A few years ago I bought a set of Robart air-up/spring-down retracts to replace my aging Rom Air set. I recently installed them in my Escape and was dismayed to find that although they would go up just fine, they would not extend and lock. The springs appear to be too weak the fully extend the gear and engage the lock. Have any of you had this problem? Are the Spring Air gear a better choice, i.e., do they extend and lock reliably? If so, which Spring-Air set would you use on a classic pattern plane such as the Escape. By the way, in the end I did use my Rom set, but with a new Robart actuating valve. But I'm still chasing down leaks.

Jeff

Sping airs are always dead reliable. I have heard of other folks saying that the Robart spring downs are not too good. I have a set and they seem to work decent on the bench, but we will see.

I have no experience with the Robarts, however, my Spring-Airs will extend (go down and lock) when inverted (against gravity). They get my vote. In fact, I just bought a set for my P-7.

This is only a guess, but I suspect that the Robarts are a cheap off-shore knock off of the Made in USA Spring-Airs. Flame suit on.

Might want to check this thread out Jeff.

http://www.rcuniverse.com/forum/m_93..._1/key_/tm.htm

Spring Air’s are my choice for air retracts, more specifically
the 300 series due to the low profile design. Rock Solid

Thanks for the thread, Paul. Sounds like Ralph had exactly my problem. I'll look into the Spring Airs.

Jeff

Not unusual when one company tries to copy a neat idea from another company that they get it so wrong! Always thought it was tacky of Robart to try that even if they got it wrong.

Jeff,
Lil Dave and I both have Spring air and Robart in our Classic pattern planes and they work everytime !! Lil Dave has a set of spring air in his arrow and I have a set of Robart in my Tipo. Both set's air up spring down and work great !!
I hope you will be able to fly with us at the Auburn contest June 11 &12th I'm sure that Escape will do the job !!
Dave P......

After installing the Robart nose gear that they converted from air up/spring down to air up/air down it worked fine for 4 flights. Then it started leaking air. I called robart and they repaired the nose unit (for about $15.00).

But I never installed the unit back in my Saturn classic pattern ship. Instead I ordered a set of the SpringAir retracts (Series 100). I installed the SpringAir nose unit in the Saturn and left the Robart mains in the Saturn.

The SpringAir nose gear is far superior to the Robart nose gear in my opinion. It works great and extends with authority every time (upside down or up right). I now have about 10 flights on the Saturn with the SpringAir nose gear (air up/spring down) and it is working perfect. It appears to me that the Robart units springs are simply too weak to extend and lock the nose gear correctly. I like Robart products and their good service but they need to fix the spring down version of their retracts.

Ralph White

Does this happen when the airplane is right side up or upside down? Sometimes, even one of Spring Airs would not totally extend and lock when I was bench testing with the plane upside down. Just a thought

The gear never would lock properly, regardless of orientation. I agree with Ralph that the springs just seem to be too weak. The good news is that I tracked down the last of the leaks in the Rom Air installation and they work great now. I did replace the air valve with a Robart air-up/air-down valve, though. This valve is nicely designed and works well.

Jeff

I also found out that no matter which retacts you use you need to make sure that the mounting rails are perfectly flat. The units cannot be twisted when you tighten the mounting screws down. I had to place a small washer under mine to make them perfectly flat.
Ralph White

Interesting point, Ralph. Just to be sure, I checked them while firmly holding the retract unit itself, so that it wasn't attached to anything. Still no luck.

Jeff

I converted from Rhom to Spring Air a while back and they have proved excellent for typical pattern aircraft and are durable enough(3/16"Dia) gear type to hold up well in 'heavier pattern birds and war birds. I must say the return springs seems sluggish at times but never had a gear failure on landing or take off.

Ditto what Ralph said. I'm still using my Rhom Airs. The P-7 has a set in them, no issues (but only a few flights too). Bench tested just fine though. I do disassembleand clean them regularly, and kept them oiled while they hibernated. I could always use an extrabelly mount nose unit if any one is ready to toss theirs!Mark

What type of oil do you use on your Roms?

Jeff