Spent more than a few hours wandering thru Amazon's maze of import clone junk. Seems like a dice roll on getting anything useable without buying one of each to see what it truly is. Lots of words in the descriptions but very little REAL information. What I need is 2 units, nonsteering, nonrotating, 1/8" wire (replaceable for custom struts), for a model of @4-5 lbs with B-47 style gear. What's currently on the market that won't fall apart after 3 flights?

I'd rather not go back to gutting big shelf clocks for the gearboxes.

Quote from: Michael LeGate on June 25, 2026, 06:38:21 PM Spent more than a few hours wandering thru Amazon's maze of import clone junk. Seems like a dice roll on getting anything useable without buying one of each to see what it truly is. Lots of words in the descriptions but very little REAL information. What I need is 2 units, nonsteering, nonrotating, 1/8" wire (replaceable for custom struts), for a model of @4-5 lbs with B-47 style gear. What's currently on the market that won't fall apart after 3 flights?

I'd rather not go back to gutting big shelf clocks for the gearboxes.

I have very little experience with electric powered scale CL models.  Most of this experience is just in observing these at the Nats for the past several years and my entry into the RTF CL electric scale activity this past year.

First, in my opinion, the CL environment for expected loads on the landing gear can be safely assumed to be less harsh than their RC counterparts.  In other words, I would think the retract units for a 4 to 5 pound (64 to 80 oz) CL scale model could be handled with a set of retract units intended for a 3 or something less than a 4 pound RC scale design.  There are a plenty of RC retract units available suitable for the 3 - 4 pound RC models as well as for the heavier RC models.

E-Flight has a wide range of retract units for all sizes of models.  These all have built-in servos.  Look at the RTF models from several suppliers.  For what you are looking for, look at the whole range of these scale models with weights around 3 or 4 pounds to the larger models with weights well over 6 pounds.  Most listings will show parts lists for each of these models, including their replacement landing gear units.  I do not have much experience with any of these except with my limited success and others I have observed with models from Flight Line and Durafly that weigh around 42 to 50 oz (before bellcrank/leadouts, tip L/O guide, and outboard tip weight, all flown over smooth pavement.  I have no idea about the longevity of the retracts in these models.  All of these models have their retract units available separately.

I see little need to even consider the pneumatic systems provided by Robart.

You mentioned your model will have B-47 type retracts which I know that they retract forward into their gear bay.  (In other words, they do not rotate on the gear leg axis so the wheels will lie flat in the wing well.)  You might want to consider getting nose gear retract units from any of these suppliers.  It might help structurally in mounting the gear but you will not need the steering capability these gear some time provide.

As you have already found out, there is a lot of "stuff" out there, some of it can be very useful, though some of it - not so much.  In the past, there have been some very elaborate CL scale models with retracts.   With products that are now available, the task of incorporating electric retracts is greatly simplified (without separate motors, separate bellcranks/pushrods and the myriad of things previously needed to get retracts to work).

(I did try to put retracts in a stunt ship in the early 60's with springs, bellcranks and a timer.  Too many ideas that did not work.)

Hope this gives some ideas on where to look for ideas on your scale quest. 

Keith

My experience with retract on a CL model...

If the retract motion is forward/rearward (e.g. your B-47), the typical RC retracts work fine.  And I agree with Keith that you could probable go with a lighter rated version than an RC model, because we try not to land as hard.

If the retract motion is inward/outward (e.g. P-51), it can get tricky because of the side loads involved.  CL model are not rolling in a straight line like an equivalent RC model.  I have seen inboard gear fold when taxiing due to the side loads.  Additionally, I have seen outboard gear fail to retract when flying due to the forces on it.  Granted, many of these were with the old pneumatic systems, but even newer servo driven retracts might be marginal if the servo is weak (plastic gears versus metal gears) or if the retract extention is long (larger moment to move).

So I do not have a complete answer to your question, but look for heavier duty servos with metal gears or direct drive units.  Check out https://motionrc.com/

I currently have several models with retracts. Over the years I have tried these systems:

1) Mechanical - retract servo is used to move the gear
2) Air retracts - you have an air tank that will retract or extend the gear - If your tank/system leaks air then the gear is not moving
3) electric - These have motors built into the retract unit that act like a jack screw

Mechanicals work, these would be my 2nd choice

Air retracts - I don't use these anymore, to many problems that can have land with gear up

electric  retracts - these are my first choice. They plug into the receiver like a servo, behave like a servo and work great. You don't need any other equipment except the retract and the receiver.

I have been using E-Flite retracts but they have been difficult to find lately
Retracts come in a variety styles....
1) angle - 85 degree for wings with dihedral, 90 degree for flat wings
2) pick the size that meets the weight range you model is in. If the retract unit is too small it might not have enough power to right hand gear which is fighting G loads. THe action of flying is pushing the wheel outboard but the retract gear is moving the wheel inboard. The weight of the wheel makes a difference, if it too heavy or big it might not have enough power to pull the wheel put on the right hand wing.

Retractable landing gear is really nice to fly with. Takeoff and then pull up the gear. Then lower the gear and flaps for landing.

Fred

another manufacturer was Robart, they are out of business, I just received my Horizon order for the 90 degree retracts yesterday (google search horizon hobby)

Motion RC also has other brands of retracts that I have not tried yet. Hobby King in the past has had a good selection, but with the market turbulence and shipping problems they are not a good source anymore.

I also like the full metal units mostly for durability. If you have a nose gear on a CL Scale model you can use a main unit since typically you don't steer the nose wheel or tailwheel (it's fixed) on the CL scale model that can taxi on the ground.

Sometimes you need more than 90 degrees to rotate the gear into the nacelle for the main gear on a B-25 bomber for example. I have found 95 degree nose gear units but the 95 or 100 degree main gear retracts have been really hard to find lately. If I was use a nose gear unit I would lock out the steering portion. E-flite does have 95 degree nose gear units last time I looked.

You can use Air retracts if you want, but if you loose air pressure your stuck with what you got when the air pressure goes away.

Fred

 Good design points by all, thank you. I've narrowed it down to wanting 2 mechanical units powered by a strong servo.  Haven't seen any inexpensive electricals (less than $100 a unit) that weren't cheap plastic with questionable quality electronics. The plane is about the same size /config as the B-47D from the '60's MAN plans minus @9" of wing on each side. @ 200 sq ins so It's gonna land FAST. Probably have to build my own but will be much easier with the Linemaster  handle doing the dirty work instead of a rube goldberg mishmash of microswitches. Pneumatics...nope not goin' there.

Quote from: Michael LeGate on June 29, 2026, 05:36:25 PMGood design points by all, thank you. I've narrowed it down to wanting 2 mechanical units powered by a strong servo.  Haven't seen any inexpensive electricals (less than $100 a unit) that weren't cheap plastic with questionable quality electronics. The plane is about the same size /config as the B-47D from the '60's MAN plans minus @9" of wing on each side. @ 200 sq ins so It's gonna land FAST. Probably have to build my own but will be much easier with the Linemaster  handle doing the dirty work instead of a rube goldberg mishmash of microswitches. Pneumatics...nope not goin' there.

Are you using the B-47D plans from Model Airplane News?  Why remove 9" of wing each side?  I built a smaller version of the B-47D for profile scale with two Norvell .049 engines with throttles.  A bit less than 200 sq in, 36" span.  It flies quite well.  Placed 3rd at the 2000 Nats in Profile Scale.  Lands quite nicely.  In fact, when throttled down, the thing floated in ground effects and it did not want to land.  Also flew it successfully in Mike Keville's 1/2A multi-engine 1/2 A Scale contests in Tucson more than 10 years ago.

The outrigger wheels on the outboard nacelles were effective.  A retract main gear should not be too much of a problem.  At the scale I had, retracting the small outriggers in the two inboard engine nacelles amid the throttle linkages would have been a bit of a problem.

Keith

Subject aircraft is a little more obscure than the B-47D. The gear, fuselage size, tail area, general moments are similar, the wing is tiny. The outriggers are small enough to be eaten up and forgotten by the fun scale rules

Quote from: Michael LeGate on June 30, 2026, 02:06:17 AMSubject aircraft is a little more obscure than the B-47D. The gear, fuselage size, tail area, general moments are similar, the wing is tiny. The outriggers are small enough to be eaten up and forgotten by the fun scale rules

Looks interesting.  When reading about XB-51, it states:
The main landing gear consisted of dual wheel sets in tandem in the fuselage, similar to the Boeing B-47 Stratojet, with outrigger wheels at the wingtips. 

Quote from: Pete Bauer on June 30, 2026, 10:11:29 AMLooks interesting. When reading about XB-51, it states: The main landing gear consisted of dual wheel sets in tandem in the fuselage, similar to the Boeing B-47 Stratojet, with outrigger wheels at the wingtips.

I can see the logic in this. By doing this then the stresses of landing are absorbed by the fuselage and not the wing truss through the fuselage and spars. Designed with the ability to carry a heavy load, ordinance and fuel.

Looks almost like a missile with wings. Seems they were shooting for the same type performance as the B-1B, said to do at least 100 knots faster flying nap of the earth versus the venerable B-52. The experiments with the B-58 was said to have such faster speeds doing nap of the earth.

Seems as a C/L model, doing a basis by features theme rather than pure scale one could come up with an interesting unique looking stunter.

Quote from: GallopingGhostler on June 30, 2026, 06:14:36 PMSeems as a C/L model, doing a basis by features theme rather than pure scale one could come up with an interesting unique looking stunter.

The 51 just doesn't have enough wing. Even cheating the wing area up by 50% you'd probably only get a sloppy wingover with 30'R corners. I'd rather get the wheels up and give it the missile persona than do stunts with what looks like a flying dump truck. It's pretty fugly wheels down.

Choose this to do in fun scale cause lack of fowler flaps, retractable outriggers would be a killer in sport scale.

Quote from: Michael LeGate on June 30, 2026, 02:06:17 AMSubject aircraft is a little more obscure than the B-47D. The gear, fuselage size, tail area, general moments are similar, the wing is tiny. The outriggers are small enough to be eaten up and forgotten by the fun scale rules

So, are you going to use ducted fans?  At least the XB-47D had props and made it fairly easy to make it a reasonable airplane to power and fly.

Keith

Quote from: Trostle on June 30, 2026, 08:51:48 PMSo, are you going to use ducted fans?  At least the XB-47D had props and made it fairly easy to make it a reasonable airplane to power and fly.

Keith

Going old school, Fox 36r/c, just enough room for an 8" prop with a 2" spinner. The 2 jet engine pods are only 1.63" in dia and too low to put props on. This was where my muffler question from a couple of weeks ago came in. The stock fox tilt muffler looked almost like a third woebegone engine pod.

Quote from: Michael LeGate on June 30, 2026, 09:09:50 PMGoing old school, Fox 36r/c, just enough room for an 8" prop with a 2" spinner. The 2 jet engine pods are only 1.63" in dia and too low to put props on. This was where my muffler question from a couple of weeks ago came in. The stock fox tilt muffler looked almost like a third woebegone engine pod.

Looking forward to seeing picture as you progress the build

Scored a trike set from Goodwill this afternoon. 10$. Nose strut and one main strut are missing. Remaining strut is slightly bigger than 1/8". They are clean, don't appear to be used. The security sticker wrapped around the cases says 2009 Horizon Hobbies. They look very fragile. Gotta dissect one to see how it works/if I can use it.

There are A LOT of modular RC retracts on the market.  No engineering required.  Just install the unit and plug the wire into your receiver. I am of the opinion that circular flight of our models in the wind puts more stress on the landing gear than into-the-wind RC.

The remaining challenge is to select a subject that fits the menu of RC retracts. 

Ok, I've had time to play with the units. The larger strut size indicates these are .25-.45 sized. They all cycle properly. The set screws on the mains were trashed, they were tiny!!! Theres enough meat on the blocks to tap 'em out for larger set screws. The geometry is all wrong for the project if flush mounted as they were designed for. Can make 'em work with a firewall type install and some oddly shaped struts. The photo shows one of the mains (.9 oz), vs an early 60's relic (4.8 oz). .049 for size reference. Well spent $10 so far.

For your consideration "free" - A brand new set of Posi-trac units. I'm in Canada, so you'd have to pay the postage + $10.00 for delivery to the post office as I live in the country.

Thanks for the offer Dennis. I think I'm good to go with the ones I've got. If you list all the dimensions of your units someone else might jump on 'em.

The workshop is starting to cool off a little in late evenings. Can't build in 120 degree heat.

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