hinges to use ?
The original design of the horiz. stab was made from a 1/4 inch sheet stock. The stab is 20 inches long and attached between the 2 vertical fins of an OV-10 Bronco. The design only calls for 5 CA hinges.
I replaced the sheet Horiz Stab with a built up one with an airfoil . Now I can't decide how may CA hinges I should install. I was thinking of using 7 but is that too many? Any recommendations?
BTW I am using only one Slim Wing servo for the elev and mounted it in the center of the stab.
I replaced the sheet Horiz Stab with a built up one with an airfoil . Now I can't decide how may CA hinges I should install. I was thinking of using 7 but is that too many? Any recommendations?
BTW I am using only one Slim Wing servo for the elev and mounted it in the center of the stab.
11-18-2014, 07:22 PM
#3
I believe I have the same airplane if yours is the 52 inch ARF. I put it together to use for a couple of RCPro warbird races. I choose to go with two servos for the elevator (HS 225's) One at each end of the elevator and I would not use more than five hinges as more than that tends to stiffen the elevator more than I would care for especially if you are using one servo. The thin single sheet control surface can be a bit flexible and stiff hinges could contribute to flutter with only one servo.
John
John
11-19-2014, 01:54 PM
#4
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I believe I have the same airplane if yours is the 52 inch ARF. I put it together to use for a couple of RCPro warbird races. I choose to go with two servos for the elevator (HS 225's) One at each end of the elevator and I would not use more than five hinges as more than that tends to stiffen the elevator more than I would care for especially if you are using one servo. The thin single sheet control surface can be a bit flexible and stiff hinges could contribute to flutter with only one servo.
John
John
I plan to use one HS-125MG slim wing servo for the elev in the middle of the stab. .The airfoil Stab I built is very stiff compared to the Sheet stab. It definitely will not flex . So maybe more hinges will help with flutter ? I can also stiffen the elev with a strip of CF tape.
BTW how does your's fly?
11-19-2014, 06:29 PM
#5
The airplane has a fairly heavy wing loading and flys accordingly She pays off rather rapidly on landing and something to watch for. Other than that and the fact that you need to avoid over rotating on takeoff it is pretty straight forward. Mine has a pair of OS .35AX's and now sports a pair of UltraThrust quarter wave pipes. These do tend to make the airplane competitive in RCPro warbird pylon bronze class . The first race I ran her in I did manage a fourth but the second there was a fuel leak and never raced her in that race.
I would avoid anything that may increase the weight of this airplane and what I decided to do was park mine for a while and extend the wing by one bay each side as I believe this would help not just in landing etc. but also in cornering in the pylon turns and it is something that would be legal in the rules.
I like the airplane but now for my biggest complaint and that is not how it flys but the included plastics i.e. the cowls and the hugh plastic tail cone in the center fuselage. As you might have found out already this stuff is garbage and far to thin, cracking I swear just by looking at it. I was able to race without the cowls but that hugh plastic dome on the back severely cracked during early rounds at that first race and by the last rounds about half of it was missing and I got by with copious quantities two inch packageing tape holding the thing on to make the last races.
I will use the down time extending the wing and building a balsa structure for the tail end
So do I like the airplane? Well sure, but definitely a pain in the Butt!
John
I would avoid anything that may increase the weight of this airplane and what I decided to do was park mine for a while and extend the wing by one bay each side as I believe this would help not just in landing etc. but also in cornering in the pylon turns and it is something that would be legal in the rules.
I like the airplane but now for my biggest complaint and that is not how it flys but the included plastics i.e. the cowls and the hugh plastic tail cone in the center fuselage. As you might have found out already this stuff is garbage and far to thin, cracking I swear just by looking at it. I was able to race without the cowls but that hugh plastic dome on the back severely cracked during early rounds at that first race and by the last rounds about half of it was missing and I got by with copious quantities two inch packageing tape holding the thing on to make the last races.
I will use the down time extending the wing and building a balsa structure for the tail end
So do I like the airplane? Well sure, but definitely a pain in the Butt!
John
11-19-2014, 08:55 PM
#6
"Enough" is just right..... LOL
IMO 5 hinges would be enough to use. Also IMO I would not use CA hinges but use a pinned hinge or my favorite the Robart hinge points. BUT use what you are comfortable with and know how to work with.
Ken
IMO 5 hinges would be enough to use. Also IMO I would not use CA hinges but use a pinned hinge or my favorite the Robart hinge points. BUT use what you are comfortable with and know how to work with.
Ken
11-20-2014, 07:46 AM
#7
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The airplane has a fairly heavy wing loading and flys accordingly She pays off rather rapidly on landing and something to watch for. Other than that and the fact that you need to avoid over rotating on takeoff it is pretty straight forward. Mine has a pair of OS .35AX's and now sports a pair of UltraThrust quarter wave pipes. These do tend to make the airplane competitive in RCPro warbird pylon bronze class . The first race I ran her in I did manage a fourth but the second there was a fuel leak and never raced her in that race.
I would avoid anything that may increase the weight of this airplane and what I decided to do was park mine for a while and extend the wing by one bay each side as I believe this would help not just in landing etc. but also in cornering in the pylon turns and it is something that would be legal in the rules.
I like the airplane but now for my biggest complaint and that is not how it flys but the included plastics i.e. the cowls and the hugh plastic tail cone in the center fuselage. As you might have found out already this stuff is garbage and far to thin, cracking I swear just by looking at it. I was able to race without the cowls but that hugh plastic dome on the back severely cracked during early rounds at that first race and by the last rounds about half of it was missing and I got by with copious quantities two inch packageing tape holding the thing on to make the last races.
I will use the down time extending the wing and building a balsa structure for the tail end
So do I like the airplane? Well sure, but definitely a pain in the Butt!
John
I would avoid anything that may increase the weight of this airplane and what I decided to do was park mine for a while and extend the wing by one bay each side as I believe this would help not just in landing etc. but also in cornering in the pylon turns and it is something that would be legal in the rules.
I like the airplane but now for my biggest complaint and that is not how it flys but the included plastics i.e. the cowls and the hugh plastic tail cone in the center fuselage. As you might have found out already this stuff is garbage and far to thin, cracking I swear just by looking at it. I was able to race without the cowls but that hugh plastic dome on the back severely cracked during early rounds at that first race and by the last rounds about half of it was missing and I got by with copious quantities two inch packageing tape holding the thing on to make the last races.
I will use the down time extending the wing and building a balsa structure for the tail end
So do I like the airplane? Well sure, but definitely a pain in the Butt!
John
My first thought was to cut out the wing tip . then splice an additional bay with one rib . Use hard balsa + CF for strength . Any comments on this method.
How did you do yours?
11-20-2014, 07:55 AM
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I could do either. The TE of the stab is only 1/4 inch thick at the hinge line . I will have to cut the hinge point shorter so as not to puncture through the TE of the stab. The stab TE is 3/4 inch in depth because when I built it I was planning on CA hinges so no back up blocks were used. Maybe not enough depth for hinge points at this time. I'ts going to be a mess to cut out small areas of balsa skin just to add the backing blocks for safety.
11-20-2014, 06:22 PM
#9
Sportflyer just use the CA hinges they will do just fine and I would recommend you use only five not seven for the reasons I spoke of in my previous post. I think you have over thought all the mods and building a new stab did not really buy you anything. What you probably ought to give some more thought to is how to keep the whole tail end of that big old plastic fuselage box from blowing off in flight as happened to me
John
John
11-21-2014, 06:10 AM
#10
[QUOTE=sportflyer I am considering adding one panel to the wing on each side .
My first thought was to cut out the wing tip . then splice an additional bay with one rib . Use hard balsa + CF for strength . Any comments on this method.
How did you do yours?[/QUOTE]
I have basically used no modifications to speak of on mine. But as noted in my earlier post I do think that extending the wings a bit is the one thing this airplane really needs. I believe for the most part this ARF was either copied or derived from the original Rich Urivitch published plans and it was only fifty inch span. I did have the opportunity to test one of those for someone in the past and it wing loading was even worse. extending the wing another few inchs I believe would make this airplane come alive especially so if one just had to have all the scale details, retracts and so forth.
Also Sportflyer doing the wing extensions as you described is easy and works well. I have used that technique on a number of cross country airplanes that I have done that a wing loading reduction was the main goal and it works quite well.
John
My first thought was to cut out the wing tip . then splice an additional bay with one rib . Use hard balsa + CF for strength . Any comments on this method.
How did you do yours?[/QUOTE]
I have basically used no modifications to speak of on mine. But as noted in my earlier post I do think that extending the wings a bit is the one thing this airplane really needs. I believe for the most part this ARF was either copied or derived from the original Rich Urivitch published plans and it was only fifty inch span. I did have the opportunity to test one of those for someone in the past and it wing loading was even worse. extending the wing another few inchs I believe would make this airplane come alive especially so if one just had to have all the scale details, retracts and so forth.
Also Sportflyer doing the wing extensions as you described is easy and works well. I have used that technique on a number of cross country airplanes that I have done that a wing loading reduction was the main goal and it works quite well.
John
11-21-2014, 07:08 AM
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Yeah, I will do the wing extension as I believe this plane has a rather high wing loading . I will extend by only the width of one bay per side . BTW I assume aileron extension is also required? It might be easier to add a new longer aileron ,
New inputs
Started the wing extension: The wood thickness are all in metric so my supply of sticks and other wood are all slightly off . I used slightly thicker sticks and have to plane it down a touch for best fit. . This is really hard going but I hope will end up better in the long run.( lower wing loading) . I added 4 inches either side so approx 15% wing area. . I also spliced in a longer aileron . Hope it does not look too far off scale when completed.
This is my first ARF that I am making so many mods. I should have bought the plans and built it from scratch.....less disheartening.
New inputs
Started the wing extension: The wood thickness are all in metric so my supply of sticks and other wood are all slightly off . I used slightly thicker sticks and have to plane it down a touch for best fit. . This is really hard going but I hope will end up better in the long run.( lower wing loading) . I added 4 inches either side so approx 15% wing area. . I also spliced in a longer aileron . Hope it does not look too far off scale when completed.
This is my first ARF that I am making so many mods. I should have bought the plans and built it from scratch.....less disheartening.
Last edited by sportflyer-RCU; 11-22-2014 at 04:41 PM. Reason: Add more info.
