RAPPTOR

My Feedback: (41)

thank you..

Chris Smith

My Feedback: (2)

NOTICE to OWNERS/PILOTS: Potential Airworthiness Issue (This is unofficial and not from the manufacturer or Shulman Aviation)

Turbinator ARF only.

Minimum actions required:
1. Inspect/repair as necessary (I/RAN).

Recommended Action:
2. Apply modification as depicted or similar.

During a routine pre-season airframe inspection a hair-line crack was noticed across the horizontal stab attach tab.
Since this tab holds the stabilizer and elevator to the fuselage; if it breaks free in flight, it is possible the stab could seperate from the aircraft.

It is not clear when the crack developed or how long the crack had been there. Since there was no way to know how fast it might have gotten worse, a simple modification was necessary. Both stabs were modified even though the other had no crack as yet.

This would be considered a mandatory Airworthiness Directive (AD) if I were the manufacturer. But since I am an individual customer/owner, I offer the unofficial fix for your consideration. Refer to the next post for the fix details.

This is such a GREAT Turbine model it is worth making sure it is taken care of.

The picture only shows the crack after I wiggled the tab to see how deep the crack was. The original crack was nearly invisible, and only noticible after slight bending. The crack was through half of the lamination. This left only 1/32 inch thickness intact for the bolt to use.

Chris Smith

My Feedback: (2)

The fix uses molded servo angle mount material available from Tamjets, Dreamworks, or BVM.

The mounts are cut down and re-drilled to accept the stab attach bolt. Since the bolt mounting tabs on the root of the stabs are not 90 degrees to the under surface, they required a little notch be let-in to the stab to accept the brace. The brace is Hysol'd in place.

lov2flyrc

My Feedback: (24)

Thanks Chris!
I'll make up some thin carbon laminates on the CNC to provide as a stiffener plate for the mounting tab. Due to the nature of the design, I doubt the stab would slide outward in flight even if this tab was completely broken off but should be addressed anyway. The spar design would require the stab to slide out directly parallel to the spars, even then the linkage would limit how far it slid. Most likely damaged in handling, not flight.
We will get a notice on the site and make up a simple bond-on reinforcement.

raptor30se

Are the manual setting for flaps a good starting point at 1" takeoff and 2.5" for landing? Also how much down elevator mix is needed for each of those settings? Getting ready to maiden mine very soon.
Thanks in advance.

macmuz

Just bought the orange one here in Oz.Wings are such a tight fit, slid them together, now extremely tight to pull apart.Also there was no pushrod guides fitted on mine.Anyway really happy with the quality and what I see so far.Couple of questions here.1. I think mine is one of the earlier kits, do you guys modify the thrust angle?2. What are your finished flying weights?3. How are you attaching the canopy to hatch? Would epoxy glue be strong enough?Thanks Mario..

Chris Smith

My Feedback: (2)

Most Turb buyers will quickly realize how versitile this model is.
It may be tempting to over think the setup and configuration, and spend too much time and money with precise control throws and computer mixing, widgets and etc.

Comments to assist all working on this model:
Put your efforts on the critical items. For example, don't concentrate on perfect elevator mixing for flap compensation, crow, precise flap throw, then accept the CG as "looks good enough".

A builder's priorities should look something like this:

1. Exact CG as published. Be sure you measure the CG from wing LE underside where it meets the fuselage, NOT where the wing meets the intake. Spend your setup time on this one item and you will be rewarded with a gem! Not that the model is dangerous without exact CG, but many setup problems go away when you set the CG correctly.

DO NOT worry about the amount of nose weight you may need! The airplane won't care! As a matter of fact the Turb still tends to float but is still slow on approach. What a hoot! I used up to 680 grams or 1.5 pounds in the nose hatch (lead shot). Make it removable in case you switch engines like Randy did.

2. Get the engine thrust as I have posted in this thread. It eliminates trim changes for throttle changes. It provides a very neutral feel with a K80 size engine throughout the speed ranges.

3. 90-100 in'oz torque servos connected to smooth controls. No need for excessive torque, digital HS or high volt servos unless you already have them. You can put digitals on elevators and maybe aileron for peace of mind, but don't get crazy. Spend the money on your scale models. Better yet buy a second Turb instead as a spare.

4. Use Todd's control settings as posted in this thread and forget about it! Go fly!

Chris

shepp

Well said Chris. The Turbinator is a joy to fly. Mine is just not as fast as yours. LOL
If you are coming to KY Jets, then we will probably have 5 Turbinators up there , kind of like last year with the shok jets.

Glenn

raptor30se

Thanks Chis -

Little confused on CG the wing I get the same measurement when at the center of the wing vs where the wing meets the scoop. The wing doesn't start to sweep back till after the scoop. Am I missing something there?

Chris Smith

My Feedback: (2)

Put a straight edge along the LE and mark where the straight edge meets the fuselage sides ignoring the intake. That imaginary point is the start point from where the CG is measured.

A designer usually dimensions a CG measurement along the fuselage chord even though the CG is calculated as a percentage of the mean chord. For model airplanes we use the measurement as defined by the chord section at the fuselage sides in the profile drawing on the plans. Some designers reference the root chord at the center of the fuselage. But, in the case of the Turbinator, use the chord section at the sides of the fuselage.

I realize this is becoming a lost art with ARF models that don't have plans. So I don't describe it clearly since I assume builders know how to measure the CG, and often they don't. My bad.

jetsett

My Feedback: (6)

I'm a little confused !
The instructions say, "The recommended center of gravity (CG) location of your model is 7 inches back from the leading edge of the wing"

so , right now my CG is abut 2 inches back? Of the correct CG?
The design of the turbinator arf has a straight leading edge at the inlet sides.
So in other words your saying.. That the CG should be 7 inches back from point where the wings would meet the fuselage sides if they extended that far?

raptor30se

Makes perfect sense now. I do appreciate your explanation. I am an assembler not a builder . One more question, is 1/8" down elevator good starting point for landing flap mix?

Thanks in advance.

raptor30se

That's exactly what he is saying.

Chris Smith

My Feedback: (2)

Start with no flap to ELE mix and test fly. Adjust as you see fit. It's better to minimize additional control mixing that may confuse your flight test evaluations.

I do not use any FLAP to ELE mix. You may find you don't need it either but it is a personal choice. I'm a firm believer that all flap positions have a max speed that is close to landing traffic pattern speeds so I make sure to slow way down to pattern speeds before using any flap. Keep in mind that flap deployment limitations are often a structural issue more than a handling issue.

Slower speeds for flap deployment may eliminate the need for elevator mixing. On an airplane like the Turb you DO NOT need any flap nor incremental flap settings in order to safely slow down. Slow down to a medium/low gear down speed, then deploy flaps.

Randy M probably has some good advice since he runs a K100 in his. That engine allows for some performance that mine does not.

Randy M.

My Feedback: (38)

I did add a touch of down elevator with flap. About 1/8 in at full flap. It's just as Chris said, you do not need elevator mix. I just added a little for those slow speed flybys. I do slow down before flap deployment. The mix just allows a little comfort for slow cruise. And I do mean SLOW.

Grodus

I have a Wren SS not doing anything and I have been looking closely at this airframe and an Elan. Is most everyone using the gear package sold by Dreamworks or are some happy with other gear? What kind of speeds would a guy expect with a Supersport pushing it? Not looking to push 200, just curous.

Cody

Randy M.

My Feedback: (38)

maybe 150

bjnginge

Hi, I have one of these on the way and was also looking at the retract/brake package from dream works especially the electric set. Does anyone have any thoughts about these ?
Cheers

PeterDays

Hello,

Will a Simjet 3000 fit this airframe?

Thanks

Pedro

jetsett

My Feedback: (6)

I also purchased the Dreamworks electric gear. My first impressions, they are bit pricey, but worth every cent. Very easy to set up. I cycled the gear over 10 times with a small 7.4 500mah lipo that I had lying around. I would recommend them. Love the electric brakes also.
Here's s short video of them in operation.
http://m.youtube.com/#/watch?v=Yu2h2...%3DYu2h2wB1ylo

Enjoy!

jetsett

My Feedback: (6)

Yes the simjet 3000 will fit.

Grodus

Ok, thanks for the feedback on the Dreamworks gear package. Does anyone happen to remember the main strut length , trunion to axle? I have a set of straight stuts from the original Comp arf Flash package and it would be really nice to use them if I could.

DominicM

Nice maiden flight by a new Turbinator owner at Middle Wallop airfield, UK, yesterday. Nice and gentle flying.

https://www.youtube.com/watch?v=1GEO4_2cyfc

macmuz

Hello there.Need help here.I think my turbinator is one of the earlier ones.I'm putting a 22# turbine in it.I think I've been supplied with extra turbine rails, but I've noticed you guys have been putting in more down thrust.The manual shows an increased angle of down thrust turbine rails then what's built into the kit but no reference to how much more.From where are you measuring from and how much more down thrust are you adding?I've included 3 pictures for you guys to look at.Thanks Mario..

Chris Smith

My Feedback: (2)

The engine thrust info you need is already in this thread.
Go to page 2 post 38. The pictures and text tell you what to do. You will need to modify the supplied mounting rails. With a 22 pound turbine you need the down thrust shown in this thread or you will likely have trim issues.