Goldberg Tiger Club
10-28-2014, 06:19 AM
#951
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Well, after a couple of years of on again, off again, I have finally resolved all the gremlins in my Tiger 3. For those of you who don't know about the Tiger 3, my brother drew plans for a 92" version to be powered by a gas engine in the 30-35cc range. The very first issue we faced was that the way we built them they were tail heavy. Way tail heavy - to the point that I had to put a 2+ pound lead weight in the nose. At 18 pounds it flew OK, but not like the Tiger we all appreciate. The next issue was one with the nose gear. with the 2 pounds of lead, a gas engine, 2 battery packs, and the fuel tank up front, the nose gear, the way we built them, simply couldn't hold the weight. All of this resolved by ripping off the tail and rebuilding it using built-up techniques rather than a solid surface. Took 6 ounces off the tail and 32 ounces off the nose. Now at just over 14 pounds, the flight characteristics are back, the landing speeds are down and everything is good. Not!!
The next issue was still the nose gear. Even with the lead weight out of the nose, a single wire nose gear, even 5/32nd music wire, won't hold the weight. Plus we had a prop clearance issue. I got real tired, real quick of breaking a $15 prop on every landing. Solution? Fults nose gear and a hard rubber tire! Solved the clearance issue, resolved the steering issue, and this gear will take a pounding! Not that I ever make a less than perfect landing
)
The next issue was one of convenience. I had to put the batteries under the fuel tank tray to help with the weight issue. If I ever lost hold of one of the leads while connecting the charger, I had to remove the fuel tank and unscrew the tray just to get to the leads. Dang, what a hassle! So much so, that more than once, rather than going through all that at the field, I just put it back in the trailer and called it a day. With rebuilding the tail, we solved the weight issue and I was able to use a Tech Aero BEC to eliminate the ignition battery. I use A123 batteries exclusively and the ones I use have 2 leads; one standard output and a balance lead. I was able to move the receiver battery (A123 - 2300Mah) back closer to the front former, and route the leads into the equipment bay above the wing. Lost more weight, made things much more convenient.
The flights since making these adjustments have been nothing short of Tigerish - and we all know what that's like!! John is currently making some revisions to the plans and sometime in the near future, I'm going to build 2 more of these incorporating everything I've learned in this very interesting process.
The next issue was still the nose gear. Even with the lead weight out of the nose, a single wire nose gear, even 5/32nd music wire, won't hold the weight. Plus we had a prop clearance issue. I got real tired, real quick of breaking a $15 prop on every landing. Solution? Fults nose gear and a hard rubber tire! Solved the clearance issue, resolved the steering issue, and this gear will take a pounding! Not that I ever make a less than perfect landing
) The next issue was one of convenience. I had to put the batteries under the fuel tank tray to help with the weight issue. If I ever lost hold of one of the leads while connecting the charger, I had to remove the fuel tank and unscrew the tray just to get to the leads. Dang, what a hassle! So much so, that more than once, rather than going through all that at the field, I just put it back in the trailer and called it a day. With rebuilding the tail, we solved the weight issue and I was able to use a Tech Aero BEC to eliminate the ignition battery. I use A123 batteries exclusively and the ones I use have 2 leads; one standard output and a balance lead. I was able to move the receiver battery (A123 - 2300Mah) back closer to the front former, and route the leads into the equipment bay above the wing. Lost more weight, made things much more convenient.
The flights since making these adjustments have been nothing short of Tigerish - and we all know what that's like!! John is currently making some revisions to the plans and sometime in the near future, I'm going to build 2 more of these incorporating everything I've learned in this very interesting process.
Last edited by Red Raider; 10-28-2014 at 07:08 AM.
10-28-2014, 01:20 PM
#953
Join Date: Jun 2007
Location: Grand Blanc,
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I guess I qualify to post in this thread, I picked up an unbuilt Tiger 2 kit at an estate sale a few weeks ago. It is high on my list for winter projects. I am debating a little on the engine. I also picked up an Irvine 40 at the sale, but I am considering putting that into a plane that I already have and using the OS 46FX from that one in the Tiger. I agree about the joy of building Goldberg kits, the Tiger manual and plans remind me a lot of building my Eagle 2 many years ago.
10-29-2014, 06:21 PM
#959
Well, after a couple of years of on again, off again, I have finally resolved all the gremlins in my Tiger 3. For those of you who don't know about the Tiger 3, my brother drew plans for a 92" version to be powered by a gas engine in the 30-35cc range. The very first issue we faced was that the way we built them they were tail heavy. Way tail heavy - to the point that I had to put a 2+ pound lead weight in the nose. At 18 pounds it flew OK, but not like the Tiger we all appreciate. The next issue was one with the nose gear. with the 2 pounds of lead, a gas engine, 2 battery packs, and the fuel tank up front, the nose gear, the way we built them, simply couldn't hold the weight. All of this resolved by ripping off the tail and rebuilding it using built-up techniques rather than a solid surface. Took 6 ounces off the tail and 32 ounces off the nose. Now at just over 14 pounds, the flight characteristics are back, the landing speeds are down and everything is good. Not!!
The next issue was still the nose gear. Even with the lead weight out of the nose, a single wire nose gear, even 5/32nd music wire, won't hold the weight. Plus we had a prop clearance issue. I got real tired, real quick of breaking a $15 prop on every landing. Solution? Fults nose gear and a hard rubber tire! Solved the clearance issue, resolved the steering issue, and this gear will take a pounding! Not that I ever make a less than perfect landing)
The next issue was one of convenience. I had to put the batteries under the fuel tank tray to help with the weight issue. If I ever lost hold of one of the leads while connecting the charger, I had to remove the fuel tank and unscrew the tray just to get to the leads. Dang, what a hassle! So much so, that more than once, rather than going through all that at the field, I just put it back in the trailer and called it a day. With rebuilding the tail, we solved the weight issue and I was able to use a Tech Aero BEC to eliminate the ignition battery. I use A123 batteries exclusively and the ones I use have 2 leads; one standard output and a balance lead. I was able to move the receiver battery (A123 - 2300Mah) back closer to the front former, and route the leads into the equipment bay above the wing. Lost more weight, made things much more convenient.
The flights since making these adjustments have been nothing short of Tigerish - and we all know what that's like!! John is currently making some revisions to the plans and sometime in the near future, I'm going to build 2 more of these incorporating everything I've learned in this very interesting process.
The next issue was still the nose gear. Even with the lead weight out of the nose, a single wire nose gear, even 5/32nd music wire, won't hold the weight. Plus we had a prop clearance issue. I got real tired, real quick of breaking a $15 prop on every landing. Solution? Fults nose gear and a hard rubber tire! Solved the clearance issue, resolved the steering issue, and this gear will take a pounding! Not that I ever make a less than perfect landing
) The next issue was one of convenience. I had to put the batteries under the fuel tank tray to help with the weight issue. If I ever lost hold of one of the leads while connecting the charger, I had to remove the fuel tank and unscrew the tray just to get to the leads. Dang, what a hassle! So much so, that more than once, rather than going through all that at the field, I just put it back in the trailer and called it a day. With rebuilding the tail, we solved the weight issue and I was able to use a Tech Aero BEC to eliminate the ignition battery. I use A123 batteries exclusively and the ones I use have 2 leads; one standard output and a balance lead. I was able to move the receiver battery (A123 - 2300Mah) back closer to the front former, and route the leads into the equipment bay above the wing. Lost more weight, made things much more convenient.
The flights since making these adjustments have been nothing short of Tigerish - and we all know what that's like!! John is currently making some revisions to the plans and sometime in the near future, I'm going to build 2 more of these incorporating everything I've learned in this very interesting process.
10-29-2014, 07:40 PM
#960
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Join Date: Apr 2014
Location: Near Deming, NM.
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Photo one shows the longer nose on my Tiger. Plane balanced perfectly. There is a thread under scratch building.
#2 is a 102" scaled up RCM Trainer built for a tow plane. OS 160 engine swinging 18x6 prop. 10.4 pounds easily handled by home made aluminum gear.
Last photo shows gear being bent. It's not hard to do at all…
Last edited by tomclark; 10-29-2014 at 07:43 PM.
10-30-2014, 06:51 AM
#963
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hairy46,
Need some photos! Especially of the bigger Tiger. Photos really tell the story…
I am thinking about building a 100" one for a winter project. The 76" version flies like a dream, and in my world bigger is always better when it comes to flying…
10-31-2014, 07:14 AM
#965
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You're right about bigger flying better. The only thing you lose is the quickness. It doesn't snap around corners, but it sure flies like it's on rails. I fly mine with a 30cc if you build a 100" version, you're going to need more HP!! At least a 35cc maybe even bigger.
10-31-2014, 09:12 AM
#966
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I've got a few pictures of mine. It's kinda rough being that I beat it around, rebuilt it and beat it around some more. But you can get the idea. I thought about lengthening the nose on this plane but, we wanted to build the first ones according to the plans. The thinking being is that if you change it too much, it's not a Tiger anymore. John's a purest - what can I say?? 
Last edited by Red Raider; 10-31-2014 at 09:17 AM.
10-31-2014, 11:43 AM
#967
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I would imagine that there is nothing purest about having two pounds of lead in the nose… Everything has room for improvement in design.
Not sure, but I would bet that 20 years ago the whole Tiger line of kits were built with all balsa, and probably not until they went to the dogs (ARFs) that the plywood was substituted to make them faster to build. Just a guess. My all balsa scratch build didn't really come out tail heavy, and I had to put the radio battery in the rear to balance it at 38%. My 6.5 pound 76" span Tiger was close to the 120 size, but used a fairly light 90 fs instead of a 120 engine, so who knows. I can't imagine that the 120 ARF was supposed to finished at 10.5-11.5 pounds. My plane is nearly the same size and weighs 6.5 lbs.
Maybe some of the old timers who built Tigers long ago can let us know how they were built back then?
Not sure, but I would bet that 20 years ago the whole Tiger line of kits were built with all balsa, and probably not until they went to the dogs (ARFs) that the plywood was substituted to make them faster to build. Just a guess. My all balsa scratch build didn't really come out tail heavy, and I had to put the radio battery in the rear to balance it at 38%. My 6.5 pound 76" span Tiger was close to the 120 size, but used a fairly light 90 fs instead of a 120 engine, so who knows. I can't imagine that the 120 ARF was supposed to finished at 10.5-11.5 pounds. My plane is nearly the same size and weighs 6.5 lbs.
Maybe some of the old timers who built Tigers long ago can let us know how they were built back then?
Last edited by tomclark; 11-03-2014 at 06:31 AM.
11-01-2014, 04:15 AM
#968
Red Raider..... Thanks for the number, and it looks like all the suppliers are sold out of the RF57J at the moment. Not even the Fults page gives you the option in the selection screen. Might have to go for the RF770, but dang, 40 bucks for nose gear!
Tom Clark..... That 38 % CG number is magic on the Tiger design. That is exactly where mine is and with that CG, it is good and stable but snap rolls on command, and slows up wonderfully with a beautiful nose high attitude on final. Would never have the CG that far back on a tapered wing like my Superstar, or heavy warbird but it sure works well with the Tiger wing and the light weights it can build to.
Tom Clark..... That 38 % CG number is magic on the Tiger design. That is exactly where mine is and with that CG, it is good and stable but snap rolls on command, and slows up wonderfully with a beautiful nose high attitude on final. Would never have the CG that far back on a tapered wing like my Superstar, or heavy warbird but it sure works well with the Tiger wing and the light weights it can build to.
11-05-2014, 06:30 AM
#969
My Feedback: (6)
I just purchased an unstarted Tiger 60 Deluxe kit, so I would like to join the group here. I would also like to hear from the members on there opions of engines and servo choices. Right now I am leaning toward an OS FS-91/ Saito 91 for my engine choice and Futaba S3151 for servos. I just found this thread, so I haven't had the time to read thru it yet.
11-05-2014, 01:51 PM
#972
I just purchased an unstarted Tiger 60 Deluxe kit, so I would like to join the group here. I would also like to hear from the members on there opions of engines and servo choices. Right now I am leaning toward an OS FS-91/ Saito 91 for my engine choice and Futaba S3151 for servos. I just found this thread, so I haven't had the time to read thru it yet.
11-05-2014, 06:09 PM
#973
My Feedback: (6)
Thanks thailazer! The canopy in the kit a picked up really needs to be replaced. At some point the top had been partially mashed inward. I straightened it out as best I could, but it has a slight crease on either side now. If you know someone that has a new or used one in good shape send them my way.
Last edited by mustangherb; 11-05-2014 at 06:14 PM.
11-05-2014, 07:21 PM
#974
Thanks thailazer! The canopy in the kit a picked up really needs to be replaced. At some point the top had been partially mashed inward. I straightened it out as best I could, but it has a slight crease on either side now. If you know someone that has a new or used one in good shape send them my way.
Last edited by thailazer; 11-05-2014 at 07:41 PM.
11-06-2014, 01:52 PM
#975
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Join Date: Jan 2011
Location: SorrentoBritish Columbia, CANADA
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The last two pages of my manual are a list of parts and an order form . It is a old manual from back when they die cut the kits so I am not sure if it is up to date or not . I am currently building a new Tiger 60 and am probably going to put an OS75 in it . Thats what I have in the one I am flying now and I am happy with it . I have been thinking about putting a big four stroke in it because they tend to be tail heavy and that's one way I could lose the lead in the nose . . I always make my Tigers tail draggers and I increase the size of the control surfaces so that adds to the tail heavy situation. I use Hi-Tec 425 Servos . They are reasonably priced and so far have never had one fail .