seanreit

My Feedback: (60)

Please post your findings and any improvements you would make.

I have one that will be here on Monday and I have read the couple of primary threads on them. I think I understand so far what the improvements are, but I want to make sure that anything that might not have been covered there, gets covered here or by PM. I'm particularly interested in knowing anything about the larger turbines as I was going to follow suit on Gary's with a P-180, but not sure without finding out what happened to his.

I have heard of at least three going in, and I'm relatively sure those guys are frequenters on RCU.

Thanks in advance,

Sean

Wren Turbines USA

My Feedback: (39)

Sean,
The stab incidence issue needs to be addressed. 2mm of up elevator for neutral is a clear design flaw.....

trevor Skedge

No1,

Or nose heavy perhaps. The one I flew had no trim in at all.

Trevor Skedge.

seanreit

My Feedback: (60)

Ron, that happened to us down here on some isobars, on the newer ones we built we just brought the leading edge of the horizontal stabs down some before we glued them to the spars/fuse so we'd carry no trim. 2mm is not a lot of trim to carry in my opinion. Would you just change the angle of the stab a little bit?

trevor Skedge

Just checked with the owner and he tells me it does have about 2mm of up. Guess I missed that one then.

Trevor Skedge.

seanreit

My Feedback: (60)

I just got off the phone with Gary, his was a simple radio programming issue. No issues with the airplane.

Thanks again Gary, and sure sorry to hear about the airplane.


Sean

ghost_rider

My Feedback: (20)

One more thing I may like to add is the idea of balancing the airplane without wigs attached. If I'm not mistaken, that was the recommendations per COMPARF. FWIW, I’ve never seen it done that way b/4.

Wren Turbines USA

My Feedback: (39)

The problem with shimming the front of the stab down is that the hatch will not fit flush. I would think that the best solution would be to remold the stab, with the proper incidence.

I thought that maybe I had the thing nose heavy on the first flights, as it took 10 clicks of up elevator for level flight. On the fourth flight I removed the nose weight and the pucker factor went off the scale. I got the plane down safely, but have since added weight and rebalanced
per instructions. After talking with Gary, on Ghostriders cell phone that night, he brought up the issue of having 2mm of up elevator. I have not since flown the plane, but if it does fly straight, I will make some sort of modification to the stab incidence, to eliminate the trim issue.
BTW..........Ghost......thanks for the support.

cheers.........

Kevin Greene

My Feedback: (85)

I have a Chip Hyde Double Vision that is balanced that way---Very uncommon though....

Kevin

seanreit

My Feedback: (60)

Well, 2mm does not seem like a lot. Without looking at the airplane, is the airfoil on the stab the same on top as on bottom? On a 737 the horizontal stab lifts downward. Just a thought that maybe the stab could be installed upside down?

Regardless, I'll set mine up on the recommended CG and go ahead and put in some up trim.

I suppose in the turns the nose is not falling out with the nose weight?

Wren Turbines USA

My Feedback: (39)

Sean,

The stab actually has anhedral, so no chance of installing inverted. And yes, with the nose weight, the plane does seem to pitch down in the turns. And as the Ghost said, balancing without the wings is difficult to adjust to. However, once I get the thing flying straight, I will post the correct balance point with the plane assembled, with the gear in the down and up positions.

seanreit

My Feedback: (60)

One option might be to assemble the airplane, take a balance point where you are for neutral balance, and then just post that as a place to start from the leading edge of the wing back or some obvious reference point?

I flabbergasted that Comp Arf didn't do that. It would seem so easy for them to balance it with out the wings, then put the wings on and tell you where the point is. I'm assuming that the wings have to change where the balance point becomes after you balance it with the wings off? They can't possibly have no influence to the flying cg point.

schroedm

My Feedback: (1)

Sean,

If you take any model with the wings on and mark the CofG, then take the wings of and mark the point where it then needs to balance in the correct position with the wings off then I cannot see why it causes confusion?? You will always know if your model balances where it should with the wings of that when the wings are put on the CofG will shift to the correct position (unless of course you start adding weights to the wings for some odd reason)

OK, hands up - knowing both points may help.

Ultimately, the wings off method is used quite often with the Comp-ARF models as they tend to be on the larger side and harder for people to balance. Wings off balancing is always easier so that is one of the main reasons it is suggested.

Rgds,
Mark

seanreit

My Feedback: (60)

They don't know what I'm putting in my wings I have no problem with suggesting a point with wings off, but seriously, the freaking CG comes from the wings. The fuse has increibly little to do with it. I agree, at a minimum they should offer the CG with the wings on, and having a cg with wings off is simply a bonus, not the other way around.

Regardless, if someone can find where they are balanced and provide a reference point with the wings on, I would greatly appreciate it.

seanreit

My Feedback: (60)

I got to thinking about that statement as I have built the Rookie, Kangaroo, and Eurofighter. None of which had a wings off CG. You must be talking about prop planes?

schroedm

My Feedback: (1)

Yes I am. The Lightning is not a small model by any means so I guess this is why they carried over that idea.

Flying Arrow

My Feedback: (6)

Thanks Sean for the info and opening this subject. I had the same concern when i read about Gary crash and I sent him a pm yesterday, but you all my q were answered by this thred. Thank you and keep it up.

Mark,
I posted a q for you in your lightning building thred , hope to answer?

Regards,
Eid

seanreit

My Feedback: (60)

Don't thank me, thank RCU. We are such a small community that no individual area (except for maybe Southern LA where Sung stockpiles hundreds of jets) can have enough models to cover what you might want to get next. As sophisticated as these models get, they all are capable of hitting the dirt for any number of reasons. And while I never expect it, I almost always maintain awareness that I'm spending thousands of dollars on a TOY.

In that spirit, this is no inexpensive airplane even by Jet standards. If there are issues with it, I want to freakin know about it My trust in Composite Arf has grown, but I've heard enough gossip about the landing gear to know Andres has not hit "bulletproof" standards yet.

Regardless, you are welcome, I'm just glad we have a place to come and share information.

Flying Arrow

My Feedback: (6)

Thanks Sean,

Guess what? The landing gear is the first concern that I have checked with Mark, and other guys about it on other threads. Based on the number of positive responses I received I went a head and ordered it from Comp arf. I bought this plane long time back and I have very slow progress in getting it ready, hope it is a gossip otherwise I will be mad and then boycott the Carf!

On another subject, what do you think about P180 vs P160. So far I didn't get a clear answer. I know that you haven't try them yet, but have get some info that you can share??

Regards,
Eid

seanreit

My Feedback: (60)

Everything I am hearing about the 180 is that it is awesome. The real deal. I have heard of no failures ZERO.

I can't speak for the European 160. The US 160 was really bad. A real negative mark to Jetcat.

The US Titan which they say is a European 160, (but I don't believe that personally). Anyway, the US titans have been running great, I've owned two of them.

pilott28

My Feedback: (27)

My plane has the 2mm of up elevator in level flight too. I was concerned at first, but it flies very well, there is no pitch change when I punch the throttle and it doesn't require much down elevator when I go inverted. I would be reluctant to try to fix something that doesn't seem to be broken.

Sean, I would think twice before putting a big engine in the plane. If the plane has one area that I would like to see improved, it is the landing gear, and the extra 5 pounds or so you are carrying with the bigger engine will punish you a bit here. I watched two friends with large engined Lightnings make three landings at Waycross that were not that bad and the strut bolts sheared on all three landings. In talking to CARF, there was some speculation it may be due to the extra weight, though this is speculation only. I have a Rhino in mine and get all the takeoff and vertical performance I could want -- the airframe doesn't seem to be very "draggy" and motors along quite nicely even at less than 1/1 thrust to weight ratios. The axels are also very soft metal and will bend if you dump the plane, even at lighter weights. My gear do not unlock smoothly either, though I have come to suspect this is due to my UP2 valve settings based on conversations with several others in the past week. I'm playing with that this weekend.

My plane is very axial in the turns, as are most of the others I have seen fly, so the tendancy to drop the nose is likely due to too much nose weight. I think the Lightning is probably the best handling turbine I have flown, particularly in the landing phase.

The method they use to balance the plane is actually very easy to work -- I thought it was clever for a big heavy airplane.

Flying Arrow

My Feedback: (6)

Great to here that about the engines. I got 2 p160 ( European) they both are great. My q was in their suitability to the lightning. I read many posts saying you don't need the P180 since it will add so much weight? I personally want the P180, but I hate excess weight?
regards

seanreit

My Feedback: (60)

When Keith talks, I listen. So his hesitations and statements related to a larger engine definately catch my ear. I continue to hear over and over that the landing gear is the weak link in this airplane.

Does Robart even make a strut good enough for this airplane?

I don't know. But I'm going to research this as I put together my plan on this airplane. Maybe Kingcat gear is the way to go??

jettset99

My Feedback: (7)

Hi Guys Im doing 2 lightnings, please update this thread with any gear or any other mods,.after seeing one fly and being in Jets from the 80s this is the Best flying Jet Ive seen Hands Down!!! Cant wait to get on the sticks Im going with the Us Titan to keep weight down ,power box with the lipos,my friends is getting the P180 combo!!!!OMG...

pilott28

My Feedback: (27)

Thanks for the compliment.

There was some talk about taking a look at the BV F100 gear to see how it would fit. I have a set here and might play with it this weekend. BV's gear certainly would be the place to start in looking for an alternative as they work so smoothly.

I did talk to CARF about the gear and they had a conference call earlier in the week where the subject was to be discussed. I think a better strut bolt and harder axels would be a good place to start. As I said, I might not have the UP valve optimized for this large gear but I'll know in the next few days.

I think you guys will be happy with the plane when you get it in the air. On windy days, it will likely be the first aiplane out of the trailer.

Gary, I take it you lost yours -- sorry to hear that.