Freewing A-4 Blue Angels Conversion

[OV10]

Not to get side-tracked but I traded with George and got this from him.

He likes the trade aspect of this hobby. Where'd he get that Stuka. ;)

[RCjetdude]

He likes the trade aspect of this hobby. Where'd he get that Stuka. ;)

Yeah I know! Probably why he has a hangar full of planes and I don't....yet.

[Pogo]

Thanks Dan. Not amazing enough to keep monkeying around with trying to get the main doors to open without servos. I am wanting to move on to finishing and painting so I am throwing in the towel, waiving the white flag and will work the mains doors with servos. I will try to make them work with just one for each set of doors to start. I ordered some 9g servos and a gear door sequencer so I will have more to post soon. Not to get side-tracked but I traded with George and got this from him.



He has already installed better fans, ESC's, retracts and servos. I am going to quickly install a receiver and get it set up to hopefully fly at a Halloween Fun Fly this Saturday. Heck with the TV and the drag shute. Should be interesting.

Steve, I don't know if you're aware of these spring hinges, available here:

http://www.sonictronics.com/xcart/product.php?productid=16476&cat=321&page=1

Might save you the weight and complexity of servos. :Cool:
Also, speaking of LX SU47's, my friend Eric (4stripes on RCG) did an extensive build and flying thread of his on RCCanada you might want to check out:

http://www.rccanada.ca/rccforum/showthread.php?t=380866

Tom

[Grossman56]

Guess there's no way that they would work using pins like on the Bearcat inner gear doors is there?

Grossman56

[RCjetdude]

Hey Tom, I had some hinges like those and just couldn't get it to work right. Dan, I thought of the Bearcat doors as well and how they work, again the geometry was just not right. Given more time and a greater determination I could maybe work it out but I am ready to get on with painting. Servos won't add much weight or complexity but will get me going forward again. I really appreciate the ideas.

I have been checking out some threads on RCG about the Berkut but will look into the one you pointed out Tom. Thanks for the information. I hope it flies as good as it looks.

[RCjetdude]

I am satisfied with the operation of the arresting hook. I did redo the hinge for it to look a little more realistic. Here is a quick vid showing it's operation.

https://youtu.be/84d0HavhqmA

[crxmanpat]

That looks awesome man!

[RCjetdude]

Thanks Pat. Right now I am waiting on servos and a sequencing module to hopefully get the main gear doors to work properly. If I can accomplish that then it will be down to lights which are still on backorder and have been for awhile now. If they don't arrive by the time I need them then I will shelve it until they do and work on other projects until then. I would really like to get a coat of paint on this bird.

[RCjetdude]

Well, it looks like the lights might be on their way soon after all as I just got a back in stock notification. I should be getting a shipping notice soon. Woohoo!

[Grossman56]

It looks great Steve, the arrester hook is a cool addition, is that going to give you a problem with the angle of attack while landing, or are you going to have it on a separate switch to deploy when you want, rather than with the L/G?

Grossman56

[RCjetdude]

It looks great Steve, the arrester hook is a cool addition, is that going to give you a problem with the angle of attack while landing, or are you going to have it on a separate switch to deploy when you want, rather than with the L/G?

Grossman56

Thanks Dan. Separate switch. It's just for show on slow passes. I forgot to add a picture of it.

[RCjetdude]

Back on the main gear doors. My 9g servos and GT Power Sequencing module arrived yesterday and I spent most of last night trying to figure out different ways I could make this work. In the end I think I am going to have to go with 4 servos. I hooked everything up to see how it would all operate together. I needed to determine servo travel and where the two reverse servos needed to go. Here is another quick video showing the operation of the gear and door servos as layed out. Pushrods will come off the bottom of the servos. That is the plan for now.

https://youtu.be/pggD8_3EeGo

[purduephigam]

Looks awesome. I'm not sure how the real version works, but will the gear doors close when the gear is down, or do they stay flapped open? Heck of a project!

[RCjetdude]

Looks awesome. I'm not sure how the real version works, but will the gear doors close when the gear is down, or do they stay flapped open? Heck of a project!

They stay open. This is turning out to be quite the challenge but I am getting it. Challenges are a good thing. They extend our abilities. Theres a new word, extendabilities.

[Ron1950]

How did you get the tailhook to work? I have one on a t28 but never did figure how to get a servo in there

[RCjetdude]

How did you get the tailhook to work? I have one on a t28 but never did figure how to get a servo in there

The A-4 has this nifty empty space in the fan cover where you can mount the servo just opposite the hinge for the hook.

[Ron1950]

thanks your a artist my friend

[RCjetdude]

Thanks for the kind words Ron.

I have been working on the gear doors for one of the mains all day and I think I finally got it sorted out. This is a major project milestone as far as I am concerned. Now I just need to duplicate it on the other side. My lights will be here Monday so once I get all the mechanical and electrical installations sorted out I can then move on to finishing. Here is another video of the main gear cycling with the gear doors.

https://youtu.be/ACDbt26gBNU

[Kloverzero]

Steve, this might be far fetched, but have you thought about trying to bend a piece of music wire and just use one servo per side? You may be able to bend one so that it is barely visible, and attach it to the strut door, so that it pushes and holds the wheel door shut as it closes. You would need to put spring loaded hinges (or bend a very thin wire) to force them to open and hold them there. It may be a little more work, but might save you the weight and extra pushrod figuring for the quad servo setup.

You are doing yeoman's work here my friend, and I am following this thread closely!!!

[RCjetdude]

Hey Michael, I have tried many different music wire arrangements. I had them closing well without servos but the opening part was not as easy. I finally decided to go the servo route because I was tired of fooling with it and ready to move on. I spent most of last night and part of this morning trying to figure out a 1 servo music wire arrangement that would work reliably and finally ended up deciding to go with a 2 servo setup. It is not that much weight and it will not be flying with ordnance or drop tanks so that saves some weight.