HobbyKing.com New Products Flash Sale
Reply
Thread Tools
This thread is privately moderated by SkylineFlyer, who may elect to delete unwanted replies.
Old Mar 22, 2011, 02:49 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Quote:
Originally Posted by firehawkzach View Post
I am looking for a set of electric retracts that will support an 8-9lb F-18 that is fiberglass. I saw on the first page of this thread that E-flite makes some but I was wondering if anyone has had experience with others?
These are well reported. RCLANDER All Metal Etract

Talk to Sonic Electric and see if you can get the Mig17 mains and rotational parts with the T-45 Nose strut if the T-45 mains don't look right.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 24, 2011, 12:15 AM
Registered User
firehawkzach's Avatar
United States, TX, Fort Worth
Joined Jan 2011
1,143 Posts
Going with the RC lander dual leg all metal retracts.
firehawkzach is offline Find More Posts by firehawkzach
Reply With Quote
Old Mar 29, 2011, 09:53 AM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
I found a potential flaw with the 46 size E-Flight retracts. The retracts were fitted in a TopGun L39 foam airplane with TamJet struts. The plane went off the runway into some brush, at a very low speed. The nose gear is the weak link in the setup.

Two problems with the gear, one makes it fatal and trash.

1. The trunnion is made from soft Aluminum, a sharp jolt will cause it stretch, hence you now have a gear that wobbles back and forth 1/16 of an inch. Not a deal killer as there is slop in many types of nose gear. This slop can easily be fixed by disassembly of the frame, then using the gentle pressure of a vice to fix the stretched trunnion.

2. The gear operates by a small geared motor that operates a screw drive. The shaft for the drive is press fitted into a gear in the tiny transmission. A jolt will pull the drive out of the gear and it will just spin without working the retract. This can be easily fixed by disassembly of the frame, then tapping the drive shaft back into position. However, this fix will not work for long. Once that drive shaft gets pulled out, it will not stay in place when re-installed. It will appear to be strong, however the slightest tap on the strut will dislodge it again.

Al
SCALEFAN is offline Find More Posts by SCALEFAN
Reply With Quote
Old Mar 29, 2011, 01:10 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Quote:
Originally Posted by SCALEFAN View Post
I found a potential flaw with the 46 size E-Flight retracts. The retracts were fitted in a TopGun L39 foam airplane with TamJet struts. The plane went off the runway into some brush, at a very low speed. The nose gear is the weak link in the setup.

Two problems with the gear, one makes it fatal and trash.

1. The trunnion is made from soft Aluminum, a sharp jolt will cause it stretch, hence you now have a gear that wobbles back and forth 1/16 of an inch. Not a deal killer as there is slop in many types of nose gear. This slop can easily be fixed by disassembly of the frame, then using the gentle pressure of a vice to fix the stretched trunnion.

2. The gear operates by a small geared motor that operates a screw drive. The shaft for the drive is press fitted into a gear in the tiny transmission. A jolt will pull the drive out of the gear and it will just spin without working the retract. This can be easily fixed by disassembly of the frame, then tapping the drive shaft back into position. However, this fix will not work for long. Once that drive shaft gets pulled out, it will not stay in place when re-installed. It will appear to be strong, however the slightest tap on the strut will dislodge it again.

Al
Could you post some pics of it disassembled.
While I'm suprised you had a failure on a 4Kg rated etract on a 1.7Kg plane, if its a press lock method, I'd have to agree with you.

IMO All that most of these need is flatter tips on the trunnions end points and the worm gear block to be thicker so that all the trunnion rotational force is driven into the block and the slots that it travels on. A larger trunnion axle would also help.

A lot of the mechanical and air retracts are already designed this way and the Lado actuators take full advanatage of that where they add only the worm gear actuator to replace the air piston.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Old Mar 29, 2011, 04:25 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
I will try to fetch it out of the trash and take a picture.

I became an unofficial expert as I have attempted to fix this no less than 10 times, disassembly and then in and out of the airplane. I was very resistant to spending another $89 bucks for a replacement nose gear from Horizon Hobby. I even tried CA, but the transmission part of the motor is like working on a tiny wrist watch gear set. There is no way to get the tiny needle shaft back in with CA on the tip.
SCALEFAN is offline Find More Posts by SCALEFAN
Reply With Quote
Old Mar 29, 2011, 05:06 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Those gears shouldn't see any load. Thats why they get away with such a tiny geared motor is because the only load it faces is to transition the trunnion. Impact load should go to the trunnion, frame and transition block. The only time its otherwise is if you apply impact load while its in transition in which case you have other pressing issues.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Old Mar 29, 2011, 07:06 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
Only the tip of the shaft is pressed in. The wider part passes through a guide and the pin finds a smaller gear way back in.

Al
SCALEFAN is offline Find More Posts by SCALEFAN
Reply With Quote
Old Mar 29, 2011, 09:34 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Well now that's not pretty. The trunnion geometry is a little different on this one. I see how during transition that this could yank the worm gear out of the gear train if it saw any force.

But if it reaches the end lock points the rotational force from the trunnion is perpendicular to the slots lock point. So I'm having a hard time seeing how force gets translated to the worm gear in the lock points. Unless the slot tolerance allows for some play. That would allow force to the worm gear and snap the gear train.

Thanks for the pics though. I take it HH isn't helping you with parts?
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Old Mar 30, 2011, 07:21 AM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
Max,

I take the easy way out, I ordered a new nose gear, it's been installed in less than 3 minutes, the plane will fly again this weekend. Work pressure is keeping me awake tonight and after a glass of wine, I had this awful thought.

What if the shaft is not press fitted? What if it snapped? What if my pressing it back in simply made it catch on the broken part?

Do you know what than means? It means finding the transmission in the trash, the trash full of garbage, mixing cups, spoons, Popsicle sticks, empty Hysol cartridges, scrap wood, plastic residua from canopy cutting, rotten oranges from our tree and torn pages from the AMA magazine.

IT MEANS PUTTING ON MY GLASSES AND TAKING APART THE GEARS IN THIS WATCH SIZE TRANSMISSION IN ORDER TO GET TO THE BOTTOM OF THE FAILURE.
SCALEFAN is offline Find More Posts by SCALEFAN
Reply With Quote
Old Apr 01, 2011, 02:10 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,246 Posts
Second time around with a new 46 size Eflight nose gear.

One minor skip on landing, 6lb foamy L39, the trunnion spread and now there is forward and backward wobble. The trunnion is made from too soft Aluminum and I will talk to Horizon about this.
SCALEFAN is offline Find More Posts by SCALEFAN
Reply With Quote
Old Apr 01, 2011, 06:41 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Quote:
Originally Posted by SCALEFAN View Post
Second time around with a new 46 size Eflight nose gear.

One minor skip on landing, 6lb foamy L39, the trunnion spread and now there is forward and backward wobble. The trunnion is made from too soft Aluminum and I will talk to Horizon about this.
And if it gets loose this puts all the force to the worm gear which its not made to with stand any major impact.

Well, thanks for the info.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Old Apr 05, 2011, 11:29 AM
I make bad look so good.
SteveC68's Avatar
League City, Texas
Joined Sep 2006
2,564 Posts
Which are the better of these two?

http://www.hobbyking.com/hobbyking/s...dProduct=12883

or these?

http://www.hobbyking.com/hobbyking/s...dProduct=11301

Also what do these weigh?
SteveC68 is online now Find More Posts by SteveC68
Reply With Quote
Old Apr 05, 2011, 09:58 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Quote:
Originally Posted by SteveC68 View Post
Which are the better of these two?

http://www.hobbyking.com/hobbyking/s...dProduct=12883

or these?

http://www.hobbyking.com/hobbyking/s...dProduct=11301

Also what do these weigh?
Here's a best guess.
Haven't tried the HK version made in copies of the ChangeSuns. If they have the metal trunnion go with those, the second link. If they are the plastic trunnion go with the PZ15090s or the first link.

The CSs 34g have a lower profile and I prefer them to the PZs 37g because of the trunnion shape.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Old Apr 06, 2011, 09:24 AM
Split S
TimJohnson's Avatar
United States, CA, Rancho Santa Margarita
Joined Jul 2006
2,043 Posts
Check out Wing Span Retracts. I ran in to them at the Toledo hobby show. Their web site is www.wingspanretracts.com . They have several different sizes.
TimJohnson is offline Find More Posts by TimJohnson
Reply With Quote
Old Apr 06, 2011, 12:14 PM
You are a "go" for reentry
Maxthrottle's Avatar
High Orbit.....
Joined Jun 2009
6,685 Posts
Quote:
Originally Posted by TimJohnson View Post
Check out Wing Span Retracts. I ran in to them at the Toledo hobby show. Their web site is www.wingspanretracts.com . They have several different sizes.
How do they work though. They look similar in concept to Lado. Same price too.
Maxthrottle is online now Find More Posts by Maxthrottle
RCG Plus Member
Latest blog entry: Freewing 90mm F-16C
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Data Comprehensive List of Batteries, Chargers, Motors, ESC, Gyros, etc. w/ Specifications write2dgray Batteries and Chargers 408 May 15, 2014 12:56 PM
Discussion PLEASE HELP- Wher to list Dumas Star 45 for sale on Long Island LCS Sailboats 1 Jul 02, 2010 08:04 AM
Data What pack should I get? An updated comprehensive list Vaffel Batteries and Chargers 20 Feb 10, 2010 07:30 AM
Comprehensive Gearbox List valkyrie83 Power Systems 0 Sep 02, 2004 02:09 PM