robart-joe

810RS is available on the website. You can enter 810RS in the search box in the top if the link below does not work. Thanks.

http://robart.com/products/810rs-100-deg-rotating-pneumatic-retract

ThunderBoat42

My Feedback: (1)

Hey Joe. Have them look at the recommended gear for the top flight p51 60arf. That should be the 90 degree. On the electric they say it correctly in the video but it's under the 85 degree. Has caused a few people some grief. Fortunately I saw the video and ordered the 90 degree. They fit and work perfectly. Those who ordered the 85 degree have been required to exchange or shim the gear.

SkyPilot101

Thanks robart Joe, ordered a set of the pneumatic rotators, at 3&11/16's they will fit the Top Flight Corsair nice'ly ! I've had no problems with pneumatic retracts, and don't understand why so many complain about them and want electrics ?

radfordc

My Feedback: (14)

Well, I'm not a happy camper. I bought a set of used Robart #590E mains for my TF P-51 ARF. When I tested them I first found that the motors wouldn't work with the Rx battery (yes, the jumper plug was installed correctly in the Aux Batt slot). I hooked up a two cell LiOn 7.4 battery to the Aux Batt port and the retracts were working OK. All at once the retract motors quit working....completely. You can see that the motor was in transit when it quit. Nothing is working now.

I guess the board is dead, but I'm at a loss to know why?

tomfiorentino

And the male to male receiver to control box jumper is not compatible with JR/Spektrum. I know, its not a huge deal, but you either have to hack/modify two compatible servo extensions into one with two males, or, you have to slightly bevel the connectors sold in the kit.

And the tri-gear w/controller kit is useless unless you also order the proprietary 2-pin actuator extensions (Part #177e12). This one has been more frustrating for several reasons:

1. Upon ordering from Horizon, sales confirmed nothing else was needed and as recently as a week ago...no picture of what was included is available on the website or on sales computer screens/product descriptions.
2. When I finally pick up the retracts to install them (10:00 PM and three weeks later) it became quickly apparent that other stuff was in fact needed. As with all proprietary stuff...you are dead in the water. While I think RCers tend to be good at improvising...there are limits.
3. The call to Horizon the next day revealed that they don't stock the actuator extensions even though they sell the tri-gear kit with controller. This is like buying a guitar that nobody knew was being delivered without strings; and then finding out you can't use regular guitar strings, you have to order special guitar strings...whatever....there is absolutely nothing with you can do with the tri-gear kit from Horizon as currently sold.
4. Ordering from Robart over the phone is tough...using on-line ships in 72 hours bla bla.
5. Further, the actuator leads coming off the retract probably won't make it out the center of the wing of a 60 size airplane because they aren't long enough. Spare proprietary actuators come in 12 or 15 inch lengths. So, unless it is feasible to plug lines directly into the control unit every time I attach the wing I need to use TWO 12 inch extensions to get me from the retract actuator lead to the control unit. Again...more hacking and retrofitting of new parts. Reading that the speed of the retracts is very dependent on voltage, the leads need to be as short as possible!! Lots of things going in the wrong direction here...

Hopefully, they'll work, no brush problems etc. etc.

Am I missing something here?

Tom

Reini450

Hi dawhale,

believe me, that is the lesser evil.
I've bought a set of the 100 deg rotating retracts (810 series) for my Hellcat designed by Chad Veich.
http://www.rcuniverse.com/forum/rc-w...oup-build.html
And what should I say, the retracts (wheels) rotate more than 90 deg.

I have found until today no way to change the rotating angle.
In this condition, I can not install or use the retracts. It is worthless.

And now comes the best: I get no reply from Robart.
During the past few days, I have three times tried to contact Robart. Two times via the contact form and one via mail direct to Eric Karl (Sales, Manager of Technical Services).
( What kind of technical service?)

I'm very frustrated and angry.
Frustrated, cause the retract installation was the last major point on the way to finish my Hellcat. And angry about the worst costumer servies.

Maybe one of you has an idea, I an at my wit's end.

Greetings from Germany,
Dirk

Chad Veich

My Feedback: (60)

I am totally bummed about this Dirk and very sorry you have run into further landing gear issues. The only reason I can think of for Robart to make the gear rotate more than 90 degress would be for airplanes like the P-40 or Skyraider that do not have a flat center section. In such a case the over-rotated gear would probably fit better in the wheel wells due to the dihedral. My old 615 Robarts are not like this by the way, nor are my Sierra rotaters. I sure wish I could offer you a solution but I'm afraid I don't have one at this point. Your Hellcat is SO CLOSE though, please don't give up!

Reini450

Hi Chad,

thanks for your encouraging words. To "Give up" is not an option.
Yesterday I spent some time to figure out, what can I do to modify the retracts.
The first part was very simple, to calculate the ratio between the 100 deg and the 90 deg rotating. It's 1:0,9.
The gear sector assembly is responsible for the rotaing of the leg/wheel.
When I would like to have an angle of 90 deg rotating, the angle of the outer teeth from the gear sector has to be 81 deg. (90 deg * 0,9 = 81 deg.)

The Robart gear sector assembly has an angle of 93 deg.
The easiest way, for the moment, is to modify the gear sector. But 81 deg are impossible cause the distancte between the teeth is limited by the holes in the side frames.
The main goal is to hold the same distance between the teeth. Otherwise the retract could block during the movment.
A good compromise should be a rotating angle of 95 deg. (Two deg to match the wheel with the bottom side of the wing, three deg toe-in and 90 deg rotating.)
This results in an angle of 85,5 deg for the gear sector assambly.
Next step is to design a new gear sector assembly under consideration of the dictance and the angle of the teeth.
I'll keep you inform.

Greetings,
Dirk

radfordc

My Feedback: (14)

Let me tell you about my experience with Robart. I bought a set of used retracts that quit working...see post #54 above.

I contacted Robart and described the problem using their website repair form. They advised me to send the gear in for an examination. I did send the gear and waited for over two weeks without hearing from them. Finally, I called them and asked for the status on the repair. Their repair tech, Justin, told me that the gear had been repaired and sent back and that I should receive them soon. They were in my mailbox an hour later. They replaced the control board and two electric motor units. Total charge....zero!

I don't know how it can get better than that.

Charlie

irocbsa

My Feedback: (12)

Wait a minute, did Robart design a set of gear that ROTATES 100 degrees and not EXTENDS 100 degrees. Please tell me I'm reading this wrong.

Chad Veich

My Feedback: (60)

They extend and retract 100 degrees but apparently rotate 102 degrees in the process. Kind of rediculous really.

da Rock

If the amount of rotation was adjustable, the design would show much more understanding than any mfg has shown to date. However, since neither the P40, Hellcat, or Corsair have dihedral that comes close to needing 10degree canted wheels when retracted, the probability is Robart really is clueless.

That is puzzling. And depressing.

And worse, Dirk's picture seems to show more than 10 degrees, although his text suggests he has measured less than the picture shows. So that's puzzling too.

Reini450

Hi Charlie,

I'm glad to hear about your positive experiences. It sounds like an excellent costumer service. Maybe I'll get in the next few days a reply from Robart.

@ da Rock,
here are two picture which hopfully better explain what I mean. 90 deg. + 12 deg = 102 deg.
(Sorry for the pure quality.)



The angle of the outer teeth is 93 deg.



Sorry for the confusion what I caused.

Dirk

stevenmax50

My Feedback: (1)

I just tried to install the retracts advertised by robart and tower as the retracts for the tf giant mustang. As noted by others earlier, an extension is needed to exit the wing to the controller. Kind of ridiculous to need a $5 part to complete a $460 gear.

raptureboy

Dirk, is it possible you don't have the strut inserted correctly? when the gear is mounted and extended are the wheels straight? It would seem very odd indeed that they would design these any different than the 615's. They are basically the same design.

Reini450

Hi raptureboy,

sorry for my late reply.
That the struts are not inserted correctly, was also my first idea.
I've checked it several times before I wrote the post.
When the gear is mounted and extended, the wheels are straigt.
This is my first attempt for my new sideframe.



The blue rounded rectangle are arranged in a new angle to reduce the angle of rotation.

Dirk

RBean

The ARF air gear that came with my Koyosho 90 size Corsair started giving me trouble and the project for which I bought the Robart 810 Electric Rotators is not going to happen, so I installed them in the Corsair. Some modification of the wing was required but not a lot. I took me a while fooling with the control box, plugs, HK sequencer, transmitter etc. Finally got both working correctly. It seems they just barely have enough power to rase the 3.5" wheels and 3/8" diameter Robart Strults. 137mm from pivot point of retract to center of axle. They extend 100 degrees as advertised and rotate 90 degrees as far as I can tell. I have not flown the airplane with this gear as I had to order some special wiring extensions from Robart and am waiting for them to come in. These should have been included with the gear. I'll report back if I ever get airborne.

RBean

An update on the Robart 810 rotating retracts. I got in the wiring extensions and got every thing hooked up. Worked ok on the ground. On the first flight only one gear retracted. Right was still down. I recycled the gear and both retracted. Both extended ok. The landing was ok but not perfect. The gear seemed to hold up ok. On second flight exactly the same. The right gear didn't retract at first but did on the recycle. On the ground the left gear seems to be slow at the start up and them comes to a "hard spot and almost stops but keeps going. Next flight several days later, the same, right gear didn't retract at first but did on recycle. Came down ok. It was gusty and landing was not the best with three bounces, one fairly hard, but no damage that I can tell. Retracts still worked ok on the ground. All this on a grass runway. The plane weights 12.3 lbs and the gear is rated for up to 18 lbs. So the gear work, but one not as good as expected. Maybe it will "ware-in". We will see.

radfordc

My Feedback: (14)

I had basically the same trouble with the Robart electrics....very inconsistent and unreliable. I sold them cheap and went back to something that works.

RBean

I hear you. But if you want this size 100 degree rotators your choices are limited. WingSpan rotators are reported to be weak and a lot of slop. Rated only to 10 lbs I think. Century Jet Rotators have their issues and are only 93 degrees and air although there is an electric conversion available.. That leaves Sierras, which are great but only air, not sure if available for this plane and also expensive. But the Robarts aren't cheap. So I guess I will continue to mess with them. Since the left gear works ok, they should be able to make the right gear work right. I'll communicate with Robart about this and see if the respond.

benjack71

The robart 810 rotating retracts are junk. I bought a set that didn't work, was in a hurry bought another set, same problem. Neither set has made it into a plane..junk. See pictures. As you can see, they attempted to thread soft aluminum, with minimum threading, and used it on a pivoting point that has torque. None of those retracts you see ever made it in a plane, they both did that right out of tha package within three test cycles. Junk. A shame robart put their name on it

RBean

benjack71. I had the same problem. The rear screws at pivot point came out, Actuator rotated extending gear and wrapped wiring around itself and pulled wiring out of actuator. This is the same side that was having trouble retracting. Left side has been ok. Sending back to Robart. We will see what they do.

RBean

Robart returned the repaired retract to me. About two weeks. As far as I can tell, it works fine on the ground. I'll report further after some flights.

dawhale

My Feedback: (20)

Finally. Lets cross our fingers. Wish they were 100 degree.

http://www.horizonhobby.com/60-120-9...tracts-eflg520

RBean

I got one flight on the repaired Robarts. They worked ok. At least once.