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Jul 18, 2020, 09:14 AM
Registered User
dbacon's Avatar
Quote:
Originally Posted by ed4353
Hello all...
When I taxi the Beeker on the runway, it will nose over without a lot of throttle and elevator management. I have seen others comment on this in this thread. So, am I correct in saying this is normal? Has anyone found a cure for it?
The grass is fairly short. CG is good. The wheel axles are about 3/4" to 1" in front of the leading edge.
Any suggestions to improve this, or should I just fly it and be happy?
Also, has anyone tried building this without landing gear, as a belly-flopper? Or does that require extensive re-designing?

Thank you for your time.

Ed

Yes, I got the big idea that my original size Beeker didn't need wheels. I have a number of planes where there is no prop strike when they are on their belly on the grass.
Well, it didn't even come close to working, even with slippery plastic on the bottom, there was way too much friction, it would nose over before it even moved, like a beach ball rolling on the grass!
Now it has wheels, and I will try again soon.

Wheels are 4.5 in, LW-PLA, 20mm wide weigh 0.7 oz.
I took out my 7 oz nose weight, and moved the wing back 1/4 inch to balance it.
Last edited by dbacon; Nov 10, 2020 at 02:54 PM.
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Jul 18, 2020, 09:28 AM
Registered User
cbalgra's Avatar
Thread OP
Quote:
Originally Posted by ed4353
Hello all...
When I taxi the Beeker on the runway, it will nose over without a lot of throttle and elevator management. I have seen others comment on this in this thread. So, am I correct in saying this is normal? Has anyone found a cure for it?
The grass is fairly short. CG is good. The wheel axles are about 3/4" to 1" in front of the leading edge.
Any suggestions to improve this, or should I just fly it and be happy?
Also, has anyone tried building this without landing gear, as a belly-flopper? Or does that require extensive re-designing?

Thank you for your time.

Ed
Thanks for your input PHerder and dbacon.

ed4353,

Unfortunately, I have never experienced any nose over issues with my Beekers. I also, fly off pretty short grass, but even with smaller wheels, 3" Dubros, the plane has not shown any tendencies to nose over when power is applied. The grass is extremely level, with no bumbs or holes as well. With the larger Fun Cub wheels, (4.8") It rolls over just about anything. You can see in the photo below, that both the prototype on the left, and my second Beeker, have their axles directly in line with the leading edge of the wing also.

An area you may want to check is the motors thrust line. With the high mounted motor, it acts as a pendulum when power is applied. 3-5 degrees of down thrust should be built in. ( when the prop blades are placed vertically, the lower blade should be closer to the tail than the upper blade.)

As far as a belly lander goes. I don't know of anyone who has tried that, but if you do, be sure to land softly as there isn't a whole lot of internal structure support. I do have experience in a hard landing on an asphalt runway that did result in the upper, forward fuselage breaking right and the wing hold down dowel. It was totally my fault, in that I let it drop in from too high and even with the super absorbing landing gear, it bottomed it out and damaged the fuse.

I hope this is helpfull in getting you Beeker to handle well. Good luck, Brad
Jul 18, 2020, 03:42 PM
Registered User
Thanks for the suggestions, guys. I'll give it a try.

Ed

I'm going to look at the thrust angle first. I may have mine set wrong. Thrust angle on a pusher is a lot different than a tractor, depending on whether the thrust line is above or below the wing, and some other factors.

Thanks again. It's been educational...

Ed
Last edited by ed4353; Jul 18, 2020 at 03:57 PM. Reason: Edit
Nov 10, 2020, 01:15 PM
Retired CAD guy
birdofplay's Avatar
Check out my NEW Wheels !

3dPrinted wiht LW-PLA foaming filament.

120mm dia ~ 36 wide too.

Too windy to test just now but I have HI hopes !

If it works on htis Slowly the Beeker is NEXT !

I might try BLACK Lw-PLA next time as it would be
Steamier and Punkier if it was nasty black color ;>}
Last edited by birdofplay; Nov 10, 2020 at 01:29 PM.
Nov 10, 2020, 02:01 PM
Registered User
dbacon's Avatar
Bob,

Those wheels look nice, if they work, please do me the favor of estimating your thrust angle, as I never got it to ROG without wheels.

Without wheels, I can't hand launch it because the motor pushes the nose down so strong, it almost bites my knees!

With wheels, I would break them when I land, of course my landings haven't been very smooth... I tried a circle of MPF glued to the inside of the wheels, but then I would break the CF axle I was using.

I really feel I need a thrust angle that points down in front, like neg 5 degrees, and that is what I will test next.
Nov 10, 2020, 04:15 PM
Retired CAD guy
birdofplay's Avatar
Dave,

Those wheels are like yours but I reworked my Size and radii to hopefully make them more durable. They "FEEL" good to me
UNFORTUNATELY the wind in BOTH our locations is bad with that cold front coming thru.

With Cold wind behind it , IT MAY WELL BE some tiem before I get these tested.

Landing theSlowly is best done with power because if you run out of lift ... it just plops.
Think ... Flying it on to the grass
Try slowing down and adjust the landing angle with ... a little MORE ELEVATOR !
Leaving the motor alone. You're controlling the angle of descent.
More elevator Slows the plane and it sinks,
Less elevator and it speeds up and stops sinking.
Maybe you should try this at altitude. ... 1st ;>}

Still with Polyhedral your NOT going to TIP stall without some serious control inputs.

Motor mount :
Down thrust is the CURE for a HIGH LIFTING UC Airfoil.
More power implys more speed and lift and the Nose would pop up.
So the Motor down is supposed to be JUST ENOUGH to keep the plane going LEVEL even with different power settings.

Of course the Right thrust angle is for Torque compensation.

Start with straight out motor, see how it works.
The Slowly has a LARGE and effective elevator. for corrections.

Then after aloft and flying level try some more power.
Climb is OK but If the nose pops up then the motor angle needs to go down a bit more.

I suppose one of those Gyro units would correct for all this crap too.

I think I have about 1/8 " ply shim under the TOP motor mount spider holes.
Nov 10, 2020, 10:45 PM
Registered User
dbacon's Avatar
Bob,

Thanks for the long and detailed explanation. I seem to have grossly misinterpreted "down thrust" because I have it backwards on my Beeker. I will change it before my next session, planned for Thursday, and I will report back.

This mistake made it difficult to adjust power on final, because the reaction was so odd. I should have known better because I have a SuperTigre 90 pusher-powered F-18 that I built to duplicate a friend's plane. I was first to give it down thrust to cure its power/pitch problems. I was so proud that I figured this out for both of our F-18's. I guess those brain cells died on me.

The F-18 was a larger plane so maybe it was easier to observe these thrust reactions, but I sure missed it here!

Also that Gyro unit might have masked this problem as I adjusted thrust angles, until I had it out of its correction-authority range. Probably better to get things right before turning it on.
Nov 13, 2020, 12:52 PM
Scratch building addict
rotagen's Avatar
One of the coolest looking planes I've seen in a long time.

How did I miss this thread !?
Nov 13, 2020, 02:13 PM
Registered User
dbacon's Avatar
You flew by at Mach 1, according to your avitar...
I just wanted to say I had a great day yesterday with the Beeker, finally got the motor set right, I had way too much offset in the thrust angle, it needs just a degree or so of down thrust.

Get the kit of cut foam from Bird of Play, Hoosier Cutout Service. Put it together with Gorilla Glue.
Nov 13, 2020, 06:33 PM
Registered User
cbalgra's Avatar
Thread OP
rotagen, Never too late to join the fun!

At the moment my original Beekers are showing quite a bit of wear, and I am hoping to build an even larger one sometime soon. But if you would prefer something smaller, check out my build thread of the Micro Beeker.
https://www.rcgroups.com/forums/show...aiden-Video%21

Another aircraft you might enjoy is my Headcase, which I am currently "restoring" after several years of use.
https://www.rcgroups.com/forums/show...-with-VIDEO%21
Nov 13, 2020, 07:22 PM
Retired CAD guy
birdofplay's Avatar
WAY TO GO DAVE !!!

Did anyone get any vidz of your Beeker ?

AND ... Thanx for the Plug ! ;>}
Nov 14, 2020, 12:33 AM
Registered User
dbacon's Avatar
Working on the video, it came out sideways. This happened once before, I forgot how to fix it.

A plug for your service is a plug for our hobby. Your work provides us with great affordable planes.
Must also thank cbalgra!

I used a very complex program called KineMaster to rotate it:
Beeker 201112 (3 min 52 sec)
Last edited by dbacon; Nov 14, 2020 at 08:32 AM.
Nov 14, 2020, 09:33 AM
Retired CAD guy
birdofplay's Avatar
There ya go , dave !

Thanx for the vid.

I have a Sideways vid also.
It's showing those original SteamPunk wheels in action.
But I don't have Kinemaster .

Must research this issue a bit today.
Nov 14, 2020, 09:51 AM
Retired CAD guy
birdofplay's Avatar
THASt was FAr too easy to believe !!!

Movie maker has a simple Rotate that did the trick with ZERO PAIN !

See pic ... unbelievable

My shirt pocket Phone cam was NOT well Aimed at the Plane so I may redo the whole thing
with my EKEN Hat Cam alternative.
Dec 15, 2020, 03:28 PM
scratchbuilder
Thomas B.'s Avatar

Indoor Beeker


Mini Beeker Maiden Flight (1 min 34 sec)


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