Its Bobcat nice
10-27-2006, 10:24 AM
#151
RE: Its Bobcat nice
Whoops....my bad.
Now that I looked a little closer, the prop needs to be mounted backwards (from normal)
with the lettering facing away from the installer, which is actually the front of the plane. [sm=stupid.gif]
It will work the way I had it, but you lose the airfoil capabilities of the prop. I thought it
looked funny the way I had it, but since everything is backwards on a pusher, I thougth
....it was just me....[sm=red_smile.gif]
I looks even funnier mounted properly, cause it still looks backwards.
Now that I looked a little closer, the prop needs to be mounted backwards (from normal)
with the lettering facing away from the installer, which is actually the front of the plane. [sm=stupid.gif]
It will work the way I had it, but you lose the airfoil capabilities of the prop. I thought it
looked funny the way I had it, but since everything is backwards on a pusher, I thougth
....it was just me....[sm=red_smile.gif]
I looks even funnier mounted properly, cause it still looks backwards.
10-27-2006, 10:54 AM
#152
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RE: Its Bobcat nice
ORIGINAL: Flyboy Dave
Thanks, Tom....
....A couple small changes, and I should be in business.I have to move the gear forward
a bit to make it easier to rotate, and I'll put a heavy hub on to help move the balance
rearward. I'll also run the engine on 20% next time, instead of 15%, and wind that YS .63
up for everything it's worth. If that's not enough change on the balance, I'll have to hack
the nose off, and remove some of the lead balls I coated with epoxy, and dropped
up in there.
The Guy with the electric Bob-Cat said his balance was all the way back to 10 inches.
Mine is like about 8".
AGR413....I drilled my wing bolts straight through, and through bolted the booms on.
They could be removed easily. Inside the booms are hollowed out, so connectors
could be unplugged, and the rear of the plane removed for transport if necessary.
FBD.
Thanks, Tom....
....A couple small changes, and I should be in business.I have to move the gear forward
a bit to make it easier to rotate, and I'll put a heavy hub on to help move the balance
rearward. I'll also run the engine on 20% next time, instead of 15%, and wind that YS .63
up for everything it's worth. If that's not enough change on the balance, I'll have to hack
the nose off, and remove some of the lead balls I coated with epoxy, and dropped
up in there.
The Guy with the electric Bob-Cat said his balance was all the way back to 10 inches.
Mine is like about 8".
AGR413....I drilled my wing bolts straight through, and through bolted the booms on.
They could be removed easily. Inside the booms are hollowed out, so connectors
could be unplugged, and the rear of the plane removed for transport if necessary.
FBD.
Thanks Dave, I think I am ready to get moving on this now. I am going to get the tower .75 because it actually weighs less than the .61 . Err wait a minute.....I found a new engine in the tower catalog OS .55 I wonder if it would be better.
here's the specs
Displacement: 0.545 cu in (8.93cc)
Bore: .91 in (23mm)
Stroke: 0.85 in (21.5mm)
Weight: 14.3oz (404g)
Recommended Props: 11x6, 11x7, 12x6, 12x7, 13x6
Light weight and swings most of the same props a .61 will swing....hmmmm
10-27-2006, 11:18 AM
#153
RE: Its Bobcat nice
ORIGINAL: R/C Foolish
Maybe I have missed it, but does anybody know what size prop I should use for an OS 61 FX?
Too bad we can't put retracts in this plane but I am going to try the new Fults Scorpion gear,
they look much stronger than the stock wire and I think there is enough hard wood in the wing
for mounting. Also what is everyone else doing, gluing the rear stab or just using the 2 bolts?
R/C Foolish
Maybe I have missed it, but does anybody know what size prop I should use for an OS 61 FX?
Too bad we can't put retracts in this plane but I am going to try the new Fults Scorpion gear,
they look much stronger than the stock wire and I think there is enough hard wood in the wing
for mounting. Also what is everyone else doing, gluing the rear stab or just using the 2 bolts?
R/C Foolish
prop that will fit. The 12-6 will work with the .61 as well.
My wire gear broke on the building table, so I bent up an aluminum job....not real fancy, but
it's all I had laying around. I wasn't about to go hacking into the wings right off the bat. If
the one was that weak, I figured the other one may not be any better.
I epoxy-ed in the rear stab, as well as used some other metal screws, because the stock ones
wouldn't screw in.
FBD. [sm=teeth_smile.gif]
10-27-2006, 11:30 AM
#155
RE: Its Bobcat nice
AGR413 ....
....go with the Tower .75.
I was going to use the Tower.75, but I went with the "more cool" YS .63 Supercharged.
I wasn't going for speed....just going for cool. If the .63 doesn't work out, the .75 will
be in there....real quick.
The OS .55 won't have near the steam the Tower .75 has, I have the Tower in an F-20
and it goes just fine. The Bob_cat is smaller and lighter than the F-20.
The 12-6 Zinger pusher prop will work fine on the Tower .75.
FBD. [sm=teeth_smile.gif]
....go with the Tower .75.
I was going to use the Tower.75, but I went with the "more cool" YS .63 Supercharged.
I wasn't going for speed....just going for cool. If the .63 doesn't work out, the .75 will
be in there....real quick.
The OS .55 won't have near the steam the Tower .75 has, I have the Tower in an F-20
and it goes just fine. The Bob_cat is smaller and lighter than the F-20.
The 12-6 Zinger pusher prop will work fine on the Tower .75.
FBD. [sm=teeth_smile.gif]
10-27-2006, 11:41 AM
#157
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RE: Its Bobcat nice
Muchas Gracias Mi Amigo.....
Hmmm......Tower .75, through bolted tail booms, SEALED HINGES......say a little prayer and go with god my son....lol
I must be a closet speak freak cause I just know that the first few flights I will be nice and easy and then one day...one day on a nice straight away I will HAMMER DOWN.......why can't I stay away from WOT I do not know.
Hmmm......Tower .75, through bolted tail booms, SEALED HINGES......say a little prayer and go with god my son....lol
I must be a closet speak freak cause I just know that the first few flights I will be nice and easy and then one day...one day on a nice straight away I will HAMMER DOWN.......why can't I stay away from WOT I do not know.
10-27-2006, 12:06 PM
#158
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RE: Its Bobcat nice
ORIGINAL: AGR413
Muchas Gracias Mi Amigo.....
Hmmm......Tower .75, through bolted tail booms, SEALED HINGES......say a little prayer and go with god my son....lol
I must be a closet speak freak cause I just know that the first few flights I will be nice and easy and then one day...one day on a nice straight away I will HAMMER DOWN.......why can't I stay away from WOT I do not know.
Muchas Gracias Mi Amigo.....
Hmmm......Tower .75, through bolted tail booms, SEALED HINGES......say a little prayer and go with god my son....lol
I must be a closet speak freak cause I just know that the first few flights I will be nice and easy and then one day...one day on a nice straight away I will HAMMER DOWN.......why can't I stay away from WOT I do not know.
10-27-2006, 12:26 PM
#160
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RE: Its Bobcat nice
ORIGINAL: R/C Foolish
But did they epoxy everything together or just bolt it like the so called manual says?
R/C Foolish
But did they epoxy everything together or just bolt it like the so called manual says?
R/C Foolish
10-27-2006, 09:50 PM
#167
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RE: Its Bobcat nice
Bob I just shook my head when I saw the 63FZ on there.... I was not the maiden pilot but I WAS the 400 yard taxi tester!
How about the Byro set-up like used on the Enforcer? Seems like it'd be a cool set-up...
How about the Byro set-up like used on the Enforcer? Seems like it'd be a cool set-up...
10-28-2006, 12:01 AM
#168
RE: Its Bobcat nice
ORIGINAL: Flyboy Dave
Whoops....my bad.
Now that I looked a little closer, the prop needs to be mounted backwards (from normal)
with the lettering facing away from the installer, which is actually the front of the plane. [sm=stupid.gif]
It will work the way I had it, but you lose the airfoil capabilities of the prop. I thought it
looked funny the way I had it, but since everything is backwards on a pusher, I thougth
....it was just me....[sm=red_smile.gif]
I looks even funnier mounted properly, cause it still looks backwards.
Whoops....my bad.
Now that I looked a little closer, the prop needs to be mounted backwards (from normal)
with the lettering facing away from the installer, which is actually the front of the plane. [sm=stupid.gif]
It will work the way I had it, but you lose the airfoil capabilities of the prop. I thought it
looked funny the way I had it, but since everything is backwards on a pusher, I thougth
....it was just me....[sm=red_smile.gif]
I looks even funnier mounted properly, cause it still looks backwards.
The wood props you put the label towards the front of the aircraft. My APC pusher the hub is mounted the same as the regular APC props. The molded prop size towards the propnut.
Well duh one day trying new prop out...stuck it on bassackwards! Well the Bobcat-Jett .50 did used 300' of the paved runway and got off and flying. One circuit of the field and I put her down and found out I had a blonde moment.[sm=bananahead.gif]
11-07-2006, 07:06 PM
#171
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RE: Its Bobcat nice
What prop is everyone using, I have an OS 61 fx. Right now I have a Zinger 12x6 P. Did the maiden on Sunday. Make sure you have a lot of elevator. Take off was not pretty but she flew nice once I had it trimmed out. Landed right on the mains but then I noticed that 1 of the bolts holding the rudder boom was loose. Brought it home and reglued the blocks that the blind nuts are in. I might thru bolt if this does not hold.
R/C Foolish
R/C Foolish
11-13-2006, 01:39 AM
#174
RE: Its Bobcat nice
I read the thread in the Jets Forum (it took awhile) and it looks like the best c/g
measurement (tested and flown) came out to be 10 to 10 1/4". Now it seems the
new planes have the c/g corrected.
No wonder mine wouldn't rotate and fly. They also had troubles with the landing
gear blocks breaking....they had practically no glue on them. From what I read
my engine choice may not have been the best, but we'll see It might help if I
put the prop on the right way, run it on 20% instead of 15%, and wind up the
RPM all the way....and back it off about 300.
They also complained the main gear was too thin and weak, and too far back, just
as I found out. I'll have to cut the nose of mine off, and remove some of the weight.
I have a new one already on the way too, a grey and orange one....
__________________________________________________ __________________
Here's the info I stole from the Jet Guys thread....
Based on calculation from http://jef.raskincenter.org/publishe...nce_point.html , Aerodynamic Center should be 9.74 from L.E. of wing root. Based on graphical solutions, Aerodynamic Center should be 11" from L.E of wing root (assuming 25% chord). Attached is a picture illustrating my graphical solution (aero experts, please make necessary corrections.) Therefore assuming balancing with a full tank, the CG should be between 9.74" and 11".
11" from leading edge instead of the 6.90 makes alot more sense when actually trying to balance one of these things. 6.90 from trailing edge would seem closer to this measurement.
I have calculated the cg several times using different websites, and formulas. They all come out about the same. Around 11" back from the leading edge of the wing AT THE CENTER OF THE FUSE or around 9.3 or so from the leading edge where it meets the fuse.
** nine inches worked **
One thing Dave, Vernon had to change is CG from 9 to 9 3/4 inch. from the LE. When he came in to land with the CG at 9" the Bobcat ran out of elevator and the plane pancake into the runway. With the CG at 9 3/4 from the LE it was perfect.
If anyone is looking for a 10" to 12" 3 bladed pusher props Zinger (www.zingerpropeller.com) makes them. Thier system uses individual blades in a machined center hub. I just bought a three blade 11-8 prop to put on my Magnum 75 2 stroke for my Bobcat.
For reference my CG is a 10" from the wing at the fuse and it seemed perfect.
The C of G was 255mm or just over 10". It was a touch too far forward and we needed some up trim. We may move it back 3mm when we fly at the weekend, it was not far out though and we did not run out of up elevator. The current consensus of 260mm or 10.25" is probably right.
__________________________________________________ _________________________________
FBD.
measurement (tested and flown) came out to be 10 to 10 1/4". Now it seems the
new planes have the c/g corrected.
No wonder mine wouldn't rotate and fly. They also had troubles with the landing
gear blocks breaking....they had practically no glue on them. From what I read
my engine choice may not have been the best, but we'll see It might help if I
put the prop on the right way, run it on 20% instead of 15%, and wind up the
RPM all the way....and back it off about 300.
They also complained the main gear was too thin and weak, and too far back, just
as I found out. I'll have to cut the nose of mine off, and remove some of the weight.
I have a new one already on the way too, a grey and orange one....
__________________________________________________ __________________
Here's the info I stole from the Jet Guys thread....
Based on calculation from http://jef.raskincenter.org/publishe...nce_point.html , Aerodynamic Center should be 9.74 from L.E. of wing root. Based on graphical solutions, Aerodynamic Center should be 11" from L.E of wing root (assuming 25% chord). Attached is a picture illustrating my graphical solution (aero experts, please make necessary corrections.) Therefore assuming balancing with a full tank, the CG should be between 9.74" and 11".
11" from leading edge instead of the 6.90 makes alot more sense when actually trying to balance one of these things. 6.90 from trailing edge would seem closer to this measurement.
I have calculated the cg several times using different websites, and formulas. They all come out about the same. Around 11" back from the leading edge of the wing AT THE CENTER OF THE FUSE or around 9.3 or so from the leading edge where it meets the fuse.
** nine inches worked **
One thing Dave, Vernon had to change is CG from 9 to 9 3/4 inch. from the LE. When he came in to land with the CG at 9" the Bobcat ran out of elevator and the plane pancake into the runway. With the CG at 9 3/4 from the LE it was perfect.
If anyone is looking for a 10" to 12" 3 bladed pusher props Zinger (www.zingerpropeller.com) makes them. Thier system uses individual blades in a machined center hub. I just bought a three blade 11-8 prop to put on my Magnum 75 2 stroke for my Bobcat.
For reference my CG is a 10" from the wing at the fuse and it seemed perfect.
The C of G was 255mm or just over 10". It was a touch too far forward and we needed some up trim. We may move it back 3mm when we fly at the weekend, it was not far out though and we did not run out of up elevator. The current consensus of 260mm or 10.25" is probably right.
__________________________________________________ _________________________________
FBD.
11-13-2006, 09:37 AM
#175
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RE: Its Bobcat nice
looks like some goofyball calculated and marked the CG based on the wing root airfoil section, not taking into account it was a tapered and swept wing.