RC_MAN

My Feedback: (11)

I'm setting up the elevon system in my F22. I'm using the JR 8411 sevo. I noticed that when the system is hooked up I get about 1/8 slop at the trailing edge of the elevon. Is this OK? This is the same setup as the f15 from Avonds.

I traced the slop to the servos. What can I do now? Please see picture for my set up. Are there other servos that may be betwr suited for this application that give at least 120 in-oz?

Thanks

S_Ellzey

Hi,
One thing you could do to reduce the slop, if you have not allready tried this, would be to set the servo travel to maximum in the transmitter and come in on the servo arm to get the right deflection. The servo will still have the same slop, but coming in on the arm will reduce it at the surface. This will also increase the power that the servo can apply to the surface, increase the position accuracy, and improve flutter resistance.

Hope this helps,

Steven

Ehab

My Feedback: (44)

1/8 of an inch is quite a lot even for the 8411. I have two of these on my Bandit and my last Roo and I had minmum slop. Try what Steven had written above. Also, make sure you go out on the horn at the surface. (I am assuming you have NO slop due to push rods or clevises)

the Hitec digis are very good too #5945. They are 140 oz plus and have almost no slop. I have them on my Hot spot and so far so good.

lov2flyrc

My Feedback: (24)

You could also swap the gear train to the nylon set which should eliminate any slop in the servo and still provide plenty of torque.
Todd

I-NAV

My Feedback: (3)

I have the same problem in the same airframe. Managed to get it down to 1/16" with lots of work. No problems thus far. I chickened out on the nylon gear option. If you drag the stabs on a touch and go and strip a gear - game over.. I also bushed my nylon bearings with K&S brass tube. It was a perfect fit on the alu rods.

six shooter

There is also play between the output shaft spline, and the aluminum servo arm. Use some blue thread locker (Loctite) between these two components. Yes, it means to get the servo arm off in the future you will need a screwdriver to pry it off (gently).

Plus the nylon gear 8411SA is a good option. Do worry about the nylon gears, the metal gears aren't indestructable either. In fact the inner pinion gears are only a press fit into the outer ring gears, and could slip under severe load.

Tom Antlfinger

My Feedback: (24)

One of our club members has been making servo arms for the past couple of years. Sold more than 8000 of them so far, including large numbers of IMAC and TOC flyers.

His name is Scott Benedix, and his CNC Machine Shop is SWB Manufacturing, not to be confused with Jeff Seymour at SWB turbines, even though they are only about 50 miles apart here in WI.

His web site is www.swbmfg.com

He is a 40% Giant Scale builder/flyer himself and got tired of all the slop in the output spline/servo arms, particularly with 8411's so he spent allot of money getting the best broach he could to make the interface slop free.

I do know quite a few jetsters have found out about them and are using them.

Tom

All of his arms are tapped for 4-40 ball links. The metal clevis into a metal servo arm just wears way too fast on Giant Scale planes and gets sloppy in short order. Jets might not vibrate as much, but I still use the ball links on all my planes except my BVM planes, which are hard to convert.

Dave Wilshere

Guy's

Shoot me down in flames, but I have always felt that the free play in the 8411 is to allow gear expansion in use.
If the gear mesh was set tight as on nylon gears they would jam in use.
I think you will find at the end of the flight the free play is less...

Dave Wilshere
UK

RC_MAN

My Feedback: (11)

Thanks for the comments guys.

Half of my problem was the loose fit of the metal arms to the servo spline. I ordered new ones as suggested. I hope they are better. The other metal units were all a loose fit. Must be that patented low height technology!

Doug Cronkhite

My Feedback: (34)

I've been using Scott's machined arms for about 3 years now on all my giant scale aerobatic aircraft. Scott's a good guy and makes a quality product.

Doug Cronkhite