ThunderTiger Rare Bear
08-14-2012, 06:42 PM
#1726
RE: ThunderTiger Rare Bear
Still slugging away. One wing is now reskinned and waiting for the filler to dry before final sanding and bonding on the tip. Second wing has the skin bonded to the aft false spar from root to tip, the first step in the process. Next is to glue the skin from the main spar aft and wait for it to cure.
The reason for this is I can maintain a straight surface much easier and minimize sanding once its done. There is the inevitable bit on the rear bond and at the LE, but it contours out nice.
Once both are done it will be waiting for the LHS to notify me the new roll of UltraCote is in. I plan to follow my normal procedure and do each panel top and bottom in a single sheet. Hate overlaps at the LE where they can debond. The root cooler inlet areas may prove to be the killer here.
The reason for this is I can maintain a straight surface much easier and minimize sanding once its done. There is the inevitable bit on the rear bond and at the LE, but it contours out nice.
Once both are done it will be waiting for the LHS to notify me the new roll of UltraCote is in. I plan to follow my normal procedure and do each panel top and bottom in a single sheet. Hate overlaps at the LE where they can debond. The root cooler inlet areas may prove to be the killer here.
08-25-2012, 10:04 AM
#1727
RE: ThunderTiger Rare Bear
Oh, boy, wings are finally complete! Put the finishing touches on this morning by mounting the last servo tray and tightening down the wire ties inside to retain the wiring.
Along the way I made a few minor changes. The covering allowed me to fold over and bond to the ailerons, so there is a much better gap seal than before. Second was to trim the oil cooler inlets some more to make their installation into the wing less obviously an add on.
While things were curing I started the work on the fuselage. Other than the gelcoat the most visible was around the battery compartment. I had to fab some new bits and pieces to fill in the area above the part of the compartment that fit within the fuse. In the last pic that is the odd shaped curved section. I also added a better block for the top center cowl screw.
There were a few breaks in the side frames towards the aft end, likely from when the fuse flexed on impact. Nothing a few minutes and some lite play won't fix. The extra structures I added for the power distribution system were hardest hit and there will need to be rebuilding with the emphasis on better strength.
I found one I did not expect at all and was there from the beginning. Due to the throttle cable routing the carb arm extended out beyond the mount. There was enough flex in the mount that the throttle setting could be compromised and/or erratic. I could have done bracing on the side beams to stiffen them up, but a simpler method was to replace it with a stiffer version. The Dave Brown mount was the ticket, except for the fact it was slightly too short to give me the distance from the prop flange to firewall. Out came a block of Delrin and a few minutes had a spacer fabricated. I had to hog out a channel to allow for the fuel line to reach from the tank to filter, but since this is not structural there should be no problem. I did slightly carve out the mount beam to add a bit of spacing to the muffler. Not anywhere near as bad as the original. With hands my size it was a bit of fun to reach in now to install the blind nuts. This is when you wish you had the 3-year old so common in advertising. Currently the spacer and mount are installed and waiting for the epoxy for the upper battery compartment case to cure.
Pulling a lot out of the way for the mount installation gave me a better chance to have a boo at the structure and composite, but it also allowed some access to the area ahead of the wheel bays. Still, installing the ply doublers for the front dowels will be exceedingly difficult now. Cannot believe I passed the fact there was nothing but composite skin for the dowel to sit in during the build and admittedly is my own fault.
Along the way I made a few minor changes. The covering allowed me to fold over and bond to the ailerons, so there is a much better gap seal than before. Second was to trim the oil cooler inlets some more to make their installation into the wing less obviously an add on.
While things were curing I started the work on the fuselage. Other than the gelcoat the most visible was around the battery compartment. I had to fab some new bits and pieces to fill in the area above the part of the compartment that fit within the fuse. In the last pic that is the odd shaped curved section. I also added a better block for the top center cowl screw.
There were a few breaks in the side frames towards the aft end, likely from when the fuse flexed on impact. Nothing a few minutes and some lite play won't fix. The extra structures I added for the power distribution system were hardest hit and there will need to be rebuilding with the emphasis on better strength.
I found one I did not expect at all and was there from the beginning. Due to the throttle cable routing the carb arm extended out beyond the mount. There was enough flex in the mount that the throttle setting could be compromised and/or erratic. I could have done bracing on the side beams to stiffen them up, but a simpler method was to replace it with a stiffer version. The Dave Brown mount was the ticket, except for the fact it was slightly too short to give me the distance from the prop flange to firewall. Out came a block of Delrin and a few minutes had a spacer fabricated. I had to hog out a channel to allow for the fuel line to reach from the tank to filter, but since this is not structural there should be no problem. I did slightly carve out the mount beam to add a bit of spacing to the muffler. Not anywhere near as bad as the original. With hands my size it was a bit of fun to reach in now to install the blind nuts. This is when you wish you had the 3-year old so common in advertising. Currently the spacer and mount are installed and waiting for the epoxy for the upper battery compartment case to cure.
Pulling a lot out of the way for the mount installation gave me a better chance to have a boo at the structure and composite, but it also allowed some access to the area ahead of the wheel bays. Still, installing the ply doublers for the front dowels will be exceedingly difficult now. Cannot believe I passed the fact there was nothing but composite skin for the dowel to sit in during the build and admittedly is my own fault.
09-09-2012, 05:04 PM
#1729
RE: ThunderTiger Rare Bear
Except for marking and drilling the blocks for the front wing dowels the fuse is done. Reverse to the build sequence I started at the front and worked aft, with the aforementioned replacement and reinforcement of the battery tray and firewall. The Saito 125 is mounted and ready to fire up again. The ply side plates were relatively intact and only needed cleaning up where the tank retainer ripped away. Not surprising when figuring at least 12 oz fuel kept moving when it hit on the roof.
Next was the power distribution panel. Originally it was run from the side plates to some structure added behind the front cockpit opening bulkhead. Not the most elegant solution and also not the strongest. In place I ran ply from the side braces up to the bottom of that ring bulkhead, then added very lite ply facing to cover the joints and add strength. The new side plates then bonded to that facing. Much shorter structural elements that should be more than adequate.
While at that I got at some other issues I had from day one. All that wiring just happened to impinge in the joiner tube area, always getting in the way when the tube was inserted. I rerouted a lot of it and then added a wood dowel across to keep everything clear of the tube opening. The only real concern was to avoid any stress on any of the wiring, especially if leading to a connection or plug. There is a LOT of wiring in there! Still some rerouting to do as both retract and aileron plugs are to the back of the wing now and I will be replacing the receiver. Even though it tests fine I never like to trust one that had a bonk. It will likely be relegated to a much lighter and less costly model.
The cracks in the gelcoat were mostly cosmetic, but there was some signs of delamination in the glass. Most got a drop of thin CA and now have most of the flex removed. Cannot do anything about the looks at this point and will have to stay until I ever need to repaint.
The tail held up remarkably well. No signs of any structural damage and the horizontal stabs feel as rigid as ever.
Coming close to checking weight-and-balance again. Will be interesting to see if yanking the extra lead from the front of the battery compartment makes a difference. That was intended to only compensate for the lack of the cowl and would have been removed anyway.
I did tilt the main gear forward a touch. It does make the wheels look a bit wonky in the wells, but still below the surface so doors should not be a problem. Really hoping that will stop that nasty tendency to try and nose over at the slightest opportunity.
I'll have some pics tomorrow. I had to send my new camera back for warranty and the trusty Canon does not like low light as much.
Not directly related, but primarily for this plane, I am collecting all the bits to fab a PVC assembly and carrying stand. It will have seat belt webbing as supports so the plane can be flipped to any attitude. Should make installation and removal of the wings and/or working on the fuse a lot easier. The sizing will be fine for the Harvard, as well. The foam holder I have been using to date came with the Seawind, a completely different shaped fuse, (amphibian) and although way off served yeoman service up to now.
Next was the power distribution panel. Originally it was run from the side plates to some structure added behind the front cockpit opening bulkhead. Not the most elegant solution and also not the strongest. In place I ran ply from the side braces up to the bottom of that ring bulkhead, then added very lite ply facing to cover the joints and add strength. The new side plates then bonded to that facing. Much shorter structural elements that should be more than adequate.
While at that I got at some other issues I had from day one. All that wiring just happened to impinge in the joiner tube area, always getting in the way when the tube was inserted. I rerouted a lot of it and then added a wood dowel across to keep everything clear of the tube opening. The only real concern was to avoid any stress on any of the wiring, especially if leading to a connection or plug. There is a LOT of wiring in there! Still some rerouting to do as both retract and aileron plugs are to the back of the wing now and I will be replacing the receiver. Even though it tests fine I never like to trust one that had a bonk. It will likely be relegated to a much lighter and less costly model.
The cracks in the gelcoat were mostly cosmetic, but there was some signs of delamination in the glass. Most got a drop of thin CA and now have most of the flex removed. Cannot do anything about the looks at this point and will have to stay until I ever need to repaint.
The tail held up remarkably well. No signs of any structural damage and the horizontal stabs feel as rigid as ever.
Coming close to checking weight-and-balance again. Will be interesting to see if yanking the extra lead from the front of the battery compartment makes a difference. That was intended to only compensate for the lack of the cowl and would have been removed anyway.
I did tilt the main gear forward a touch. It does make the wheels look a bit wonky in the wells, but still below the surface so doors should not be a problem. Really hoping that will stop that nasty tendency to try and nose over at the slightest opportunity.
I'll have some pics tomorrow. I had to send my new camera back for warranty and the trusty Canon does not like low light as much.
Not directly related, but primarily for this plane, I am collecting all the bits to fab a PVC assembly and carrying stand. It will have seat belt webbing as supports so the plane can be flipped to any attitude. Should make installation and removal of the wings and/or working on the fuse a lot easier. The sizing will be fine for the Harvard, as well. The foam holder I have been using to date came with the Seawind, a completely different shaped fuse, (amphibian) and although way off served yeoman service up to now.
09-09-2012, 07:06 PM
#1730
RE: ThunderTiger Rare Bear
Just picked up on this thread, I have been flying my T.T. Rear Bear since this spring. I converted it to electric (didn't want to spoil John Penny autograph on the wing with glow fuel), powered with an E-flite Power 110, Castle HV85 Esc, 8 cells 5000mAh lipo and a small 1800 Life for the electronics, APC 18X10 propeller and the weight came out 12.5 lbs with batteries( I built the blue version powered with an OS 120 pump that weighted 13.5 lbs). I have been flying with an Aurora9 loaded with the telemetry, the level ground speed recorded is 120 miles/hr with the fastest recorded ground speed at 159 miles/hr. My wind are holding fine but had to rebuilt the section where the retractable gear mount due to poor wood quality and design. I fly mostly big gas warbirds but this Rear Bear is fun to fly!
09-10-2012, 01:19 PM
#1731
RE: ThunderTiger Rare Bear
flyingchef, nice looking bird and some radical speeds there. In fact, far faster than many have been able to achieve without tail failures. Did you mod anything there?
It also looks like a single cockpit release. Along with some of the interior, would love to see some pics of that setup.
It also looks like a single cockpit release. Along with some of the interior, would love to see some pics of that setup.
09-10-2012, 03:26 PM
#1733
RE: ThunderTiger Rare Bear
No cockpit details, just some silver paint sprayed in the canopy interior. The canopy deck is reinforced with glass fiber mixed with micro-balloon, some guide pins inserted forward and in the sides. A BVM latch is used for release, very easy to do giving a quick access to install the 8 cells battery that sit in the from behind the firewall. The retractable tail wheel setup is fom Robart and mounted on a carbon-fiber former, the elevator control horn is home-machined glued/pined on a carbon-fiber tube that control both elevators. I extended the main gear legs have a enough propeller clearance, it also give a nicer looks to the Rear-Bear on the ground. I which Thunder Tiger would put back this model on the market, updated and in the new Rear Bear colors also setup for optional EP power (change the cockpit deck to a true quick release hatch).
09-10-2012, 03:41 PM
#1734
RE: ThunderTiger Rare Bear
As promised here are the pics. Since these were taken earlier I replaced the receiver and rerouted some of the wiring. For some reason, although I did a direct Berg 7P swap the elevator was reversed. During the reprogram I reset some of the EXPO on elevator and rudder to make it a bit more behaved. Will have to check the ailerons and gear once the wings are on. On that note, right now waiting for the drill to recharge as I'm hogging out the front dowel blocks in the fuse. That should be the last item on the list before taking it out and firing it up again.
You can see the extra bracing I added for the battery compartment in the last pic. Everything is now fuel-proofed with thinned epoxy.
You can see the extra bracing I added for the battery compartment in the last pic. Everything is now fuel-proofed with thinned epoxy.
11-17-2012, 02:09 PM
#1735
RE: ThunderTiger Rare Bear
I finally got the chance to fly the Bear again today and thought I would be coming home with a bag of bits again. Holy THEEIT[X(]! If the pilot had a barf bag it would have been full to overflowing!
Once airborne it was immediately apparent the elevator was far, far too twitchy. It took microscopic movements to try and stabilize the plane long enough just to trim it out. That and the shakes kept things interesting, to say the least. After gaining some height I worked on feeling out the controls through the different speed range before getting up enough guts to bring it back down again. Took 3 approaches before I felt comfortable enough to touch down and to avoid ripping the gear out I landed with them retracted. Other than a wad of grass ripped up by the exhaust pipes the ONLY evidence was the fact the muffler pivoted aft to the firewall. Will have to unbolt it to retighten the adapter, but that is minor.
I checked the CofG before and, due to the fact the elevator reacted as if tail heavy, again after the flight and it was bang on the rear of the wheel opening. Still, along with some Tx reprogramming I reattached the small bit of lead originally mounted to compensate for the lack of cowl for the first few flights.
I found the RH retract hung up when I retracted them before coming in for a skid and finally figured out why once I had it on the stand. When I fabbed the new mount pads the Eflites were fit very tight to the slot. With me adding a spacer to the aft mount to tilt the gear slightly forward, tightening everything down placed side stress on the gear mech making them bind. As soon as I loosened the mount bolts the gear worked a charm. An easy fix with a bit of trimming to the opening.
I think I can be confident in the wing repair as there was no tendency for tip stalls with very little trim required once airborne. Good thing, with the rest of it.
Once airborne it was immediately apparent the elevator was far, far too twitchy. It took microscopic movements to try and stabilize the plane long enough just to trim it out. That and the shakes kept things interesting, to say the least. After gaining some height I worked on feeling out the controls through the different speed range before getting up enough guts to bring it back down again. Took 3 approaches before I felt comfortable enough to touch down and to avoid ripping the gear out I landed with them retracted. Other than a wad of grass ripped up by the exhaust pipes the ONLY evidence was the fact the muffler pivoted aft to the firewall. Will have to unbolt it to retighten the adapter, but that is minor.
I checked the CofG before and, due to the fact the elevator reacted as if tail heavy, again after the flight and it was bang on the rear of the wheel opening. Still, along with some Tx reprogramming I reattached the small bit of lead originally mounted to compensate for the lack of cowl for the first few flights.
I found the RH retract hung up when I retracted them before coming in for a skid and finally figured out why once I had it on the stand. When I fabbed the new mount pads the Eflites were fit very tight to the slot. With me adding a spacer to the aft mount to tilt the gear slightly forward, tightening everything down placed side stress on the gear mech making them bind. As soon as I loosened the mount bolts the gear worked a charm. An easy fix with a bit of trimming to the opening.
I think I can be confident in the wing repair as there was no tendency for tip stalls with very little trim required once airborne. Good thing, with the rest of it.
02-02-2013, 12:31 PM
#1737
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RE: ThunderTiger Rare Bear
Is this the last one to be built?
I always wanted one and found one last year left in stock in the uk
Standard build with just beefed up retract wells and the wing bolt mod. OS 91 fx with the TT silencer.
Not ready to fly yet, still to be set up and I have only flown a trainer so far, so maybe a month or two off- ha ha-
Watch this space
I have posted a pic, but have no idea where it went.
I always wanted one and found one last year left in stock in the uk
Standard build with just beefed up retract wells and the wing bolt mod. OS 91 fx with the TT silencer.
Not ready to fly yet, still to be set up and I have only flown a trainer so far, so maybe a month or two off- ha ha-
Watch this space
I have posted a pic, but have no idea where it went.
02-02-2013, 01:53 PM
#1738
RE: ThunderTiger Rare Bear
The pic is there and it looks a beaut. However, can you give us more details, ie. retract units, if this one has the updated tail and how you are retaining the canopy. Also wondered what the final weight ended up to be and what you used to simulate the polished exhaust ducts.
Mine has taken second seat to some other winter projects, (Mits A6M5 and BAE Hawk) but there is a list of things to check and/or complete before our field opens again for grass ops.
As for the last one, not sure. I have a member on our RCC forum that has the unopened kit and I missed out on a NIB in Vegas last year, so perhaps we will see some new postings.
p.s. It looks like you at least realize this is not a beginner craft.
Mine has taken second seat to some other winter projects, (Mits A6M5 and BAE Hawk) but there is a list of things to check and/or complete before our field opens again for grass ops.
As for the last one, not sure. I have a member on our RCC forum that has the unopened kit and I missed out on a NIB in Vegas last year, so perhaps we will see some new postings.
p.s. It looks like you at least realize this is not a beginner craft.
02-03-2013, 09:54 AM
#1739
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RE: ThunderTiger Rare Bear
Retracts units are the simple TT mechanical retracts, having set them up, i hope to leave the wings attached and find a way to hang it from the roof of the shed in the garden, which is where i have my bench etc. the canopy is as per TT instructions and screwed on, if i leave the wings on, no need to take the canopy off again, i have put the on/off switch, complete with battery charge point in the wheel well. Also used a remote glow and two fuelling valves, one for fill, in the feed line and one for the overflow from the tank, in the pressure line, i have yet to test if the engine runs well with this configuration. I still have to set the balance point so am unsure of all up weight. I guess a load of lead may be needed. As for the tail unit, i had a real problem finding out if it was upgraded, in the box was a set of extra instructions about fitting the tail, but it did not seem to have extra ribs, so we will see. I did my best to ensure it was well,glued and i made sure that I did not push the tubes through the ribs. All in all I tried to keep to the TT instructions except for the well recommended mods.
As for flying it, i have built a WOT 4, which I intend to graduate to if we ever get decent weather, when i can fly that with few worries, then i might consider trying the Bear. By the way, i hope to fly this in a scale manner, so no fancy aerobatics and only scale speeds, so no more than 1/6th of 500 mph i.e. 80ish.
I would be interested to hear how many of these are still in use, I just think they look fantastic and it is a pity that TT decided to discontinue them rather than make a few mods to fix a couple of issue.
Cheers
Al.
As for flying it, i have built a WOT 4, which I intend to graduate to if we ever get decent weather, when i can fly that with few worries, then i might consider trying the Bear. By the way, i hope to fly this in a scale manner, so no fancy aerobatics and only scale speeds, so no more than 1/6th of 500 mph i.e. 80ish.
I would be interested to hear how many of these are still in use, I just think they look fantastic and it is a pity that TT decided to discontinue them rather than make a few mods to fix a couple of issue.
Cheers
Al.
02-03-2013, 09:56 AM
#1740
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RE: ThunderTiger Rare Bear
Ps, the silver in the exhaust duct is self adhesive heat resistant aluminium foil sold in car and bike shops to use in engine compartments and the like, i just happened to have a roll in the garage.
Lets see how it reacts to glow fuel!
Lets see how it reacts to glow fuel!
07-22-2013, 08:04 PM
#1742
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RE: ThunderTiger Rare Bear
Thanks to all of the people who shared their thoughts and experience on the TT Rare Bear. Lots of god advice on the modifications.
Are there any of the horizontal stabilizer repair kits floating around?
Also looking for decals and the TT RBI muffler.
Thanks Bill
07-23-2013, 05:15 AM
#1743
RE: ThunderTiger Rare Bear
The decal sets and muffler are still available. I've found them on both Tower and Fleabay:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBENU
http://www.shopwiki.com/l/Thunder-Ti...8B000BRXXG0%29
I would not recommend the 2-stroke install for this large a plane anyway unless you buy your fuel in 50 gal drums.
As for the horizontal tail, no luck finding a replacement or I would have scooped it up. If you are willing, it's not that hard to fix it yourself. You simply deskin one side, (recommend the bottom) and go over all the glue bond areas. Also check for soft wood and cracks. As they are too long, you will likely have to shorten the C/F rods to prevent damage upon installation. If you buy thicker wall replacements this step is required anyway. The thinner wall tube would work if you inserted wood dowels and filled the gap with Gorilla Glue or epoxy. Just try to keep the weight down.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBENU
http://www.shopwiki.com/l/Thunder-Ti...8B000BRXXG0%29
I would not recommend the 2-stroke install for this large a plane anyway unless you buy your fuel in 50 gal drums.
As for the horizontal tail, no luck finding a replacement or I would have scooped it up. If you are willing, it's not that hard to fix it yourself. You simply deskin one side, (recommend the bottom) and go over all the glue bond areas. Also check for soft wood and cracks. As they are too long, you will likely have to shorten the C/F rods to prevent damage upon installation. If you buy thicker wall replacements this step is required anyway. The thinner wall tube would work if you inserted wood dowels and filled the gap with Gorilla Glue or epoxy. Just try to keep the weight down.
08-29-2013, 04:46 AM
#1744
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It flies
OK, so after a couple of years I finally got around to trying the Rare Bear, note I am a fairly inexperienced pilot, only been at it for 18 months and cannot do all that inverted stuff, aeros or anything but I can take off/fly around and land.
Having followed this thread I was extremely worried, that It would be too much. Note the RB was the first plane I built, I built the trainer afterwards, the RB was the plane I wanted one day to fly.
So, taxying is a problem, with the elevator set to recommended throws, until the engine is developing a bit of thrust it just noses over,( grass strip) so the only answer is to open the throttle quite fast and get it moving, after that, easy to fly, couple of clicks of down trim and away she went. I did a couple of circuits and brought her in to land, she has to be kept moving a fairly fast approach but she flairs our quite smoothly. One more flight this time gear up and again, no real problems, half throttle gave a nice level flight, still fast enough for me though.
I built this exactly to TT specs except for beefing up the retracts. An OS 91 FX, scale exhuast, TT retract units, cg as specified, throws as specified AUW within the limits.
I am happy and I think that many of the problems that others have suffered may be due to too many changes away from spec. Still who knows, time will tell. Perhaps when I am more enthusiastic the tail will give way!
here is a pic just before the maiden flight
Having followed this thread I was extremely worried, that It would be too much. Note the RB was the first plane I built, I built the trainer afterwards, the RB was the plane I wanted one day to fly.
So, taxying is a problem, with the elevator set to recommended throws, until the engine is developing a bit of thrust it just noses over,( grass strip) so the only answer is to open the throttle quite fast and get it moving, after that, easy to fly, couple of clicks of down trim and away she went. I did a couple of circuits and brought her in to land, she has to be kept moving a fairly fast approach but she flairs our quite smoothly. One more flight this time gear up and again, no real problems, half throttle gave a nice level flight, still fast enough for me though.
I built this exactly to TT specs except for beefing up the retracts. An OS 91 FX, scale exhuast, TT retract units, cg as specified, throws as specified AUW within the limits.
I am happy and I think that many of the problems that others have suffered may be due to too many changes away from spec. Still who knows, time will tell. Perhaps when I am more enthusiastic the tail will give way!
here is a pic just before the maiden flight
08-29-2013, 02:11 PM
#1745
Beautiful looking bird and glad you had a successful maiden.
I've been flying scale warbirds for a long time. Even with the CofG bang on spec, I found the Bear the worst I've seen for that nose over tendency.
And no, it had nothing to do with modding away from spec.
The problem with a lot of scale examples like this is that when the plane is horizontal, (basically at flying attitude) the wheels are almost directly below the CofG. It then takes very little drag to have it "Do the Goat".
The only cure for the Bear was to fab tapered wood wedges to fit between the gear mounts and units, basically lifting the rear pad downward. This required hogging out my nicely formed rib plates, but even with this forward inclination the main wheels still fit below the wing surface, allowing me to later fit the doors.
NOTE: The tapered wedges that extend all the way across are necessary to maintain alignment for the mount pads. If you add only a spacer to the rear you will then misalign the two, creating quite a lot of stress to the retract units. They can then bind or even crack.
Moving the main wheels forward is an old trick and one that was mandatory on models such as the P-51 when working from grass. The tall gear, (and relatively small tires for scale) create a lot of torque, allowing the plane to get ahead of the mains.
I've been flying scale warbirds for a long time. Even with the CofG bang on spec, I found the Bear the worst I've seen for that nose over tendency.
And no, it had nothing to do with modding away from spec.
The problem with a lot of scale examples like this is that when the plane is horizontal, (basically at flying attitude) the wheels are almost directly below the CofG. It then takes very little drag to have it "Do the Goat".
The only cure for the Bear was to fab tapered wood wedges to fit between the gear mounts and units, basically lifting the rear pad downward. This required hogging out my nicely formed rib plates, but even with this forward inclination the main wheels still fit below the wing surface, allowing me to later fit the doors.
NOTE: The tapered wedges that extend all the way across are necessary to maintain alignment for the mount pads. If you add only a spacer to the rear you will then misalign the two, creating quite a lot of stress to the retract units. They can then bind or even crack.
Moving the main wheels forward is an old trick and one that was mandatory on models such as the P-51 when working from grass. The tall gear, (and relatively small tires for scale) create a lot of torque, allowing the plane to get ahead of the mains.
Last edited by Cougar429; 08-29-2013 at 02:14 PM.
08-30-2013, 12:48 AM
#1746
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You are absolutely right. So far that's the main issue with the RB. My resolution is to get some prop wash on as fast as possible then take of is ok. On landing the problem for me is that as she slows, so the effectiveness of the elevator reduces and at the end of the landing run, over she goes. I may try flicking to high rate at the end of the touchdown run to see if that helps bit I fear that the mods you suggest are the only real solution.
Thanks for the advice
Thanks for the advice
09-29-2013, 08:31 AM
#1749
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Hi folks!
Nope, I got one on the workbench, too. I haven't made much progess during summer and last winter. I started building the kit just before last winter by reinforcing the tailsection. As described here I started by simply deskinning one side and reconstructing the ribs and by that filling all the gaps with thickened epoxy. Be told, there were many gaps... It took me a couple of weeks to update the tail on my model. Right now, I'm looking for inspiration on the engine, working on the retract mounts and wing fixation. During research I came across this thread and hope to find some inspiration for my build.
Over summer I found some spare parts on Ebay (cowling, canopy section) and last week I managed to acquire a TT Rare Bear muffler
. Right now, I'm looking for the suiting engine. I gave up my original plan of mounting a ZG20 gas engine, due to missing space for an adequate silencer and the tight noise restrictions on our flying field. So @Willyuk, how's the noise level on your setup? And how's flight performance?
Kind regards!
Kai
Nope, I got one on the workbench, too. I haven't made much progess during summer and last winter. I started building the kit just before last winter by reinforcing the tailsection. As described here I started by simply deskinning one side and reconstructing the ribs and by that filling all the gaps with thickened epoxy. Be told, there were many gaps... It took me a couple of weeks to update the tail on my model. Right now, I'm looking for inspiration on the engine, working on the retract mounts and wing fixation. During research I came across this thread and hope to find some inspiration for my build.
Over summer I found some spare parts on Ebay (cowling, canopy section) and last week I managed to acquire a TT Rare Bear muffler
. Right now, I'm looking for the suiting engine. I gave up my original plan of mounting a ZG20 gas engine, due to missing space for an adequate silencer and the tight noise restrictions on our flying field. So @Willyuk, how's the noise level on your setup? And how's flight performance?Kind regards!
Kai
09-29-2013, 11:07 AM
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Join Date: Nov 2005
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Hi Kai,
1st off I am a fairly inexperienced rc pilot, beginner to intermediate level, so anything I say must be taken with that in mind.
i am using os91fx, as recommended with the scale muffler. It is really very quiet note I am using the three blade prop. After half a dozen short flights I have removed the washers that reduced the down thrust and right thrust that many recommended. on full throttle it went up very sharply and needed lots of down trim, with the down thrust back where designed it is fine.
For me it is darned fast, I find I have to throttle back to about 50% for just stooging around! otherwise it uses lots of sky, we have a fairly restricted area with a couple of no fly zones, so for me more power would be wasted, mind you a fast flyby looks very impressive. I am still trying to get familiar with it and have been restricted in time due to the wind being across the runway for the past few weeks.by the way I beefed up the retracts as specified in this thread and they are fine, the gear legs bent on one rather inept landing but they easily bent back again.
stick to the specified engine and it will be fine. By the way my tail is standard and so far is solid. Les hope it stays that way!!
rgds
Hi folks!
Nope, I got one on the workbench, too. I haven't made much progess during summer and last winter. I started building the kit just before last winter by reinforcing the tailsection. As described here I started by simply deskinning one side and reconstructing the ribs and by that filling all the gaps with thickened epoxy. Be told, there were many gaps... It took me a couple of weeks to update the tail on my model. Right now, I'm looking for inspiration on the engine, working on the retract mounts and wing fixation. During research I came across this thread and hope to find some inspiration for my build.
Over summer I found some spare parts on Ebay (cowling, canopy section) and last week I managed to acquire a TT Rare Bear muffler. Right now, I'm looking for the suiting engine. I gave up my original plan of mounting a ZG20 gas engine, due to missing space for an adequate silencer and the tight noise restrictions on our flying field. So @Willyuk, how's the noise level on your setup? And how's flight performance?
Kind regards!
Kai
Nope, I got one on the workbench, too. I haven't made much progess during summer and last winter. I started building the kit just before last winter by reinforcing the tailsection. As described here I started by simply deskinning one side and reconstructing the ribs and by that filling all the gaps with thickened epoxy. Be told, there were many gaps... It took me a couple of weeks to update the tail on my model. Right now, I'm looking for inspiration on the engine, working on the retract mounts and wing fixation. During research I came across this thread and hope to find some inspiration for my build.
Over summer I found some spare parts on Ebay (cowling, canopy section) and last week I managed to acquire a TT Rare Bear muffler
. Right now, I'm looking for the suiting engine. I gave up my original plan of mounting a ZG20 gas engine, due to missing space for an adequate silencer and the tight noise restrictions on our flying field. So @Willyuk, how's the noise level on your setup? And how's flight performance?Kind regards!
Kai
1st off I am a fairly inexperienced rc pilot, beginner to intermediate level, so anything I say must be taken with that in mind.
i am using os91fx, as recommended with the scale muffler. It is really very quiet note I am using the three blade prop. After half a dozen short flights I have removed the washers that reduced the down thrust and right thrust that many recommended. on full throttle it went up very sharply and needed lots of down trim, with the down thrust back where designed it is fine.
For me it is darned fast, I find I have to throttle back to about 50% for just stooging around! otherwise it uses lots of sky, we have a fairly restricted area with a couple of no fly zones, so for me more power would be wasted, mind you a fast flyby looks very impressive. I am still trying to get familiar with it and have been restricted in time due to the wind being across the runway for the past few weeks.by the way I beefed up the retracts as specified in this thread and they are fine, the gear legs bent on one rather inept landing but they easily bent back again.
stick to the specified engine and it will be fine. By the way my tail is standard and so far is solid. Les hope it stays that way!!
rgds