It is the gap on the bottom aileron hinge lines. The gap opens up more during a snap. I have it for years on my racing gliders. No ill effects, just a lot of comments.

Eric.

Hi Guys,

Initial weight of the stock rudder was 66 grams. After cutting off the beveled LE, and incorporating a light balsa LE (carved to a triangular shape), AND adding the phenolic control horn, the total weight is now 69 grams!! Thus, only 3 grams were added.
Jim

Hi Guy's,

Well here it is, photo taken last Sunday but the wind was blowing like crazy!
The Explorer belongs to my youngest son Ryan (13). Ryan will be using this for the 2005 season in Standard class F3a, whilst I will be using the Impact in Senior class (waiting for the new Masters schedule in 2006 before I move up [8D] ). i'm really happy with the fixes i've made to the fuselage and can't wait for the calmer weather to arrive so that I can finally start to practice!

Regards,

Andy.

I spent most of yesterday modifying my IMPACT to use 4 bolts to hold on the wings. The single bolt near the wing tube was allowing too much movement and letting the wing move and rub on the fuselage. I fitted the bolts like a pair of wing adjusters and took advantage of the moment to dial in some incidence to remove the current need for left aileron trims. The rear anti-rotation CF tube was removed as it was no longer needed,

I am using a mix-carb and had positioned the two servos for throttle and mixture control back at the rudder servo tray. The OS 1.60 was not as heavy as I thought it might be so these servos were moved to a location above the UC brace formers. The removal of the materials cancelled out the weight of the addition of the extra two bolts and ply plates.

After a dumb-half-hour-of-engine-not-starting I figured out that the mixture control servo was now using the other side of the servo arm and needed to be reversed!

With the engine running a tad rich the test flight was initiated. It went very well indeed. The reset aileron-trim was right on. I had raised the TE of the left wing a 3/32" and lowered the TE of the right wing by the same amount. The up and down lines were still straight with no rolling. The horizontal roll was funky and the nose raised itself when I applied aileron. A field session with two "Magic gadgets" and we had corrected uneven ailerons and poorly implemented negative differental. The instructions used mm's and I had used degrees. I finished up with 10 degrees up and 11 degrees down and no differential dialed in the radio aileron options.

It was all worth it. The new settings made it a lot more fun to fly. Straighter and much more axial. The wings had left no new marks on the fuselage sides and were very solid when used to handle the plane.

I would pronounce this plane now ready to fly in a competition, all we have to do now is wait for mid June in District-1 :-)

Regards,

Eric.

Hi Eric,

Interesting about your left aileron trim.

I was about to glue my wings in place before I decided to remeasure one more time. This time I measured my wing incidence at 3 places on each wing panel . The left hand wing panel looking from the rear was spot on, however the right hand wing panel measure perfect at the root and mid wing span. When I measured the tip I noticed that the my wing had a slight twist by just over 1/8th of a degree therfore the measured incidenceat this point was +0.1 degrees instead of +0.25.

Since there is little I can do with the wing l have decided to install a rear wing adjuster as I felt the only way to get it right was with flight trimming.

Interesting thing is my model would have had the same trimming correction as yours.

I will take aboard your comments about the front wing bolt. If you get a chance a picture of the front wing bolt area would be great.

How does it rate now against the Pinnacle?


Thanks

Peter

I think that all of the wings, going as far back as the Rev-pro have this twist in the wing. Mine was set dead-on using the roots. This left a 1/16" right roll twist at the right wing tip.

It is no big deal, however, because once adjusted I could find no ill effects. Often you get a slight roll in down lines etc. Many of my foam wings have a slight twist. None cause any flying issues. If I climbed to a great height and let it dive hands off it stays straight all of the way down. I did this in all four wind directions. It weather-vanes into the wind a little, but that is just fine by me.

The four bolts just made everything easier, including the positioning of the fuel tank. I now have a long list of what I want to do the second one. :-)

The Pinnacle is a super pattern plane. It is hard to compare because they both do everything very well. If you pay $900 for an IMPACT and build it with all of teh advice in this thread, you will be happy. If you pay $2800 for a PINNACLE and just install the equipment, you will be very happy. Yo need a lot of building skill to put together an IMPACT.

You need the same flying skill to fly either of them. They both make the patterns easier to fly, no kidding! I am much happier in the P-05 rolling maneuvers with these planes. However, if pushed I would say the PINNACLE is a close first.

Here is the wing bolt before, after and the new holes in the sides. You can see the wear on the fuselage sides before I used 4 bolts. None since.

Here are the photos of the inside... the last photo shows the previous wear.

Eric on my Impact wing roots I applied a thin dense foam strip. I found these sheets of foam next to the felt at a Hobby Lobby, or other craft store. Just cut into strips and CAd it on. I also used soft balsa filler blocks to increase the bearing area of the wing root on the fuse in the area of the bolt and pins. This has prevented the marks you have on yours and the foam seems to have a high friction coefficient so the root doesnt slide around against the fuse.
Just another way to skin the cat.

Im enjoying flying this plane also. Have the same slight aileron trim issue but mostly leveled the ailerons using trim adjusters.

I have had some gear leg issues and have ordered a set of Bolly gear hoping they are more reliable.

Brian

I began with Bolly's because our fields are rough at the begining of the year. I'll swap in the weaker, but lighter, supplied gear as the year progresses. The Bolly's are very good and I think that it KE loops better with them fitted.


The TruTurn 3-1/2" spinner came today. That saved .9 of an ounce over the Hurricane spinner that was already on there. Now I can use an electic starter with a standard cone for the first spin of the day. :-)

Regards,

Eric.

Eric,
Where did you end up on the wing incidence? The left wing at +.25 and the right +.25 at the tip? Or did you split the difference on the right wing? I'd like not to add adjusters.
Regards, Jim

I had my wings originally set equal. So when I corrected the trim I move the left TE up 3/32" and the right TE down 3/32". This seemed to work just fine. I decided to not adjust only one wing, because the elevator was working so well. Doing both wings kept it the same. It also maintained the very good KE. Said another way, still needed no KE mixes on elevator or aileron .

Made two new rudders this PM from an old Hydeaway rudder and a Temptation rudder. Both planes are deceased but the rudder always survives, right :-)

I used a big tennon-saw to split the rudders down their hinge lines. Removed some foam from one and glued it back together at the correct width and shape tp repalace the IMPACT rudder. Expanded the other a bit with some balsa wood to achieve the same result. I now have two spare rudders that are at least one ounce lighter than the stock rudder. Will fit one to the "light-weight" version IMPACT #2 and use the other to lighten #1 the next time it rains in NJ - shouldn't be long :-)


Regards,

Eric.

Hi Jim,

Great tip with the felt, I too have the same friction marks on the side of the fuse and have been wondering how to deal with it. Seems you've found a simple fix that fits the bill [8D].
Having now flown a few snap rolls with the Impact, I have noticed that the elevator is VERY powerful during this manouver, how much elevator movement are you using for this?

Any help would be appreciated.

regards,

Andy.

Im running 24mm up and down elevator throw, 24mm up and 28mm down aileron throw, 40 mm rudder.

Snaps pretty good at this setting.

I tried the low rate settings recomend in the CompArf manual and felt it was too slow. Rudder at 40mm may be too heavy though, fairly sensitve around center.

Brian,
A side effect of the four wing-bolts is that the fuselage center section got stiffer and the Canopy is tight while the engine is running. And the cat has no fur :-)

Now that I have my lighter TT spinner in place, the old rudder has been cut-off. I'll fit the new lighter one tonight. Going for a double bevel on number 2 to reduce the side displacement that can foul the elevators. The lighter rudder should get my balance to be a bit nose heavy. No biggy, just move pack back again.

One secondary observation is how much quieter they are with the pipe inside the big tunnel. Custom pipe mount did not melt either... Must be nearly summer....

Eric.

Hi Brian,

Thanks for the info, sorry about the typo [sm=spinnyeyes.gif]. I agree the rudder is very sensitive around the centre, I'm running 80% expo to deal with it. I'll check my elevator throws and adjust if needed. My cg is between the wing bolt and the wing tube, feels nice with no nasty's when I slow her up and only a very small amount of down elevator whilst inverted.

thanks again,

Andy.

Will be testing this slightly less tall rudder today. "The sun has got his hat on hip hip ......"

Received my Bolly F3A Electric Gear - 4.7oz

Hi All,

This topic of building an IMPACT has become very well covered

Here is yet another build thread from Japan.


http://f3a.sakura.ne.jp/radiocontrol...ct/impact.html

New look !

Tightened up stab tube with CA thickner.

It flies really well now and handles the side wind on down lines much better with the smaller. less tall, rudder. Now if I can get 7 ounces out of number 2....... Where can I buy some more midnight oil???

Eric.

Do you think the KE manouvers suffer from the smaller rudder or does it make no difference?

Put it this way. I can still do KE loops on low rudder rate. It has no mixes for KE flight at all. It is now much smoother in the transition between level flight and KE etc.

I think the original rudder had just a bit too much bite as it went in. The nose tended to lift unles you delayed the input and then you had to "catch" it. Now I can finess it in. Been having a ball getting the local club guys to try and count my 32 point roll attempts. Bad rudder shows up a lot if you try and do this goofy stuff. Not hurting any more.. :-)

Not a scientific test buy definitely a fun one !

Regards,

Eric.

I finally made the decision yesterday and went to a four bolt system to secure the wings. The primary reason is the ability to change the incidence easily after flying it by opening the holes in the fuse and bonding on new "donuts". I did mine by putting 1/4 inch poplar on the inside of the root rib and then tapping it for a 1/4 - 20 nylon thumb screw type bolt. I'll probably add anti rotation pins after I know the incidence is right just to aid in assembly of the plane.

Another cat skinned :-)

I think that you will like the 4 bolts a lot. I intended to use the doughnuts like you plan to do, but the wings were so close the second time that I don't need to mess with it any more.

Must be getting close to a test flight?

Regards,

Eric.

Eric, can you lay the original Impact rudder on top or your new one and show us a photo to give an approximation of the change?

I made two rudders. One is 1/2 shorter on the top,. That is the one I am flying right now. The Number 2 Impact rudder will be 3//4"shorter when I finish carving it. I do that last so that it mates correctly with the fin before I cover it. All material that is removed is from the top counter balance area.

I'm sorry but its not pratical to take the photos that you want because the c-board horns get completely in the bloody way.

Nite!

Eric. (EST)