Robart (Ziroli) P-47 "Gabby" version
07-02-2016, 02:29 PM
#151
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Ive had the same problem with the gear. The pins robart uses are too soft. I removed the pins and welded in new pins I made from the shank of a 1/4" long reach drill bit from home depot. In addition, I used a spare set of cam blocks and mounted them on the back side of the originals for the second pin to go into. With the high tensile steel drill bit pins and double cam blocks, the gear are now tough as nails. Here's a few pics
Evan Q.
Evan Q.
07-02-2016, 04:34 PM
#152
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Well done! I happen to have another set of cam blocks to get started.
I've talked with a couple of guys at Robart and they seem content to be in denial about the soft pins and hang it on pilot technique. Unfortunately, I think it'll be the same on the tail flutter.
Thanks again for your comments.
I've talked with a couple of guys at Robart and they seem content to be in denial about the soft pins and hang it on pilot technique. Unfortunately, I think it'll be the same on the tail flutter.
Thanks again for your comments.
07-03-2016, 12:29 AM
#153
As I have already posted, mine does not flutter even when doing full power fly bys. However, my elevator servos are ultra high resolution MKS 1240s with 1/2 inch servo arms. These servos produce 250oz of torque on 6.6 volts. Otherwise my setup is stock. Of course I cannot say my servos are THE reason I have no issues, perhaps my flying style, which is more on the scale side, along with the servos, is keeping mine out of the flutter zone. Mine is powered by a Evo/MVVS 80 turning a Zoar 26 X 12 prop so it's making a lot of thrust at 6200 RPM.
I've had version 1 and 2 now and the gear issue is a valid criticism. I have not bent a trunion pin but I have bent the mounting tabs on the gear mechanisms. These are 40-pound models, the gear is a bit on the spindly side so yes, something will give under heavy side loading. So Robart's pilot technique response is also valid. I check the winds before landing to remind myself of any required crosswind contol inputs. My crosswind technique is to hold sufficient rudder to keep the fuselage aligned with the runway all the way down final and throughout the landing roll out. The resultant wing low attitude on approach will mean the upwind aileron is deflected up, which when maintained through landing roll out, will keep pressure on the upwind gear. Its when this gear gets light and the wing lifts that the dreaded ground loop occurs.
Food for thought, your results may vary.
I've had version 1 and 2 now and the gear issue is a valid criticism. I have not bent a trunion pin but I have bent the mounting tabs on the gear mechanisms. These are 40-pound models, the gear is a bit on the spindly side so yes, something will give under heavy side loading. So Robart's pilot technique response is also valid. I check the winds before landing to remind myself of any required crosswind contol inputs. My crosswind technique is to hold sufficient rudder to keep the fuselage aligned with the runway all the way down final and throughout the landing roll out. The resultant wing low attitude on approach will mean the upwind aileron is deflected up, which when maintained through landing roll out, will keep pressure on the upwind gear. Its when this gear gets light and the wing lifts that the dreaded ground loop occurs.
Food for thought, your results may vary.
07-03-2016, 02:44 AM
#154
Hi Guys.
Here are some pics on mod i made on my plane on elevator flutter. I took some hard ply and drill a hole the same dia as the tube on elevator that runs thru the G-10.
then i cut the blocks in half. Then i sanded the blocks and G-10 to make good contact when i carefully Hysoled the blocks to the G-10 with some pressure pushing forward.
there is zero play in the elevator,as before the mod..there was i my opinion way to much play and i would had have the the same problem. In my opinion i would have to put a bearing in there,but because it was pre-assembled,it can not be done. it would have been if they designed that way,but i guess the cost of production would go up.
Thanks,Vincent
[ATTACH]2171047[/IMG][ATTACH]2171048[/IMG][ATTACH]2171049[/IMG][ATTACH]2171050[/IMG][ATTACH]2171051[/IMG]
Here are some pics on mod i made on my plane on elevator flutter. I took some hard ply and drill a hole the same dia as the tube on elevator that runs thru the G-10.
then i cut the blocks in half. Then i sanded the blocks and G-10 to make good contact when i carefully Hysoled the blocks to the G-10 with some pressure pushing forward.
there is zero play in the elevator,as before the mod..there was i my opinion way to much play and i would had have the the same problem. In my opinion i would have to put a bearing in there,but because it was pre-assembled,it can not be done. it would have been if they designed that way,but i guess the cost of production would go up.
Thanks,Vincent
[ATTACH]2171047[/IMG][ATTACH]2171048[/IMG][ATTACH]2171049[/IMG][ATTACH]2171050[/IMG][ATTACH]2171051[/IMG]
06-30-2017, 03:53 PM
#157
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elevator problem fix
take a look at this
Hello all,
I have a V2 No Guts No Glory Robart P-47. It has about 15 to 18 flights on it with a ZDZ Super 80. It also has gps speed/altitude read out thru the Hitec A9. It's a great flier but about 4 flights ago started developing an ugly horizontal stab/ elevator flutter at high speed (anything above 90 mph or so). This is really ugly and I feel certain will result in a total failure of the empennage and airplane loss if allowed to continue. The flutter stops as soon as the speed is decreased.
After flight inspection reveals nothing loose or any structure imperfections or issues. As you all know, there iare quite a few bucks tied up in these planes. Flying it around at Super a Cub speed is no fun. I had a V1 Miss Eileen but lost it due a receiver battery issue. I think it was a better bird than V2.
I saw a video of a guy named Ryan who won one in a NASA raffle. On his first flight (in the video) he had the identical problem and got it back on the ground. I can't find any follow up to the problem. Has anyone heard or know anything about this? I suspect the crash described in this thread was caused by this problem.
I'm really perplexed about this. Any ideas out there?
I have a V2 No Guts No Glory Robart P-47. It has about 15 to 18 flights on it with a ZDZ Super 80. It also has gps speed/altitude read out thru the Hitec A9. It's a great flier but about 4 flights ago started developing an ugly horizontal stab/ elevator flutter at high speed (anything above 90 mph or so). This is really ugly and I feel certain will result in a total failure of the empennage and airplane loss if allowed to continue. The flutter stops as soon as the speed is decreased.
After flight inspection reveals nothing loose or any structure imperfections or issues. As you all know, there iare quite a few bucks tied up in these planes. Flying it around at Super a Cub speed is no fun. I had a V1 Miss Eileen but lost it due a receiver battery issue. I think it was a better bird than V2.
I saw a video of a guy named Ryan who won one in a NASA raffle. On his first flight (in the video) he had the identical problem and got it back on the ground. I can't find any follow up to the problem. Has anyone heard or know anything about this? I suspect the crash described in this thread was caused by this problem.
I'm really perplexed about this. Any ideas out there?
06-30-2017, 05:10 PM
#158
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Gabby P-47
Dick,
Do you know of anyone (besides me) who is building a 40% Piel Emeraude? I found an old (19060-70s) kit with build manual, but no plans. Jerry Van Heeswick designed the model. He is gone, the kit manufacturer (Hanger one of Mntgomery AL is gone and the remaining parts of kits were sold last year to an unknown. Mine is 95% complete except for the bubble canopy. A fellow who had made 5 canopies, then destroyed the mold, and the company who made them (Miami, FL) has gone out of business. The canopy with windshield is 16 3/4" wide X 36" front to back.
I would love to communicate with any other Emeraude builder. At 40% the w/s is 10'- 6". I am using a DA 100 twin for power.
NASA member Don (Pilotdb09)
Do you know of anyone (besides me) who is building a 40% Piel Emeraude? I found an old (19060-70s) kit with build manual, but no plans. Jerry Van Heeswick designed the model. He is gone, the kit manufacturer (Hanger one of Mntgomery AL is gone and the remaining parts of kits were sold last year to an unknown. Mine is 95% complete except for the bubble canopy. A fellow who had made 5 canopies, then destroyed the mold, and the company who made them (Miami, FL) has gone out of business. The canopy with windshield is 16 3/4" wide X 36" front to back.
I would love to communicate with any other Emeraude builder. At 40% the w/s is 10'- 6". I am using a DA 100 twin for power.
NASA member Don (Pilotdb09)
