ThunderTiger Rare Bear
08-30-2015, 06:59 PM
#1876
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I shimed me gear so they are angled more toward the front.with the flaps you have to carry power so that help the elev stay effective,so yeah with out flaps you may need more to flare.flaps really help.they worked well on the navy version so that's why I went to the effort to put them in. Glad you got a flight in it will be faster with the cowl on and gear up.
08-31-2015, 02:35 PM
#1877
I have mine as far forward as they can go and still be within the wing when retracted, (otherwise would have to build bulged gear doors). I'm sure on anything but grass this would be moot. Those small wheels make for some interesting taxis,as well, getting hung up whenever they feel like it.
You really make me kick myself. Perhaps this winter I will set aside the Seawind, (AGAIN!) and do the deed. If so will need to get some mult-connectors as I already have two each wing to connect every time.
Cannot remember, are yours split or conventional flaps? Pics of how you set yours up would be nice.
May also opt to narrow the framework behind the receiver tray. Bit difficult to fit my fingers between that and the fuse sides to install/remove the wing retainers.
You really make me kick myself. Perhaps this winter I will set aside the Seawind, (AGAIN!) and do the deed. If so will need to get some mult-connectors as I already have two each wing to connect every time.
Cannot remember, are yours split or conventional flaps? Pics of how you set yours up would be nice.
May also opt to narrow the framework behind the receiver tray. Bit difficult to fit my fingers between that and the fuse sides to install/remove the wing retainers.
08-31-2015, 04:09 PM
#1878
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mine are conventional flaps in the glow to electric confersion thread over in RC Groups I posted pics of the flap mod. I believe I posted a link to it a few pages back.also im using robart wheel which are bigger than the stock wheels .
08-31-2015, 04:14 PM
#1879
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09-08-2015, 04:55 PM
#1880
Took up the Bear for a couple more flights yesterday and can say I have the controls pretty well dialed in now. In flight elevator limits to the specified 1/4" are all that are required, but on landing I need more authority. Upped the throw. Now just have to get the expo set so I don't balloon on approach.
However, it's getting annoyingly predictable for it to nose over at the slightest opportunity and guarantee to go over on its back on landing. Just does not like grass. My friend has his jet event coming up in a couple weeks and may ask to try it on asphalt once regular flying over with. Getting comfortable enough to fly it in front of crowds and this will hopefully prep me for some scale events next season.
Even though it does not like to slow down, it's not as fast in the air even with the cowl installed as I hoped, (think my Saito 100 powered Super Skybolt would blow past it straight and level). I tried a Graupner 3-blade with the original spinner and could not get it off the grass.
Only other tweak would be some elevator mix to compensate when the gear is up, (one or two clicks of down trim gets it back to normal).
One other negative is this plane needs a retractable tailwheel. Having that rather wide wheel hang out the bottom when cleaned up kind of detracts from the looks. Anyone know of one not as blatantly obvious, but does the job?
However, it's getting annoyingly predictable for it to nose over at the slightest opportunity and guarantee to go over on its back on landing. Just does not like grass. My friend has his jet event coming up in a couple weeks and may ask to try it on asphalt once regular flying over with. Getting comfortable enough to fly it in front of crowds and this will hopefully prep me for some scale events next season.
Even though it does not like to slow down, it's not as fast in the air even with the cowl installed as I hoped, (think my Saito 100 powered Super Skybolt would blow past it straight and level). I tried a Graupner 3-blade with the original spinner and could not get it off the grass.
Only other tweak would be some elevator mix to compensate when the gear is up, (one or two clicks of down trim gets it back to normal).
One other negative is this plane needs a retractable tailwheel. Having that rather wide wheel hang out the bottom when cleaned up kind of detracts from the looks. Anyone know of one not as blatantly obvious, but does the job?
09-08-2015, 10:43 PM
#1881
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I got 2 more on mine on mon.mine is going right at or a I tad faster than 100 mph.and the vert is huge.I shot some approach s and it felt floaty.did not want to come down.we had cross wind so I let my boy land it.I did both takeoff.he can land it 3 pointed with out tip stalling.if you try to do that with too much speed it will bounce a bit.
09-09-2015, 09:52 AM
#1882
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Took up the Bear for a couple more flights yesterday and can say I have the controls pretty well dialed in now. In flight elevator limits to the specified 1/4" are all that are required, but on landing I need more authority. Upped the throw. Now just have to get the expo set so I don't balloon on approach.
However, it's getting annoyingly predictable for it to nose over at the slightest opportunity and guarantee to go over on its back on landing. Just does not like grass. My friend has his jet event coming up in a couple weeks and may ask to try it on asphalt once regular flying over with. Getting comfortable enough to fly it in front of crowds and this will hopefully prep me for some scale events next season.
Even though it does not like to slow down, it's not as fast in the air even with the cowl installed as I hoped, (think my Saito 100 powered Super Skybolt would blow past it straight and level). I tried a Graupner 3-blade with the original spinner and could not get it off the grass.
Only other tweak would be some elevator mix to compensate when the gear is up, (one or two clicks of down trim gets it back to normal).
One other negative is this plane needs a retractable tailwheel. Having that rather wide wheel hang out the bottom when cleaned up kind of detracts from the looks. Anyone know of one not as blatantly obvious, but does the job?
However, it's getting annoyingly predictable for it to nose over at the slightest opportunity and guarantee to go over on its back on landing. Just does not like grass. My friend has his jet event coming up in a couple weeks and may ask to try it on asphalt once regular flying over with. Getting comfortable enough to fly it in front of crowds and this will hopefully prep me for some scale events next season.
Even though it does not like to slow down, it's not as fast in the air even with the cowl installed as I hoped, (think my Saito 100 powered Super Skybolt would blow past it straight and level). I tried a Graupner 3-blade with the original spinner and could not get it off the grass.
Only other tweak would be some elevator mix to compensate when the gear is up, (one or two clicks of down trim gets it back to normal).
One other negative is this plane needs a retractable tailwheel. Having that rather wide wheel hang out the bottom when cleaned up kind of detracts from the looks. Anyone know of one not as blatantly obvious, but does the job?
Trouble with the tail wheel mod would be added weight at the back and consequently more lead at the front!
good luck
Al
09-09-2015, 10:47 AM
#1883
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I got this Rare Bear at Muscular Dystrophy Association Fly-a-Thon at Fort Bend R/C for $100.
The Rare Bear has not see the air and has all new servo. I mounted a DLE-20 to the front of the plane and will be fixing all the problem the kit has.
The Rare Bear has not see the air and has all new servo. I mounted a DLE-20 to the front of the plane and will be fixing all the problem the kit has.
09-09-2015, 11:04 AM
#1884
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Stone welcome aboard.you got a great deal.please fix the problems with the tail and mount the elev servo in the rear of plane,or it won't last long with that big motor.reglue as much of the wing as possible. I can highly recommend putting flaps in too .a bit of work but we'll worth the solid landing glide and reduced landing speed.
09-09-2015, 11:23 AM
#1885
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Stone welcome aboard.you got a great deal.please fix the problems with the tail and mount the elev servo in the rear of plane,or it won't last long with that big motor.reglue as much of the wing as possible. I can highly recommend putting flaps in too .a bit of work but we'll worth the solid landing glide and reduced landing speed.
Or
Run two 4-40 rod to elevator and connect to the servo?
09-09-2015, 01:53 PM
#1886
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yes I believe that would work ...best to use some smaller high torque servos ...as tail weight means ballast up front ...but with a dle 20 in there you may need some tail weight. the vibes from that big motor is going to be hard on the airframe. do you know if you have the version 2 stabs? and the heavy duty C/F spar. read my posts on the spar I used a unidirectional C/F tube the stock one I had was a joke as it was not uni directional.
09-09-2015, 02:35 PM
#1887
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yes I believe that would work ...best to use some smaller high torque servos ...as tail weight means ballast up front ...but with a dle 20 in there you may need some tail weight. the vibes from that big motor is going to be hard on the airframe. do you know if you have the version 2 stabs? and the heavy duty C/F spar. read my posts on the spar I used a unidirectional C/F tube the stock one I had was a joke as it was not uni directional.
Can I tell with out removing the elevator?
09-09-2015, 03:52 PM
#1888
You lucky dog! I bought the box full of plastic wrapped bits at multiples of that cost.
Functionally, mounting servos that way would be fine, but a bit on the ugly side if looking at a scale build.That's the primary reason I try to hide all the controls internally. Not possible with the way they have the ailerons. You cannot see that sitting on the ground, nor in flight, so not so bad. Some have installed thin-wing servos, (such as my fave, the HS-125MG) in each stab similar to what is used for the ailerons. Nothing wrong with that, but as stated, I like things internal and that only requires one servo. In that case you will want one of good quality with no gear slop.
The V2 tail had supposedly better bonding and thicker walled cross tubes. I checked my V1 and with the other mods the standard tubes looked fine for the rather small size of the stabs themselves. So far so good as I suspect the same flutter that was causing failure of the stabs may have also caused problems there.
Pay attention to the 1/4" deflection limit of the stock elevators. For scale flying this would demand a good control system, something the stock setup could not supply. It also should not impose huge loads on the stab structure if flying it scale. In that most turns would be relatively tame, with no swapping of ends. Just high speeds that can and will induce control flutter if not prevented.
Make note of the fact flutter is almost exclusively a result of high speed showing deficiencies in the control system, airfoil design or structure. I believe the fact this airplane was capable of more than what the horizontal tail could handle was the result of a deficient control design, rather disproportionate elevator/stab area and questionable build quality. We've pretty well settled on the correct fixes and they seem to work well.
That brings up another factor. I rarely work with the stock hinges and hardware supplied with kits or ARFs like these and go with trusted gear such as DuBro.CA hinges are a definite NO with anything larger than park flyer in any event, (they will fail at some point, higher loads and/or cold weather simply accelerates that process) so pin type would be mandatory here. If installed correctly they will be smooth and slop free, another guarantee towards limiting flutter.
On a final note, that DLE 20 may be perfect if my comparisons are correct, (the Satio G-20 is the petro version of the 125 I have in mine). One thing to watch is more critical if you use the stock vibration damper mount supplied with the kit, (yours looks like a composite plastic type so not likely a problem). In some cases it actually increases what gets into the airframe by allowing the motor/mount assembly to move so much it builds up energy along the way. Even so, I would make one recommendation to start with a wooden prop. This is my standard procedure for new airframes as any mistake that leads to impact sacrifices the prop, but saves the motor.
Having said that, I should follow my own advice here. The Bear does not have time to work up elevator on landing as it flips immediately upon touching down.
I have been a conventional gear convert for years, to the point I am much more comfortable with a tailwheel than one on the other end. As will most, the Bear likes a bit of toe-in on the mains for good ground behavior. If there were any way to shorten the legs things would likely be fine.
As mentioned, there are a few other issues other than the tail, one in particular the bond job inside the wing where the tube is fit. The balsa ribs were pitifully soft and on mine not bonded to the spars at all. Ripped loose the second flight.
Also, do not count on the stock gear mounts holding up. Again, very soft wood all round and questionable bonding job. I learned along the way to spend more time on critical areas like these BEFORE they come out to bite.
Stone17, have you had time to read through this thread?
Functionally, mounting servos that way would be fine, but a bit on the ugly side if looking at a scale build.That's the primary reason I try to hide all the controls internally. Not possible with the way they have the ailerons. You cannot see that sitting on the ground, nor in flight, so not so bad. Some have installed thin-wing servos, (such as my fave, the HS-125MG) in each stab similar to what is used for the ailerons. Nothing wrong with that, but as stated, I like things internal and that only requires one servo. In that case you will want one of good quality with no gear slop.
The V2 tail had supposedly better bonding and thicker walled cross tubes. I checked my V1 and with the other mods the standard tubes looked fine for the rather small size of the stabs themselves. So far so good as I suspect the same flutter that was causing failure of the stabs may have also caused problems there.
Pay attention to the 1/4" deflection limit of the stock elevators. For scale flying this would demand a good control system, something the stock setup could not supply. It also should not impose huge loads on the stab structure if flying it scale. In that most turns would be relatively tame, with no swapping of ends. Just high speeds that can and will induce control flutter if not prevented.
Make note of the fact flutter is almost exclusively a result of high speed showing deficiencies in the control system, airfoil design or structure. I believe the fact this airplane was capable of more than what the horizontal tail could handle was the result of a deficient control design, rather disproportionate elevator/stab area and questionable build quality. We've pretty well settled on the correct fixes and they seem to work well.
That brings up another factor. I rarely work with the stock hinges and hardware supplied with kits or ARFs like these and go with trusted gear such as DuBro.CA hinges are a definite NO with anything larger than park flyer in any event, (they will fail at some point, higher loads and/or cold weather simply accelerates that process) so pin type would be mandatory here. If installed correctly they will be smooth and slop free, another guarantee towards limiting flutter.
On a final note, that DLE 20 may be perfect if my comparisons are correct, (the Satio G-20 is the petro version of the 125 I have in mine). One thing to watch is more critical if you use the stock vibration damper mount supplied with the kit, (yours looks like a composite plastic type so not likely a problem). In some cases it actually increases what gets into the airframe by allowing the motor/mount assembly to move so much it builds up energy along the way. Even so, I would make one recommendation to start with a wooden prop. This is my standard procedure for new airframes as any mistake that leads to impact sacrifices the prop, but saves the motor.
Having said that, I should follow my own advice here. The Bear does not have time to work up elevator on landing as it flips immediately upon touching down.
I have been a conventional gear convert for years, to the point I am much more comfortable with a tailwheel than one on the other end. As will most, the Bear likes a bit of toe-in on the mains for good ground behavior. If there were any way to shorten the legs things would likely be fine.
As mentioned, there are a few other issues other than the tail, one in particular the bond job inside the wing where the tube is fit. The balsa ribs were pitifully soft and on mine not bonded to the spars at all. Ripped loose the second flight.
Also, do not count on the stock gear mounts holding up. Again, very soft wood all round and questionable bonding job. I learned along the way to spend more time on critical areas like these BEFORE they come out to bite.
Stone17, have you had time to read through this thread?
Last edited by Cougar429; 09-09-2015 at 04:06 PM.
09-09-2015, 04:18 PM
#1889
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i would not take the chance .do surgery on the lower stab skin re glue ,and add a bays length of spar. and buy a real C/F unidirectional spar from CST or other composite supplier ,it is too nice of a plane to not do what it takes to make it last ...or else sell it to me .
09-09-2015, 11:01 PM
#1890
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So, have got an MKS glider wing servo metal gear for the tail, a Roto25 for the front, and ACE 1050mg for the wings. Bolt conversion for the wing, and opened up stabs. Fuel tank to remain in stock position since the gasser is not much effected, and angled the mains slightly forward.
Stab area, great planes torque connector with single horn. Lightplyed the area for the servo mount.
Will get some pics of the progress further on
Stab area, great planes torque connector with single horn. Lightplyed the area for the servo mount.
Will get some pics of the progress further on
09-15-2015, 04:25 AM
#1892
My friend has his turbine jet event this weekend and I'll be practicing my "Radio Voice" over the PA again. Even though not one of that type, got permission to drag the Bear down and try it on pavement. Will see if I can keep the tail down.
Hope so as asphalt at high speed is like a belt sander.
ps. Got my first exposure to turbine stick time at a scale event last month. Hoo Doggy! Slow throttle response and build up speed in a REAL hurry on the way down.
Hope so as asphalt at high speed is like a belt sander.
ps. Got my first exposure to turbine stick time at a scale event last month. Hoo Doggy! Slow throttle response and build up speed in a REAL hurry on the way down.
09-16-2015, 06:58 PM
#1893
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good luck on the pavement our F-8 and RB handle well on hard pack ...with flaps down on a touch and go ya have to hold the tail down ...not as bad on the RB as im using a 15.75" 3 blade the F-8 had a 21" prop and had scale prop clearance so you had to keep the tail down or else.im using as long a strut as use ,the tire barly clears the inner wall of the wheel well. the longer the strut the further fwd of the C/G the wheel will be .
09-20-2015, 07:14 PM
#1894
As you posted, plane worked remarkably well. With slow throttle up it tracked straight on take off and flew like it was on rails. Only problem was the trim change with the gear up and I just set up a mix for both conditions. Will take some flights to get the amount correct as it only takes 4 clicks trim to balance out once the gear is up, (trim set for 1 increment changes).
Only one minor screwup on landing and was my own fault. Got notice of a full size wanting to head out so was in a bit of a rush to get it down. Hit a bit harder than I wanted. Looked like I compressed the suspension to the bottom, yet taxied back fine. Found one leg bent back slightly when I pulled it apart for transport. Am looking at a different set of struts I had set aside for the P-51 that are the same length with a longer stroke.
The Saito 125 is getting more economical with each flight. Was up 5 minutes and estimate still had half a tank.
Since the set screw is only in plastic, still having a problem with the tailwheel moving in the steering arm. Going to look at filing a flat on the wire.
It was surprising how much interest it generated from the jet guys once I had it sitting on the flight line. Quite a few stated that was one of their favorite Grummans and one had partially finished a Zirolli kit, (till he found out the scale gear ran well north of $1200 USD!).
Only one minor screwup on landing and was my own fault. Got notice of a full size wanting to head out so was in a bit of a rush to get it down. Hit a bit harder than I wanted. Looked like I compressed the suspension to the bottom, yet taxied back fine. Found one leg bent back slightly when I pulled it apart for transport. Am looking at a different set of struts I had set aside for the P-51 that are the same length with a longer stroke.
The Saito 125 is getting more economical with each flight. Was up 5 minutes and estimate still had half a tank.
Since the set screw is only in plastic, still having a problem with the tailwheel moving in the steering arm. Going to look at filing a flat on the wire.
It was surprising how much interest it generated from the jet guys once I had it sitting on the flight line. Quite a few stated that was one of their favorite Grummans and one had partially finished a Zirolli kit, (till he found out the scale gear ran well north of $1200 USD!).
09-21-2015, 03:59 AM
#1896
Was also surprised it looked quicker there than at our field. Perspective, I guess. Had some of the other pilots give me confidence it was moving a lot faster than it looked. This from guys that spent the day pushing at or exceeding 200 MPH!
Anyone GPS theirs?
Anyone GPS theirs?
09-28-2015, 02:03 PM
#1899
Stone, someone cut the rear tube too short, (looks like they matched the front). It should reach the next set of ribs, as you can see from the doubler.
Even so, the original tubes were all slightly too long and would deform or break apart the ribs when the stabs were forced in to meet the fuse on installation. Only required slight trimming to fit.
I would second the previous post and recommend working on getting a solid elevator control setup. Most often that means mounting the servo in the tail so the linkage is short as possible. Even C/F tubes over the entire original length did not work that well and I strongly believe that is what allowed flutter to start and destroy the tails.
Even so, the original tubes were all slightly too long and would deform or break apart the ribs when the stabs were forced in to meet the fuse on installation. Only required slight trimming to fit.
I would second the previous post and recommend working on getting a solid elevator control setup. Most often that means mounting the servo in the tail so the linkage is short as possible. Even C/F tubes over the entire original length did not work that well and I strongly believe that is what allowed flutter to start and destroy the tails.
Last edited by Cougar429; 09-28-2015 at 03:12 PM.
10-19-2015, 03:52 PM
#1900
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I agree .I used a spar from CST .it is unidirectional ,very strong .we flew the RB in az at chino valley .it flew awesome and handeled cross wind landings with a breeze. there should be pics and vid showing up on RCG in the electric events under the name of chino valley fly in.