Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Its Bobcat nice

Reply
Old 10-25-2007, 12:28 AM
  #376
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,424
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Im running the keecat, which is slightly larger, and a Super tigre .90 with the 11x8 graupner. it runs fine on it, as well as the towe 75 that I saw last week. looks to go about 100-120 ish.
gooseF22 is online now  
Reply With Quote
Old 10-25-2007, 08:24 AM
  #377
bob27s
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: zeuglodon

will he have one to fit the tower 75?
not sure if Dub has made a 60-90 size one yet..... but would be the same approach.

If you want one, order one ...
JS-90 muffler, pusher configuration, Tower 75 engine.
bob27s is offline  
Reply With Quote
Old 11-10-2007, 10:26 PM
  #378
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

I thought I would let people know, if they already haven't seen it, Master Airscrew now has a 3 blade 10 X 7 pusher prop. I ordered one to go on my YS .60 FS which I am installing in the Bobcat. I also went with a Hobbico CS-59 low profile servo for the elevator. It has 61 oz. of torque at 4.8 volts with .18 sec speed. I am putting the servo in the stabilizer (made my own servo rails) so that the control rod is in the center of the elevator.
orstraycat is offline  
Reply With Quote
Old 11-10-2007, 11:49 PM
  #379
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: orstraycat

I thought I would let people know, if they already haven't seen it, Master Airscrew now has a 3 blade 10 X 7 pusher prop. I ordered one to go on my YS .60 FS which I am installing in the Bobcat. I
Actually I tried that a couple of months ago and I was not overly impressed with the performance. It wasn't horrid, just not any improvement.

The 11x7 pusher does a better job IMHO.

opjose is offline  
Reply With Quote
Old 11-11-2007, 12:18 AM
  #380
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Well that is good to know. I have already ordered the prop so I guess it's too late now. Does anybody know the number or color name for the yellow covering for the Bobcat and/or the type of covering ?
orstraycat is offline  
Reply With Quote
Old 11-11-2007, 04:57 PM
  #381
still4given
 
still4given's Avatar
 
Join Date: Jan 2006
Location: Victorville, CA
Posts: 1,526
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

I finally got a chance to fly my Bobcat again. I let a couple of other club members fly it this time and they both liked it. One made the comment that it didn't seem as fast as it sounded like it was. The Tower 75 was spinning pretty good with the Graupner 11x8. I'll have to film it next time and have someone do the doppler test on it. My first landing of the day was bad again. It slows down faster than I expected it to and I stalled it again about 10" off the ground. No damage except to my ego. Last landing was much better because I just flew it on to the ground. I might try setting up spoilerons before the next flight. I'm just about convinced to get a new one and swap over the gear. I think I'll try it again next weekend just to be sure.

Blessings, Terry
still4given is offline  
Reply With Quote
Old 11-11-2007, 09:33 PM
  #382
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Picture of low profile servo in stabilzer modification. All I need to do is add a little red trim to finish it out.
Attached Thumbnails
Click image for larger version

Name:	Qo39339.jpg
Views:	6
Size:	101.7 KB
ID:	801872  
orstraycat is offline  
Reply With Quote
Old 11-11-2007, 09:47 PM
  #383
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Prop direction clarification PLEASE. I have a APC 11 x 7P prop, from what I have read on this forum, if I am understanding correctly, the lettering on the prop faces the nose of the aircraft. If this is the case the spinner won't fit due to the angle of the blades. Do they make a pusher prop spinner or am I being a dummy?
orstraycat is offline  
Reply With Quote
Old 11-11-2007, 09:55 PM
  #384
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

4 blade prop, http://www.zingerpropeller.com/4_bladed_propeller.htm ,anyone use one?
orstraycat is offline  
Reply With Quote
Old 11-11-2007, 09:57 PM
  #385
Crazy4Flight
 
Crazy4Flight's Avatar
 
Join Date: Sep 2002
Location: Milford, MI
Posts: 3,013
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

the hitec low profile aileron servo I once had seemed to be weak on holding torque...
meaning I was able to backdrive the servo with ease.

My next bobcat 50 will have spring air retracts Jett 75 and a Hitec digital thin wing servo for the elevator.
Crazy4Flight is offline  
Reply With Quote
Old 11-11-2007, 10:03 PM
  #386
orstraycat
 
Join Date: Mar 2006
Location: Albany, OR
Posts: 73
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

The servo I am using has 61 oz torque @ 4.8 volts..............
orstraycat is offline  
Reply With Quote
Old 11-11-2007, 10:14 PM
  #387
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: orstraycat

Prop direction clarification PLEASE. I have a APC 11 x 7P prop, from what I have read on this forum, if I am understanding correctly, the lettering on the prop faces the nose of the aircraft. If this is the case the spinner won't fit due to the angle of the blades. Do they make a pusher prop spinner or am I being a dummy?
Just use a prop hub "nut" instead.

e.g. one of these

http://www3.towerhobbies.com/cgi-bin...H=Prop+hub+nut

[link=http://www3.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=Prop+hub+nut]Click ME![/link]
opjose is offline  
Reply With Quote
Old 11-12-2007, 02:02 AM
  #388
AGR413
 
AGR413's Avatar
 
Join Date: Mar 2005
Location: Mesa, AZ
Posts: 442
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Still,

Set up your spoilerons before your next landing, I finally got them dialed in and it completely changed the personality of this plane for landing. I actually brought it in under power and set it on the mains and set the nose down on purpose today! What a difference!

The amount of spoileron I am using is very small but it makes a huge difference, I think all you will need is about 4-5 clicks.

Best of luck.
AGR413 is offline  
Reply With Quote
Old 11-12-2007, 10:53 AM
  #389
bob27s
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: orstraycat

Prop direction clarification PLEASE. I have a APC 11 x 7P prop, from what I have read on this forum, if I am understanding correctly, the lettering on the prop faces the nose of the aircraft. If this is the case the spinner won't fit due to the angle of the blades. Do they make a pusher prop spinner or am I being a dummy?
Yes, the lettering faces forward. Curved side of the airfoil faces forward, flat backside of the blade faces aft.

Not sure on the spinner..... first I have heard an issue on that.
bob27s is offline  
Reply With Quote
Old 11-12-2007, 11:42 AM
  #390
Flyboy Dave
Moderator
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,774
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

....these Du-Bro spinner nuts fit right into the cone on your starter.

Bobcats rule !!
Attached Thumbnails
Click image for larger version

Name:	Vt57656.jpg
Views:	5
Size:	142.2 KB
ID:	802263  
Flyboy Dave is offline  
Reply With Quote
Old 11-13-2007, 12:30 AM
  #391
still4given
 
still4given's Avatar
 
Join Date: Jan 2006
Location: Victorville, CA
Posts: 1,526
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: AGR413

Still,

Set up your spoilerons before your next landing, I finally got them dialed in and it completely changed the personality of this plane for landing. I actually brought it in under power and set it on the mains and set the nose down on purpose today! What a difference!

The amount of spoileron I am using is very small but it makes a huge difference, I think all you will need is about 4-5 clicks.

Best of luck.
Will do. I have had so much trouble getting my Race planes to stay on the ground I just assumed it would be the same with these. Not so I have found. The last landing I set it down at about 1/4 throttle. No wonder these aren't that fast. They slow down so quickly, there must be quite a bit of drag.

Everyone commented on how good it looks in the sky however. It does a decent knife-edge and flies well inverted. I even did a couple of hammer-heads.

As to the spinner, I doubt a regular spinner would work well, even if they made one for reverse pitch. The flat face would be facing forward and creating a lot of drag. I just used an Acorn prop nut to fit my starter cone. I would think ideally you wouldn't want it any bigger than the hub of the prop.

Blessings, Terry
still4given is offline  
Reply With Quote
Old 11-13-2007, 11:53 AM
  #392
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: still4given


No wonder these aren't that fast. They slow down so quickly, there must be quite a bit of drag.

Blessings, Terry
I dunno... mine doesn't seem to slow down that quickly and it's fairly fast with the GMS .76 engine.

That's why I have problems with hot landings.

opjose is offline  
Reply With Quote
Old 11-13-2007, 05:01 PM
  #393
AGR413
 
AGR413's Avatar
 
Join Date: Mar 2005
Location: Mesa, AZ
Posts: 442
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

opjose,

I feel your pain buddy I'm flying the Tower .75, trust me spoilerons are your savior.....

Prior to the spoilerons I was coming in hot and cutting the throttle way out and using a high speed nose down approach and trying to level it out over the runway so than when it slowed down enough it was only 6-8" off the deck, I was using alot of runway for landings and usually ended up bouncing at least once. Factor in wind currents and it really became fun (not).

With spoileron I brought it in under power nose slightly raised (due to the spoilerons), it did not dive at the end of the field (we have a rotor from a wash that runs perpendicular to the field), I flew it right up to where I was standing feeling well in control of the landing reduced the throttle and set it down.

In short I no longer dread landing this plane, hell I may try a few touch and goes.
AGR413 is offline  
Reply With Quote
Old 11-13-2007, 05:34 PM
  #394
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: AGR413

opjose,

I feel your pain buddy I'm flying the Tower .75, trust me spoilerons are your savior.....

Prior to the spoilerons I was coming in hot and cutting the throttle way out and using a high speed nose down approach and trying to level it out over the runway so than when it slowed down enough it was only 6-8" off the deck, I was using alot of runway for landings and usually ended up bouncing at least once. Factor in wind currents and it really became fun (not).
Yup you describe my landings EXACTLY!

I've been trying spoilerons, but I'm unsure as to how much to use.

I've played with different settings... 1/4" seems to be too low, more than that and I'm floundering.

opjose is offline  
Reply With Quote
Old 11-13-2007, 07:03 PM
  #395
AGR413
 
AGR413's Avatar
 
Join Date: Mar 2005
Location: Mesa, AZ
Posts: 442
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Actually I think 1/4" is a little too much, that is about where I started and only tried them up high and decided it was too drastic. I can measure but I think mine are more like 1/8". You won't think they are doing much, they don't show much effect at altitude. I figured since they didn't have much effect at altitude they would not jeopardize my landing so I turned them on when I turned final and was pleasantly surprised.

Believe in the force..the spoilerons will work!
AGR413 is offline  
Reply With Quote
Old 11-13-2007, 07:38 PM
  #396
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

Out of curiosity, are you off-setting the up-pitch with down elevator mixing?
opjose is offline  
Reply With Quote
Old 11-13-2007, 11:32 PM
  #397
AGR413
 
AGR413's Avatar
 
Join Date: Mar 2005
Location: Mesa, AZ
Posts: 442
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

I am not using any elevator offset, just spoileron. I actually just went back to the other thread, I started my experimenting because of some of the discussions you and others were having about the spoilerons. You have probably performed more experimentation all together than I did to achieve the results I desired.

It was one of your statements that really got me thinking,

Quote:
No. The spoilerons ALONE are producing the pitch up effect. Don't thing of the Bobcat like a standard plane. Think of it more like a delta wing.
http://www.rcuniverse.com/forum/m_45...anchor/tm.htm#

The wing on the Bobcat does act more like a delta than a traditional planform. But the chord of the wing is so wide the the spoilerons impart a downforce effect on the back of the wing which brings the leading edge up.

So it is I who should be saying, thanks for the idea.

By the way, is the G3 model you have a variant or an original, if it is an original I would love to have it, I'm running G3.5 and could really use a Bobcat model?
AGR413 is offline  
Reply With Quote
Old 11-14-2007, 11:54 AM
  #398
opjose
 
opjose's Avatar
 
Join Date: Nov 2005
Location: Poolesville, MD
Posts: 12,588
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice


Quote:
ORIGINAL: AGR413


So it is I who should be saying, thanks for the idea.

By the way, is the G3 model you have a variant or an original, if it is an original I would love to have it, I'm running G3.5 and could really use a Bobcat model?
It's a variant on the Kingcat from add-ons disk 2.

If you have the add-ons PM me...

I may just post it to the G3 swap pages tonight if I have a chance.

opjose is offline  
Reply With Quote
Old 11-18-2007, 09:06 AM
  #399
patzane
 
Join Date: Nov 2005
Location: Glendale, AZ
Posts: 653
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

just flare it out a little 3' from ground alway helps and will grease her in.
patzane is offline  
Reply With Quote
Old 11-19-2007, 10:55 AM
  #400
z06kal
 
Join Date: Jun 2004
Location: Woodland Hills, CA
Posts: 208
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Its Bobcat nice

I'm going to be starting a build thread with Bobcat 50. I am doing an electric setup in the 2500-2800 watt range. Will be playing with different props and possibly motors but right my goal is to turn a 12x12 pattern prop at about 12,000-13,000rpm. Doing air retracts as well. I'm trying to make the airframe as clean as possible so I'm going to try to avoid having any servo's protruding except for maybe the aileron servos. Going to do a HS-125MG inside the horizontol and HS-125mg's inside the vertical fins for rudders. These servos have plenty of torque if you power them with 6 volts and I have used them to move bigger control surfaces on sailplanes going well over 200mph so I don't see how they would be a probelm on this plane which I honostly think will be lucky to break 120mph even with this much power ~3.5hp.

I'm thinking about maybe building it first without rudders just steerable nose wheel to see how bad it actually needs the whole dual rudder thing for the higher speed sections of take offs and landings where the nose wheel doesn't have any bite. Any comments?
z06kal is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 08:11 PM.