Zeeb

My Feedback: (41)

I'm not aware of a controller that slows the electrical operation of the retract servo, but there is a controller that slows down the pneumatic gear from Century Jet retracts that I mentioned in a post just a few above this one. As I understand it, that controller works by restricting the airflow through the valve, not restricting servo speed. I've got the CJ set, but have not started building my Corsair yet since I still need a receiver and servos.

Are you using the factory mechanical retracts, or the CJ pneumatics?

Geoff_Gino

Hi Zeeb

Thanks for the answer (second one I got) I must have mis-read the post. Thought it was an electrical unit that could slow the servo down. Will have to stick to the setup as it is. Have found though that I will have to change my retract servo for one with more pull, the standard Hi-Tec servo won't pull the gear in unless the plane is inverted.

Geoff

Zeeb

My Feedback: (41)

Geoff,

I was just thinking about your question again and I've got an idea if you have a transmitter that will do it?

Set up your retract servo on one of the VR switches and you could retract them at whatever speed you wanted. It's not quite the "flip the switch and forget it" type of thing, but it would slow things down as long as you remember to completely retract and more importantly, extend the gear.

Just a thought for you to consider...

RCPILOT78

HEY ZEEB..HAVE YOU CHECKED OUT THAT RETRACT THEORY...I WAS UNDER THE IMPRESSION THAT A RETRACT SERVO ONCE ACTIVATED CANNOT BE CONTROLLED IT SIMPLY RUNS FULL TRAVEL TO THE SERVO STOP AT NORMAL SPEED. BE INTERISTING TO KNOW IF THAT IDEA WOULD WORK ON A RETRACT SERVO.....BUT I DOUBT IT......

Zeeb

My Feedback: (41)

Hey RCPilot,

Well I don't have any experience with "retract servos" if there is a specific type for that, but he said that he was going to have to go to a bigger servo since the one he has won't work unless the plane is upside down.

So, if you're going to put a bigger servo on it, why wouldn't it work just like a throttle or flap servo?

I've put flaps on my Nexstar, and the flaperons on my Funtana can be activated as flaps too. I set up my Futaba 9C with those servos on the left hand variable slider switch, and I can deploy as much or as little flap as I like. You just set the servo travel limits for whatever max travel you want or need, and voila!

Why wouldn't that work for him?

RCPILOT78

I SEE WHAT YOU ARE SAYING ZEEB..BUT THOSE ARE PROPORTIONAL SERVOS...THE RETRACT SERVO IS NOT..THATS WHY I FEEL THAT YOU CAN'T CONTROL SPEED...DO YOU SEE WHAT I AM GETTING AT.....

Zeeb

My Feedback: (41)

I understand what you are saying about a retract servo not being proportional, my premise is that he's going to have to change the servo he's got, so why not go with a proportional servo like you'd use for a throttle?

Or is there a size difference in the servos that wouldn't allow that kind of substitution?

RCPILOT78

THERE IS ZEEB THE RETRACT SERVO HAS A GEAR GRAIN THAT IS HIGH TORQUE. HE WOULD HAVE TO GO TO A LARGE SERVO SUCH AS THE ONE'S USED IN QUARTER SCALE PLANES...OR THE EQUIVELENT TO A HIGH TORQUE SERVO... I DON'T KNOW IF THE GEAR TRAIN CAN HANDLE THE RETRACT LOADS....

SkyStalker

Hey Guys,

All retract servos have reazonably enough torque to move any common retract system if it is in good condition. The fact that the servo in question can only retract the gear being the plane upside down coud be either that the mechanism is too tight somewhere or the servo is damaged.
I would suggest checking both options. Some of these problems have happened to me too.

Just my opinion.

Thanks.

Richard L.

My Feedback: (24)

Can't use a proportional servo for the retracts unless that servo has 180 degrees of travel. Plus, when a standard proportional servo binds, it will continue to draw current while trying to move the servo arm. When a retract servo binds, it stops.

Zeeb

My Feedback: (41)

That's one of the reasons I love this site, I'm constantly learning something new... [8D]


Thanks Richard, your posts in particular have been really helpful. I've got a question for you about props if you don't mind?

It seems like you've been able to give some recommendations, so here it is;

I've got a YS 110 I'm going to put on my Corsair so I can swing a three bladed prop. I'm at 4500' above Sea Level so we loose a chunk of power up here, but the YS 110 in my Funtana will swing a 16x6 two blade about 9500 RPM if that helps for reference.

Thanks in advance!

Richard L.

My Feedback: (24)

Zeeb, the YS 110 can swing a 14x7 3-bladed prop above 9K rpm. An MA 14x7 3-bladed prop will be slightly too small since it has narrow blades. I would try a Graupner 14x7 3-bladed prop and paint it black with insignia yellow tips.

AcpAce

I am finaly getting back to building the corsair and now am stuck. After mounting the wing servos and runing the extension i am puzled .Do you have to have a Y extension to plug in the rx?

Richard L.

My Feedback: (24)

Yes, use a Y harness plugged into the Rx for the aileron servo extensions.

Geoff_Gino

Hi Richard/Zeeb and all who answered my retract poser.

You are of course all correct in what has been said. Unfortunately my Radio is the equivalent of the JR6210 and does not have a "potentiometer" control on it, only switches. Radio's like the Hi-Tec Eclipse 7 does and putting the gear on one of them should do the trick.

Also correct in saying that there is some binding on my retracts is probably correct. Actuating the gear servo arm by hand even takes a lot of torque and I will have to look at the linkages. Bummer tho' the wing is already joined and it won't be easy. Need to get on with it if the the guys at my club will let me have the time (to busy building planes and dashboards) as I am getting quite excited about getting this bird in the air, Richard's video's are a joy to watch.

Geoff

Engineman

I started off with a HiTec Servo for my Hanger 9 retracts. It had a gear failure and then burned out, running on 5 cells, 6 volts, which it needed to give enough power to retract the servo's. I changed this for a Super Tech, cheaper and more powerful. This has worked but is quite fast.

All retract servos travel 180 degrees, which is needed for the retracts. They are not proportional. They have limit switches which switch off at each end of the stroke. These are needed to prevent stalling and burning out of the drive transistors. There are electronic slowing up devices available, in UK for about £10. I understand these control the motor speed by mark-space switching, which switches on and off at high speed with the on to off ratio adjustable. I plan to buy one and try it. As the Hanger 9 retracts are so poor and take so much power, it may not work or may destroy the servo, but worth a try.

Geoff_Gino

Hi Engineman

Glad that I was not totally mistaken about the electronic control. I will be very interested in finding out how it goes if you go ahead with your test.

Geoff

AcpAce

Dose the JR 513 retract servo work in the H-9 Corsair i seen that it is made for the low profile servo. Will the small retract bee to small?

AcpAce

An other question were should the best place be to mount the Rx and Battery? about were are your guys.

RCPILOT78

ACPACE....I MOUNTED MY RECIEVER ON THE PLYWOOD SERVO TRAY SUPPLIED...MY BATTERY IS MOUNTED UNDER THE FUEL TANK ALL THE WAY FORWARD AGAINST THE FIREWALL....I DID THIS BECAUSE I NEEDED WEIGHT UP FRONT TO BALANCE THE PLANE....IN YOUR CASE YOU NEED TO DETERMINE WHERE YOUR CG IS AND WHERE THE PLANE WILL BALANCE..YOU MAY HAVE TO MOVE THE BATTERY FORWARD OR BACK TO BALLANCE THE PLANE....USE THE WEIGHT OF THE BATTERY INSTEAD OF ADDING EXTRA WEIGHT TO BALLANCE THE PLANE IF YOU CAN...

Geoff_Gino

Hi Richard

Checked my retract servo last night. It has an 112 oz pull. Should that be enough for the gear?

Geoff

Richard L.

My Feedback: (24)

Hi Geoff, 112 oz pull should be enough if you are using light wheels. I'm using 100 oz-inch retract servos in most of my smaller warbirds.

Geoff_Gino

Hi Richard
I am using the wheels that came with the kit and they feel very heavy. I think perhaps I should go for a servo with more torque anyway, along the lines of, better to have it and not need it theory.
Thanks
Geoff

Engineman

Geoff,

I use the original wheels without trouble. I am sure you coulf find lighter, but they will retract. I also cover my legs with Robart plastic dummy oleo's, which add more weight. Once I sorted the linkages and made the rods more direct, they do retract. Unfortunately, they also bend back slightly on most landings and have to be corrected and checked before the next flight.

Engineman.

Zeeb

My Feedback: (41)

Hi Richard,

First, thanks for the three bladed prop recommendation, the only problem I had was finding them, but I have two on the way now.

As long as we're talking about retract servos and I now understand the difference, I got the mechanical retracting tailwheel from CJ when I ordered the gear. But there are absolutely no instructions with it, I guess they figure if someone orders that part they know how to set it up...

So my question is; Should I get a retract type servo for the tailwheel for the above mentioned reasons?

Would you Y harness it with the servo for the pneumatic mains, or give it a channel of it's own and use a mix on the computer radio?

Thanks!