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Mechanical Retracts For Corsair Models?

Old 06-28-2016, 09:31 AM
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Default Mechanical Retracts For Corsair Models?

My Dad and I have been wondering if there are any mechanical servo driven retracts for a F4U Corsair Model. 60 to 90 size aircraft weighing around 10 lbs. The model is the F4U Corsair by Top Flite. http://www3.towerhobbies.com/cgi-bin...&I=LXHU80&P=ML

I noticed a guy on youtube using some mechanical servo type retracts on his CMPro 75" I never heard of it before.

http://www.youtube.com/watch?v=MHlPWAxm8eM Also what do you guys think about using mechanical retracts that got to turn to go down?
Old 06-28-2016, 01:25 PM
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World Models had a system that used one retract servo and bellcranks,, so why not
Old 06-29-2016, 04:21 AM
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Originally Posted by scale only 4 me
World Models had a system that used one retract servo and bellcranks,, so why not
I'm just curious to find out if this kind of retract is capable of holding up to taking off and landing a plane as heavy as mine on a grass runway. The first electric retracts I tried ... I don't think can ... I think I should do a short youtube video showing why I think that.... And those are not even controlled by a servo. They have their own motor, metal housing etc. Anyways the manufacture went out of business last summer. Can't repair them because I can't get parts etc. I am also planning on starting another thread about the possibility of converting my model over to fixed landing gear, as another way of solving the problem.

World Models "had" a system that used one retract servo and bellcranks

That's one of the things I'm afraid of....

Last edited by gregoryshock; 06-29-2016 at 04:26 AM.
Old 06-29-2016, 04:30 AM
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The retracts have up and down locks where it is mechanically over center. The servo does not hold the gear.
Old 06-29-2016, 06:41 AM
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Originally Posted by TFF
The retracts have up and down locks where it is mechanically over center. The servo does not hold the gear.
That makes sense.

I made my short (10 minute) video talking about my Wingspanretracts electrics. I hope it helps you guys to understand why I'm thinking the way I'm thinking...

http://www.youtube.com/watch?v=3OfhTm4GIbo This video was made a year before the crash. It demonstrates the issue I had from the beginning. Eventually He got them working for me by re engineering them. Within that same year He went out of business.

http://www.youtube.com/watch?v=jCDOGuA1UhA
Old 06-29-2016, 11:25 AM
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Electric retracts for Corsairs is a long, sad tale.

However, you should take a look at the Eflite 90-120 95degree rotating electrics before dropping the curtain on presently available electrics. I'm using them on my 60 size H9 Corsair, H9 Hellcat and TF P40 Warhawk. They are adequately robust and have proven to be a far more appropriate design than LADOs. I won't mention how much time and money was wasted on Wingspans, starting with their first offering. Nor mention Robart at all.

I have also fitted the Eflites into the model you're trying to find something for. I'm confident they will work as well in it when it's completed as they work in my present models. Did they fit without adapting? Nope.

My Corsair started life with mechanicals. They were perfectly adequate but took a bit of learning just like most things in the flying model hobby. I would suggest that fitting them to any model not designed for them is a task for very experienced RC modelers and none of them the least bit faint hearted.

BTW, My "50 size" Corsair model in the picture above shows the Eflite 25-46 100degree rotating rotators that work just fine. It happens to be an electric. The picture was taken on it's maiden day and before struts were retrofitted.

Also, my experience with wire gear, either fixed or retracting, suggests strongly they should be replaced with "shock absorbing" struts like the Robarts. The wound wire simply does not give in a useful direction and the plane lands and taxis like it's got two wooden legs.

My 60 size Corsair (below) also started with mechanicals but was the testbed for LADO, countless Wingspans, and finally the Eflites. Had I to do over again, I'd simply have fitted Robart struts and not wasted so much money and time. The picture was taken when it was on LADOs. That didn't last long. LADO never really understood that rotating retracts needed to extend more than 90degrees. The 3 planes that have that type gear are terrible ground handlers without the tire position an extra 5-10 degrees gives. Wingspan got it. But produced lousy designs.
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Last edited by da Rock; 06-29-2016 at 11:59 AM.
Old 06-29-2016, 03:05 PM
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Originally Posted by da Rock


Electric retracts for Corsairs is a long, sad tale.

However, you should take a look at the Eflite 90-120 95degree rotating electrics before dropping the curtain on presently available electrics. I'm using them on my 60 size H9 Corsair, H9 Hellcat and TF P40 Warhawk. They are adequately robust and have proven to be a far more appropriate design than LADOs. I won't mention how much time and money was wasted on Wingspans, starting with their first offering. Nor mention Robart at all.

I have also fitted the Eflites into the model you're trying to find something for. I'm confident they will work as well in it when it's completed as they work in my present models. Did they fit without adapting? Nope.

My Corsair started life with mechanicals. They were perfectly adequate but took a bit of learning just like most things in the flying model hobby. I would suggest that fitting them to any model not designed for them is a task for very experienced RC modelers and none of them the least bit faint hearted.

BTW, My "50 size" Corsair model in the picture above shows the Eflite 25-46 100degree rotating rotators that work just fine. It happens to be an electric. The picture was taken on it's maiden day and before struts were retrofitted.

Also, my experience with wire gear, either fixed or retracting, suggests strongly they should be replaced with "shock absorbing" struts like the Robarts. The wound wire simply does not give in a useful direction and the plane lands and taxis like it's got two wooden legs.

My 60 size Corsair (below) also started with mechanicals but was the testbed for LADO, countless Wingspans, and finally the Eflites. Had I to do over again, I'd simply have fitted Robart struts and not wasted so much money and time. The picture was taken when it was on LADOs. That didn't last long. LADO never really understood that rotating retracts needed to extend more than 90degrees. The 3 planes that have that type gear are terrible ground handlers without the tire position an extra 5-10 degrees gives. Wingspan got it. But produced lousy designs.
Thank you for the info. It's nice to know that I'm not the only one that ran into issues with the Wingspan Retracts. Your plane looks awesome!

My Corsair wing had to be changed some to make the Wingspan retracts fit. I can google it but if you already know what Eflites website is please give me a link. I don't think I will be trying LADO.... I already tried to order them, and back when I tried the website didn't have any to sell and they never came available. Confusing.

If you could provide some pictures or a video showing the alterations you had to make to your model to make them fit. That would also be helpful.

I made a short video. I try to explain and show what Wingspan changed on my retracts. Before the changes they wouldn't even go up 50 percent of the time!

http://www.youtube.com/watch?v=bqBOmBQB2Bg

Last edited by gregoryshock; 06-29-2016 at 03:08 PM.
Old 06-29-2016, 04:37 PM
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The mounting flanges need simple blocks of hardwood under them that glued to the plywood rib supports inside the wing. iirc, when the Eflites replaced the last set of Wingspans not much trimming was needed. The blocks were made on a band saw in maybe 5 minutes. And that included the couple of trial prototypes.... they were truly cut-and-try.


http://www.horizonhobby.com/60-120-9...tracts-eflg520
Old 06-29-2016, 05:06 PM
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Don't bother with LADO. They don't seem to understand the need for gear travel beyond 90degrees. The axis of rotation of the trunions is usually significantly aft within the frames, and the frames simply cannot be installed far enough forward in the wing to get the tire footprints forward of the CG enough to keep the models from nosing over from the slightest provocation. In fact, even if the frames of all 3 brands stuck through the wing LE, 90 degree gear would handle poorly if the plane was balanced "safely nose heavy" the way most of todays "experts" demand.

The 100degree gear in the smaller Corsair handles safely. It's CG was moved aft significantly from the mgf's recommendation. It flies like a dream and taxis without fear. The larger planes gear, being only 95degree, got mounting blocks with a 3degree pitch to them. The wheels don't bottom out in the wells at all. The Hellcat showed the "least good" ground handling of the 3 and prompted me to retrofit it's mounting blocks to get more than the 95degrees the Eflite's provide.

I notice you're familiar with Robart struts. They do a very good job of solving the problem wire struts with coils cause. When wire/coil struts angle forward on a tail dragger, they don't give at all when the tires run into bumps and such. Good thing about the Eflites coils are they are far enough down the strut when the wire is cut (dremel abrasive wheels work well) next to them, the wire stub that remains is perfect for the Robart struts to attach to.
Old 07-02-2016, 04:53 AM
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Originally Posted by da Rock
Don't bother with LADO. They don't seem to understand the need for gear travel beyond 90degrees. The axis of rotation of the trunions is usually significantly aft within the frames, and the frames simply cannot be installed far enough forward in the wing to get the tire footprints forward of the CG enough to keep the models from nosing over from the slightest provocation. In fact, even if the frames of all 3 brands stuck through the wing LE, 90 degree gear would handle poorly if the plane was balanced "safely nose heavy" the way most of todays "experts" demand.

The 100degree gear in the smaller Corsair handles safely. It's CG was moved aft significantly from the mgf's recommendation. It flies like a dream and taxis without fear. The larger planes gear, being only 95degree, got mounting blocks with a 3degree pitch to them. The wheels don't bottom out in the wells at all. The Hellcat showed the "least good" ground handling of the 3 and prompted me to retrofit it's mounting blocks to get more than the 95degrees the Eflite's provide.

I notice you're familiar with Robart struts. They do a very good job of solving the problem wire struts with coils cause. When wire/coil struts angle forward on a tail dragger, they don't give at all when the tires run into bumps and such. Good thing about the Eflites coils are they are far enough down the strut when the wire is cut (dremel abrasive wheels work well) next to them, the wire stub that remains is perfect for the Robart struts to attach to.
If I get new retracts for the Corsair I will follow your advice.

On the Eflite retracts I was wondering how to do they attach the struts to the retract? I'm asking because the Wingspan Retracts used two tiny setscrews. I couldn't get them tight enough to keep my struts from turning while taxiing on my grass runway. I tried making flat spot on the struts for the setscrews to turn against, and that didn't work. Next I tried adding some JB Weld between the retracts and struts and it would just crack off while taxiing. How are you securing your struts?

BTW: I sent you a private message.
Old 07-03-2016, 05:16 AM
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Originally Posted by gregoryshock
If I get new retracts for the Corsair I will follow your advice.

On the Eflite retracts I was wondering how to do they attach the struts to the retract? I'm asking because the Wingspan Retracts used two tiny setscrews. I couldn't get them tight enough to keep my struts from turning while taxiing on my grass runway. I tried making flat spot on the struts for the setscrews to turn against, and that didn't work. Next I tried adding some JB Weld between the retracts and struts and it would just crack off while taxiing. How are you securing your struts?

BTW: I sent you a private message.
All the "shock absorbing" struts I've used had those setscrews. The flats I grind/file are about the diameter of the setscrew. The first ones I made up were Robarts which required cutting to length, pressing in the inserts, drilling and tapping the screw holes as well as placing flats in the right place on the stubs they fit over. I've purchased a number of different brands of "S.A." struts but never found any that did not require correcting the length to suit my models. So far every project wound up on Robarts as rigging them is a lot less work.

The first ones I did slipped as the flats were insignificant. Widening them assured their alignment, and apparently gives the gib screws greater leverage. It also deepens the reach the screw must match. I've always used locktite on all gib screws in retracts and never had a slip (after that first one).

As for the pm. Talking to the gear "developers" themselves back in the day was disappointing. They didn't seem to have a very deep understanding of a number of details specific to the market. Such as the CG situation P40/F6F/F4Us present. The Eflites showed up after a couple of years effort to get 95-100degree extension from LADOs (or anyone) and more design/component quality from Wingspan. And then Eflite did nothing for so long after coming out with the 46size, I finally assumed the 46size hadn't sold in sufficient quantity. There wasn't a popular warbird kit or ARF of that size that took rotators after all. Which suggested to me they weren't very up on the market. And I assumed they'd decided there wasn't sufficient demand for the larger, more expensive ones and I gave up the crusade. I was shocked when I finally saw the big ones. And of course, they were "too big" for either the P40 or TF F4U I had suspended construction on after the LADO/Wingspan promise had fizzled. I was actually pleasantly surprised after risking the price of the big Eflite ones to find they are the same size of the 60size predecessors.

It is probably true the present RC marketplace has few customers capable of the metalwork required to rig suitable length Robarts. Which may explain why I can't find any nowadays. But then the 60size ARF warbirds aren't around now either like they used to be. It is a hard market to supply apparently.
Old 07-03-2016, 07:38 AM
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for my taylor corsair , i would GLADLY go with MECHS , BUT nobody makes a heavy set
back in the day that was all they used , now i'm acting old , jeeze!!!!
Old 07-03-2016, 07:40 AM
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if i could find a set ID USE EM!!!
Old 07-03-2016, 09:09 AM
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How big is your Taylor Corsair?
Old 07-03-2016, 12:19 PM
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82 span version , the big robarts wont fit , the retract area is small , the tf giant corsair has got a thicker wing in the retract area.
Old 07-04-2016, 06:24 AM
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Originally Posted by da Rock
All the "shock absorbing" struts I've used had those setscrews. The flats I grind/file are about the diameter of the setscrew. The first ones I made up were Robarts which required cutting to length, pressing in the inserts, drilling and tapping the screw holes as well as placing flats in the right place on the stubs they fit over. I've purchased a number of different brands of "S.A." struts but never found any that did not require correcting the length to suit my models. So far every project wound up on Robarts as rigging them is a lot less work.

The first ones I did slipped as the flats were insignificant. Widening them assured their alignment, and apparently gives the gib screws greater leverage. It also deepens the reach the screw must match. I've always used locktite on all gib screws in retracts and never had a slip (after that first one).

As for the pm. Talking to the gear "developers" themselves back in the day was disappointing. They didn't seem to have a very deep understanding of a number of details specific to the market. Such as the CG situation P40/F6F/F4Us present. The Eflites showed up after a couple of years effort to get 95-100degree extension from LADOs (or anyone) and more design/component quality from Wingspan. And then Eflite did nothing for so long after coming out with the 46size, I finally assumed the 46size hadn't sold in sufficient quantity. There wasn't a popular warbird kit or ARF of that size that took rotators after all. Which suggested to me they weren't very up on the market. And I assumed they'd decided there wasn't sufficient demand for the larger, more expensive ones and I gave up the crusade. I was shocked when I finally saw the big ones. And of course, they were "too big" for either the P40 or TF F4U I had suspended construction on after the LADO/Wingspan promise had fizzled. I was actually pleasantly surprised after risking the price of the big Eflite ones to find they are the same size of the 60size predecessors.

It is probably true the present RC marketplace has few customers capable of the metalwork required to rig suitable length Robarts. Which may explain why I can't find any nowadays. But then the 60size ARF warbirds aren't around now either like they used to be. It is a hard market to supply apparently.
Thank you for writing me. I found it insightful.

I will try making my flat spot deeper and report back.

Last edited by gregoryshock; 07-04-2016 at 06:30 AM.

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