Topflite Giant P-47 Club
07-31-2016, 01:13 PM
#851
Hello everyone.
Thinking about throwing one of these beauties together to utilize a G-62 that I may have resurrected with the help of Adrian from CH Ignitions.
I am planning on doing the bubble canopy model and leaving it pretty much stock, though the work some of you have done on these models in this particular thread is absolutely astounding, my hats off to you.
My question is in regard to the retracts. I was strongly leaning toward Robart Electric retracts, but I have read a few saying the air set-up is more sturdy and reliable. I have dealt with air retracts somewhat in a 60 size corsair, and they never worked right. I don't doubt that it was likely setup error and not a problem with the retracts. In any event, just wondering if someone could shed some light on this subject. I really like the idea of easy setup and operation of the electric retracts, but if they're just going to fold on landings and not work right all the time I guess I could study hard and try and learn how to setup air properly. Thanks for any input!
Thinking about throwing one of these beauties together to utilize a G-62 that I may have resurrected with the help of Adrian from CH Ignitions.
I am planning on doing the bubble canopy model and leaving it pretty much stock, though the work some of you have done on these models in this particular thread is absolutely astounding, my hats off to you.
My question is in regard to the retracts. I was strongly leaning toward Robart Electric retracts, but I have read a few saying the air set-up is more sturdy and reliable. I have dealt with air retracts somewhat in a 60 size corsair, and they never worked right. I don't doubt that it was likely setup error and not a problem with the retracts. In any event, just wondering if someone could shed some light on this subject. I really like the idea of easy setup and operation of the electric retracts, but if they're just going to fold on landings and not work right all the time I guess I could study hard and try and learn how to setup air properly. Thanks for any input!
NOTE: Propstopped and NO GEAR.
Last edited by HoundDog; 07-31-2016 at 01:30 PM.
08-12-2016, 12:26 PM
#862
My Feedback: (35)
I cut the pipes down on the Pitts mufflerand welded a copper 90 degree fitting on to each. High temp tubing connect it to another piece of aluminum pipe with a 90 degree bend in it. I also coated to interior on the front fuselage and the pipe with bvm heat shield to help protect against heat. Here I a video that shows the engine area with the cowl off. No smoke system yet but I plane to put one on later.
Last edited by bigstew60; 08-12-2016 at 12:32 PM.
08-15-2016, 03:59 AM
#863
My Feedback: (3)
Adamsbro, I have the P47 and I put the electric Robarts in instead of the air. They run great, no idea why anyone would put air retracts in these days. There is one part I don't like and that is the control box shell. Its made out of this cheap thin plastic. The electric plugs from the retracts are supposed to plug into the control box. They rely on the cheap plastic to snap in. Well it doesn't work. Mine didn't even snap in, so I ended up having to tie down each plug into the box with some fishing line, then I used hotglue to hold the plugs down. Horrible setup for $600 retracts but whatever, they work great besides that.
Hello everyone.
Thinking about throwing one of these beauties together to utilize a G-62 that I may have resurrected with the help of Adrian from CH Ignitions.
I am planning on doing the bubble canopy model and leaving it pretty much stock, though the work some of you have done on these models in this particular thread is absolutely astounding, my hats off to you.
My question is in regard to the retracts. I was strongly leaning toward Robart Electric retracts, but I have read a few saying the air set-up is more sturdy and reliable. I have dealt with air retracts somewhat in a 60 size corsair, and they never worked right. I don't doubt that it was likely setup error and not a problem with the retracts. In any event, just wondering if someone could shed some light on this subject. I really like the idea of easy setup and operation of the electric retracts, but if they're just going to fold on landings and not work right all the time I guess I could study hard and try and learn how to setup air properly. Thanks for any input!
Thinking about throwing one of these beauties together to utilize a G-62 that I may have resurrected with the help of Adrian from CH Ignitions.
I am planning on doing the bubble canopy model and leaving it pretty much stock, though the work some of you have done on these models in this particular thread is absolutely astounding, my hats off to you.
My question is in regard to the retracts. I was strongly leaning toward Robart Electric retracts, but I have read a few saying the air set-up is more sturdy and reliable. I have dealt with air retracts somewhat in a 60 size corsair, and they never worked right. I don't doubt that it was likely setup error and not a problem with the retracts. In any event, just wondering if someone could shed some light on this subject. I really like the idea of easy setup and operation of the electric retracts, but if they're just going to fold on landings and not work right all the time I guess I could study hard and try and learn how to setup air properly. Thanks for any input!
08-15-2016, 04:07 AM
#864
My Feedback: (3)
Has anyone had issues with the Robart wheels being too fat, causing your gear doors to stick out higher than the bottom of the wing surface? I see some posts in this thread, but its mostly guys building the kit, and they have options thats I don't have with the ARF.
My gear doors caught the wind and blew off on the 2nd flight. I've been flying without them since.
I made some new gear doors out of thin plexiglass, and heated and curved them so they are cupped, that way they won't grab the air as easy. I'm also thinking of installing a wire loosely around the part that goes down by the axle, that way it will hold the bottom of the gear door down so it won't get sucked out of the wing when I'm flying at high speed. The wire would be loose so that the shock can still work in the strut... Just wondering if you guys experienced anything like this and what you did to fix it.
Of course I could always buy thinner aluminum wheels and tires if they exist somewhere?
Thanks
My gear doors caught the wind and blew off on the 2nd flight. I've been flying without them since.
I made some new gear doors out of thin plexiglass, and heated and curved them so they are cupped, that way they won't grab the air as easy. I'm also thinking of installing a wire loosely around the part that goes down by the axle, that way it will hold the bottom of the gear door down so it won't get sucked out of the wing when I'm flying at high speed. The wire would be loose so that the shock can still work in the strut... Just wondering if you guys experienced anything like this and what you did to fix it.
Of course I could always buy thinner aluminum wheels and tires if they exist somewhere?
Thanks
08-15-2016, 04:08 AM
#865
Join Date: Jan 2015
Location: Metamora, Michigan U.S.A.
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I would of used the electrics too but the release from Robart was put off many times and I needed gear in my hands. Maybe next time. The gear I got from them for my Ziroli P-38 are mechanically sound but the springs are all wrong. I literally have no rebound from completely collapsed position. I was sent new uncut springs but for 800 plus dollars I'm disappointed.
08-15-2016, 04:12 AM
#866
Join Date: Jan 2015
Location: Metamora, Michigan U.S.A.
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5 inch tires are 1 9/16 to 1 5/8 wide. I had to completely remove wing rib and reinforce skin on inside with heavy cloth. Then I resigned beams to change closed position. Now they layflush and I have inner doors also completely sealed. Go wY back and look at Tony builders pics for full wing mods to rework gear completely. Later I'll attempt to upload my pics. I'm on a cell phone now and it's a pain.
08-15-2016, 04:29 AM
#867
Has anyone had issues with the Robart wheels being too fat, causing your gear doors to stick out higher than the bottom of the wing surface? I see some posts in this thread, but its mostly guys building the kit, and they have options thats I don't have with the ARF.
My gear doors caught the wind and blew off on the 2nd flight. I've been flying without them since.
I made some new gear doors out of thin plexiglass, and heated and curved them so they are cupped, that way they won't grab the air as easy. I'm also thinking of installing a wire loosely around the part that goes down by the axle, that way it will hold the bottom of the gear door down so it won't get sucked out of the wing when I'm flying at high speed. The wire would be loose so that the shock can still work in the strut... Just wondering if you guys experienced anything like this and what you did to fix it.
Of course I could always buy thinner aluminum wheels and tires if they exist somewhere?
Thanks
My gear doors caught the wind and blew off on the 2nd flight. I've been flying without them since.
I made some new gear doors out of thin plexiglass, and heated and curved them so they are cupped, that way they won't grab the air as easy. I'm also thinking of installing a wire loosely around the part that goes down by the axle, that way it will hold the bottom of the gear door down so it won't get sucked out of the wing when I'm flying at high speed. The wire would be loose so that the shock can still work in the strut... Just wondering if you guys experienced anything like this and what you did to fix it.
Of course I could always buy thinner aluminum wheels and tires if they exist somewhere?
Thanks
Come to think of it I have a set of the Older Robart Electrics I bought off Ebay or RCU. Replacing them and removing the air system seems to be a lot of work and U know what I think of work. Besides te Jug is pretty much a Hanger Queen. Just sits in the trailer case there's no room left in the house except for the front room.
08-15-2016, 04:30 AM
#868
Join Date: Jan 2015
Location: Metamora, Michigan U.S.A.
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Here's a thought now that I take time to reread your post. Is it possible to have gear doors mounted so in retract position the leading edge is tucked in lower than the wing edge and back edge of door above wing edge so it acts like a wedge pushing door closed.
08-15-2016, 04:42 AM
#869
My Feedback: (3)
I actually have the new ones I made like that. I used a heatgun and I curved the leading edge of my plexiglass wing door so that it doesn't stick out.
But theres always the case that forward flight creates a low pressure area inside those wheel wells, and it will suck the gear door out anyways. So thats why I'm going to try to anchor the wing door down to the axle area somehow, that way its fully supported. I'll post some pics later.
But theres always the case that forward flight creates a low pressure area inside those wheel wells, and it will suck the gear door out anyways. So thats why I'm going to try to anchor the wing door down to the axle area somehow, that way its fully supported. I'll post some pics later.
08-15-2016, 05:23 AM
#870
I've had problems getting my gear to retract fully and lock in the wheel wells due to the gear doors acting like "wings". The curved shape of the doors causes them to develop lift pulling away from the wing. They pulled so hard that the pneumatic retracts couldn't hold the wheels in the wells.
I added a "spoiler" to the outer surface of the doors and it works much better now. The spoiler is a piece of 3/16" square balsa about 5 inches long glued to the high point of the curved gear door.
I added a "spoiler" to the outer surface of the doors and it works much better now. The spoiler is a piece of 3/16" square balsa about 5 inches long glued to the high point of the curved gear door.
08-15-2016, 05:37 AM
#871
I've had problems getting my gear to retract fully and lock in the wheel wells due to the gear doors acting like "wings". The curved shape of the doors causes them to develop lift pulling away from the wing. They pulled so hard that the pneumatic retracts couldn't hold the wheels in the wells.
I added a "spoiler" to the outer surface of the doors and it works much better now. The spoiler is a piece of 3/16" square balsa about 5 inches long glued to the high point of the curved gear door.
I added a "spoiler" to the outer surface of the doors and it works much better now. The spoiler is a piece of 3/16" square balsa about 5 inches long glued to the high point of the curved gear door.
08-15-2016, 09:24 AM
#873
Join Date: May 2005
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Just a quick crazy thought about the air pressure sucking out the gear doors... this would only work if you have inner gear doors and built your gear wells so that they are more or less air tight.
The air pressure on the upper side of the wing is lower than on the underside. If you drill a few holes through the upper sheeting, near the main spar, where I think the air pressure should be the lowest (?), it might suck out enough air so that the air pressure inside the wheel well is always lower than on the outside of the gear doors. Neatly sucking the doors shut. If it sucks so much that your gear wont come out again, you'd have to reduce airspeed to zero and lower your landing gear in a stall turn. Have I completely lost my mind, or does that sound like a plan?
EDIT: A model airplane has so many holes, the biggest ones in the firewall, where the engine is pushing lots of high pressure air into your airplane. So I guess the air pressure inside your model airplane is generally higher than the outside air pressure. Isolating your landing gear wells from this is starting to seem like a good idea if you want to keep your doors shut. END EDIT.
That being said, I'm still some time away from even starting to build, but Tony's wing modification is starting to look more and more attractive. Is anybody having no problems getting the gear doors to work properly in standard position (as intended n the kit)?
Greetings,
Hardy
The air pressure on the upper side of the wing is lower than on the underside. If you drill a few holes through the upper sheeting, near the main spar, where I think the air pressure should be the lowest (?), it might suck out enough air so that the air pressure inside the wheel well is always lower than on the outside of the gear doors. Neatly sucking the doors shut. If it sucks so much that your gear wont come out again, you'd have to reduce airspeed to zero and lower your landing gear in a stall turn. Have I completely lost my mind, or does that sound like a plan?
EDIT: A model airplane has so many holes, the biggest ones in the firewall, where the engine is pushing lots of high pressure air into your airplane. So I guess the air pressure inside your model airplane is generally higher than the outside air pressure. Isolating your landing gear wells from this is starting to seem like a good idea if you want to keep your doors shut. END EDIT.
That being said, I'm still some time away from even starting to build, but Tony's wing modification is starting to look more and more attractive. Is anybody having no problems getting the gear doors to work properly in standard position (as intended n the kit)?
Greetings,
Hardy
Last edited by Hardy_H; 08-15-2016 at 09:38 AM.
08-15-2016, 09:35 AM
#874
My Feedback: (3)
I thought of this too. A vent hole in the top of the wing might prevent so much pressure from sucking the gear doors downwards. I have an ARF so all I'd have to do is pop a hole in the top and decorate it somehow to make it look like its supposed to be there. Good idea!
Just a quick crazy thought about the air pressure sucking out the gear doors... this would only work if you have inner gear doors and built your gear wells so that they are more or less air tight.
The air pressure on the upper side of the wing is lower than on the underside. If you drill a few holes through the upper sheeting, near the main spar, where I think the air pressure should be the lowest (?), it might suck out enough air so that the air pressure inside the wheel well is always lower than on the outside of the gear doors. Neatly sucking the doors shut. If it sucks so much that your gear wont come out again, you'd have to reduce airspeed to zero and lower your landing gear in a stall turn. Have I completely lost my mind, or does that sound like a plan?
That being said, I'm still some time away from even starting to build, but Tony's wing modification is starting to look more and more attractive. Is anybody having no problems getting the gear doors to work properly in standard position (as intended n the kit)?
Greetings,
Hardy
The air pressure on the upper side of the wing is lower than on the underside. If you drill a few holes through the upper sheeting, near the main spar, where I think the air pressure should be the lowest (?), it might suck out enough air so that the air pressure inside the wheel well is always lower than on the outside of the gear doors. Neatly sucking the doors shut. If it sucks so much that your gear wont come out again, you'd have to reduce airspeed to zero and lower your landing gear in a stall turn. Have I completely lost my mind, or does that sound like a plan?
That being said, I'm still some time away from even starting to build, but Tony's wing modification is starting to look more and more attractive. Is anybody having no problems getting the gear doors to work properly in standard position (as intended n the kit)?
Greetings,
Hardy