Jack Devine

My Feedback: (6)

I have used the Robart gear with good success on two Top Flight Corsairs and a Top Flight P-40. It has been mentioned before but I think it's important to realize that a few things are critical to this type of gear. One is the mount has to be perfectly parallel so the retract unit can be screwed down tight with no binding. If your gear binds a bit or slams up and down loosen the mount screws up and see it that problem goes away. If it does there is an issue with your mounting rails that you have to deal with. Mounting the rails to the gear and then epoxying them in might help but it could also be a pain trying to keep everything alligned while the epoxycures. Next with the gear down and locked the axle on the wheel needs to be parallel with the leading edge of the wing or you take away the ability of the oleo strut to deal with the shock loads induced on landing. The idea of the oloe is to let the spring in it absorb the landing load rather than the strut bars. The further the wheel axle is behind the leading edge the more shock load is transfered directly to the parts that you are seeing bend. All of these gear should be set up if you are using struts to be slightly toe-in. As the landing loads are induced your gear will toe out and the idea is to have that toe out movement bring the gear to a zero toe setting as it absorbs the landing load. Your plane will taxi better if you have the toe-in as well. As the struts age the toe factor will get amplified because the scissor on the strut will wear and it will allow a greater toe angle change on landing. Toe out is a wreck because it causes an instant bind the second the wheels tough the ground. Last but certainly not least is the two set screws that secure the landing gear wire to the retract "duck foot". You have to use the wire wether you use the oleo strut or not and just tightening the little set screws won't keep the wire tight. If the wire turns inside the "duck foot" the toe angle changes dramatically and that is a BAD thing. You need to remove the strut wire and grind the flats in the area where the two allen set screws contact it. Once you remove the wire you will see the little marks left on the wire by the allen screws. Grind a small flat on the strut wire to match those marks and reinstall it and now that wire will stay put and prevent the toe changes that occur when that wire rotates.
It is a bit of extra work to do all of this but it makes these gear work and that's what is important. I'm satisfied with my Robart gear.

Jack Devine

GalenC

tkaris
My gear have had the gear jump out occasionaly but what really seems to cause it is the tiny bolt and tap at the 90 degree bend of the arms. The tap has a shoulder which must fit through both the arms and the frame. If this is loose, and it will work loose. the gear will pop out of the frame. I put loc-tight on the little bolt to cure this, but won't make it much fun next time it has to come apart. Hope this helps. GalenC

rusgmil

My Feedback: (1)

I totally agree with "scale for me" comments. I've had these retracts in a TF P40 and now have them in a Wing Hellcat and a TF Corsair. I also use the Robo Struts. The only problem I have had was 2 or 3 times the wire going into the Robo Strut has bent a little on a bad landing. I consider this the "weak link ". And I fly off not so smooth grass.
You have to glue the mounting rails in with the gear attached or your asking for trouble. The side rails appear to be stamped metal and will distort if the rails aren't parallel and will bind the rotation. Before installation, hold the retracts by the rails ( with the wheel and/or Robo Strut) and the gear. It should almost drop and lock in place. If not, its time to find out why in the shop. And after installation the gear should also almost drop and lock in place with the air lines disconnected.

rusgmil

My Feedback: (1)

Also, the allen set screws that come with the Robo Struts (and most other accessories) are to short. Go to to Ace or any other large hardware store and purchase longer set screws. They will also have deeper slots for the allen wrench and don't strip flats on the wrench or inside the screw.
I think the 615 are as good as any other brand retract. And any retract will not hold up under a bad landing.

Jack Devine

My Feedback: (6)

Galen: When ever you use Locktite to set a screw or bolt that has to stay tight and for some reason you later need to remove the screw or bolt, take a good heavy duty soldering gun and heat the fastener. The heat softens the locktight and the fastener comes right out. I have used this many times and it works very well. Just a little info that can keep you from stripping or worse yet breaking off a fastner that was installed with Locktite.

Jack Devine

daw

My Feedback: (6)

Just had my first two landings with the Corsair. UGLY, SCARY but no damage. Believe me these landings tested the retracts and they did their job better than the pilot. Both landings had a lot to be improved upon but the retracts held up. One landing caused one retract to spin 180 degrees on the cammed gear (not tight enough) still did not fold. After tightening second flight came in just as ugly but no damage except to my pride. An experienced warbird pilot was talking me in and stressed landing on the mains then rolling the speed off until the tail drops. Just a reverse of the take-off. The plane can't drop or stall in, it must fly in then slow down. I've witnessed many landings done in this fashion without any problems. Hope my luck holds out until I train my thumbs to do what my brain tells them. Maybe my problem is the plane looks so good I just want to look at it and I forget I'm flying it

SMALLFLY-

My Feedback: (19)

The most important thing on curing my problems was throwing away all thse tiny allen set screws and going to home depot and getting 1/4" long replacements. You can actually torque on those without stripping your allen wrench almost immediately. that and the struts have solved my problems with the 615's. I am guessing your retract is not actually jumping a tooth ( I have pounded on mine and they have never budged) but your wire is slipping and it rotates in relation to the the teeth. Then again maybe not. It seems like with these retracts you just have to keep working at it until you hit the magic formula

redxfred

My Feedback: (3)

This has almost become a P-40 thread which is great because my winter project is the Top Flite .60 size model. The Robart info is invaluable! Has anyone encountered any other major "Do's & Don't's" while building this kit? I have ALL the accessories recommended by Top Flite and plan to use the OS 1.20 w/pump. (Don't try to talk me out of it. I already have the mount!).

I want to try pull-pull connections for weight savings. Has anyone tried it?

Here's a picture from "Bomber Field" in Texas. I can't find any info on the manufacturer or builder but it is absolutely extraordinary in this photo!

CITYPICKLE

A member of our club reworks robart retracts. I baught a set of 85* rotating . They have the heavy struts not the cheap wire with heavy shocks. You will tear the muunts from the wings before you damage the gear
Call Ray Lightfoot He sells stock& custom shock absorbing gear for1/8 to1/4 scale aircraft
phone # 864/886-0095 E-maill [email protected]
LITE-FLYTE PRODUCTS

LQUAN

My Feedback: (17)

Hi all with Robart 615 retract problem,

I just went to www.morrishobbies.com saw that VQ has come out with his new 60 size P-40 (63") early this year. He also has custom rotating retracts on this bird. I am trying to get some information on these VQ retracts from Morris Hobbies via email. From the looks of some of the pictures, they seem to be sturdier retracts than Robart 615. They have a dedicated arm to rotate the retracts; just like on the real P-40s. There is one thing that I don't know about the VQ rotating retracts is that do they swing out 100 degree or 90 degree. I am very interrested in using a set of these on my Top Flite P-40E if they are 100deg rotating retracts.

If anyone has specs on these retracts, please post it here. Thanks.

ganu

interested in what you find out.

LQUAN

My Feedback: (17)

Hi ganu,

I have sent them several emails, but they never respond.

Peter_OZ

My Feedback: (1)

agree these 615s are pretty ordinary and really do robart an injustice as 99% of robart gear is excellent.

I have them in my TF P40 and yes have had a few probs with them. In fact I complined to Tower about my first set and they replaced them, no charge including shipping to australia so thank you Tower! They would toe in and occasionally jump a tooth on the rotation cog.

On the set that I currently use I have robostruts and secure them with 4 grub screws to stop toe in. I have also paid a lot of attention to he mount rails so there is no binding at all.

I fly off grass and have had a few heavy landing and so far it has soaked it all up with no probs.

when somebody can offer a better product at the right place, with firm delivery dates and I do not have to change all my mounts around to suit then I will go that road, till then I'm sticking with the robarts


cheers
Peter

Hellcat716

My Feedback: (2)

The retracts on the VQ Models P-40 are junk.

LDM

My Feedback: (15)

Vq has pulled the Gear from there P40 do to problems, they will release the plane in April without gear . I have the Robart and Century , Century is the way to go .

manetta23

Hello  guys and I would like to know  what can be a nice set ot landing retract for my nasty p51 mustang  wingspan 57 length 51  thanks

Antoinebobrob

I just orderd these retracts on tower hobbies! I hope they will work well. I am using them on my topflite p40. I am planning to use the O.S 120 w/pump and it will wiegh 11 pounds. I hope everything goes well. If they dont i will purchase the sierra retracts.

scottrc

Read the post by Jack Devine and follow those instructions and you should be fine.

I have had a set I have used in two Corsairs and this same set is going into a third this winter. As long as they are set up and maintained they work fine. Flying and making good landings is the hard part