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Old Aug 30, 2012, 02:54 PM
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Iflyrc_vic's Avatar
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Motor Mount

Quote:
Originally Posted by G-Forced View Post
No, I just used standoffs from a duel sky standoff kit - I went with this as it was an " off the shelf adjustable ( within the limits i needed ) package that worked well. It is still just a little to much spacing between spinner plate and cowling end but nothing that I cant live with.

Let me know if you need my process i used... G
I have used an aluminum adjustable mount, weighing only 69g, for 40xx size motors as shown in the attachment. They are very sturdy and give you a comfortable feeling when using a big motor. I might just go with the stock mount as it looks pretty sturdy. I am also going to use Hitec 225MG servos on all control surfaces.
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Last edited by Iflyrc_vic; Aug 31, 2012 at 07:02 AM. Reason: adde servo info
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Old Aug 30, 2012, 04:51 PM
Battery Puffer
Orange, California, United States
Joined Nov 2001
1,109 Posts
I just used standoffs as well. My motor wouldn't have worked with the mounts anyways because the mounts are too long for my motor. Your mount should work great. Your going to enjoy mounting those wheel pants to the wing. I found most of the hardware was good except the eye bolts and clevis connectors. Some of them are way too loose to even be usable but luckily I had some left over from another project. I used 225 mg Servos as well. Mines all done now and ill get a pic of it to post tommorow.
Mark
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Old Aug 30, 2012, 06:50 PM
Team Park Pilot - Airborne
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Australia, NSW, Sydney
Joined Nov 2006
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Yes I found that to Mark. They don't seem to click in properly do they ? luckily they are very cheap to swap out for better Dubro ones.
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Old Aug 31, 2012, 06:57 AM
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USA
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Motor Mount

After making measurements, the stock plywood motor mount (76g) will not work for the Scorpion 4035 motor. The Scorpion motor is a "back mounted" type motor that mounts on the stationary part with the rotating drum facing forward. Therefore I will use the aluminum mount (69g) similar to the installation shown here for my Lancair.

My measurements show about 127mm from the face of the plywood motor box to the front of the cowl. The Scorpion motor is 70mm which leaves only 57mm for the motor mount.

The ESC can be mounted as shown or below the plywood motor box that extends out from the firewall on the Gee Bee.
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Old Aug 31, 2012, 08:39 PM
Team Park Pilot - Airborne
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Australia, NSW, Sydney
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L overly Lancair !! Is the the great plane one ?
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Old Aug 31, 2012, 08:46 PM
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Holes in Wing

OK guys, what's up with these holes in the wing? I did not see these in the instructions or on the video from TBM that shows how to put this plane together. I also did not see these holes in any of the photos of any planes in this thread. I know what they are for - access to the gear mounting tabs. But I thought there was an access hatch for each mounting tab with a "plug" to cover the hole.

There was no covering in the kit to cover these holes so I guess they leave it up to the builder to cover or not to cover.

I saw the square access plug type setup on the video from G-Force. This must be their new design to reduce cost - bad design. Anyone else have a kit like this?
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Old Aug 31, 2012, 09:39 PM
Battery Puffer
Orange, California, United States
Joined Nov 2001
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Yes I used the leftover clear from the decal sheet just so it can't get inflated with air. The big 66 decal covers some of the holes as well. I wasn't too happy either when I saw the holes but soon got over it.
Mark
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Old Aug 31, 2012, 10:41 PM
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USA
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Quote:
Originally Posted by G-Forced View Post
L overly Lancair !! Is the the great plane one ?
Yep. Its the 60 size Lancair from Great Planes. Flies like a dream. Better on 8S electric with the OS .50 motor than with the .91 four stroke. Drop the flaps and grease the landing for a high five from the guys in the pits. Love that plane.
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Old Aug 31, 2012, 10:51 PM
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Quote:
Originally Posted by MarkF View Post
Yes I used the leftover clear from the decal sheet just so it can't get inflated with air. The big 66 decal covers some of the holes as well. I wasn't too happy either when I saw the holes but soon got over it.
Mark
Glad I'm not the only one with this new design. It was obviously a cost savings change. I'll try to cover the holes with some Monokote.

I am going to have to drop the front end of the cowl a bit to get it square with the firewall. Results in the black pin strip a little misaligned, but not too much. Close inspection of G-Forces model shows the same situation. Hardly noticeable.

Wonder what else they changed?
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Old Sep 05, 2012, 09:53 AM
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Building the plane

I saw a few ideas on another forum that I plan to incorporate:

I added the side reinforcements inside forward part of the fuse.

I plan to install the balsa sheet on the front of the firewall and cut some holes in it for air flow - some folks had issues with too much pressure inside the fuse that blew off the canopy. I can always increase the size of the holes if things get hot.

I will cut some air exit holes in the underside of the fuse.

I have heard a lot of complaints about the poor quality and functionality of the flying wires. Anyone have any suggestions on how to upgrade the flying wires?
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Old Sep 05, 2012, 11:15 AM
Battery Puffer
Orange, California, United States
Joined Nov 2001
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I used those side pieces to make a battery tray. They are for support for running a gas motor. I covered up the firewall too but will not be making any openings. I think that's what caused the pressure to build up and pop the canopy. I avoided a near disaster on my maiden flight. The plane ballooned up and rolled left so bad it took all of my stick travel to correct it. I'm very lucky to get it down in one piece. One thing that happened was one of the wires came off on one of the wings and I think that caused a bad warp in the wing. I changed some of the hardware but didn't have enough to change all of them. The mount out in the middle of the wing were the wire goes to was the only thing that broke and I made a pretty soft landing. I will be changing all of the pull pull hardware now to new and will fix the wing. There's a good video of this plane and some instructions on Troybuilt models website.
Mark
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Old Sep 05, 2012, 11:35 AM
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Quote:
Originally Posted by MarkF View Post
I used those side pieces to make a battery tray. They are for support for running a gas motor. I covered up the firewall too but will not be making any openings. I think that's what caused the pressure to build up and pop the canopy. I avoided a near disaster on my maiden flight. The plane ballooned up and rolled left so bad it took all of my stick travel to correct it. I'm very lucky to get it down in one piece. One thing that happened was one of the wires came off on one of the wings and I think that caused a bad warp in the wing. I changed some of the hardware but didn't have enough to change all of them. The mount out in the middle of the wing were the wire goes to was the only thing that broke and I made a pretty soft landing. I will be changing all of the pull pull hardware now to new and will fix the wing. There's a good video of this plane and some instructions on Troybuilt models website.
Mark
WOW! Glad to hear you got her down OK. This looks like a model that deserves a lot of close inspection before the maiden. I will check the flying wires and may make some mods to beef them up. My thoughts are to go with 2-56 steel push rods and metal clevices instaed of the wire on the bottom of the wing that seems to take a beating due to their attachment to the landing gear. Not sure the top wires are functional.

I have seen the videos from Try Built Models.

1. Did you ever get the plane into a straight and level flight or was it just a quick up, around and back down? Just wondering about CG.
2. Did the wire come off just after takeoff or after you landed?
3. Did you go with the 8S power system?
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Last edited by Iflyrc_vic; Sep 05, 2012 at 01:32 PM. Reason: 2-56 push rod mod
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Old Sep 05, 2012, 03:46 PM
Rangers Lead the Way
United States, CA, Claremont
Joined Mar 2010
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For CG / maiden purposes, guys, recommend you always start no further back than 25% root chord from the LE. Mark's situation sounds like possible tail-heavy, along with p-factor, and not letting the roll-out speed build up enough before lift-off (probably due to holding too much up-elevator). These conditions, operating together, are virtually guaranteed to produce the dreaded "death roll" to the left. This design has a short tail-moment, so p-factor will always be present, no matter what prop you use. Move the throttle up, release any elevator you had fed in to keep the tail down on taxi, apply right rudder to counterract left yaw, and let your speed build up. Once she's up on the mains moving straight down the runway, give just enough elevator to lift her off the deck and gain altitude gently - no more than 15 degrees climb angle. Once she's in the air, the tail will gain full authority and rudder is no longer needed to keep her tracking straight.

It took me a lot of practice to do this consistently, but it is now second-nature to me. This is standard to all tail-draggers with higher wing loading and especially the .60 size and up warbirds. The hardest part for me was how much rudder to apply without over-correcting and having the plane all over the runway. I tried expo but that just made it worse. In the end, I use full rates with 50% expo for taxiing (the expo is there in case I forget to flip the switch prior to take-off) and 50% rates no expo for flying / take-off roll. Again, the Cermark FR is a good practice rig because it has many of the same characteristics as the larger plane, including tricky ground handling. Good luck!
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Old Sep 05, 2012, 04:14 PM
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Quote:
Originally Posted by TTRotary View Post
--- Move the throttle up, release any elevator you had fed in to keep the tail down on taxi, apply right rudder to counterract left yaw, and let your speed build up. Once she's up on the mains moving straight down the runway, give just enough elevator to lift her off the deck and gain altitude gently - no more than 15 degrees climb angle. Once she's in the air, the tail will gain full authority and rudder is no longer needed to keep her tracking straight.---
TTRotary, I agree, in theory, with the method you prescribe for performing take-offs with tail draggers. In most cases I do exactly what you have prescribed. However, as you also said, this takes a lot of practice.

For some of the more difficult models, I have just resorted to the "gun-it-and-go" method. For this model, I have only seen the easy roll-out method used successfully on the realy big 100CC size planes. Nearly all of the videos I have seen of take-offs with the small size model has been tricky. Even that "expert" guy at SEFF seemed to just "gun-it-and-go" with a short roll-out.

The long roll with the tail coming up slowly then a gradual rise off the runway is a beautiful thing, but hard to master. I suspect it is hard to master with this model.

Hope I can get this bird in the air successfully, one way or the other.

Vic
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Old Sep 05, 2012, 08:00 PM
Rangers Lead the Way
United States, CA, Claremont
Joined Mar 2010
2,168 Posts
Quote:
Originally Posted by Iflyrc_vic View Post
TTRotary, I agree, in theory, with the method you prescribe for performing take-offs with tail draggers. In most cases I do exactly what you have prescribed. However, as you also said, this takes a lot of practice.

For some of the more difficult models, I have just resorted to the "gun-it-and-go" method. For this model, I have only seen the easy roll-out method used successfully on the realy big 100CC size planes. Nearly all of the videos I have seen of take-offs with the small size model has been tricky. Even that "expert" guy at SEFF seemed to just "gun-it-and-go" with a short roll-out.

The long roll with the tail coming up slowly then a gradual rise off the runway is a beautiful thing, but hard to master. I suspect it is hard to master with this model.

Hope I can get this bird in the air successfully, one way or the other.

Vic
The problem with "just gunning it" is that sometimes it works - and sometimes it doesn't, resulting in the plane reverting to kit form. Mastering the technique and also deveoping consistent landing skills should be done before one owns these more expensive and complex models. It will save you a lot of heartache and expense in the long run. I am new to flying (2.5 years into it) but I made sure I mastered take-offs and landings and make sure I stay in practice - especially landings. It's well worth the effort...
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