tim thompson

I have century jet retracts and want to put gear doors on. the problem is they will not be flush or scale. I wonder if the slipstream will do funky things to the airflow. Is the tf giant 47 made the same way or are the gear in a scale manner

tim thompson

hello can anyone give me some input?

Skypoint

My Feedback: (7)

Hi Tim,

I am in the finishing stages of my TF P-47. I don't have CJ's, but I have Robarts with the same problem. I think I could get the doors on if I didn't use struts, but even then there's not much room, and the robarts have too much slop in them to stay completely closed anyway.

I would think that you'll have some adverse affect if you use doors that don't close all the way, even if it's just drag.

I've decided to use the doors for static only and avoid the headaches.

rustyrivet

My Feedback: (6)

Skypoint,

The origional set of struts would not fully fit in the wheel well. About 9 months ago Robart fixed the probem. There were plenty of these old style retracts floating around out there though, and you obviously have this type. You can send off to Robart, and for about $40 get the newer replacement struts that will permit the door to fit flush to the wing. But I think you will have to set the entire gear lower. See Top Flite's TOPA0415 Technical Notice on their web site for details.
Tim has Century Jets, so perhaps his will never fullt retract inside the wing. Perhaps Tim could call Top Flite's Tech Support and ask about air turbulance if nobody else here knows. Being the old style retracts didn't close fully anyway, I don't think this woud be a real concern.

Skypoint

My Feedback: (7)

Randall,

Thanks for the tip! :thumbup:

tim thompson

Since the doors stick out from the bottom of the wing I really think airflow would be disturbed. I need to know if the tf giant scale has SCALE gear retraction, what retracts to use.

Tim 989 797-3645

warbirdz1

Tim....As I recall the P-47 had a strut compressing actuator to allow the gear to fit in the wheel well.....I.E. reason for 2-piece outer doors to allow for strut compression.......I have the "Z" P-47 and want to put the strut/wheel doors on as well...with same problems....I'm thinking to try just a strut door first and see how that goes.....then maybe see what can be done for the lower door............I know several guys have tried various door arrangements and they impeded gear retraction.....Bill........

Steve Collins

My Feedback: (8)

Sure, there is bound to be some drag but it would be a whole lot less than the same plane with fixed gear. Just from a drag or airflow situation, I do not think that flying characteristics would be degraded at all.

I have a similar situation with my Hangar9 P-51. I have not seen any negative aspect of the door not being exactly flush other than a little drag.

You might try to mold a gear door with some slight curvature to it such that the leading and trailing edges of the door would at least be even with the wing skin.

smchale

My Feedback: (67)

I've ran into this before on some models (not on a P-47) and it really didn't effect the air flow. It did however make a really neat whistling sound on flybys.

If you are going to use doors on the wing and on the leg perhaps you could put a slight bend in them or a blister to cover the legs. It may not be too noticable.

tim thompson

I think ill leave them bare until I maiden her this spring. Then after I get a feel for the handling i will experiment. Does anyone know if the giant scale p-47 by tf has scale retaction or is it done on the le like the 60 size?

Tim

heavy date-RCU

Scale retraction would be pretty tough on the P-47 as the gear struts compress 8 inches on the way up. Not a real easy thing to do with what we have to work with.

I think at one time someone made a scale set for the F-8-F Bearcat It's gear also compresses on the way up so they will fit in the wing.
Hans

chipmunkflyer

Sierra Precision makes a set of gear that has the compression bar on it. It is only for the larger size ships... Ziroli, maybe a giant Top Flite... but it is about twice the cost of the Robarts (about $500!). I'm in the process of building the TF giant P-47, and I have the newer Robarts... I'm going to try gear doors that stay on the plane in flight. If I have good success flying this bird I may try and add the inner doors as well. I don't want to go to the extra work and expense before flight testing. Both the fuse and wing are built now, soon I'll be fiberglassing!

Sonny

tim thompson

I agree, i will see about doors after we fly. With all the bad press on cj I will see if they hold up. So far the work great and withstood a drop test of 1 foot with no problems

Tim

AirRayInc

My Feedback: (7)

Tim,
I have flown with gear struts and tires in the slipstream as well in the past. No real ill affects in the air.

http://hvnmodels.com/hvn_page_4.htm

There are some assorted Jugs built by a friend of mine, (Henry) all with CJ retracts.

Ray

JL1

My Feedback: (93)

The F8F gear actually folds up. There is a joint about 3/4 of the way up the strut.

chines

My Feedback: (2)

The entire gear, wheel and mechanism are fully within
the wing, except for that portion of the strut that bends out and
around the wheel, which protrudes something like 1/4". To get the
strut completely inside the wing, it would have required thickening the
wing or placing the wheel right where the spar is. Both of these
alternatives would have been costly and the second would have added
much complexity. Robart now offers an optional specialized strut
which we do not carry. Call Robart directly to order.
http://www.top-flite.com/techsupport TOPA0415tech.html includes data
on installing functional gear doors.

ramcfarland

My Feedback: (44)

Hey Sean-
So thats where that neat whistling sound comes from on my 1/7 scale 47- I "molded the main gear doors leading edge with a bit of a curve,which matches the under side of the wing.