Redshift; Used Purchase

[Konrad]

No Idea why - totally can't explain it, but I'm a really good thermal pilot.

Not Wurtz level - needless to say - but somehow I can sniff them out and keep in them pretty good.

Doc.

We going to read a flight report of your TopModels Samsara?

 

[Doc James Hammond]

We going to read a flight report of your TopModels Samsara?

All done and ready to go, but it hasn't even taken to the air Konrad - I'm ashamed to say.

Your reports were pretty useful though.

Like all things...I'll get round to it.

Doc.

 

[Doc James Hammond]

Well, the other flap control horn popped out. This has to be the bane of sub-contractor work. Such a minor process omission as sanding the control horn costs so much. In my case this cost some damage to the wing wiper, but more important it cost me the ability to keep flying the Redshift in a race.

I knew I should have pulled this horn out as the other side had demonstrated that the bond was totally inadequate. But I feared that my "controlled" attempts to remove the flap control horn would result in more damage to the wing. As it happened the operational failure of the bond result in less damage than what I'd have expected had I attempted to remove the horn.

Now I haven't dealt with this control horn bonding issue as I normally install my own control horns (spoons) in the way of IDS installations.

While this OEM (Zohe?) results in products being much better than what we get with RCRCM. I ecstatic that Aeroic has dumped this OEM (Zohe?) for one that routinely makes ships that withstand the forces of DSing. I know Aeroic doesn't condone DSing with its ships, it is nice to know that there has been a huge step up in quality.

Hi Konrad. Its "Zhou" and yes this is one of the things that really gets my goat.

Question 1 to the manufacturer: How long does it take to abrade the bottom inserted sides of a G10 insert?
Answer: Possibly 10 seconds? Not even one minute per model?
Question 2 to the manufacturer: What is the impact of not doing this? (sorry for the pun)
Answer from the manufacturer: The model might crash so he will need a new one - Hooray!
Answer from the designer: The model might crash and cause injury but at the very least will probably be badly damaged or destroyed.

Little things like this, begin just like that - a few little things, then it goes to more little things, then when added together you end up with a model that is dangerous, and thats where I got to with Zhou. I had three models crash because of negligent manufacture and that was it.

There is a phrase often used in the Chinese language: "Tsa bu Duo" It literally means "Not so different" but what it is used for is inevitably an excuse for not doing a job. Abrade the control horns/not abrade the control horns = Tsa bu Duo...

Zhou Quote: "Our workers don't like to make models your way as you are only the designer" Ho Hum.

Like it or not, these slope toys are inherently dangerous, so as a responsible person purveying them, the very least I can do is to make sure nothing in the manufacture could cause catastrophic failure.

But now there is light...Now I have a manufacturer who LISTENS. If I explain why I want something done just so, then he can see the logic and sense in it. I have seen this creeping into the models recently - they are getting turned out better in every way.

More news:

Soon my new guy will move to a new factory which will be better organised and utilised than the original, and that will include SOP "Bible" instructions for each process of each model manufacture and will include a thorough quality system from incoming materials, through manufacturing steps to finished models. I'll go to China later C19 permitting and get it all set up.

I still have nightmares about Zhou - I mean really I do.

Cheers,

Doc.

 

[Konrad]

SOP are nice in that they try to document and standardize what works. Hopefully this cuts down on the tribal knowledge that often gets lost as shifts change or personnel move.

 

[Doc James Hammond]

SOP are nice in that they try to document and standardize what works. Hopefully this cuts down on the tribal knowledge that often gets lost as shifts change or personnel move.

Exactly right Konrad.

Doc.

 

[Konrad]

When I re-glued my right flap horn I should have done better inspection of the left flap. My failure to find that the left flap had delaminated cost me half a race last weekend. In that race we were flying two ups. The "second round" was flown after bringing the flaps out and slowing down to mimic a second launch. In my attempt I was going too fast I must have added more than normal air loads, as the flap got hung up on the wiper. The delamination allowed the flap to twist (deform) and bind on the wipers.

I need to make it clear that I think the delamination of the flap was a a result of my earlier crash into the back side of the hill at the SLoT. In that crash a tore off all the control surfaces. I'm sure that along with the hinge damage there were forces that caused the surface to delaminate.

Again this was another in flight emergency that should have been caught on the bench.

 

[Doc James Hammond]

We are using "System three" industrial adhesives to join wings now, Konrad, though I'm not sure it would have helped in this case.

Curious - How was your feeling with a faster model?

Cheers,

Doc.

 

[Konrad]

Yep. I'm not blaming this on anything other than my poor inspection. I actually see where the balsa split rather than a delamination as a result of a poor bond between the parts of the flap.

As to speed I like the faster Redshift. With the faster Redshift I can start to get into a rhythm making the turns. With the slower Strega's I actually need to use a count to gauge the turn at the gates.

I think I'm about to reach the next plateau in speed. With the Strega's I'm doing 53 seconds. With the Redshift I'm seeing 43 seconds. At the 43 second point I can start to work on my starts and pumps. Right now I'm working on my bunts and am starting to feel better about them. The reason I'm working on my bunts is that I'm often making cuts at the gates because of my lack of speed.

With the Redshift I need more rudder mix than I think I should. And a stall/snap takes a bit longer and more work to recover from, than I think they should. Like I said before I think I need more effective rudder area. I'm thinking of bringing the V tail angle from 104° to 100°. You have said to add more area to the tail but I'm not ready to do that when I know the Redshift Spada is in the works.

 

[Doc James Hammond]

Yep. I'm not blaming this on anything other than my poor inspection. I actually see where the balsa split rather than a delamination as a result of a poor bond between the parts of the flap.

As to speed I like the faster Redshift. With the faster Redshift I can start to get into a rhythm making the turns. With the slower Strega's I actually need to use a count to gauge the turn at the gates.

I think I'm about to reach the next plateau in speed. With the Strega's I'm doing 53 seconds. With the Redshift I'm seeing 43 seconds. At the 43 second point I can start to work on my starts and pumps. Right now I'm working on my bunts and am starting to feel better about them. The reason I'm working on my bunts is that I'm often making cuts at the gates because of my lack of speed.

With the Redshift I need more rudder mix than I think I should. And a stall/snap takes a bit longer and more work to recover from, than I think they should. Like I said before I think I need more effective rudder area. I'm thinking of bringing the V tail angle from 104° to 100°. You have said to add more area to the tail but I'm not ready to do that when I know the Redshift Spada is in the works.

Hey - 43 secs is getting there!

As to the odd Konrad - both are incorporated in the new model.

I'll keep you in the loop.

Cheers,
Doc.

 

[Konrad]

Good news bad news.

The good news is that the repaired wing box is holding up just fine to the full weight, air and landing loads.

The bad news is that I find that I tested this with a wing loading of over 82g/ dm^2. This is about 10% over the legal FAI limit! It helps explain why the guys were, heck I was, shocked at my approach speeds. The wing box shows no distress as a result of my dives to Base "B" followed by a full elevator stick pylon turn. The wing box withstood some tip contact on landings. Again I didn't notice any distortion in the wing skins. So I'm now confident that the wing box repair tying into the sine wave spar is solid.

I'm also happy to verify that what I noticed was in fact as a result of being over ballasted. I was complaining that the Redshift was looking at times like she was plowing through the air. Again I'm impressed at how the wing tips held on. I don't recall and tip stalls on land or while making the pylon turns.

I think I was following the other pilots as they were all saying that they were adding all the ballast they had. The air at the last F3F race at the slot was very turbulent. So I got a bit excited and followed what I saw the other pilots doing. Now this was the first time I tried to use the wing ballast brass. I did this to experiment with using ballast as a dampener against the turbulence. Now I was still using the 5 tungsten fuselage slugs. Again I had never used this much fuselage ballast.

So by my math I was over the legal FAI limit! My empty ship weighs 2.6kg and the added ballast of about 1.85kg and came to a flying weight of about 4.45 kgs. Add to this that the Redshift is a bit small with an FAI surface area of 53.8 dm^2 and I was cheating, or at least illegal!

I knew something was amiss as my times rose and the plane slowed down far too much as I pulled the elevator. I'm sorry I didn't figure this out earlier but I happy I noticed performance loss as a result of being too heavy. I'm of the opinion that you can't solve a problem if you can't observe the problem.

I'm now going to have to make up a chart that keeps me under the FAI weight limit and still allows me to maintain my CG.

I'm really starting to like the Redshift. I'm now moving up to the next learning plateau. By the end of the season I hope to be within a few percentage points of the fast guys.

For the record my personal best time was done at an FAI legal weight.

 

[Doc James Hammond]

Good news bad news.

The good news is that the repaired wing box is holding up just fine to the full weight, air and landing loads.

The bad news is that I find that I tested this with a wing loading of over 82g/ dm^2. This is about 10% over the legal FAI limit! It helps explain why the guys were, heck I was, shocked at my approach speeds. The wing box shows no distress as a result of my dives to Base "B" followed by a full elevator stick pylon turn. The wing box withstood some tip contact on landings. Again I didn't notice any distortion in the wing skins. So I'm now confident that the wing box repair tying into the sine wave spar is solid.

I'm also happy to verify that what I noticed was in fact as a result of being over ballasted. I was complaining that the Redshift was looking at times like she was plowing through the air. Again I'm impressed at how the wing tips held on. I don't recall and tip stalls on land or while making the pylon turns.

I think I was following the other pilots as they were all saying that they were adding all the ballast they had. The air at the last F3F race at the slot was very turbulent. So I got a bit excited and followed what I saw the other pilots doing. Now this was the first time I tried to use the wing ballast brass. I did this to experiment with using ballast as a dampener against the turbulence. Now I was still using the 5 tungsten fuselage slugs. Again I had never used this much fuselage ballast.

So by my math I was over the legal FAI limit! My empty ship weighs 2.6kg and the added ballast of about 1.85kg and came to a flying weight of about 4.45 kgs. Add to this that the Redshift has a bit of small an FAI area of 53.8 dm^2 and I was cheating, or at least illegal!

I knew something was amiss as my times rose and the plane slowed down far too much as I pulled the elevator. I'm sorry I didn't figure this out earlier but I happy I noticed performance loss as a result of being too heavy. I'm of the opinion that you can't solve a problem if you can't observe the problem.

I'm now going to have to make up a chart that keeps me under the FAI weight limit and still allows me to maintain my CG.

I'm really starting to like the Redshift. I'm now moving up to the next learning plateau. By the end of the season I hope to be within a few percentage points of the fast guys.

For the record my personal best time was done at an FAI legal weight.

Wow, this is a really good example of getting to know what you are flying. In the UK we used to call it 'Getting the model sorted' - though I suspect it was more of a case of getting oneself sorted!

I've often thought that this model knowledge is some of the magic. Pierre Rondel, an old friend of mine seems to have this knack of assessing the potential performance of the model and adding just enough ballast to keep it on its limit. An envious skill. He's also a superb pilot so I guess that helps too.

Me? I just fly it as high as I can un-ballasted and add ballast until it wont fly above 30 ~ 50 feet

Actually Konrad, I have found that as I develop my models I tend to go along similar design paths for the fast slopers so that actually the newer ones - Like Wayne's Forza (Stormbird 2.5) and the Redshift fly in a very similar manner despite the difference in the tail arrangements.

I'm sure its due to the optimised lift distribution, and I do notice that some designers are also beginning to use this approach instead of the old planky style wings with the lift in unnecessary places. I wonder how long it will take them to figure out what is happening at the tips...

What is making me smile so much is charting your analytical journey through this new (to you) F3f task, because I can see rapid progress at each step. I think you are helping us all with the practical and well recorded flying analysis under different conditions.

Cheers, Doc.

 

[Konrad]

I see that many of the fast boys are using 2.7m ships at the slot. While I as an engineer love the very high aspect ratio 3 meter, and the wing of the Redshift in particular. I'm thinking that I should try a smaller ship. I have the Alpha 2.8 but it really is a dated design, even though it has a slip on nose and bottom servo tray. I recall you having a 2.75m ship based on the wing we see on the Redshift. I like the cruciform tail as they wiggle a lot less than most of the V-tails I see. With that wiggle V-tail can't be faster but they seem to be in vogue.

I'll need to ask @Wayne when his order of Aeroic is due to land.

But truth be told I need to stick with one design for a while. I spent 2 or 3 years with the Strega and she taught me a lot. I'm loving the performance upgrade I see with the Redshift even after slamming her into the backside of the SLoT. I have a second Redshift to build (already flipped the tails).

 

[Doc James Hammond]

I see that many of the fast boys are using 2.7m ships at the slot. While I as an engineer love the very high aspect ratio 3 meter, and the wing of the Redshift in particular. I'm thinking that I should try a smaller ship. I have the Alpha 2.8 but it really is a dated design, even though it has a slip on nose and bottom servo tray. I recall you having a 2.75m ship based on the wing we see on the Redshift. I like the cruciform tail as they wiggle a lot less than most of the V-tails I see. With that wiggle V-tail can't be faster but they seem to be in vogue.

I'll need to ask @Wayne when his order of Aeroic is due to land.

But truth be told I need to stick with one design for a while. I spent 2 or 3 years with the Strega and she taught me a lot. I'm loving the performance upgrade I see with the Redshift even after slamming her into the backside of the SLoT. I have a second Redshift to build (already flipped the tails).

"I'll need to ask @Wayne when his order of Aeroic is due to land."

Sorry Sorry Sorry to all those waiting for Wayne's new Aeroic order to show up at Aloft.

We have been completely reorganising the factory to make it faster and more efficient, and this has taken time. Wayne has had an order outstanding from me since the beginning of the year, (!) but the good news is that its now being made.

We are getting there, and the good news is that the all-new models: Sessanta 60, Forza 108, Corsa 118, and the as yet unseen Alpenbrise 157 will all be another notch better than the previous production. Lighter, stronger, better fits and better finishes - plus a lot of cool accessories like wiring looms etc coming with the new planes.

As Winston Churchill said:

"This is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning."

I hope so!

Doc.

 

[Konrad]

The gods must be laughing at me!

I found what looks like a bit of hanger rash on the stabs of my Redshift Mk1. Looking at things I see it is a bit more than that. The damage is as a result of the fuselage falling over and the stab hitting the ground. This buckled the top skin a bit. But much to my surprise it split the stab boss. This split boss is going to "allow" me to try to change the V angle. As the Redshift has shown to be stable in pitch at my CG. I think I can go down from 104° to somewhere between 100° & 95° to aid in directional control.

I saturated the balsa skin with thin CA. I then block sanded the damaged area and will be adding 0.7oz cloth as a patch. That takes care of the stab, but what to do with the boss?

It looks like there isn't much fiber running circumferentially around the tail cone area (boss). I could just glue the crack together and hope. Or I can cut some troughs across the crack and add some fibers.

 

[Konrad]

Since I'm back here repairing the V-Tail mount I decided to change the V-Tail angle to 100° to match the new coming Spada angle. I hope to re-fin these Mk1's with the larger tails. I was going to down as low as 94° but as I've learned that the tails will physically be interchangeable I thought it best to keep thing a bit mild rather than going radical, head long into uncharted waters.

I was actually surprised at just how much the V-tail tips came closer together with only this 4° change.

 

[Konrad]

Much to my surprise that worked well. I didn't think 4° really would have been visually noticeable. I do note that the V-tail mount now looks a lot like the V-tail mount found on the Great Wall (2.8 Meter JIRC glider, AKA Alpha 2.8). This leads me to think that the kink in the Great Wall was as a result of stability issue with the prototype. Flight test must have shown that there needed to be more directional stability. Now as I think the Great Wall was a copy of the RCRCM Tango I have to ask myself why didn't JIRC correct this when making new molds. This would have been easy to do in the CAD file. But not so easy if the Great Wall was actually copied using a Tango and a parting board. I have to ask is there any aerodynamic reason for a kinked V-tail mount?

Back to the Redshift. I just don't like the idea of only using glue to fix the back end split. I'll now cut some shallow troughs across the crack and fill with some carbon tow. With a bit of luck I can test fly this V tail angle modification at the last F3F race of the season on Sunday.

 

[Konrad]

Well, I'm here to say that math actually works, trig that is! That is I've now measured the V-tail angle and I come up with 98.6° to 99° as measured at the camber line. In my book that's dead nuts! I did preload things a bit when I glued the pins in, thinking that any clearance in the pins would flatten the angle. Also as I didn't have any real fixturing other than some plasticine stops this really is good.

Now a minor problem has surfaced in that the control arms collide with the narrower angle. Still have to wait for the epoxy to fully cure (it has only been about 16 hours). But I really want to flight test these mods.

 

[Konrad]

Doc, I know you have taken a bit of grief over the rather radical design of the Redshift. I too have voiced some of my concerns with the mechanical design, material and configuration aspects of the design. But now I'd like to say; THANK YOU for the design.

Changing the V-tail angle from 104° to 99° now results in the Redshift coming out of the turns like a tennis ball off the racquet! Today I sport flew my Redshift MK1 for 2 hours. While the air wasn't the best, it was a good enough to test the set up of the plane in different wind conditions. Today I never got that slowly dampening wiggle we so often get coming out of a turn if we pulled a bit too hard. It is now so much faster entering into the straights. While I haven't test it as thoroughly as I should. the spin recovery appears to be much improved.
Now the only downside was that I had to up the elevator throws to get the same action. This is actually a good thing as it allowed me to use more of the servo's motion hence resolution.

With the 104° tails, 11mm control horns and 6 mm servo arms I was using something like elevator 76 weight in Mike Shellim's templet. With the 99° V-tail angle I had to up this to 96 weight to get much the same elevator action (snap [departure] at full elevator). Aileron roll rate has also improved noticeably as I now am running close to 2:1 differential (mechanical) with little programed differential. The vertical fin is now much more effective. I think with the 104° V-tail angle I was using a bit over 3.5:1 differential. With the 99° angle I'm using a little less rudder mix and a lot less differential and I'm able to trim the fuselage angle (attitude) to come out of the turn level. (see some of my photos in this post for the less than desirable nose down result of using too much aileron differential).

Doc, It has been a battle at times, but I think the design is coming into its own. I'm sure the Spada will be the barn burner we have been waiting for. True, I've only have about 2 hours flight time on this configuration. But I now know that the 100° V-tail is a move in the right direction with those fantastic high aspect ratio wings!

I was surprised at how much I had to rework the radio programing. This is why I chose not to use the Redshift in today's race. As is typical for me, my flight test program was interrupted by an F3F race!

Again today I was flying in an F3F race, and hearing the Freestylers just screaming as they ripped through the air. I was also flying my Strega and it was making some howling noises on some of the faster passes. But the Redshift was silent, it reminded me of an owl.

 

[Konrad]

I'm ashamed to admit it, but I've suffered an engineering failure! Yes, me!!!
I failed to realize that the earlier skin buckle was indicating that the stab spar was broken!

If anybody has any doubt that the stab is adding a downward component to counter the airfoil's negative pitching moment. They need only look at this stab. The top skin of the stab broke in flight under tension! The original break was from compression as a result of the fuselage dropping as I was unloading the car.

I'll need to cut into the top skin and lay some new carbon fiber along the spar break. As I'll only be able to patch the outside of the skin, I think I'll try some light carbon as a patch over the shin fracture.

 

[Hank GB Z]

Did the skin make any sounds when it failed? Or how did you realize the break occurred in flight?

Hank