Redshift; Used Purchase

[Konrad]

slightly off-top I cured the damn landing approach from 14.June
We will see if it holds, fuse ballast tube is now out of order

@Konrad flying stuff from slot, wrecker or the coast??

Are those 4x4 carbon? Can you added carbon tow (cording) on top of the tray and under the snakes? And bond this to the inside of the fuselage.

I test flew at the coast. Nice predictable air.
I still have to make a few adjustments. I hope to do another test flight sometime mid week. And with a bit of luck race the Redshift for the first time on the 12th. (Still need to make up my ballast kit).

All the best.
Konrad

 

[Konrad]

I swear I must take two steps forward and three steps backwards.

I had an aileron servo tray let loose. I had glued these in with 15 minute epoxy and cabosil. I'm learning that nothing much bonds to the plastic housing of these trays.

I see where Servorahmen has supplied a micro ledge. This is here to allow for the epoxy fillet to flow over to mechanically lock the tray in place. Do not rely on the epoxy bond strength. Make sure that there is a good amount of flow over to hold the tray in place.

The good news it that having to re-install the servo tray is allowing me to change my geometry to get more up travel in my ailerons.

All the best,
Konrad

 

[Konrad]

I tried the pig tail connector system for hooking up the wing harness and found it frustrating and potentially dangerous. I saw a lot of stress on the wing wiring loom flex, pinched and pulled wires. These all lead to premature wire failures. All this just to up the survivability in a mid air. To my way of thinking this is an error, almost 100% chance of wire failure for the low probability of mid air survival.

As the Redshift has the wing ballast option this becomes even more of an issue (cycle failure, wire fatigue) as the wings are pulled on and off to change out the ballast as the lift changes through out the race.

I was able to place the Multiplex 6 pin connector to be parallel to the wing joiner within 0.05mm. Note that the Redshift uses a root part line that is not square to the wing joiner. Do not glue the wing connector 90° to the wing part line.

I woke up to the epoxy for the wing connectors and the aileron servo trays having cured. And I was able to separate the wing from the fuselage. ( I had waxed the root part line and the fuselage side of the connector to allow this).

All I have left is to reprogram the ailerons, the servos are now in a new location from where they were on the maiden. Add the covers and I'll be ready for another test flight.

Then the boring stuff of painting. Not sure I want to change the stab. I've actually gotten use to the Red and White squares behind the camo wings. I'll see what input I get at the July race.

All the best,
Konrad

 

[Konrad]

Now for the weighty subject of mass.

Still being nose heavy (CG @ 93mm), my AUW dry (no ballast) is 2452g
My wing ballast is 1533g after cutting some of the bars. I lost 7 grams to the hack saw blade kerf.
This brings my total weight to 3985g. This leaves me only 50 grams, assuming the FAI wing area of 53.8 Dm^2, to play with for trim balance. (Full ballast in the wings shifts the CG forward).

I have to ask do you guys laterally balance the wings? My left wing comes in at 755g and my right wing is 747. So if I balance the wings that now leaves only 42 grams for trim balance. Since the plane is turning sharp do you also match the center of mass for the wings (dynamically balance)? If so how do you place the weight inside the wings?

Now I hope that moving the CG aft from 93mm to 100mm (96mm seems the sweet spot) will gain me maybe another 25+ grams.

All the best,
Konrad

 

[Konrad]

I found the center of mass for the wings. And as I feared the heavy wing is heavy towards the wing tip. To balance the wings I'll be adding weight to the light wing's wing tip. Right now it looks like the only access to the inside of the wing will be through the aileron servo pocket.

All the best,
Konrad

 

[jbblunck]

I really like that auto plug in set up. Whenever I see stuff like that I want to tear up my plane and start again. Ha!

 

[Konrad]

LOL,

Now auto plug in harnesses aren't without their own set of issues.

 

[Konrad]

Doc has some solutions to the pig tail harness.

Soaring USA gift certificate (Strega purchase?)

I just came back from sport flying my Strega. She is slowly getting better (read I'm getting better at trimming her). I've now taken out half the down trim I added to take care of the "incidence" issue. the elevators and stabilized are now close to being in line using my preferred CG. At speed...

forum.alofthobbies.com

 

[Konrad]

As I've been using these wedges a lot to pull apart the wings from the fuselage. I just noticed a nice feature of these little red wedges. That is the max thickness of the wedge corisponds to the thickness of the Multiplex green 6 pin connector. This is a real nice feature in that one knows the connector is free if one can pass the wedge through the gap.

Wing Removal Tools - Servorahmen

Finally, a tool to remove stubbornly tight wings on our beautiful, close tolerance, moldies.They are pretty simple, a pair of smooth plastic wedges designed specifically for separating tight fitting wings from their fuselages, now available in 3 different

alofthobbies.com

All the best,
Konrad

 

[Konrad]

Well much to my surprise I was able to get the wings to balance within 1 gram and 1mm of each other.

Some might ask why I said that it was unfortunate that I had to add mass the tip of the light wing.

To aid in roll authority I like to keep the wings center of mass as close to the fuselage as possible. Adding weight to the tip moved the center of mass outboard to match the heavy wings center of mass.

It was just as likely that I’d have had to add weight to the root of the light wing to balance the wings. While I hate adding dead weight it would have moved the center of mass inboard for the light wing. Again with my wings, this wasn’t the case.

I liked how the maiden went, enough to throw another $100 at the Redshift.
I was able to find a set of KST X10. I hope these are from new old stock. As I was installing these to allow me to use a 2 cell Lipo power system. It dawned on me that the only part of the original build are the flap servo trays and corresponding push rods.

Later this afternoon I hope to perform my second set of test flights. It really is a second maiden. Repositioned aileron servos, new flap servos, moving the CG aft, corresponding program changes and antenna mounts.

All the best,
Konrad

 

[Konrad]

Well the test flights didn't materialize. That is the lift didn't develop at the slot today. I spent 4 hours waiting for good lift. I was happy I had brought along my light lift inland sloper the Mefisto. I'm sure the Redshift would have flown in the lift available. But as it wasn't in trim and I wasn't familiar with the Redshifts habits I thought it best not to risk her. I'll try again on Thursday.

Wow, an extra meter of wing sure adds a lot of presents.

 

[Konrad]

WOW, The second maiden flight was fantastic.

Now many of you might recall that the tone of this thread was a times a bit confrontational between Doc and myself. This was mainly focused around the engineering. And to Doc’s credit he did admit there where some issues. The only fatal mechanical issue I noticed were the short elevator control horns. Doc has said that these and the few other issue, mainly focused on preference will be addressed with Redshift V2.

So to my mind the only issue left is how does the Redshift V1 fly. Today the flight testing consisted of about an hour of air time and 5 extra landings. I need to remind folks that I’m using Mike Shellim’s fantastic F3F OpenTX templet. The real changes from the first maiden flight are the re-mounting of the aileron servo, the added upward throw was noticed. And the changing out of the KST DS125 servos for X10 servos. The maiden last week showed that a CG of 93mm was too nose heavy, making more trim flights non productive. This and that I was using 6v servos on an 8.4v battery put an end to test flying that day.

Today I started the flight testing with the CG at 100mm. While the Redshift was honest at 100mm, she seems a bit tail heavy as shown by the tuck in the dive test. And if pushed will flick into a spin if the elevator is pulled too hard. These spins took over 3 revolution to recover. Not a confidence builder if racing close to the ground! With a CG at 100mm she was controllable in all flight modes as long as you stayed out of the stall. Post stall took active controls to recover. You couldn’t let go and just let the ship build up speed.

After my heart rate returned to normal I placed the CG at 96mm to 97mm. The dive test indicated that this was the neutral point. I’m finding that the ailerons are a bit slow as I need to use a bit more aileron differential. (I expected the dual cusp airfoil to minimize this a bit). I suspect with the long time to recover from a spiral and this aileron differential that the Redshift needs more vertical fin. Doc. did say he was going to narrow the V-tail angle a bit, from 104° to maybe 102° and add a bit more area to the surfaces. Again I only have a an hour of air time and it looks like this might be needed. With the CG at 97mm she does track rather well through the turns. I’d like to see the mention of 90mm for the CG be removed from the manual, it really is too nose heavy and destroys much of the grace and elegance of the flight.

I’m noticing that the manual is correct in that the snap flap only needs about half what we currently use in todays crop of airfoils. I think this is because the airfoil has a bit more camber than most modern airfoils.

I only flew the RedShift empty (no ballast). Now that I know the CG I’ll have to make up a set of spacers and trim weights. Even without a set of ballast weight I’m hoping to race her on Sunday. I’m torn should I stay home on Saturday and make up a set of trim spacers, or do some more flight test to get comfortable with her prior to racing.

I didn’t notice any unique sound to the Redshift. Maybe I haven’t gotten her on step.

With only an hour of flight time I can say I’m sorry Aeroic had so many quality issues with the OEM. I think we the flying public lost an opportunity for 2 years to have a great F3F ship at the $1500 price point. If you can find some old new stock It might be worth the effort to correct the short V tail arms. I think the threaded servo arms shown by Jonathan Wells, and used here by me, is key to making the Redshift V1 work.

I can only imagine how much better RedShift v2 will be. I don’t think it will be a drastic change in its flight characteristics. But it should address the short horns and have a narrower modern fuselage. Not sure how I feel about adding mass the the wings, dampening the roll, just to cut down the cross section of the fuselage. I’m not sure where the drag curves cross. For now I like the RedShift v1 and how she flies. I can only think how much better she will get as I get more and more familure with her.

Thanks Doc.
While this one was a bit more work (used purchases almost always are) I'm very happy with the result.

All the best,
Konrad

 

[Doc J]

WOW, The second maiden flight was fantastic.

Now many of you might recall that the tone of this thread was a times a bit confrontational between Doc and myself. This was mainly focused around the engineering. And to Doc’s credit he did admit there where some issues. The only fatal mechanical issue I noticed were the short elevator control horns. Doc has said that these and the few other issue, mainly focused on preference will be addressed with Redshift V2.

So to my mind the only issue left is how does the Redshift V1 fly. Today the flight testing consisted of about an hour of air time and 5 extra landings. I need to remind folks that I’m using Mike Shellim’s fantastic F3F OpenTX templet. The real changes from the first maiden flight are the re-mounting of the aileron servo, the added upward throw from was noticed. And the changing out of the DS125 servos for X10 servos. The maiden last week showed that a CG of 93mm was too nose heavy, making more trim flights non productive. This and that I was using 6v servos on an 8.4v battery put an end to test flying that day.

Today I started the flight testing with the CG at 100mm. While the Redshift was honest at 100mm, she seems a bit tail heavy as shown by the tuck in the dive test. And if pushed will flick into a spin if the elevator is pulled too hard. These spins took over 3 revolution to recover. Not a confidence builder if racing close to the ground! With a CG at 100mm she was controllable in all flight modes as long as you stayed out of the stall. Post stall took active controls to recover. You couldn’t let go and just let the ship build up speed.

After my heart rate returned to normal I placed the CG at 96mm to 97mm. The dive test indicated that this was the neutral point. I’m finding that the ailerons are a bit slow as I need to use a bit more aileron differential. (I expected the dual cusp airfoil to minimize this a bit). I suspect with the long time to recover from a spiral and this aileron differential that the Redshift needs more vertical fin. Doc. did say he was going to narrow the V-tail angle a bit. from 104° to maybe 102° and add a bit more area to the surfaces. Again I only have a an hour of air time and it looks like this might be needed. With the CG at 97mm she does track rather well through the turns. I’d like to see the mention of 90mm for the CG be removed from the manual, it really is too nose heavy and destroys much of the grace and elegance of the flight.

I’m noticing that the manual is correct in that the snap flap only needs about half what we currently use in todays crop of airfoils. I think this is because the airfoil has a bit more chamber than most modern airfoils.

I only flew the RedShift empty (no ballast). Now that I know the CG I’ll have to make up a set of spacers and trim weights. Even without a set of ballast weight I’m hoping to race her on Sunday. I’m torn should I stay home on Saturday and make up a set of trim spacers, or do some more flight test to get comfortable with her prior to racing.

I didn’t notice any unique sound to the Redshift. Maybe I haven’t gotten her on step.

With only an hour of flight time I can say I’m sorry Aeroic had so many quality issues with the OEM. I think we the flying public lost an opportunity for 2 years to have a great F3F ship at the $1500 price point. If you can find some old new stock It might be worth the effort to correct the short V tail arms. I think the threaded servo arms shown by Jonathan Wells, and used here by me, is key to making the Redshift V1 work.

I can only imagine how much better RedShift v2 will be. I don’t think it will be a drastic change in its flight characteristics. But it should address the short horns and have a narrower modern fuselage. Not sure how I feel about adding mass the the wings, dampening the roll, just to cut down the cross section of the fuselage. I’m not sure where the drag curves cross. For now I like the RedShift v1 and how she flies. I can only think how much better she will get as I get more and more familure with her.

Thanks Doc.
While this one was a bit more work (used purchases almost always are) I'm very happy with the result.

All the best,
Konrad

Glad you are taming the beast Konrad.

Once you get the feel for this bird I'm sure you will like it. Try a teeny bit of reflex if you have a nice wind.

Anyway, as you have found out its a little it different compared many F3f models - the biggest differences being that its definitely not F3f-fashionable and it don't cost limb amputation to own!

Despite those significant disadvantages, it has made a creditable appearance at the world champs, and also cleaned out very strong opposition to get the fastest time at one of the Euro Tour events.

Thanks for the valuable inputs, all taken into consideration for the Mk II - which is now under way.

Cheers,

Doc

 

[purview]

Yes, I've to agree that spiral spins can occur suddenly in turbulent air while turning. Less unstability margin can compensate or tail surface.

Good to hear that you like her... it's all ready known REDSHIFT to be an awesome "racing" plane
WE WILL SEE?
look up!

 

[Konrad]

Doc. That’s a good point, one needs to learn how to use new equipment. Like your set up notes to limit the use of snap flaps. As I didn’t have any ballast with me I did fly a bit with reflex. I may have had more than I should thinking that with the added chamber I would want added reflex. (Actually the reflex looks normal, but as the Redshift has a small chord it ends up being more than normal). I know I still have a long way to go in understanding the Redshift and optimizing her set up.

As the forecast for Sunday is light but flyable I think I'll make arrangements with SWMBO (AKA the wife) to go flying today and get some more practice.

FYI:
I don't think I brought forward anything you didn't already know about the Redshift. I think you had already addressed the issues and trends with the MK II before I even got my hands on a Redshift Mk I. I just hope that this thread helped in letting you know what issues a normal* flier/owner might notice (market data).

I hope this thread gives some owners of a Mk I some ideas as to how to make their Mk I more practical (better control response). Flipping the V-tail, making the control horns and push rods should be well within the scope of most modelers, that would be flying F3F, with just basic hand tools.

* I know, I know Abby-Normal

 

[Konrad]

I've found that my actual CG is now 95mm to 96mm by balancing the model on a the knife edge of a glass table. I'm using the LE at the fuselage part line as my datum. I state this more as a validation of Doc's stated CG rather than a correction of my finger tip measurements.

I made up a set of spacers to use some of the 155gram tungsten slugs I had laying around for the fuselage center line ballast tube. With this ballast tube I'm able to ballast the Redshift a bit with 465 grams of mass. I have less than 1mm shift in the CG.

Today I got 2 more flight in. I'm really starting to like how the Redshift turns. While I may have had some issues with the form and fit of this particular Redshift Mk I. I'm really starting to like the function. That is it really is flying well!

I must be tone deaf as I couldn't hear her on any of my high speed passes.

This Redshift is flying so well that I'm going to use her as my primary ship in tomorrow's race. I'm sure there is a lot more performance to be extracted, but in her current trim she is flying so much better than my white and red Strega.

 

[purview]

must be tone deaf as I couldn't hear her on any of my high speed passes.

I agree, I've seen and heard others F3f loud screaming while the REDSHIFT in same speed range is not much noisy

It sounds more like a turbine, maybe you don't like that

 

[Doc J]

Its a magic wing.

The lift is where it needs to be and nowhere else.

Doc.

 

[Konrad]

I'll pay more atttention to the high Cl portions of the flight, listening for her unique sound

 

[Doc J]

I'll pay more atttention to the high Cl portions of the flight, listening for her unique sound

When it gets on the step it sounds a little bit like a Star Wars Tie Fighter?

The vortexes leaving the wingtips are abrupt and depart at very high compression.

Maybe "Redshift" is the new "BUZZ" word...sorry..

Cheers,

Doc