jmason904

I'm installing pneumatic retracts in a Top-Flite corsair, with a micro servo to activate to v/r valve. Problem is that with only one mounting hole at each end of the servo, the servo wants to rock on the rubber isolators, but works just fine if I don't use them. Do I really need to use the isolators? Will this cause problems in flight?

blvdbuzzard

If you do not use the rubber grommets it may fail from vibration. I am just about where you are with my red box corsair. I was playing around with the way I was going to mount the servo for the retracts in my Curare and am just going to use double sided foam tape to mount the servo.

Dru.

Waltaz

I'm sure I'll get flamed for this but for applications such as gliders I just use Loctite contact cement and glue my servos to the sides of the fuse. They stay put. A little persuasion will pop them off and acatone will clean them up.
For Tailwheels use a servo protection set up.
Walt

Shihtzutan

Not using the rubber mounts is no big deal, but its not recommended, per the reason given by blvdbuzzard. However considering some plastic wing servo holders don't use the rubber isolators, my guess it's a carry over when servos weren't as reliable as they are today. I've never seen a failure from a servo mounted in this fashion.

Secondly, a little servo flex is no big deal since it's only a retract valve you're actuating and the flex could save your plastic gears from stripping teeth.

I mounted a mini-servo on the retract actuator on my Kyosho Corsair (I robbed it from my Top Flight Corsair still under construction) and it worked just fine. It is a Robart set- up, complete with the functional struts and I must say it’s a pain in the butt. Here’s why:

Slight toe-in helps you track straight, but because these retracts rotate; a little too much toe-in or toe out can side load the strut, causing them to want to rotate, hence collapse! I wanted scale retraction, and used restrictors in my lines, but I found this prevented a positive lock. If its grass you’re flying off of, the increased drag compounds the problem.

The Robart functional struts look nice, but this aggravates the situation even more. File flats for every set screw on your gear and make your landings greasers. This is my third year on my Corsair and it always attracts a lot of attention at the field. Gear-up rolls and low passes are awesome! Good luck, I hope this helps.

jmason904

Thanks for all the info. I know what you mean about the robart system, I'm using the exact set-up with the functional struts, and I think I've spent more time fitting all the components than I have building up the wing and fuse. Was wondering about how well they would hold up. It doesn't seem to take much pressure to make the rotating gear slip. Sure wish robart would come up with a better design. I have them set-up with a little toe-in.

blvdbuzzard

I am still try to decide what retracts to get for my Corsair. I have heard so much bad about Robart and Century that I dont know what to think. One will swear up and down how good they are then there is 1 guy who just swears at them. I am in the middle and not getting any where.

Dru.

Shihtzutan

I know the feeling, but it's the old Chevy vs. Ford argument on which one's better! The answer is that they’re both good or they wouldn’t be in business this long, so it's a matter of preference. I've got Century's in my TF Mustang because they seemed stronger and Robart’s in my Corsair because they are much more scale looking, especially with the functional struts installed. I’ve replaced components in both set of gear and the service is good for both of them. Don’t throw away any of your paperwork, it’ll make ordering replacement parts easier when its time.

In my opinion, I think I going to switch to mechanicals because the servos bring up the gear in a more scale fashion, which is in my opinion, part of the thrill, which by the way, has to be done on the initial climb-out for it to look scale enough for an orgasm from an onlooker. Achieving lock down with an air-actuated valve slowed is risky. Without the restrictors or variable valve set to full, the gear snap down and lock without a problem, but again as in the case of the rotating retracts, they come down with such force they sometimes slip and alter the tow-in setting. The links also tend to bend, they can be straightened a few times, but you’ll need to order these and keep a set of spares around.

Currently, I’m eyeing a set of retracts from Likes Line, they are electric and work with a jack-screw, however they are a bit more pricey that Robart or Century. If something like this interest you, the website is www.aero-sports.com/likesline.

blvdbuzzard

I have had a set of Robarts for over ten years and they work just fine. The problem seems to be that when they get into the rotating part both comanies have there critics. I am using the restrictor valve with teh standard set and they seem to lock just fine, but then again I will be getting the rotating set so I don't know. I am leaning towards the CJM set because it comes all in 1 box. I think that the biggest problem with both sets is the weight of the models. I think if I keep it as light as posable I should be alright.

Thanks.

Dru.

3dd

My Feedback: (6)

you didn't say what size wire you ran thru the valve to operate it .make sure it is small enough to allow some side movement inside the activater piston or it will bind up your servo and drain your batteries.as long as the servo is not binding up you will be ok with a little rocking but i would never have a servo that was solid mounted it will destroy the potometer in time and then fail