Hello guys, I just received my Impact today and as I was advised by Jason Shulman I'm going to try an OS 160, I just got tired of waiting for the YS (been flying YS for several years), but after reading most of the post I'm now scared, I don't want to have an impact with the ground, I really don't have the time I wish I could have to read all posts to gather the information on how to reinforce the airframe, so any advise will be appreciated, also I can't find a Pipe/muffler for it, I was thinking going Hatori but can find one.

I already know about all the bad comments and looking forward to hear the ones to improve the aircraft.

Thanks to all.

I am running the OS 160 in my Abbra. I am using Karl Mueller header. You can contact him at [email protected]. He custom made the headers. I am using a carbon EDS carbon pipe that you can get in Central Hobbies. Another option is the Aeroslave pipe that many pilots have been using with good results. If you need to get the links to Central Hobbies and Aeroslave check the NSRCA web site at www.nsrca.org I assume that you will install the tank in the CG. You will need the Perry pump. The combination has been working very well using OS F plug.

Vicente Bortone

Hi
I think the better way is to reinforce internal fuselage with /résin and carbon sheet
if it's possible to go in the internal. Fuselage tears in front of the tail because skin is to thin or composite
is bad making regarding stresses due to vibrations and aerodynamics forces.
To buy exhaust pipe or muffler in Modelltecknik-Lorenz, it's cheap.
http://www.f3alorenz.de/
Regards

May also want to build a new rudder to save some weight. Here are some pics of how I did a ladder set up in mine.

Hi Aperiera

I haven't flown mine yet but I have spent a fair amount of time over the months reading the very long thread on the Composite arf Impact build alng with two or three others that are in the RCU pattern section. It is my understanding that some of the parts that were "developed" during the course of these threads are now included in the "kit." What I think I have learned (the proof is in the flying and longevity of the plane) is that in addition to the short horizontal stab brace that ties into a vertical piece, another vertical rib/bulkhead/ also should go in to stiffen the fin. I ran a ("hollowed out" lite ply for lightness) bulkhead from the bottom of the fuselage to the top of the fin. It touches the top of the fin at about the point where the top becomes horizontal. I felt that even with the stab brace and vertical piece there was a possibility of flexing at the point where the fuselage curves in along the sides and then kicks up to become fin (even with the rudder post). This aft piece has solidified that.

Another thing to consider is some kind of horizontal bracing as rgreen shows in his picture. It was my understanding that Comp. Arf was going to include a piece of Depron foam to accomplish this. I used the foam (ordered my own and cut it to fit and integrated it with the DEPS elevator pushrod system. I made the DEPS system first with the long 1/4" sticks and the tubes and a couple of spacers setup to work in my fuselage and then glued the aft ends of the sticks and then Depron crutch to the sticks, the sides of the fuse, and the vertical stab brace all at the same time (well -- sticks in first then the crutch right after). Be sure the servo end of the pushrods is finished and the servo real close to where it will live -- this will provide front end support (another set of hands) during the gluing (the exit slots aft will hold the other end in place while putting the foam crutch in place). I also put the foam piece on top of the DEPS sticks -- it puts the foam closer to the vertical middle of the fuselage where it will do the most good.

At the front of the crutch, tie into a vertical or slanted bulkhead that goes right behind the canopy opening. There are several good photos of this in the big thread. Continue this stiffening forward not necessarily in the same plane as the Depron but close for max help. This more forward piece can be used as a rudder servo mount. Use the middle of the rudder for the aft ends of the pull cables instead of the bottom as the factory advises.

Whatever system used for stiffening it is very important to tie (touching and glued) all the sections together -- vertical stab brace to crutch -- crutch far enough forward to prevent flexing right behind the wing -- etc.... The forces that will break anything, know how to find the weakest point and breaks in the continuity become soft points.

One piece of advice that I would give is that because of a few failures I have heard of behind the wing, I would reinforce the belly of the fuse in the area where the muffler will exit and where there will be vent exit slots/holes -- reinforce from the inside. These vent/exit holes take away some of the eggshell that gives the structure it's strength. It is much easier to reinforce now when the fuselage is empty than after the floor is in (don't ask...). Rough it up and add a layer of glass cloth that will make the stresses go around the cutouts instead of through them -- through them means breakage...

Holler if you have any questions,
Tom

that ladder look like the ones we put in all of our kits 15 years ago -anyway put a tiny triangle of 1/64" ply at each glue joint to increase glue area . vibration has a way of popping those things .

I used a depron foam crutch in mine. It has held up through many flights in AMA masters with that upside down avalanche.. Be sure you get it joined to the rear former. You may find a picture of mine by searching that other huge thread on the impact.

Thanks to all for the inputs.

Regards

Hey Dick, good to see you posting on the pattern list. Did you get my last Email ?? Ed M.

Hey, I've got my Impact, I put it together, equiped with YS160DZ with ES tuned pipe. This Friday started to fly it. It seems to be good aiplane. Plenty of power, makes nice knife endge.

Only one thing. The long ailerons are making the plane very sensitive. I fixed it by playing around with expo and throws. I can fly it, but I don't think it's the optimum. I'm not interested in 3D.

I looked at a picture of Jason's winning Impact on Composite ARF pages and it looks like he has shorter ailerons.

Does somebody know something about this? Or what is your setup on ailerons. Other controls I got plus/ minus fine.
Thanks

All I can suggest is read to other IMPACT forums. 1-2 nights invested will save you down the track. There is a lot of very good info in those forums. sometimes it is better to understand "why" than just knowing "how".

Hey folks,
I've been flying my Impact for a couple of months now. Ryan M & I have used the same set up. OS 160's with the perry pump, I have the Aeroslave pipe, he was using the ES pipe, Meuller headers. We didn't do anything special to the kits. Built them how they said to build it including the Depron and former. I've been flying through the FAI F-07 sequence and it seems to be doing fine. I think this plane has gotten a bad reputation. Yep, some of them broke. They fixed it. I like mine more as I get it set up.

I fly with Jason pretty regularly and my understanding is that his is a stock kit with a different paint job.

Joe W.

Hey DIPS --

PeterP's advice about digging through the big Impact thread is sound -- there is a wealth of information on control throws, CG etc. some of which is personal taste and some of which really directly affects how well the plane flies. Because of the way I like a plane to feel my control throws are somewhat less than some people will use but those adjustments can be made after trying some settings -- tweak it until it goes where and how you like it. Remember that optimum is your optimum -- for the way you fly and like an airplane to feel.

For the CG, I started with one recommended point (center of wing tube -- wings off) and after a dozen flights used a different recommended spot (just outside the back of the wing tube) by moving the battery back as far as I could and adding 5/8 oz in the tail (I hated adding the weight but curiosity got the better of me). Also sealed the elevator and aileron hinge lines. Nicer control responses, better looking snaps, and no more shrieking (in snaps) -- the CG changes may have had something to do with all but the shrieks, also.

Besides the "main" Impact build thread there are two others worth looking over: Rolling Issues with Composite Arf Impact; and Aileron Differential on the Impact. There is a fair amount of chaff to filter out in all of them but the material is worth reading and digesting and learning from -- I know I have learned a lot.

Good flying and keep digging -- the Impact is worth the time. PM me if you have a specific question for me.
Tom

Tom,
Thanks for advices. I like the idea of sealing the aileron and elevator gaps. It sounds really badly, especially in snaps.
I will look into the forum. Fixing the rolling issue.. that would be cool.

Pavel

Hi,

We are some guy`s up here in the north that have been flying the Impact a great amount without any trouble .. We all fly the P-07 with it ,and the bird have a great potential.. no doubt ..

We all did some modifications ; both structural , and flying performance. The structural where as mention before ; a kind of ladder construction in the tail, and the flying performance ; CG position and aileron modification.
The CG ended up , after a lot of testing , at the rear edge of the wing tube ( everything installed except the canopy ).
Ailerons where thickened at the rear to decrease the sensivity at neutral . This was done by splitting the skin and insert a 2x10mm balsa sheet. The gap between the aileron and wing was sealed to reduce drag at higher deflections.

The Impact rolls different than many other craft`s , specially the transit between level to high side .. but i belive it is more a issue to get known to it ... Now the problem are gone .. .

I definitely concur with the CG, canopy off, just behind the tube. I just adjusted the expo to about 55% in the ailerons and the feel is much softer now (as expected...) Mine started out very heavy with the Hatori pipe, Hyde mount with the integrated nose ring, stock wing tube, etc. Just weighed it this weekend and now it is 10 1/2 lbs with the Aeroslave pipe, hyde with a homemade wood nose ring and a new carbon wing tube from Jerry Budd. Snaps great, spins are pretty darn nice with just rudder & elevator. I still have the whistle during the snaps... But I kind of like the sound! LOL Everyone wants to stand out, right?

Now that I have changed everything, time to fly it and get used to it again!

Good luck with yours.

Joe W.

Dick,
How would you get the glue down the joint in to the tail section of the fuse?
There can be a considerable reach to install some of these "ladders" and "floors".
Thanks!
JLK

Hi Vellum2 --

Is the Aeroslave CF muffler lighter than the ES CF muffler?

I'll have to check to see where my CG is with the wings on. I have it set right now at that same spot without the wings and with the Canopy on. We'll see.

Thanks,
Tom

Tom,
Don't know the exact weight difference, but I think they are both pretty close to 3 oz. I started with the Hatori pipe which was 5 oz.

Joe W.

AeroSlave pipes weights about 3 oz but is a lot stronger then the
ES pipe at about 2.5 oz

Big diff is the AeroSlave pipe is way less expensive at a cost of about $165.

WG

Joe, I am a little late joining this forum, but am about to start building my Impact. (Got the kit for a good price from a guy who had 2 flying. This was before I began to read the very large build thread.) I would appreciate knowing how your Impact is doing. Also, am I to understand that you made no modifications to the rudder or fin? Where did you mount the rudder and elevator servos? I plan to use the same engine set up as you. Any issues? Thanks.

John

I had a early model Imact that self destructed. I have seen the later models and they do have better construction. In particular, the thickness of the fuse is more consistant expecially near the tail. Mine was fairly thin in the back. My continuing complaint is that Composite ARF and Jason Shulman refused to stand behind their product. I replaced my Impact with a Temptation and have never looked back.

Hey F-4 --

I had an Impact from the earlier production run but did not build it for about a year because of other projects that were ahead of it. I benefitted from the collective wisdom of the huge building thread -- all the internal mods having to do with the fuselage from center rearward. Mine didn't come with any of the parts or templates but I added them. I flew mine with a 160 DZ and it stayed together until I buried it -- long story -- no fault of the plane. The crash pretty much tore up the front half of the fuselage from the wing tube forward, but did not break the tail off -- didn't even crack it. I had used my own 1/4" Depron crutch from just forward (1 -2") of the wing TE back to the tail brace. I did add one more tall vertical bulkhead slightly behind the stab tube -- full height top to bottom but "hollowed" to about 1/4." This stiffened the fin -- it seemed on mine to want to flex at the line where it stopped being fuselage and started becoming fin. I also cut off the rudder counter balance and glued it ot the top of the fin. I pitched what was left of the rudder (and their fin post), and built a balsa rudder that was hinged conventionally. Much lighter!

For the elevators I used Central's DEPS system which survived the crash, by the way... one servo up under the rudder tray, fastened to the pipe floor with some lateral stiffeners. I had to remove/"uninstall" the servo.

I had some vibration related issues with the DZ and the stab -- the stock anti-rotation pins would work slightly loose and needed fattening up periodically. I did end up gluing the tube (had a choice of CF or aluminum -- chose the CF) into the center socket. That helped solidify the stab and slow down the pin wear. A two stroke probably will not have that much of an issue back there.

If your kit doesn't have the parts discussed in the big thread by all means take the time to make and use them. I just picked up another Impact kit from the late production run. It has all the additions and the production quality seems even nicer than the first one I had. Build it right and straight -- you'll like the way it flies. I have another plane to finish first but hope to fly the new Impact next Spring. They were/are a great airplane. Holler if you want more.

Enjoy,
Tom

One thing to watch for is that like many other pattern planes the Impact will fly with the CG much further aft than is desirable. It wont do any nasties like dropping a wing when slowing for landing or flying inverted with little or no down elevator.

What it will do is fail to lock onto lines, especially in yaw, and be difficult to land as it appears to run out of lift suddenly without wing dropping. Mine kind of snuck up on this situation as I worked with progressively lighter large electric props and a change in spinner. Moving the flight batteries forward to restore the CG to the back of the wing tube was a revelation in its flying characteristics.

Malcolm

Hi,

The Impact is a great flyer in most aspect ... mine have past 200 flights and i have used it for the P-07 program. Today it is my backup for the Integral.

Like most other, i have reinforced the fuselage just to be sure, and everything have hold up just fine. In the beginning, mine was powered by OS140 RX, then i put the YS160 into it. The YS is the best/perfect powerplant for this plane and i had no issues about vibration what concern this model.

Both elev and rudd servos needed to be put into the fuselage to avoid a tail heavy situation.

Adjust the CG to a forward position and it flies really great. No issues about couplings , track or any unpredictable situations. This is important to get it right!

Good Luck and enjoy a great flyer in a high level class!

Kjell Olav