smcouch77

What are the pros and cons with retracts. Any preferences?
Steve

abufletcher

As a WWI fan, I obviously don't know much about retracts. But I would think the most important questions for competition is "which allows a more scale presentation?"

smcouch77

Watching video of B25s, the gear moves slow and smooth. Also, the main doors open to lower the gear and then close, leaving a small door open for the leg. the small leg door is linked to the leg, but the main doors open and close independently. I hope I can keep that in order!
Steve

TFF

Mechanical has to have the linkages perfect, if servo driven, to prevent hangups. Air has the more flexible mounting. Their are electronic and air sequencers that can mimic the real things.

dhal22

Spring Air and others have pneumatic retracts that spring down and lock in place if you lose air pressure.

abufletcher

How do you work retracts on a CL model anyway?

vertical grimmace

My Feedback: (1)

One thing i will recommend is do not get cheap with them. Buy the best that you can afford. I went the cheap route on a 1\4 scale Mig 3 and I have since paid for the better retracts in damage and lost props. I think generally the pneumatics are better. If you have a servo stall with mechanicals it can drain the battery fast. So, if you go the mechanical way, you should use a seperate battery and switch to power those servos independantly.
It would be nice if Lado would really get their act together as that seems to be a great system. They use a slow moving selenoid basically that is integral with the retract unit.
Still, it seems Sierra is the best out there but they are pricey and you may have to wait. Such is our lot with this hobby.
What airplane, size are you looking for? That will weigh heavy on your decision. Regardless, retracts are expensive.

Boomerang1

I have used both types. Pneumatic retracts tend to be hard to control speed, they seem happiest when they can thump up & down & can get touchy when slowed down with restrictors. Sequencing can be arranged with either seperate valves driven by other servos or electronic programmable sequencers. Electronic sequencers are mainly aimed at the jet flyers & everything for jets is expensive.

The mechanical retracts I use are cheap Hobbyco units from Tower. Originally I used an Ace 'servomaster' gadget which controlled sequencing & speed. This did not last very long at all. Currently I'm using a cheap, 2 channel servo slowing device I bought at the local hobby shop & I sequence the doors manually.

I use a large Royal servo to drive the main gear, a standard Hitec for the nose wheels & a mini servo for the doors. VG makes a good point about gear problems draining the radio battery, I use a simple voltage regulator from the flight batteries to drive the gear & keep everything seperate from the radio battery. Take a look how it has worked for 13 years & hundreds of flights. - John.

http://www.rcuvideos.com/video/Elect...ery-loading-un

BobH

My Feedback: (2)

Steve you didn't say what plane you plan to use the retracts on, that makes a difference. I've used both and prefer (by a wide margin) pneumatic.
You can slow them down using the right type of air valve. You can even have one leg faster/slower than the other if you prefer.
Two important features favor the pneumatic types: 1 is ease of installation. Plumbing isn't to critical with air lines. You just need to keep the air hoses free of pinching. Two is the ability to lift heavy wheels/struts. This may matter depending on the size of plane etc.

Likes line is an electric retract that will lift large wheels.
Hank Likes
The Likes Line
PH:1-717-732-0636

smcouch77

The retracts are for a B25 with an 84" span. The mains are 4" and the nose is 2 3/4". They need to sequence just like John's B36.(Sweeeeeet!!)
There are two ways to operate functions on a control line model. The old way is to have extra lines. The new way uses an electronic setup that works like a radio except that the signal is sent along the lines instead of radio waves. It uses the same systems as R/C to control all functions except elevator control. That has to be mechanically linked to the handle.
Steve

rc34074

My Feedback: (5)

I have tried mechanical and air (pneumatic) retracts. the biggest problems seem to be in the 40 and 60 size retracts where people want to buy dirt cheap retracts.

The Robart 600 series mechanicals have very weak plastic frames- avoid them like the plague. for some reason top flite still recommends these on their planes. i think if you fly at a paved runway they can be made to work but for the majority of pilots who fly at a typical grass strip or one that is not graded and rolled they will give you lots of problems. Anmother problem area is rotating retracts that are used on corsairs, p40s, hellcats, etc. Robarts rotating retracts are weak here as well.

My favorite retract is the air operated retracts that retract using air and extend using springs inside the air cylinders. these are made by Spring Air and now by Robart as well. Spring air had a patent on this design so for a number of years Robart could not make retracts using this approach, but a ferw years ago the patent expired so Robart started making this style retract. Spring Air has retracts for 40 size and up planes using this approach. www.retracts.com is their web site. Robart has two series of retracts with this design - a 500 series and a 700 series of retracts.

Some people like Lado retracts which have electric motors built into the retract. this line seems to be limited in the versions you can get but get good comments from some modelers. Likes Line also sells electric powered retracts but since they don't seem to have a web site (at least I haven't found it) they are a bit harder to find and talk with. I have some of their oleo struts which are machined from aluminum and are strong and look great on my 60 size Mustang

Most of the retracts for giant scale operate using air up and down designs. Robart makes good retracts except for some reason their retracts for the Top flite 85 inch Mustang and the new Top flite 85 inch P47 Thunderbolt are designed using a plastic piece that is weak. Sierrs Giant Scale has designed a replacement part for the Robart retracts which makes them much more robust. Spring Air has very good reacts for giant scale planes too - their 400 series.

The best/most scale retracts for giant scale are made by Sierra Giant Scale and Shindin Machine. thye cost more but if you want strong retracts they make great units. Sierra has a great set of rotating retracts for 60 size planes.

Ed

tevans55

smcouch77-
I have used both mechanical and air and have replaced all of the mechanical with air. I have found that the air retracts are typically a little more robust (which is very important to me) and I like scale working oleos. I have replaced everything with Century Jet retracts in a B-25, Spitfire, and a Corsair. Have had no gear failures in the last three years. Robart and Sierra also make nice gear. I like the all metal feature of Century Jet with a more affordable price. CJ also has a huge selection of gear and when I made my KMP SPitfire they did not have these in their stable so I took my wing to their factory and they made the gear for this plane.

Good Luck with your search!

KitBuilder

How come there are no electric retracts....seems like the way to go.

tevans55

http://www.lado-tech.net/

frager14

Has anyone tried the electric retracts that Mike is talking about? I am considering putting either them or pneumatic robarts in my Top Flight P-47. They seem like the way to go if they are reliable because you don't have to worry about pumping air into the tank or installing all of the hoses and linkages and such.

dhal22

there is a huge thread on lado retracts in the warbird forum.

crasher1

My Feedback: (31)

Down & Locked make the BEST conversion , a bit pricy, I have them on my Giant Scale P-47, these are screw type and are amazing...