jfetter

OK, I have scoured the boards ahead of time so I'm pretty sure I have a good idea what I'm in for. I came across a Composite-ARF Impact for $843 (new, in box with e-motor kit included) and offered $650, the guy accepted my offer and it arrived today! I had done some skimming of the boards leading up to the week I seriously decided to make an offer and found pretty much all the negatives regarding the tail crack/break issue and the subsequent C-ARF fix, this kit came WITH the tail bulkhead included (not installed) as well as the stiffener foam board for the length of the fuse so I believe I'm covered (yes, I've read the issues from folks with the fix that still broke as well).

To get started, I created a new thread because the old one was dead, it hadn't been posted to for quite some time and I was worried no one would look for new posts. I want feedback because I want to do this right; this plane is absolutely slick but certainly requires a fair amount of work that would normally be done for you. My skills are up to the challenge but I noticed right off the bat that advice on gluing the stiffener (for example) would be welcome since the thing extends some 28" into the fuse, making getting the glue to it a challenge. Also, I'd like to use BVM Aeropoxy for the entire thing (all glue joints) is that good, bad?

My intent is to make it electric but not using one of the 2 options they show. I am Hackered out to death (they sound like blenders, might as well be glow) and the Plettenberg is one ugly-***** motor. No offense to anyone that has one but I expect form AND function, the form portion of the pletty seems to be missing (are those burn marks I see in the picture?). Again, not to offend, from what I read it is a good motor but I've decided to go with the Axi 5330/F3A, the Jeti Spin 99 and 2 x FlightPower EVO 5000 6S2P (series) for a 12S pack. I know, I know, 12S is a little high but I already own a large amount of TP 8000 4S packs and EVO 5000 6S packs, I can't mix and match and 8S isn't going to cut it so to try and use what I have, 12S is where I plan to start.

I'd like some tips from the guys who have built one of these bad boys already, my experience is limited with large and composite/glass aircraft so if you can help me out and avoid an issue later, I'd be obliged. I read the manual 3 times, I feel I have a grasp over sequence, the areas I'd like advice are stab servos (mount via hatch as they do or in the end with a hole cut into the fuse to accept), rudder assembly (seems to me it would be easier to glue the rudder end piece in before mounting the rudder to ensure proper glue coverage and bond) and finally, motor mounting (I've got a Budd Engineering Electric Soft Motor Mount coming). Oh, I also plan on using a DX7 radio, I have had one for 2 months now, been flying it in my Fliton Inspire 60 and LOVE it, this would be my first composite/glass installation though.

To kick off the thread, I want to talk about quality, this kit has it! I was worried about the thinness of the fuse, particularly in the rear but I have to say this thing is solid, I can't squeeze it and warp it near as easily as the JP Models Lexx (electric plane) I have, that thing will break if you pick it up wrong but I get the impression the Impact is indeed able to take some abuse (though that is not my intent). The fit and finish is very nice (why couldn't they paint the canopy though, please!) and the included parts seem solid (though again, they don't fit together dry, seems like a lot of fine tuning is required). So please chime in, follow the sequence in the book, use Aeropoxy, etc. I welcome comments!

JFetter

jfetter

By the way, before you question why an Impact, I looked and looked for a decent sized, composite-type pattern plane and came up with many hits but the Galaxy, Pinnacle, Astral, Infinity, etc are just too expensive. It seems this niche has simply gotten out of control and these planes now can't be found under $1K. I also remember reading about it back when I was flying electrics and everyone was looking at me like I was crazy when Jason Shulman won the 2004 Nats, good enough for Jason, good enough for me ;-)

I also happen to love the color scheme of this plane, solid red on bottom and the very nice graphics on top make for a good contrast and the size is something I need (my Inspire 60 is electric, flies great but at a distance the clear covering is terrible and the size makes it harder to make out the attitude, I'd like a larger, color-contrasting, capable plane to solve that issue).

My experience level with electrics, even large is expert, I know the systems, the various technologies, I have a broad range of experience with different motors, batteries, chargers, etc so that part isn't problem, my flying skill though are not up to this planes capabilities. I am only learning more advanced pattern maneuvers but I figured why not start with something that will take all the variables out of the equation so the maneuvers are learned pure. So, I've talked enough, anyone?

JFetter

Malcolm H

Hi JFetter,

As a confirmed Impact enthusiast I look forward to your project with interest. My only word of caution is that I really have some misgivings that you can make the 5kg weight limit with your chosen setup. My two Impacts, one Hackered and the other Pletted both need careful prop and spinner selection to be legal. This is using 10S 5300 TP Prolites. You are correct in that the Impact feels solid but the potential weakness is that the internal glass skin is very thin and if cut the foam core underneath is easily cracked, spalled or otherwise damaged leading to a failure. Both my models have been fitted with a balsa ladder crutch in place of the foam one as I feel that this allows better access for rudder closed loop and servo lead runs but otherwise have been built pretty much as per the kit instructions. I did add wing and tail adjusters though.

Good luck!

Malcolm

Stuart Chale

My first thought agrees with Malcolm. How can you make weight with two extra cells. The evo batteries are a more robust cell to start with over TP 5300 packs and would weigh about 4 oz more in the 10S configuration.
Good luck,
Stuart

BrianB

My Feedback: (2)

Be carefull with the Jetti/AXI combo as I have a friend that lost two planes and he confirmed that the Jetti contoller with AXI motor produced radio problems.

jfetter

Stuart and Malcolm,

I guess I should have qualified this one point, I do not intend to compete so the 11 lb weight limit isn't an issue for me (by the time I get good enough to complete I imagine this plane will be nothing but a fond memory). I did run the numbers through MotoCalc using "real" weights (verified with a scale) and my setup should come out around 10.475 lbs plus the motor mount, aeropoxy, tailwheel and flightpack. I imagine the finished weight someplace near 11.25?

JFetter

rgreen24

My Feedback: (6)

Brian that is the combo, that I was planning un using this year. How did he indentify that the controller was causing the problem?

jfetter

Malcolm,

Do you think the balsa ladder is easier to install? I understand the point about being easier to route stuff around and I think I even came across some pictures but the installation, getting the glue joint correct is my main concern. Using the included foam it would also be quite easy to fabricate the ladder since I can use it as a pattern as well...

JFetter

jfetter

Ah yes, this should be a moot point as I am using a DX7 2.4GHz radio which (from my flying to date) seems immune to interference from the on-board electronics. Spektrum is so confident they even instruct the user to not use chokes or other filters on long servo leads. I fly the DX7 so I have experience with it but I'm not saying it's impossible, this is what they say regarding noise interference;

"In many instances, yes it will. The radio interference caused by noisy motors, speed controllers, metal rubbing metal, noisy bearings, etc, generates all its interfering noise below 300MHz-right where we've been operating our 72 and 75mHz models. The Spektrum system operates at 2.4GHz, that's 2400mHz and is well above the frequency that model generated noise is on, so the Spektrum system is unaffected."

We'll see!

JFetter

Malcolm H

JFetter (wish you would use your first name - its easier to be friendly!)

Installing the ladder is 10 minutes work. Use the supplied foam crutch as a tempate to fabricate the balsa one. Slide in the fuz and sand where necessary to get contact along its length.

Sand the inside of the fuz to remove any mould release agent (attach paper to balsa sticks with doublesided foam pads to get compliance).

Coat the ladder with 20 min epoxy mixed with chopped cellulose fibres and slide in place - job done!

Malcolm

jfetter

Malcolm,

Thanks! It certainly sounds easier than I expected, probably easier to get a good glue joint as well with more surface area to work with (compared to the foam), I think that's the route I'll take as well.

What do you think of my desire to use Aeropoxy for pretty much all the joints? I would always use this for gluing a firewall but considering the materials here (glass and composite), it seems like the ideal bonding solution? have you worked with this stuff before? I like that it doesn't droop (it's called a "thixotropic" which according to their web site (BVMJets.com), means that it stays where you put it and won't run), I have had great success with this stuff in the past and the joint is like iron when cured.

Jack (JFetter)

Malcolm H

Sorry Jack,

I'm not familiar with Aeropoxy but as I said any 20-30 min epoxy mixed with milled glass or cellulose fibres to give both filling and thixotropic properties will be suitable for installing the formers and the crutch.

Malcolm

PeterP

Aeropoxy otherwise known as Hysol $$$$ works very well but I would limit its use to high stress areas because it is heavier than epoxy mixed with microballons.

I posted a lot of material in the other IMPACT forums regarding build and alignment. I would suggest you look through those. I dont really have the time to go through that again.

I am still flying my IMPACT almost 1.5 years later with YSDZ160 power and it is holding up well.

I have started to build another IMPACT because the kit was going cheap. I will be making a few mods to this one after my experience with the first.

The model does fly very well. Dont take the alignment settings already marked on the fuse as they are a fair way out.

Peter

jfetter

If you had to list the top things you'd change the second time around (which you in-fact are doing), what would they be? Yes, I did read the other forums, pretty detailed and gathered a lot of great info in there, I just didn't want to startup again in there for fear no one would check back that might have been an original contributor. I am concerned about the alignment comment, my experience with incidence and aligning wings, stabs is well, nil, I have never had to do it and simply relied of manufacturer settings or markings. Is this tough to do?

Thanks for the tips!

Jack

OhD

I found the alignment extremely difficult and would not build another Impact for that reason. One would do himself a big favor buy buying a true ARF where the alignment has been set with jigs at the factory even if it costs $400 more. My opinion.

Jim O

Eggert

....no it is not difficult, but it is a secret

Motor at -1,5 degree( down pull) , wings at +0,2 degree ( LE is higher than TE ) and tail in 0 degree. You also need at least 2,5 degree right pull on engine max 3. Your Impact flys with the same alignment figures as my Elaine. I made precise measurements and then you do not need adjustments going out on the first flight. Only small clicks on elevator and ailerons. A horizontal laser beam and a piece of paper taped to the fuselage does the trick ....

Mail me if you are still in doubt of how to

jfetter

I am a little worried about setting up the wings now, never had to do this type of thing before. So I assume for the wings it would make sense to at least trust the center tube and drill that out and glue in the tube and then work on the incidence with a laser level? Is it safe to trust this molded in mark or is this even something I can't take for granted?

Thanks again,

Jack

Malcolm H

Jack,

I wouldn't be put off the Impact because of the need to set up the incidences etc. Afterall if you were building a model from scratch you would have to do it. Adding wing and tail incidence adjusters certainly gives you some insurance because if you get your measurements wrong you can almost guarantee getting a flyable model by making some adjustments.

Don't take the centre tube markings as gospel. Here is my method: start by opening up both marked centre holes slowly until the wing tube (not the socket) is a tight fit in the holes. Assuming you have the gear formers in and the gear bolted on set the model on a level surface and use a laser level to get the fin vertical by shimming under one gear leg end. Now fit the wing tube and use he laser level to check if it is truly horizontal and perpendicular to the fin. If it isn't, keep your best fitting hole as it is and gently open out the other hole at the top or bottom as required until the tube is level. To take up the gap, remove the tube and run some medium cyano onto the edge of the hole and hit it with kicker. Repeat this until the gap is taken up and the tube is a snug fit and perfectly perpendicular to the fin. It might take a few goes cyanoing and removing material to get this right but it is important.

Now slide on the wing panels and begin adjusting the roots for a snug fit against the fuz sides as per the kit instructions. You need to keep the wing pretty much at the correct incidence by reference to the incidence marks while doing this. Once you have the panels snugged against the fuz sides you can now check for correct fore and aft wing tube alignment by measuring from the wing tips to the top front edge of the fin using a length of non stretching material such as kevlar kite string or even thin wire. If the tube has to be adjusted use the sand and cyano method this time on the front or rear of one hole. I must emphasise that the amounts of material that have to be removed are very small to make a significant change out at the wing tip. Once you are happy bond in the tube sleeve and reinforcing rings as per the kit instructions. I fit two Gator wing adjusters on liteply plates in the fuz on the rear incidence pin positions. I then fit the matching sleeves in the wings using small pieces of carbon tube to fatten up the Gator sockets to fit in the premade holes in the root ribs. If you do this it is essential to install the original incidence tube and load spreading rings inside the fuz just forward of the adjusters to brace the fuz at this point.

Fitting the tail tube is as per the above but use the wing tube as your datum. I made my own incidence adjust setup using old type Gator wing adjusters. The pics show my first model which used two adjusters but the second model used one spaced out on a balsa block. It works just as well.

Malcolm

patternflyer1

My Feedback: (11)

There are plenty of us running this combo with no problems though. And some of the problems seem to be with the 2048 receivers IMO. They are very sensitive. Plus some people put their receiver too close to the esc.
Plus you can always run a choke. Seems that the Futaba needs it. Or at least, most I know with this setup.

My setups use the Airtronics Stylus's with a 1024 and have never glitched once.


I believe this to be an electric problem in general. Not just with the Axi, jeti. If you put your rec too close to the esc you may have issues. Just like in gassers.
Just my opinion though.

I've had 4 of these setups with no issues. Always put the rec at the back and the esc at the front..

Chris

jfetter

Malcolm,

Thanks for the tips regarding wing/stab incidence, I have made some build progress (if I could only quit my job, get a full-time nanny for the 5-year-old and hire some help around the house for my "honey-do" list) and have gotten the bulk of the cutting, sanding, aligning and gluing out of the way. I am working slow simply because I have limited time and I am still absorbing the manual, some other builds I have viewed online and the info I am getting here. I went with a solid, non-adjustable wing mount (glued main and pivot tubes) and am considering adjustable incidence for the tail as you have done.

I have a few questions if you don't mind me taking advantage of your Impact experience?

1.) Do you think I need reinforcing around the firewall? I used AeroPoxy and used the included firewall from the e-mounting kit, I know this is strong but I am considering gluing in the second firewall (it's the one used when mounting a hacker, to hold the rear of the motor) and some spacers between the two to really "lock" in that area. Waste of time or worth considering for the extra 4 ounces?

2.) My kit didn't come with a stab outer tube, not the tube that inserts into both stabs but the one they show in the fuse between the 2 reinforcing rings. Now it appears that they simply intend that I glue the reinforcing rings in the fuse and slide the tube through to mount the stabs (the holes are fit right for this 10mm tube), it just seems to me something needs to hold the fuse apart back here (without the outer tube in the fuse you can push the sides in a bit) and I would lke to know if you went with the outer tube as show in the manual or have the one I describe?

3.) The pull-pull setups I have seen (only 2) show a slot cut for the wire to exit the fuse, I don't want a slot and would rather use a sleeve where the wire exits the fuse (aligned as best I can so there isn't much side-to-side pressure on the wire), is this acceptable? Any concerns?

4.) Do you recommend gluing the tail wood in before gluing the hinges (after a perfect dry fit)? Seems to me gluing in the entire thing in one-shot will be harder to get good glue coverage. Any tips?

Here are some pics, nothing too far along yet, just the basics and core parts...

Jack

Chris Moon

My Feedback: (8)

Jack, I would be concerned about adding an extra 4oz. The Aeropoxy will hold that firewall just fine. In fact, the soft mount is not going to do much for you except add some weight. It is a good product but I don't think you have the weight to spare. I know a friend flying the Impact with the Axi F3A and it was flying at 11 1/2lbs so it is tough to make weight with this combo. Although even at 11 1/2lbs it flies fantastic.

Malcolm H

Hi Jack,

1) I agree with ual767 you don't need to reinforce the stock bulkhead, I used it for my Plett outrunner installation and it is fine. I also don't think the softmount will do anything but add weight but assuming you positioned the bulkhead with it in place you are going to have problems removing it now. I am also a little concerned that you haven't any air outlet holes through the bulkhead. These are needed for proper cooling.

2) You absolutely must have an outer tube to hold the sides apart as you describe. This being missing or damaged seems to be a feature of many Impact kits. Its easy to make one as the finish on the outside is unimportant. Wax your tail tube and wind a thin strip of glass cloth round it for several layers impregnating with 30 min epoxy as you go. When cured slip off and trim the ends.

3) Like you I didn't want slots and installed a small piece of plastic tube through the fuz sides where the cable exits. This has been fine on both my models.

4) I installed the rudder and hinges onto the hinge post before fitting to the fuz. Its easier make sure that the hinge points are properly glued and filleted if done this way and there have been some suggestion that improperly hinged rudders have contributed to fuz failures. Don't forget to install the spacer pieces on the sides of the hinge post as per the instructions and when glueing it use a couple of stiff wooden battens down either side of the fin to spread the load of your clamps and ensure the sides of the fin remain straight. Be careful not to push the finpost in too far which will restrict the available rudder movement. Get the depth correct by deflecting the rudder fully before the glue dries and once happy with the depth tape the rudder straight before fitting the battens and clamps.

Good job so far!

Malcolm

Malcolm H

Jack,

I forgot to add (and forgive me if this is obvious) that the finpost needs to be deeper into the fin near the bottom than at the top to accomodate the greater radius of the leading edge of the rudder. In the heat of gluing and checking the rudder deflection this can be lost!

Malcolm

jfetter

Malcolm,

This one I would have missed. One thing though, wouldn't this change the rotational center? If the hinges are pulled in a little as you go down, it seems you are giving a tiny bit of down when you use rudder (no, I am nowhere near skilled enough to notice or care for my flying!), just clarifying in case I interpreted your answer in Madarin Chinese...

;-)

Jack

jfetter

OK, I will trust the AeroPoxy (it's been good to me so far, that stuff dries like iron). I am trying the softmount mainly because I see it in their manual. They have one for the Hacker (the ring in the rear is basically a vibration dampener) and Pletty (they include rubber even) so I assumed (perhaps incorrectly) that it was mandatory. I fly nothing but electrics and I have had issues in the past with glass fuses resonating at a specific RPM, the soft-mount seems like a decent idea and worth a try though if it proves a hassle or a problem in itself, I can replace the soft-mount with rods (though in the end the 1.5 ounces it weighs will just be offset by rods and longer bolts)...

Jack