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-   -   Maybe I'll call it "Warp 7".. (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/8410578-maybe-ill-call-%22warp-7%22.html)

MJD 01-28-2009 01:37 AM

Maybe I'll call it "Warp 7"..
 
1 Attachment(s)
This evening, I decided I'd start some airframe work on the Whiplash. So far, all I had ever done is decorate parts of it & epoxy the vertical stab set on.

First things first, I didn't like the squareish LE shape which was more pronounced on the right side, so decided to dress those up a llittle. that went alright, now I'll reglass them and feather that in to reinforce it where I cut a bit deep to even things up. I was told it really didn't make much difference, and I will believe that. But, I wanted to shape them a bit anyways.

In the past, I had flexed the elevons to free them up, nearly sprainig my wrists in the process. Now they move, but those poor servos. So this evening I turned it around to stare at the tail end and I just about flipped. The right elevon has a huge twist in it, and the left a smaller one. In the pictures I have taped the outboard end of the elevons to match the fixed portion of the wing - and you can see the twist in the right side easily. Yuck! No way I am flying with those on there. Guess I'll redo the hinges at the same time.

The vertical stabs are very badly warped too. Each is cup shaped, and the pictures show a straight edge being held flat against the rear portion of the stab in various locations - check out the gap at the LE. Ouch - those are coming off.

So maybe I'll fabricate tip fins and glass them in, and make some new ailerons. No way am I carrying on with it in this state. Or move on to something else, maybe the sport speedster I was working on before. I gotta think about this one. Sure am thinking I got a POS on my hands though. [:@]

Time for bed. Maybe the warp fairies will find it tonight and make it straight.

MJD

MJD 01-28-2009 01:47 AM

RE: Maybe I'll call it "Warp 7"..
 
1 Attachment(s)
More pics

combatpigg 01-28-2009 01:58 AM

RE: Maybe I'll call it "Warp 7"..
 
Now this deal reminds me of ARF Q-500s that are supposed to be such great timesavers [and values]........ as long as you are willing to strip off all the covering, re-enforce the firewall & landing gear, deal with the waxy hot glue residue that repels the re-enforcing efforts, replace all the control linkage and hardware with quality stuff, re-do all the allignments and incidences, stiffen and unwarp the wing, recover the whole works......and during the whole process try not to judge too poorly the poor, dumb SOBs who would produce a racing plane with all the covering seams facing INTO THE WIND :eek:.

You might be able to salvage the fins by capping them off with strips of hard balsa or pine.

rmenke 01-28-2009 04:49 AM

RE: Maybe I'll call it "Warp 7"..
 

MJD:

Gotta agree with CP, that should have never left the shop. Must defend the ARF guys a little, specifically Rusty VanBuren. His work on a Miss Ashley he built for me was outstanding, streight and 0-0-0 with a very acurate incidence meeter. Yours would fly and trim out, but would never be clean. You are going in the right direction. I like skin hinges, but they sure have got to be done by a craftsman to work without creating long term servo problems. Have a F-3D and LR-1 from china that were very stiff. After working them in, I wonder how long they will stay on the airplane. A LR-1 with a Jett 40 racing engine stuffed in is a little scary anyway, would hate to loose control of the thing WFO. Keep it going. ENJOY

freakingfast 01-28-2009 08:22 AM

RE: Maybe I'll call it "Warp 7"..
 
I think the delta has just been sitting around a while and the epoxy just flowed, yielded or it was near a heat source. Perhaps its own weight or something sitting on it.
Try some opposite twist focused on one area at a time. Id start with the left wings excessive wash out, the left elevon may come back on its own or be much less. Twist it for a few hours, or days and check periodically to see if it progresses. Not too much or it could delaminate somewhere.

I had a skinned hinge on a Whiplash crack several inches and I feathered the area out and used light Kevlar mat to repair, a lot of work. A few flights later, the stock control horn failed on the other side and that was the end of that plane. They are tuff but there are limits. I got to see the inside of it, not impressive.

MJD 01-28-2009 10:04 AM

RE: Maybe I'll call it "Warp 7"..
 


ORIGINAL: freakingfast

I think the delta has just been sitting around a while and the epoxy just flowed, yielded or it was near a heat source. Perhaps its own weight or something sitting on it.
Try some opposite twist focused on one area at a time. Id start with the left wings excessive wash out, the left elevon may come back on its own or be much less. Twist it for a few hours, or days and check periodically to see if it progresses. Not too much or it could delaminate somewhere.

I had a skinned hinge on a Whiplash crack several inches and I feathered the area out and used light Kevlar mat to repair, a lot of work. A few flights later, the stock control horn failed on the other side and that was the end of that plane. They are tuff but there are limits. I got to see the inside of it, not impressive.
The fin warps were there, but much less so, from the outset. So yeah, they have progeessed. I imagine they are not polyester but epoxy, but I had wondered about shrinkage.

The leading edges always had a bit of the F102 LE droop towards the tip. Not much, just a hair and somewhat even, so originally I figured I would look at that as a tiny bit of reflex and move one. Not that it needs a visible amount at the speeds it flies.

But the elevons have most definitely developed this over the last couple of years. I am hesitant to straighten them with heat and force, wouldn't they creep back there anyways? It almost sounds like less effort to make new parts altogether, plus I could install my own live hinges.

As far as I am concerned the verticals are outta here. I don't see any harm and perhaps a little fun blending in tip fins. Or a larger single central fin molded in to the rear of the pipe cowling.. hmm. Another option I considered was to replace the two verticals with a pair located at the root of the elevons, and blend the linkages inside somehow. Time for some doodling and head scratching.

I guess I may as well have a go at fixing it up. Nothing like a challenge to slow down progress and build character. It's all good practice anyhow I suppose.

MJD


daven 01-28-2009 10:33 AM

RE: Maybe I'll call it "Warp 7"..
 
It is not uncommon for Q40 wings to twist over time. Many racers will use the heat gun and slightly overtwist things back into shape.

You may need to retweak them over time, but it does work.

Mike Connor 01-28-2009 10:48 AM

RE: Maybe I'll call it "Warp 7"..
 
What stood out to me was the blunt trailing edges. You have some work to do if you want straight and fast.

daven 01-28-2009 11:37 AM

RE: Maybe I'll call it "Warp 7"..
 
My whiplash had pretty blunt trailing edges also, it was very overbuilt. Stong as an ox, but it was on the heavy side. Bought it on E*bay for under $100 several years ago.

MJD 01-28-2009 11:38 AM

RE: Maybe I'll call it "Warp 7"..
 

ORIGINAL: Mike Connor

What stood out to me was the blunt trailing edges. You have some work to do if you want straight and fast.

They are blunt , and about 0.1 inch thick. Straightening the TE first is my #1 prioirty, and I would consider extending the surface lines to a sharp TE if that is worth the effort. I can dam one side and build up some material to shape it down fairly easily I suppose. I may mate two pieces of Al bar to match the elevon angle, and mold new bits in that.

Oddly, it has been stored fairly kindly - in a cool basement and sitting on my wing racks. So any distortion is not from external pressure, only time and mild temperature cycling if anything.

I am eyeing two sections of gapless-hinged TE/LE stock I bought years ago - I bet they could be successfully grafted into new elevons and the existing TE and do the job well.

MJD

p.s. the fins are history already, I trotted downstairs after my 3rd tea this morning and hacked them off brutally with a Dremel cutoff wheel. It felt good.. [>:]


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