Redshift Mk I (New Purchase)

[Konrad]

No wind no race! Make up date is the 17th if we can find a qualified CD.

 

[Konrad]

Well it looks like I might have a 96 degree Redshift for the last race of the 2022 season. I’ve been able to repair my first Redshift’s set of wings (used purchase) and fit them on this fuselage with the 96 degree V-tail.

I will have to write another program for this hybrid but I really wanted to get some more time on the 96 degree V-tail.

After flying a Freestyler 5 I really like the added control of the larger v-tails. The Freestyler might actually have too large a tail. I’m hoping that with the small Redshift V-Tail but at 96degree that it might be what the Redshift needed all a long.

Shown with 100 degree V-Tail fuse on the side. I did notice a huge improvement between the much better 100/99 degree V-tail and the stock 104 degree V-tail.

 

[Doc J]

Well it looks like I might have a 96 degree Redshift for the last race of the 2022 season. I’ve been able to repair my first Redshift’s set of wings (used purchase) and fit them on this fuselage with the 96 degree V-tail.

I will have to write another program for this hybrid but I really wanted to get some more time on the 96 degree V-tail.

After flying a Freestyler 5 I really like the added control of the larger v-tails. The Freestyler might actually have too large a tail. I’m hoping that with the small Redshift V-Tail but at 96degree that it might be what the Redshift needed all a long.

Shown with 100 degree V-Tail fuse on the side. I did notice a huge improvement between the the much better 100/99 degree V-tail and the stock 104 degree V-tail.

View attachment 12203

I'm interested to hear how that went Konrad. The Spada project is now lurching back to the front of the queue after more mods to the wings and tails.

Note that due to a said wing/tail mods, the new Spada wings/tails will NOT be interchangeable with the old fuselages.

Looks like you are developing your own Kuston Kamo Scheme...

Cheers,

Doc

 

[Konrad]

I'm interested to hear how that went Konrad. The Spada project is now lurching back to the front of the queue after more mods to the wings and tails.

Note that due to a said wing/tail mods, the new Spada wings/tails will NOT be interchangeable with the old fuselages.

Looks like you are developing your own Kuston Kamo Scheme...

Cheers,

Doc

That’s actually good news about the fuselage. The Redshift’s fuse had about twice the frontal area needed.

As to camo this is an in process state. I use primer to fill dents and act as a guide coat for the repair (aerodynamic concerns). If she survives the flight test and racing I’ll then look at the aesthetics, assuming the test show that the airframe is worth the effort.

 

[Doc J]

That’s actually good news about the fuselage. The Redshift’s fuse had about twice the frontal area needed.

As to camo this is an in process state. I use primer to fill dents and act as a guide coat for the repair (aerodynamic concerns). If she survives the flight test and racing I’ll then look at the aesthetics, assuming the test show that the airframe is worth the effort.

I think anything that has been through your testing regime, Konrad, is lucky to be alive, whatever the paint condition is.

You are dead right about the fuselage frontal area, but you have to remember that when Redshift was designed, arund 2010, those lovely tiny powerful servos were imagination only. I wonder if I should design a fuse for the 6mm servos...probably not.

2 x 6mm servos mounted directly in the tails, IDS drive and no push rods? Hmmm that has potential.

Just for interest, I never ever use primer for anything. Its about the heaviest paint you can get. But each to his own.

Looking forward to the testing comments.

Cheers,

Doc.

 

[Konrad]

Yep. I'm known as TD (Test to Destruction)! Unfortunately most of the testing resulted in learning more about the manufacturing and materials of the product rather than the aerodynamic characteristics. Oh and a learned a bit about flying an F3F ship (RIP the glass green Redshift).

2010 might be pushing history back a bit. The earliest mention I find of your Redshift F3F and V-tail is early 2016. Some low wing configuration ship with huge draggy fillets and canopy style hatch!

Tail mounted servos would be nice! I see Aer-O-Tech has the Impulse 2 with them. I really liked them on my Alpha 2.8.

The 6 gram servo now has the electronics (drivers and motors)* that can handle the load. But today the limitation is mechanical. The gears can't take the real world application of controlling the mass of the control surface. The gear material and construction can't handle the landing shock loads. But, the elimination of the push rod mass from the equation does make it possible (almost) for use on the F3F V-Tail flippers. If you are pushing the envolope, and I encourage you do, make provisions for easy replacement of the servo as gear life will be a problem.

Primer/paint
Yes, that is the point of primer to fill fast. To do that it has a lot of pigment (solids) to give each layer body. This means that if measure by a layer it is heavy! The primer body is used as a fast filler of low spots. If used properly 90% of this is sanded off. Now using topcoat paint as a filler actually results in a denser finish. It also takes many many more coats of paint (time) to get the same fill. Paint binder is actually heavier than the primer solids. So for the same surface finish a primer base is a lighter finish than the classic 32 layers of hand sanded paint.

Now as to paint weight, white paint is the heaviest by far, as to get any kind of coverage takes an inordinate amount of pigment! A black paint finish is noticeable lighter (less mass, and less pigment).

*I'm finding that the KST and MKS 8 and 9 gram servos (X0-8 and 6100) are having lower motor life than the 12/15 gram servo. I just replace 3 MKS servos (6100) for poor electrical performance on my used FreeStyler 5. No I don't know how many hours where on these. I suspect 2 where less than a season.

 

[Konrad]

I'm getting ready to remaiden this Redshift. This Redshift is made from the first used one's wings and the second Redshift's fuselage with the 96° V-tail.

Now these wings are the ones that had the wing joiner box damaged. The repair of the wings have resulted in the wings being a bit out of balance. It takes 3 grams of weight out at the tip to statically laterally balance the wing.

But to dynamically balance the wings will take about 15 40 grams of weight place as shown. I find that dynamically balanced wings results in a much better feeling glider as the left and right high G turns are much the same. A wing that is not dynamically balance really starts to act weird as the G loading goes past 2 or 3 G's.

What is your experience with laterally balancing these long glider wings?

 

[Konrad]

I just finished flying the 96° V-tailed Redshift at the slot. The wind was straight out of the west and at over 50mph ( A typical moderate day for the SLoT),

Let me start off by saying WOW, WOW!!! I flew her for an hour and a half of air time with close to 2 dozen ridge running landings. In the hover landing I had great rudder and elevator authority. It was real fun running down the cliff lip yawing hard into the wind drop the flaps and allow the ship to fly backward a bit past the landing zone, lift the flaps to stop the rearward drift and land like a butterfly with sore feet. The 96° V-tail had more than ample control, as I was able to put the Redshift where I wanted in the landing zone. I only had one "bad landing" where I miss judge the need for flaps and made a touch and go. Again I had full control.

At speed she really really shined! I was able to remove almost all the aileron differential for a much faster roll rate. I did up the aileron to rudder mix. This and in race trim the flaps being dead in roll resulted in the Redshift looking like she was hit by a tennis racquet coming back from the turn.. She was very well behaved as the nose stayed level through out the whole turn! Not just once but time after time!

Elevator authority was strong I could stall the plane whenever I wanted, ether upright or inverted. The transition from a positive turn to a negative punt and back to a high G turn was smooth. With these changes we are at a whole other step in controllability. I saw no spiral instability.

I think we now have a rather simple fix for the Jimmy Durante nose.

Now to finish repairing that camo paint and breaking out the buffing wheel.

 

[Konrad]

Test flying, now that's a novel idea, was showing that the mass issue was resulting in a bit of a tuck in high G turns to port. I noticed that I was carrying a bit of right rudder. So this confirmed that there is a trim issue with the repair.

Not surprising as there are at least 2 major repairs to the left wing box. Weighing the wing I found that as last flown they are out of balance about 40 grams. I checked the wing's center of mass and confirmed that they were different by about 35mm. So with the 40 grams of lead I was able to place it in such a way as to move the center of mass to have both wings with in 3 grams of each other and the center of mass with in 2mm of each other. This should help with the high G turns. Even in the straight aways as I can remove some of the rudder trim for even more speed!

What surprised me was that statically the wing could be balanced with only needing 3 grams on one tip. But the actually mass needed for correcting the center of mass issue was 10 times that. Ah, such is the cost of a proper repair!

 

[Konrad]

Well, Well, Well!

I was prepping this bird for Sundays race (maybe) and found a failed servo. The last crash happened when I was making my down wind pass crossing over the lip (Near the telephone pole at the SLoT). I thought at the time that I may have pushed the Redshift into a high speed stall trying to come around into the landing zone as the nose went straight down (yaw to starboard).

But now I see that one of the V-tail servos will loose its positioning feedback at times and just run. I suspect that this servo got damaged after the first crash where the aft end of the ballast tube let go. The servo tested fine with the servo tester. But if I load the output shaft the servo can loose its position.

So I now have a high level of confidence that the second crash was as a result of servo failure. I’m glad that the servo held on through last weeks fight testing. So to my mind I now now have another free ship!

 

[Wayne]

Good catch, and yes, some good luck on the test flights.

I think your account must be paid up (or now depleted) with the slope gods.

 

[Konrad]

When it comes to the gods, no matter how many sacrifices I make, I'm always in the arrears!

 

[Konrad]

Sport flew the Redshift 96° V-tail again for about another 1.5 hours after yesterday's F3F race. She is finally starting to look like she can run with the big boys. Today the air had very little lift. Unlike the test flight on Tuesday of last week.

The mass balanced wing showed an improvement, not day and night but an improvement.

I also had to rework the elevator compensation in crow. As the narrower V-tail angle does effect the amount of surface to counter the wing's pitching moment the amount of control movement does need to be adjusted. I was surprised at how much this adjustment was needed when I went for the poor responding 104° V-tail to the 100° V-tail. So I was expecting some fine tuning moving from my conservative 100° V-tail to the 96° V-tail. With the rather effective 96° V-tail, I had to add the compensation a bit faster (sooner) on the comp curve. As it is now I can put her in crow whenever I want and add as much as I want with no noticeable changes in pitch attitude. (I need to thank Mike Shellim's templet for much of this mixing power).

CofG is looking real nice at 96mm. Again the changes to the horizontal stab will effect the fore and aft (pitch) margin of stability. (I think with the 104° V-tail Aeroic recommended that the CofG be place at 98mm to start with and moved aft from there as preference dictated).

With the poor lift I was able to work with the interaction between the elevator and snap flaps and really nbotice the effect. I was able to back off the elevator about a third, and stand on the snap flap a bit more. This added a lot more stability coming out of the turn as the tail didn't squat and the Redshift as able to maintain her speed coming back from a turn.

Now to go back to the 100° V-tail Redshift, to add the lessons learned from the 96° V-tail.

 

[Doc J]

Sport flew the Redshift 96° V-tail again for about another 1.5 hours after yesterday's F3F race. She is finally starting to look like she can run with the big boys. Today the air had very little lift. Unlike the test flight on Tuesday of last week.

The mass balanced wing showed an improvement, not day and night but an improvement.

I also had to rework the elevator compensation in crow. As the narrower V-tail angle does effect the amount of surface to counter the wing's pitching moment the amount of control movement does need to be adjusted. I was surprised at how much this adjustment was needed when I went for the poor responding 104° V-tail to the 100° V-tail. So I was expecting some fine tuning moving from my conservative 100° V-tail to the 96° V-tail. With the rather effective 96° V-tail, I had to add the compensation a bit faster (sooner) on the comp curve. As it is now I can put her in crow whenever I want and add as much as I want with no noticeable changes in pitch attitude. (I need to thank Mike Shellim's templet for much of this mixing power).

CofG is looking real nice at 96mm. Again the changes to the horizontal stab will effect the fore and aft (pitch) margin of stability. (I think with the 104° V-tail Aeroic recommended that the CofG be place at 98mm to start with and moved aft from there as preference dictated).

With the poor lift I was able to work with the interaction between the elevator and snap flaps and really nbotice the effect. I was able to back off the elevator about a third, and stand on the snap flap a bit more. This added a lot more stability coming out of the turn as the tail didn't squat and the Redshift as able to maintain her speed coming back from a turn.

Now to go back to the 100° V-tail Redshift, to add the lessons learned from the 96° V-tail.

That the old tail modified Redshift can (almost) run with the 'big boys' is good news. Getting there! Thanks for the upate, Konrad.

Bit I'm perplexed. If I may quote from another KD Post:

"The fatal flaw, if it has one, in the REDshift is not the V-tail. Rather it is the excessive side area ahead of the center of pressure. The reason for this nose is discussed here. This is known as the Jimmy Durante on this side of the pond or Cyrano de Bergerac nose elsewhere. Unfortunately forward side area has a destabilizing effect on aircraft control and stability. It is one of the function of the rear vertical area to counter the destabilizing effect of the the nose. Now when anybody asks me about the finer points of the REDshift and its stability. It is the problem with the nose that I mention that contributes to the control issue I’ve and others have reported, not the V-tail. Now, I do like the downward droop of the nose to meet the upward flow of air."

So all in all I'm happy, and yet I'm surprised, as the biggest, most influential and detrimental factor that was reported by you as affecting the model's performance - in fact a completely insurmountable problem - "The (Dreaded) Jimmy Durante nose" is still very much in evidence, but apparently no longer causing the handling havoc that it was.

Anyway, I'm also happy to say Jimmy is gone to sit at another piano and has not made a guest appearance on the new Spada, and so he no longer CAN cause problems.

Cheers, and thanks again for the update.

Doc..

 

[Konrad]

That the old tail modified Redshift can (almost) run with the 'big boys' is good news. Getting there! Thanks for the upate, Konrad.

Bit I'm perplexed. If I may quote from another KD Post:

"The fatal flaw, if it has one, in the REDshift is not the V-tail. Rather it is the excessive side area ahead of the center of pressure. The reason for this nose is discussed here. This is known as the Jimmy Durante on this side of the pond or Cyrano de Bergerac nose elsewhere. Unfortunately forward side area has a destabilizing effect on aircraft control and stability. It is one of the function of the rear vertical area to counter the destabilizing effect of the the nose. Now when anybody asks me about the finer points of the REDshift and its stability. It is the problem with the nose that I mention that contributes to the control issue I’ve and others have reported, not the V-tail. Now, I do like the downward droop of the nose to meet the upward flow of air."

So all in all I'm happy, and yet I'm surprised, as the biggest, most influential and detrimental factor that was reported by you as affecting the model's performance - in fact a completely insurmountable problem - "The (Dreaded) Jimmy Durante nose" is still very much in evidence, but apparently no longer causing the handling havoc that it was.

Anyway, I'm also happy to say Jimmy is gone to sit at another piano and has not made a guest appearance on the new Spada, and so he no longer CAN cause problems.

Cheers, and thanks again for the update.

Doc..

Say what?

To give context this is where the above quote came from.

I maybe over stating the effect of the 96° mod.

To be clear nowhere have I said that the 96° V-tail has solved the directional instability problem. I just said that it has dramatically improved it. That should give one an idea of just how bad it was/is. If one is going to keep the very destabilizing front area of the Jimmy Durante nose there needs to be a lot more vertical area given to the rear or add a lot to moment arm for the vertical area already there. If selling this design I would not put my name on it as it was sold. This has nothing to do with the manufacturing issues with the REDshift.

I thought that the the large Jimmy Durante nose was as a result of the desire to add a ballast tube house servos, allow the push rods to clear the wing joiner, and add more moment arm to the nose weight. But reading your reasons for this large side area, it is clear to me that some of the forces involved in control and stability are not fully understood by some. I really should have googled control issues with the F3F Redshift much earlier.

All one needs to do is see how engineers deal with the added side area when re-powering an existing design to a turbo prop. To maintain balance with the much lighter turbine the designers place the engine further out on a boom to give the engines mass more of a moment arm. This often adds side area to the front of the aircraft. To counter this destabilizing effect they add a lot of side area to the rear in the way of added fins.

Much of the pleasure I get from this hobby is trying to make a silk purse out of a sows ear. Thank you for providing the sow’s ear in the form of the REDshift.


As my credibility is coming into question and that the Redshift in no longer be sold by Aloft. I think it best that I come straight out and not mince words. It is my opinion and proven out in practice that the Redshift is a horrible aircraft. This can be traced to a plethora of design issues. First are the mechanical ones. one can’t align the servo output with the control horn as a result of interference with the ballast tube. The stabilizer control arms are far too short to get any useful resolution from the servos. and that the contact area in the assembly of the wing is far too narrow for the method and and adhesives used. And then there is the near fatal aerodynamic flaw with side area and the stability issues that presents. And last a very minor issue with the V-tail junction angle are it pertains to high aspect ratio wings. So while I like what I see in the reverse elliptical wing the Redshift as the sum of all her parts has been found severely lacking.

 

[Doc J]

Say what?

To give context this is where the above quote came from.

I maybe over stating the effect of the 96° mod.

To be clear nowhere have I said that the 96° V-tail has solved the directional instability problem. I just said that it has dramatically improved it. That should give one an idea of just how bad it was/is. If one is going to keep the very destabilizing front area of the Jimmy Durante nose there needs to be a lot more vertical area given to the rear or add a lot to moment arm for the vertical area already there. If selling this design I would not put my name on it as it was sold. This has nothing to do with the manufacturing issues with the REDshift.

I thought that the the large Jimmy Durante nose was as a result of the desire to add a ballast tube house servos, allow the push rods to clear the wing joiner, and add more moment arm to the nose weight. But reading your reasons for this large side area, it is clear to me that some of the forces involved in control and stability are not fully understood by some. I really should have googled control issues with the F3F Redshift much earlier.

All one needs to do is see how engineers deal with the added side area when re-powering an existing design to a turbo prop. To maintain balance with the much lighter turbine the designers place the engine further out on a boom to give the engines mass more of a moment arm. This often adds side area to the front of the aircraft. To counter this destabilizing effect they add a lot of side area to the rear in the way of added fins.

Much of the pleasure I get from this hobby is trying to make a silk purse out of a sows ear. Thank you for providing the sow’s ear in the form of the REDshift.


As my credibility is coming into question and that the Redshift in no longer be sold by Aloft. I think it best that I come straight out and not mince words. It is my opinion and proven out in practice that the Redshift is a horrible aircraft. This can be traced to a plethora of design issues. First are the mechanical ones. one can’t align the servo output with the control horn as a result of interference with the ballast tube. The stabilizer control arms are far too short to get any useful resolution from the servos. and that the contact area in the assembly of the wing is far too narrow for the method and and adhesives used. And then there is the near fatal aerodynamic flaw with side area and the stability issues that presents. And last a very minor issue with the V-tail junction angle are it pertains to high aspect ratio wings. So while I like what I see in the reverse elliptical wing the Redshift as the sum of all her parts has been found severely lacking.

Blah blah blah - Konrad - I think you might have the record, at least that I have seen, for the most about-turns ever. First, its one fatailty in the design, then its another. Added to that, you have a really amazing ability to find 'near fatal' problems with planes that others fly pretty well. Could it be that your credibility is thus affected?

So I'll say only one more thing:

If you know what you are talking about - REALLY KNOW - then let's see YOUR design Konrad.

Put your money where your mouth is.

i.e: Put up or shut up.

Doc.

 

[Konrad]

Blah blah blah - Konrad - I think you might have the record, at least that I have seen, for the most about-turns ever. First, its one fatailty in the design, then its another. Added to that, you have a really amazing ability to find 'near fatal' problems with planes that others fly pretty well. Could it be that your credibility is thus affected?

So I'll say only one more thing:

If you know what you are talking about - REALLY KNOW - then let's see YOUR design Konrad.

Put your money where your mouth is.

i.e: Put up or shut up.

Doc.

LOL,

By your read I can see that. But improvements don’t equate to solutions, nor does potential mean realization.

Really that’s your response?

Been there done that. And actually that is what I’m doing here redesigning the mechanical and the stability issues inside the scope of work using tools most modelers would have available. I could make a new set of flippers, hum….

Now, “A man got to know his limitations"-Dirty Harry

Here you might hear me expound on how that wing turns, particularly in smooth coastal air. But if the REDshift is subjected to any disturbance, ether from pilot inputs or turbulent air, the stability issues become glaringly obvious.

FYI; The problem with camera perspective makes the red nose look so much larger than it is. Yet the green REDshift nose can still be seen for almost 360° around the red nose

 

[Doc J]

Just as I thought - 2.

Doc.

 

[Konrad]

Yep, as you can see we understood the idea of pressure gradients with the placement of the canopy and belly scoop. It also had a rather large expanding radius fillet per Hoerner.
And like the Redshift it was a failure in the market place.

 

[Doc J]

I think I’m going about this all wrong.

Konrad, Since you are now expounding on your findings that there is, with certainty a deadly relationship between the actual size of my Redshift V-Tail and the projected side area of the nose - Note I say MY Redshift - then can I ask you for the specific scientific literature and the formulae, that you used to expose and to make absolutely sure of this?

Thanks,

Doc.