RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hey RichardGee,
I'm sure I am not the only one wondering if your Gee Bee went airborn this weekend. Flight reports are mandatory and very much enjoyed.
I will be flying my Gee Bee at Monster Planes USA, at Lake Wales Airport, Lake Wales, FL. in Oct.
DWR, Any news on your parts? Jim

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

GeeBee Gents....

I WISH I had a flight report for you, but it just wasn't to beeeee... However, I will share a valuable lesson that may save some of you some grief in the future -

I have killed two Hitec servos, in as many days - and here is how:

I originally set up my throttle on a used Hitec 225MG. I have always had good luck with this relatively small and fast servo for throttle control. But, in observing the servo action, I could see a very small 'jitter' at about 15% throttle setting. Not wanting to take any chances, I replaced it with a brand new 225MG and proceeded to test run my engine (DA 150).

While exercising the throttle on the ground, checking idle and top end, after about 2 minutes the servo went to full throttle and would no longer respond to stick inputs. (Thank God for a strong 16 yr. old son and electronic engine kill....)
I found that the new servo had simply quit working..!!?? I plugged in another servo, and it worked fine, but the 'new' Hitec 225MG was a dead dog. So, I returned it to the hobby shop and purchased its digital counterpart, the Hitec 5245MG, installed it, checked it out via throttle linkage set up, and called it good - VERY thankful my 225MG had died on the ground instead of the air.

So... next morning (this morning - Sunday), I pack up and go to the field. After all the oohs and ahhs and explaining 'til I was blue in the face, I gassed up the mighty Gee Bee, started the engine and performed a range check - ALL was well.

Brought her into the pitts to top of the fuel, put her back on the line and started up. As my holders were keeping the GeeBee from rolling, I was adjusting the idle lower and lower as it just wanted to roll away. After a minute or so, the throttle went to about 30% BY ITSELF and STAYED THERE !!

I killed the engine (I highly recommend an electronic kill!!!) and brought it back to the pitts, puzzled and irritated.[:@]

Long story short, I KILLED yet ANOTHER Hitec servo by running it at too high a voltage - I found my voltage regulator was set to 7.55v !!!

NO - I never checked this because none of my other Hitec digital servos NOR MY Futaba Gyro, had given even a hint of any problem. I also had understood the voltage regulator was factory set to 6.1v.

Apparently, this smaller designed Hitec has a different amplifier section than the larger standard digitals and analogs, hence, its inability to cope with the high input voltage while all the other Hitecs in the plane (5625 and 5645) had no issues.

So, it's back to the building board to replace the servo and adjust my voltage regulator DOWN to 5.5v.
(I must have gone through a thousand tie wraps and a gallon of Loctite assembling and disassembling the entire front section of this Gee Bee MANY times):eek:

I feel as though I dodged TWO bullets Saturday and Sunday as both the analog 225MG, then digital 5245MG died ON THE GROUND rather than in the air!!!:)

Moral of the story - check your voltage regulator's output!!!:D

See my field pix from today - NOTE: I have not yet added my painted pilot bust, TW cuff or wheelpant flying wire covers.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

I love the third picture - a great perspective!!

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hey Dirtydingus, the Monster event sounds awesome! Does your Gee Bee weigh at least 35 lbs dry? That is one plane that would not be happy with adding ballast to meet a minimum weight limit. Hope that you get to fly and represent us Gee Bee lovers!
Good Luck Danny

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Richard, so glad you dodged those bullets on the ground. I don't even like to think about a GeeBee in the air with no throttle control. Yikes. So maybe next weekend? The pictures are great!

I ordered the wings for mine which I was told are being shipped from Thialand. Rats. I have yet to get a response about an ETA.

Jim, I heard about the Lake Wales event. I may try to get up there. What are the dates? DWR

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

YIKES, INDEED!![X(]
I literally could not sleep last night thinking of the many scenarios that may have transpired... NONE of them ending well.

New throttle servo is installed now; V-reg is adjusted to 5.5v (taking Futaba Gyro into consideration); and currently fiberglassing my tailwheel pant cut out of 1/64" ply (not plastic as suggested). Painting pilot bust and will be making LG flying wire mounting covers.

Also wanted to point out that I was quite wary of what appeared to be very small (3mm?) bolts that capture and tension the entire flying wire assembly - inner gear wires to fuse belly - I dug out blind nuts and replaced the bolts with 10-32. Not only are they far more robust, I can now tighten them easily with a much larger allen driver.

YES - looks like next weekend for the maiden:D

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

More updated pictures of the Gee Bee build. Ray Powell is burning the midnight oil! More coming . . .

Perry

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Richard your plane looks great!

I have been pondering about contacting Solo Props to build a scale hub and prop for the Gee Bee. I am running the DA-150. Anyone have any experience with Solo?

Perry

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Perry,

THANKS. The back of your engine dome is exactly the way it SHOULD be done! You need the reinforcement so your DA150 isn't wobbling all over hell and gone AND you've provided platforms for mounting your equipment. Great Job!

I was eventually going to make a dummy prop hub for static... had not thought of an actual usable one. Probably talking big bucks and what about balance? Might be more trouble than its worth, but intriguing idea...

btw: I utilized a thinner clear plastic for my canopy parts as the included stuff was scratched (no protective film) and very thick, making it very hard to work with. However, I am already seeing hazing and cracking all through what I used. Can't win for losing[&o]

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

We were actually thinking of using a thinner plastic for the canopy due that mine was very scratched. I will post what we come up with.

Perry

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

We might form the included clear plastic for the canopy and then maybe shoot a coat of clear. This should hide most defects.

Perry

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

I had a local machine shop build a prop hub from drawings I made from Delmar's book.It is not true scale but is stand-back and that looks about right! The full scale one is unusual and my machinist kept asking me"Are you sure you want it like this?"

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

I have attached pictures of my tailwheel fairing. Built from 1/64" ply, with one balsa former (just to get proper shape), and used the template provided in the manual.

Unit is fiberglassed with 2 oz. cloth, sanded and primed. I substituted allen bolt for Fultz axle and embedded a nut in wheelpant. Bolt/axle holds everything together and 2 Fultz retention allens are still utilized to capture axle.

I also substituted a hard foam tailwheel for the Robart I was using. The lighter weight of this foam TW offsets the very slight increase in weight caused by the fairing.

I will be painting fairing after another coat of primer.

Note: damage to fuselage was caused by Fultz TW assembly spinning 180 deg, due to wimpy Nyrod TW pushrod assembly; has since been replaced with CF pushrod. Damage has been repaired and will be touched up when I mix up paint for TW fairing.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Looks good RichardGee, What pilot did you end up with?

Hey hotrodblazer. With the smoke system, my plane is about 35.5 lbs. and for that show smoke is a must. I have a simple but fast paced routine that I hope will keep the crowds attn.

DWR. Hope you can make the show. It is put on by Frank Tiano (top gun promoter) it should be great.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Ended up with Great Planes unpainted pilot bust. Even after augering out most of the bottom plastic, leaving just a small 'ring' to glue to platform, and augering away some of pilot back area (not seen) it still comes in at nearly 4 oz. unpainted.
May not seem like much, but has a PROFOUND effect on CG.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

[>:]OK guys, I am completely baffled and frustrated[:@]

After killing 2 throttle servos, I adjusted my V-reg down to 5.5v, installed another new Hitec 5245MG throttle servo, let the whole thing 'burn' on the bench yesterday for almost an hour and a half. NO PROBLEMS.

I go the field today, assemble the GB, take a few more pix (pilot and TW fairling addition) and proceed to start her up and adjust the throttle.

Just to be on the safe side, I exercised the throttle up, down and everything in between for about 10 minutes or so.
I then pulled out onto the runway for taxi tests. A few seconds later, the throttle began to advance BY ITSELF![X(]

I killed the engine (again, thank goodness for 42% Opto Kill) and walked up to the Gee Bee on the runway - another THROTTLE SERVO DEAD AS A DOORNAIL!!!

What the heck is going on ???!!! This has everyone stumped!!!

I will be pulling everything apart for the umpteenth time trying to find out what in the world is going wrong and will let you know when I find it...[&o]

Until then, the Gee Bee stays on the ground where, for the 3rd time, I have been lucky enough to have my throttle servos die, rather than in the air...[8D]

btw: I am using XOAR 30x12 prop

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

I fly alot of giant scale here, Richard, Is your Servo a stamdard size or Mini?, I have always used 8411s on throttle and NEVER had one problem, Also what kind of linkage set up are you using ,{ Metal rod or Nyrod}?

Doug D

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

And were is your servo located?

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

The one difference I have noticed between MY throttle servo set up and seemingly everyone elses - mine is located on the Fuel tank tray, behind engine dome and is in no way attached to engine dome.

Both Hitec 225MG and its digital twin, 5245MG, have died the same death, in the same location, in the same manner.

Pushrod is Nyrod with ball link at throttle arm of engine and clevis at servo. Servo arm is nylon.

As I previously stated, unless engine is running, throttle servo will run and run and run, with nary a jitter.
Right now, my theory is that the fiberglass engine dome flexes enough with the DA150 that throttle servo output is being pushed and pulled / stressed to the point where it burns up. Since servo is in no way attached to the dome, it cannot move with the dome.

I have checked servo extension for frayed wires (Air Wild, 20 guage) and they are perfect.

Other than this theory, I still have no clue as to what is killing the servos and will have to rely upon a diagnosis from Hitec to find out.

btw: I have used the 225MG on throttle many other times, on large gasoline planes, with freshly charged 6v NiMH packs, and have never had any issues.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Hmmm, I think your on the right track, That would the next try is moving sevo to dome, I see some else in this thread has done that, I will have to watch to see what happens here, I need to get minr started soon, Im finishing up a Kmp, F7F tigercat.

By the way Rich, Your GB lookis Fantastic!

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

RichardGee,
I can't help but think it must be a voltage issue. It is true that the dome may flex but the throttle arm is the only thing attached to the servo and that moves very freely and would simply move with any flex. What would you think about swapping out the battery with a 6 volt NiMH.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

Great point. I hadn't thought of that - you're right that the DA throttle arm moves very freely.

I don't have an answer, but I DO need the nose weight of the two 6 cell NiMH on the dome and cannot substitute anything but similar weight and sized packs.

Here's what I have already done:

:eek:Built servo mount on back of dome.
:eek:Using Hitec 5625 (like on elevators) instead of the mini 5245.
:eek:Eliminating completely the 5245 throttle servo and mounts on Tank tray.

I agree this sounds like a voltage issue, but why on earth do my other Hitec aileron, elevator and rudder servos have no problems? Nor even my Futaba gyro which admonishes user to 'stay below 6v?'

My IMAC planes all use Lithium packs regulated to 6.5v and NONE of my Hitec or JR servos have any issues. Of course, I am not using any mini Hitec servos on those aircraft.

ONLY the mini Hitecs - whether its the analog 225MG or the digital 5245MG - seem to have the problem as all have died the same death in exactly the same way whether the voltage was set at 7.5 or 5.5v.

I have also wondered if it could be this particular receiver channel, but that makes no sense as the Rx is getting the same regulated 5.5v and any current output would be the result of the 'load' (servo). I also checked the throttle servo extensions for frayed or shorted wires - nothing.

So... I have revamped the throttle servo set up.

I will update when I have more info... thanks for the suggestions:D.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

The last plane I had kept loosing the 5245's. The servo would over rotate and it was over. This was running thru a Smart Fly Expander and no one could answer what happened. Switched to a 5625 and no problems. On my Gee Bee I will run a 5985 since I have that servo. Have you programmed the servo thru the HITEC programmer?

Put a Nicad or NIMH on the throttle and see what happens. As you know this allows you to bypass the reg or another point of failure. Try wrapping a lead around a ferrite ring.

Perry

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

You are right the motor dome from the factory is a flexing pile of garbage and I could see that this may be killing the servo. Seems like whats talked about needs to be addressed by everyone anyways.

RE: Composite-Arf 33% Gee Bee R2 - First Flight - Pics - Videos - L@@K
 

VERY glad to hear someone else has had "unexplainable" failures with the Hitec mini servo.

I am switching to the 5625 and mounting it directly to motor dome. I have re-re-re-verified that my V-reg is set to exactly 5.5v. This should NOT be an issue with the 5245 since it is rated at 6v.
However, I have always experienced the failure after setting ATV for high and low throttle end points.... perhaps these mini servos are very frail and subject to "over rotation" ??? I dunno.

I have experienced NONE of this with the mid to high end digital Hitecs or JRs.. ?[X(]

Yes, dome is like limp linguini.... hard to believe CARF thinks you can hang 10 pounds and 17 HP on this thing...[:-]
But that is why I added PLY cross-bracing.

Even after all the assembly/disassembly; loctite and tie wraps until I can't see straight; HOURS in my workshop... the Gee Bee R remains the coolest plane on the planet, as far as I'm concerned:D