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Nitro models pusher Bobcat?

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Old 12-13-2007, 10:59 PM
  #2701
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Default RE: Nitro models pusher Bobcat?

Yup, not a big deal.

Just sand down the wing roots and the fuse until they are even.

I had to do this on two of these planes.

A circular sander makes short work of it.



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Old 12-14-2007, 11:12 AM
  #2702
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: wflineman2

I got my Bobcat the other day, put the main wings on bar and pushed up against fuse and they did not line up, one hit the front first and the other hit the back first with a gap on each. The holes in the fuse is at an angle. Has anybody had this trouble.
I had some of what you are talking about, I installed wing bolts, when they are tightened down the gaps go away. Well all except the ones at the trailing edge, I used some crystal clear duck tape to eliminate the gaps at the rear. Yes I'm a fan of the KISS principle.
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Old 12-14-2007, 08:28 PM
  #2703
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: wflineman2

I got my Bobcat the other day, put the main wings on bar and pushed up against fuse and they did not line up, one hit the front first and the other hit the back first with a gap on each. The holes in the fuse is at an angle. Has anybody had this trouble.

Are you talking about the wing tube or the anti-rotation rod?
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Old 12-14-2007, 10:04 PM
  #2704
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Default RE: Nitro models pusher Bobcat?

The wing tube is out of line, when I measure from wing tube to anti-rotation rod there is 1/8" difference.
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Old 12-14-2007, 11:00 PM
  #2705
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Default RE: Nitro models pusher Bobcat?

can someone tell me where to get the wesson pusher pipe in the USA
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Old 12-14-2007, 11:38 PM
  #2706
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Default RE: Nitro models pusher Bobcat?

Shouldn't be too difficult to straighten out alingment of the wing tube. Dremel out the holes in the fuse to get wings lined up correctly and glue in some plwood plates with the correct size hole inside the fuse (oil or wax the tube first). Cut two or three sticks slighly longer than the fuse wedge between the plates to use as clamps while the glue cures on plywood plates. Tape the wings in place to insure alignment. When that cures fill in holes on outside of fuse.
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Old 12-15-2007, 05:10 PM
  #2707
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Default RE: Nitro models pusher Bobcat?

Quote:
The wing tube is out of line, when I measure from wing tube to anti-rotation rod there is 1/8" difference.
The left wing was off a little. I used a round file and elongated the anti-rotation hole in the fuselage and the wing slightly and everything was OK. No need to make it complicated at this point. After everything is together alignment can be more easily checked and then adjusted.

Bill
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Old 12-15-2007, 06:03 PM
  #2708
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: wflineman2

The wing tube is out of line, when I measure from wing tube to anti-rotation rod there is 1/8" difference.
Good advice from fw190pilot. This would be my method as well. I wouldn't do any sanding of the wing roots or fuse as these areas are not the source of the problem. Just be sure to try fitting the wings without the anti-rotation rod to make sure it is the wing tube holes that are off.
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Old 12-15-2007, 06:14 PM
  #2709
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: Meekskin

can someone tell me where to get the wesson pusher pipe in the USA

Here's the website:
http://www.westonuk.co.uk/index_090.htm

Based in UK but USA orders get shipped from Chicago branch so you only pay USA shipping rates.
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Old 12-15-2007, 06:17 PM
  #2710
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: Stick Jammer


Good advice from fw190pilot. This would be my method as well. I wouldn't do any sanding of the wing roots or fuse as these areas are not the source of the problem. Just be sure to try fitting the wings without the anti-rotation rod to make sure it is the wing tube holes that are off.
Did I misunderstand the problem?

I though that he referred to the wing not sitting flat against the fuselage, in addition to the alignment pins being off.

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Old 12-15-2007, 08:20 PM
  #2711
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Default RE: Nitro models pusher Bobcat?

that sounds good..Thanks for the link and I'll order the pipe.

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Old 12-15-2007, 08:30 PM
  #2712
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: opjose


Quote:
ORIGINAL: Stick Jammer


Good advice from fw190pilot. This would be my method as well. I wouldn't do any sanding of the wing roots or fuse as these areas are not the source of the problem. Just be sure to try fitting the wings without the anti-rotation rod to make sure it is the wing tube holes that are off.
Did I misunderstand the problem?

I though that he referred to the wing not sitting flat against the fuselage, in addition to the alignment pins being off.


The way it sounded to me, one wing is touching the fuse at the leading edge of the root with a gap at the trailing edge and the other wing is touching the fuse at the trailing edge of the root with a gap at the leading edge. This would indeed seem to be a misalignment of the wing tube holes in the fuse. I forgot how far back into the fuse the wing tube actually sits, so fw190pilot's method of gluing in the plates may not be too easy. If the wing tube holes are indeed misaligned I would definitely find a way to get them where they belong but at this time I can't suggest an easy method without being in those shoes.
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Old 12-15-2007, 09:13 PM
  #2713
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Default RE: Nitro models pusher Bobcat?

Thanks.

I misread it then.

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Old 12-20-2007, 07:39 PM
  #2714
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Default RE: Nitro models pusher Bobcat?

http://www.youtube.com/watch?v=oEFBtqjmIuM


very funny, bobcat was the winner
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Old 12-21-2007, 08:20 AM
  #2715
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: wflineman2

I got my Bobcat the other day, put the main wings on bar and pushed up against fuse and they did not line up, one hit the front first and the other hit the back first with a gap on each. The holes in the fuse is at an angle. Has anybody had this trouble.
I also tapped the wing rib and used 1/4-20 nylon bolts to secure the wing to the fuselage. As the wing tightens up any fit inaccuracy is hidden. The nylon bolts go in from inside the fuselage and knurled bolts were used. I used one bolt for each wing.

Bill
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Old 12-21-2007, 11:34 AM
  #2716
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Default RE: Nitro models pusher Bobcat?

Has anyone purchased the Gensis pusher pipe from Weston in the UK. I bought one and cannot get the company to reply to any emails about the shipping date. I have sent them an email each day for the past week....no replys at all..not very good company at this point.
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Old 12-22-2007, 09:45 PM
  #2717
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Default RE: Nitro models pusher Bobcat?

When you guys balanced your bobcat, did you balance up side down or right side up...I have retracts in mine and assume it needs to be balanced up side down with the retracts up. what you think??
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Old 12-23-2007, 03:15 AM
  #2718
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Default RE: Nitro models pusher Bobcat?

Always ballance upside down

Dennis
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Old 12-23-2007, 11:47 AM
  #2719
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Default RE: Nitro models pusher Bobcat?

I had some glue in a blind nut holding the nose gear steering. With a little tap, tap the former came loose and out. It was good to get the former out to replace the blind nut. It was not good that the former came out so easily.

Consider reinforcing the former to fuselage joints or at least inspecting the joints after the initial flights.

I balance in a string cradle and it doesn't matter which way is up.

How much weight did the retracts add?

Bill
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Old 12-23-2007, 12:34 PM
  #2720
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Default RE: Nitro models pusher Bobcat?

Bills,,,,I'm really not sure but my total weight ready to fly is 7lbs 12oz. I am using Robart retracts (older ones with hard plastic housing) which is lighter than the all metal retracts. I could lose a oz. or so by getting a smaller air tank. Some mods to the firewall former were required like taking out the factory installed rails and putting in a plate that allows the retract to sit lower in the plane. This allows the wheel to retract inside the plane. I am using the Magnum 52 engine with a Weston pusher pipe. This engine turns 16,500 with the stock pipe and will easily turn 18,000 plus with the weston pipe. I am really please with the way the jet went together and plan on the maiden flight soon after the new year.

My first attempt at balancing the plane shows it to be nose heavy with the battery up in the nose but this was trying to balance using my fingers and I don't know for sure its nose heavy.

I have gone over all glue joints that I could reach. The glue and the coverage from the manufacture is not good. I have the Bobcat 25 that I am flying with a OS32 and its a great plane to fly so I am expecting the 52 to fly even better. With the weight under 8 lbs. and the great motor, I am expecting level flight speeds to be over 100 mph. Other than the mod for the nose retract, I built the jet stock. The mains fit perfect and work fawless. I'm using 3/16 wire for the mains and 5/32 for the nose and when they are in the up position the jet looks really clean.

I will post some pics now that I'm almost finished.
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Old 12-23-2007, 05:03 PM
  #2721
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Default RE: Nitro models pusher Bobcat?

Quote:
ORIGINAL: bigplumbs

Always ballance upside down

Dennis

When you say "always", do you mean any plane or this one? General rule of thumb is to balance with the bulk of the plane facing down for the simple reason of having more mass below the point of balance which tends to make the process easier. Other than that it doesn't matter if the plane is upright or inverted. I balanced my Bobcat upright with no trouble at all.
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Old 12-23-2007, 06:21 PM
  #2722
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Default RE: Nitro models pusher Bobcat?

Mine is now balanced and I did it upright. I just held the plane at eye level and used one hand. Also a few pics of the gear tucked away.
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Old 12-23-2007, 06:27 PM
  #2723
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Default RE: Nitro models pusher Bobcat?

It's a very good idea to use the carriage washer as you've done, to spread the force out over the surface.

I'd recommend doing so to anyone else as well. You can find these specialty washers in most hardware stores.

They have a relatively small hole but are large in area.

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Old 12-23-2007, 07:04 PM
  #2724
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Default RE: Nitro models pusher Bobcat?

Opjose, I agree with you on the carriage washer. I also put a metal tube inside the wing which allows the screw to be tightened down really tight. No movement on the booms. I also recommend everyone to use locktight on all metal to metal screws. There are 3 members in our club that's building the Bobcat and we will all maiden the same day....at least thats our plan. I will take pics and post them here when we fly. Also hope to get Radar gun to check speeds to see who is the fastest. Course, is its not me, I will be disappointed.
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Old 12-23-2007, 07:48 PM
  #2725
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Default RE: Nitro models pusher Bobcat?

Quote:
I am really please with the way the jet went together and plan on the maiden flight soon after the new year.
Good looking pictures. Hope the maiden is very successful.

Bill
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