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RE: Impact
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It still bothers me is not knowing, for sure, why the failures have occured.
I fly my IMPACTs with George Asteris, he had built two for himself and aligned two for me. We put the rear former in, as advised, in all of them. I went further and installed a rear fuselage lengthways "ladder" in both of mine. George flew his a lot more than I did this year, No sign of any failures. Gerge destroyed his first two in two different ways. The first was due to a dead-stick DZ in a strong down wind position. Hit the hill on the way back, hard. No damage however in the area that has been failing. The second one had a mid-air with a BIG vulture. Destroyed the plane but still OK in the "danger-zone". (George is a renowned designer and pattern builder. I mention this because he has now almost finished his third IMPACT. The plane must have impressed him a lot for him to make three for himself.) My two Impacts have been FAI'd and Master'd with multi snaps and flown in tough wind conditions. Still holding up. Where I am going with this story is that braced or not ALL of these ones held up. Yet some others have sadly and clearlly failed. (I forgot to mention that all of ours have light balsa/foam rudders). I have put up a bunch of theories on this forum, but they are only theories. I can neither condem the supplier or exonerate the plane. Do we have any new theoreis or ideas out there as to why some have failed and the rest have not? Curious as ever - Eric. ORIGINAL: BillB Hello Magne, I had installed a rear former and a horizontal plate, just as is recommended in CARFs update on their website. I also had installed a bulkhead directly behind the canopy. From that bulkhead to the rear former I installed a 1" thick piece of foam horizontally. It was glued to the sides of the fuse and to the former . The break in the fuse was right at the former. The glue joint between the former and the foam stiffner had not broken all the way through. I had my elevator servo mounted between the wing. Except for using a bellcrank in the tail with pull pull cables back to the servo, and real Robart hinge points, the tail assembly was stock. [img][/img] |
RE: Impact
Only a theory, but during my post mortem I noticed two grooves in the leading edge of the stock rudder that lined up with the rear of the fuse. As you commented, Eric, none of the aircraft you have been commenting on have the stock rudder. I wonder if the unsupported section of the hinge points between the rear of the fuse and the rudder are causing some kind of vibration. I never heard anything remotely like flutter, which I definitely heard when my Rev Pro came apart. My Impact had never been snapped or spun. It did have a horizontal stab failure where the aluminum tube sheared off right at the edge of the fuse. I replaced it with a carbon fiber tube. The stab landed in a swamp. Thanks to Dave Snow for donating his stock stabs.
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RE: Impact
I love and hate mysteries like this.
If you are of an engineering background you tend to move into "conclusion and fix mose" pretty rapidly. If you have a scientific background the desire for data that can be analized is immense. A bit like breathing when you have been under water too long. Irresistable but can be fatal. I can't get into engineering-mode until I can get past the data-mode. Unfortnately a scientific approach would involve a lot of money and testing to get good data. I can relate too, and sympathise with, the engineers who want to move on and either fail or fix. I appreciate those of you who keep posting infomation. I know, there is NO CURE!!!! Enquiring-Eric. ORIGINAL: BillB Only a theory, but during my post mortem I noticed two grooves in the leading edge of the stock rudder that lined up with the rear of the fuse. As you commented, Eric, none of the aircraft you have been commenting on have the stock rudder. I wonder if the unsupported section of the hinge points between the rear of the fuse and the rudder are causing some kind of vibration. I never heard anything remotely like flutter, which I definitely heard when my Rev Pro came apart. My Impact had never been snapped or spun. It did have a horizontal stab failure where the aluminum tube sheared off right at the edge of the fuse. I replaced it with a carbon fiber tube. The stab landed in a swamp. Thanks to Dave Snow for donating his stock stabs. |
RE: Impact
So let me get this straight.
Comp ARF released a plane called Rev Pro that was really the Cocaine in Europe. It was blowing up left and right all over the country. SO they released a new model called Impact based on the same design and made some mods to it. But this time instead of doing the work themselves they made it a kit where the pilot/builder is now at fault for the grenade action. Seems to me they named it correctly. :D:DBIG SMILE:D:D I suppose that you get what you pay for. I don't like the fact that European kits are so expensive but the reality of it is that if built properly the average guy can have them stay together eh? |
RE: Impact
When they first released it, I remember commenting about what an unfortunate name choice they made. In retrospect, you gotta smile at how apt the name is; but it's no laughing matter to the many who have had theirs break in flight
Nevertheless, when built correctly, it's a fine flyer. I believe the one I built is still flying. Brian you out there? One thing I discovered on Brian's broken impact was this: the rear of the fuse, just in front of the stab LE, had buckled (compression buckle) but only on one side. The other side was not affected. Once I took it apart, it was obvious that the fuse side thickenesses were not the same. I suspect their supply of urethane foam material is suffering from low QC. Couple that with hand lay-up of 2 oz glass cloth and the variables could easily stack up against you too often. Other than that, it's a great product. MattK ORIGINAL: AAM So let me get this straight. Comp ARF released a plane called Rev Pro that was really the Cocaine in Europe. It was blowing up left and right all over the country. SO they released a new model called Impact based on the same design and made some mods to it. But this time instead of doing the work themselves they made it a kit where the pilot/builder is now at fault for the grenade action. Seems to me they named it correctly. :D:DBIG SMILE:D:D I suppose that you get what you pay for. I don't like the fact that European kits are so expensive but the reality of it is that if built properly the average guy can have them stay together eh? |
RE: Impact
Hand lay up of 2 oz glass cloth. Not likely!! When I was poking around the break in my fuse with a eye to repairing it I stuck my fingernail right through the cloth. I thought maybe it was weak as it was right on the edge of the break so I stuck a small screwdriver into another section. I use 1/2 oz. cloth on my wings when I build my own and that is a whole lot stronger than whatever it is that Composite-ARF uses on it's fuse. It's about as strong as a rotten t-shirt. That's when I figured that it wasn't worth trying to rebuild. It would just fracture on the edge of the repair. I do agree that it is a shame. It's a great flying airplane.
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RE: Impact
Hello guys,
With high interest I am watching this thread since I am about to replace my VERY OLD Dalotel 60 with one new Impact by Composite ARF. May I hear suggestions about selecting a fuel engine or Electric .... ???? I appreciate your suggestions !!! :D |
RE: Impact
Hi
Did you see planes by Wistmodel named Prestige (885 E taxe included, without shipping) or by Modelltechnik-Lorenz like El-Tiburon (Abbra), Rhapsody, Cocaine. Prices of theses planes are near price of Impact, and they are very reliable. I didn't see or hear failure of theses planes. http://www.wistmodel.com.pl/ http://www.f3alorenz.de/ Regards. |
RE: Impact
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I currently have 50+ flights on my Impact without problem. I am impressed and will probably build another. Anyone who has seen my previous posts in this thread will know what extent I went to avoid the failures these models are suffering.
It is easily the best flying model I have ever owned. After a little tweaking and adjust from the intial flights I am happy to report that this model is very true with no trim or mixes. My final settings are somewhat different to their instructions. DZ160 power is a perfect combo for this model if you plan to use IC. Electric is proven if you have deep pockets. Make sure you make the changes as suggested in this thread. If you look at my suggestions you should be fine. Here's a couple of pictures for those that are interested. Peter |
RE: Impact
ORIGINAL: MTK When they first released it, I remember commenting about what an unfortunate name choice they made. In retrospect, you gotta smile at how apt the name is; but it's no laughing matter to the many who have had theirs break in flight Nevertheless, when built correctly, it's a fine flyer. I believe the one I built is still flying. Brian you out there? One thing I discovered on Brian's broken impact was this: the rear of the fuse, just in front of the stab LE, had buckled (compression buckle) but only on one side. The other side was not affected. Once I took it apart, it was obvious that the fuse side thickenesses were not the same. I suspect their supply of urethane foam material is suffering from low QC. Couple that with hand lay-up of 2 oz glass cloth and the variables could easily stack up against you too often. Other than that, it's a great product. MattK ORIGINAL: AAM So let me get this straight. Comp ARF released a plane called Rev Pro that was really the Cocaine in Europe. It was blowing up left and right all over the country. SO they released a new model called Impact based on the same design and made some mods to it. But this time instead of doing the work themselves they made it a kit where the pilot/builder is now at fault for the grenade action. Seems to me they named it correctly. :D:DBIG SMILE:D:D I suppose that you get what you pay for. I don't like the fact that European kits are so expensive but the reality of it is that if built properly the average guy can have them stay together eh? I'm here Matt, I lost the second Impact the end of last season, it failed right in front of the crutch I installed!! Hope you and your family are doing well and I know your enjoying the warm weather, LOL. Been flying the Majestic. |
RE: Impact
Dear papaone,
Thanks a lot for your time to inlight me about the other models. The reason for me to select Impact is no other than this. Two friends already bought them and built them so they have experience for the construction as well trimming of the model in flight. I saw the model flying at the annual F3A contest in Greece and it really suprised me. I can tell you tha I made a test flight with the one fo the two I am telling you above. I really liked it. Anyway thanks a lot for the effort !!! Have good landings ! |
RE: Impact
Hello tmark65,
I think that the El Tiburon(Abbra) from F3ALorenz or better yet the Prestige from Wistmodel are better choices than the Impact. They also have a different look (esthetically better IMHO) than your friends planes. I also read that the El Tiburon is an especially good flyer. Have a nice day Tasos |
RE: Impact
File Stavro,
mphka sto xoro kai lew na parw kati kalo. Me ebale sto louki o Vangelis ... Ante na pioume kafe sto ergasthrio kai na apraggeiloume ta specialakia. Filia Tasos |
RE: Impact
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Hi Tmark65 and Tcsravros
I like forum to discuss about passion with other modelist of others country. I visited Greece and Crete (Heraklion) when I was young. Very very beautifull countries. I have a Cocaine and it fly great (Cocaine is similar Impact), dealer is Lorenz for Europe but builder is Jaroslav Mach (Republic Tcheque). The advantage of this plane is sleeves for carbon tubes are already fixed in the fuse, wings and stab so incidence and "triangulation" are perfect. Frame for support fixed gear is also fixed. |
RE: Impact
Dear Papaone,
Thanks a lot for your recomendation !!! I searched about Cocaine and I understood that it is the predecesor of Impact, am I wright ? I am flying an old Dalotel 60 with a Hano Pretner Special but the competition is going up and my Dalotel is tooooooo fast to be accurate, so the need for an upgrade is a demand. rcStavros has helped me a lot, I suppose he replied to my post in a hurry, this is why he din't realize who I am. He is a champion in the Greek F3A NATS and on the edge about F3A. Have you ever think about visiting Greece again ? Maybe in one of our F3A event ? How's that ???? I am looking forward to here from you again. Till then I am searching for my new project. The only think I hate is the expenses for the package and handling to get the aircraft from a dealer around Europe. Usually the ask for something like 200Euro's or 240USD. Anyway ...... |
RE: Impact
Hello Tmarc65
It's not the same plane. Cocaine is different of Impact even design is similar. Impact is made by Composite Arf in Asia. Fuselage is not made idem way. Impact has a herex fuselage. Wings and stab sleeves are not fixed, incidence is not done. There is much work to do Impact than Cocaine. Cocaine is made in Républic Tcheque and sold by dealer Modelltechnik-Lorenz (Wolgang Lorenz is the manager). Fuselage is made with fiber glass/balsa/fiber glass and reinforcement carbon. Every sleeves are fixed. Triangulation and incidence are already made and I think it's very important for quality of very good flight. I think shipping of Cocaine is not very expensive, now about 90 E from Germany to the south of France. I payed 80 E (I live near Marseille). I equiped mine with Yamada. Its an expensive engine but it's four stroke engine. I think two stroke OS140 RX is very good Engine and cheaper ( about 330 E in Bichler modellbau in Germany, pipe 20 E and reso 97 E in Lorenz) http://www.modellbau-bichler.com/ind...fd6713952e1d3c I visited Greece in my hollydays. Very beautifull country and nice people. So Parthenon is awesome. Regards |
RE: Impact
Papaone,
Thanks a lot !!! I already email Lorenz, he replied back and I am waiting fro him to tell me availability, color schemes and amount of expenses. I hope you will help me with fotos and assistance for setting up the Cocaine. THANKS !!!!!!!!!! |
RE: Impact
Taso, otan soy steilei to kostos gia shiping, sfyra.
Papaone thank you for the shop suggestion. But I think this one (Bichler) is a little late on its orders. Do you have any personal experience ? stavros |
RE: Impact
Hello Eric.Henderson
You are talking about Mr. George Asteris. Do you know if he is Greek ???? If yes, can you tell me a way to contact him ? Thank you !!! |
RE: Impact
Hello Rcstavros
Yes Bichler is little late with orders. But my friend Olivier Gomez (he lives near Paris) received his engine 140 RX and was satisfied. He ordered exhaust pipe (20 E ) and reso (97 E) in Modelltechnik Lorenz and received every pieces. Regards |
RE: Impact
Hello Tmark65
I know Wolfgang Lorenz. He is confidence. You can choose design in his list of designs and choose colors in his list of colors and associate them like you want. Yes no problem to mount this plane it's very easy and quick to do. I 'll inform you and 'll send you pictures you 'll ask me. Cocaine fly very very well. Very good in strong wing. I think you looked to my pictures I posted on this forum. Regards |
RE: Impact
Hello Tmarc65
I forgot to tell you that colors of my Cocaine are too clear and I don't sse it very well in the sky. Regards |
RE: Impact
Hi Papaone,
Thanks a lot for your assistance !!! As I wrote, I am waiting from Lorenz his reply to order it !!!!!! I was wondering if it worths to buy the cheaper version, the one with balsa wings. I am thinking that the composite, if I have a problem, it's gonna be harder to repair, with balsa is easier. On the other hand I am saving almost 300Euro's. What do you thing Thanks !!!!!!!!! |
RE: Impact
Hello
You are right. It's not possible to repair full composite if you touch ground, may be you do that but it wil be bad. Full composite is ok if you never do a mistake. Cocaine-pro is good. Triangulation, fixed gear frame is already installed. The kit is very advanced. You have to finition with Oracover and painting the fuse. Regards |
RE: Impact
Hello tmark65
There is a little difference of weight bettween composite wings and balsa/foam wings. composite wing painted without servo = 400 / 410 g balsa/foam wing with oracover without servo = 435 g stab full composite painted = 80 g stab balsa /foam with oracover = 93 g Regards |
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