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-   -   Showtime (https://www.rcuniverse.com/forum/3d-flying-82/3106917-showtime.html)

mxwrench 11-13-2005 11:06 PM

RE: Showtime
 
Bubba, I still plan to build the Showtime I have sometime. But I think I will wait till they get this dead spot thing sorted out. In the mean time I will start building the QQ 85" Yak as soon as it hit's the porch!

We should probably keep this thread related to the Showtime and not let it bacome another Yak thread! haha

Sorry again about your misfortune!

BK

bubbagates 11-14-2005 07:40 AM

RE: Showtime
 
We will be looking a little bit more into the stab versus wing relationship sometime this week, but last night I went out and did a few measurements and it appears my stab is directly on the same thrust line as the wing was. Our problem is going to be is that we will not be able to check the incidence since the fuselage was destroyed right at the wing tube.

Ron Kinsey 11-14-2005 08:29 AM

RE: Showtime
 
The stab and wing are on the same thrust line. That's the reason this plane flies like it's on a wire.

rmh 11-14-2005 09:44 AM

RE: Showtime
 
The Showtime takeoff "character" Bubba, is usually due to the restricted AOA from the relatively long tail wheel setup-
At least the stock setup does this . Mine did the same thing and I ran into this long ago on other "flat" landing gear setups - (control line stunt models)
A small foamie which sets flat will even do the same thing. They will hug the ground then pop into the air
The plane simply can not rotate to a good takeoff angle till speed builds then it "pops" off the ground, mains first , tailwheel last.
Typically -simply lenghtening the main gear or shortening the tail wheel will fix this.
The "dead spot " on approach is again rather typical of short wing long tail setup where the model can be held controllable in a high sink but until flying speed is rebuilt the sink rate will simply increase as the pitch control is added . Power added , has to be huge to overcome the sink.
The best approach is to add power first then add elevator. The model will accelerate more quickly if it is at the lower angle of attack.
Maybe this was not exactly what happened in your case -but it is a typical scenerio

bubbagates 11-14-2005 10:17 AM

RE: Showtime
 

ORIGINAL: dick Hanson

The Showtime takeoff "character" Bubba, is usually due to the restricted AOA from the relatively long tail wheel setup-
At least the stock setup does this . Mine did the same thing and I ran into this long ago on other "flat" landing gear setups - (control line stunt models)
A small foamie which sets flat will even do the same thing. They will hug the ground then pop into the air
The plane simply can not rotate to a good takeoff angle till speed builds then it "pops" off the ground, mains first , tailwheel last.
Typically -simply lenghtening the main gear or shortening the tail wheel will fix this.
The "dead spot " on approach is again rather typical of short wing long tail setup where the model can be held controllable in a high sink but until flying speed is rebuilt the sink rate will simply increase as the pitch control is added . Power added , has to be huge to overcome the sink.
The best approach is to add power first then add elevator. The model will accelerate more quickly if it is at the lower angle of attack.
Maybe this was not exactly what happened in your case -but it is a typical scenerio
Interesting note Dick. You are so close to what happened you should be a mind reader.

I had read earlier in this thread where someone thought the same thing and used another tailwheel setup to lower the tail and that cured his takeoff issue. I never even remembered it until you brought it up. For the landing, I was nose high but not that much, just going into the flair trying to stop the sink rate and it now sounds like I did not add enough power, soon enough and the landing was somewhat faster than usual when it quit flying and pancaked. I was sinking more than normal and recognized it but I guess I did not try to overcome it quick enough and in the proper sequence.

So based on everyone's comments I'm thinking it was pilot error, basically just me simply not understanding the characteristics of the plane.

Since yesterday I have re-thought my position on the plane and I really did love the way it flew so I may just go and buy another. To get the parts to repair the damaged one would cost more than buying a whole new one besides the LHS has one on discount for $215.99 which is not bad at all.

Mmoose 11-14-2005 03:05 PM

RE: Showtime
 

Guys I just purchased a very lightly used Saito 180 and should be getting my ST in a couple of days.....I've gone through the posts and have seen one or two people mention that they will be using this engine but have not heard anything since.

The question is does any body know how the plane will handle this....I know its an overkill but would like some inside info....Thanks for the help guys

R/C Foolish 11-14-2005 03:29 PM

RE: Showtime
 
IMHO it is too much power. I have a YS 110 in mine and I had a Saito 120 in it before. Both of these engines are more than enough. The 180 is just a lot of wasted weight up front. Everybody has there own preference though.

R/C Foolish

Dealspeed 11-14-2005 04:03 PM

RE: Showtime
 
Yes but the 180 only weighs 3oz's more then the 120 so thats not alot of wasted weight.
I say go for it bud this planes handles the extra weight just fine

kennyandannie 11-14-2005 06:08 PM

RE: Showtime
 
Use the 180... you won't be sorry you have the extra power. If you get into trouble, the extra power will help tremendously.

I'm flying mine with a Saito 150 and your motor is a little lighter and a little more powerful, just remember you don't have to use all of the power.

Ken

bubbagates 11-14-2005 07:40 PM

RE: Showtime
 
If you use the 180, pin the firewall and most definitely reinforce the gear area. The gear area needs it no matter what engine you use

kennyandannie 11-14-2005 07:48 PM

RE: Showtime
 
Good call, Bubba.

Ken

Mmoose 11-14-2005 08:55 PM

RE: Showtime
 

Thanks alot guys for all your replies....I'll keep you all posted !!.....Can't wait to get this baby in the air !!

MIXMASTER 11-15-2005 09:35 AM

RE: Showtime
 
Do you have any suggestions for the snapping with elevator input? My ST is snapping to the right in loops or down lines when I pull up elevator, I tried it in outside loops and it did seem better that way. I,ve tried several things to fix or at least minimize this, went over the lateral balance, elevator throws/expo,CG(went forward). I did try putting in some opposite rudder(left)trim and this tamed it , if I put in enought left trim, the plane starts snapping to the left. The problem with that is elevators,harriers & hovering is now harder to hold. The rudder was trimmed straight before,didnt seem to have any deflection that was out of norm. I also noticed that the SFG's do help some, I even tried just using the top halves of SFG's, (I think using top&bottom is a bit too much area for stable slow HA KE, using just the tops made it better for that maneuver and still tamed the snapping a bit.) The snaps happen at speeds above stall up to moderatelty high speed so I guess they are high speed stalls-IMO. My ST is about 10lbs with a Moki 1.35, CG is back to recommended spot. I wonder if the problem is having too much throw when flying conventional pattern style, maybe a pattern design does not handle well with 3-D throws untill it is post-stall speed?? I did set my expo to -100% on elevator, and I use tripple rates but almost never fly with max rate on, I use the middle position of the switch with 85% rate. One last thing, it also falls to the right when executing a wall- hope I didnt go on too long,would appreciate any suggestions/comments on this-my ST is a keeper no matter what, I'll learn to avoid the snaps if I have to.

R/C Foolish 11-15-2005 09:50 AM

RE: Showtime
 
Maybe I am not the best pilot around but my ST doesn't have any problems and I do not fly with max throws. Cut your throws done a bit and see if the problems go away. Too much elevator on any plane will cause a snap.

R/C Foolish

ItsShowtime 11-15-2005 10:46 AM

RE: Showtime
 
I have a 180 on my ST and I love it. Make sure to reinforce your firewall and landing gear though. I have yet to find the perfect prop for it yet and judging by the snow on the way here today that won't be happening any time soon. I've used a 16 X4W 17X8 17X6 and seem to like the 18X5 the best so far. I also put in a 24 oz tank because the 180 sucks fuel like crazy. I can now get a 13-14 minute flight with that. For a few dollars more than the 150 and the same weight, you can't go wrong with the 180.

ME

Rocketman_ 11-15-2005 11:10 AM

RE: Showtime
 


ORIGINAL: R/C Foolish
Cut your throws done a bit and see if the problems go away. Too much elevator on any plane will cause a snap.
R/C Foolish
I believe that has been suggested several times but it continues to fall on deaf ears. Maybe it is fun to continue to search for a way to defy a basic law of aerodynamics,................'til your luck runs out.

A good model to horse around the sky in tight maneuvers using lots of control surface throw is the U-Can-Do 3D .46 and similar models with a fat wing and low wing loading.

R/C Foolish 11-15-2005 02:22 PM

RE: Showtime
 
Rocketman,

Where do you fly in Ma.? I am at the Middlesex Club among others.

R/C Foolish

MIXMASTER 11-15-2005 02:22 PM

RE: Showtime
 
I'm not giving it up just yet, I haven't tried anything beyond reason and have had some success, so far the plane flys closest to my style with just the top SFG's on. I don't mind a little experimentation, with some tinkering I've made some planes do what most people at my field have said theirs have never done. I've never owned a pattern plane so this is a bit of a learning curve for me.
You are right about the UCD, you can slap it around high or low and its forgiving,just plane fun type of flying with some 3-D capability. I understand the difference in wing design and loading for the ST is not as forgiving as a UCD but I'm just trying to make it as close as possible so I can enjoy all types of flying with one plane. (I am working on my 2d 60 UCD)

LarryMagoo 11-15-2005 02:38 PM

RE: Showtime
 
I fly an Electric ST and have the Elevator set to only 8 degrees up and 10 degrees down and have never experienced the snap everyone seems to be talking about.

My brother flys 30-40%ers and he always says the the recommended settings seem to always be too much....especially for pattern flying.

I also have the Ailerons low rates set the same. It rolls plenty fast even on low rates.

It sure flys nice though.

Great thread for being 50 pages!!

Magoo

Rocketman_ 11-15-2005 03:26 PM

RE: Showtime
 


ORIGINAL: R/C Foolish

Rocketman,

Where do you fly in Ma.? I am at the Middlesex Club among others.

R/C Foolish
Me too!!

Mmoose 11-15-2005 10:03 PM

RE: Showtime
 

ItsSHOWTIME thanks for the info.....I'm kinda starting to get worried about the fuel consumption.....after you've been flying gassers for a while you tend to forget how much glow fuel costs.....but still can't wait to get er in the air....I ordered a 18x6W APC prop...hoping that will work well..

rcflip 11-25-2005 02:27 AM

RE: Showtime
 
Hi,

Has anyone glued the aluminium wing tube... the manual does say to glue the stab tube but not the wing tube.

Cheers,
Flip over and out!!

BoneDoc 11-25-2005 03:51 AM

RE: Showtime
 
it's a bit too big to transport if you glue the wing tube I think. Besides, the method for securing it is solid as it is

kennyandannie 11-25-2005 06:16 AM

RE: Showtime
 
You could glue in one side, I suppose, I leave the tube in one wing anyway.

Ken

Ron Kinsey 11-25-2005 08:42 PM

RE: Showtime
 
I drilled a hole through the fiber tube, into the wing tube and tapped it for a bolt. I leave the tube in at all times, but it's easily removed if needed....


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