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Soaring USA gift certificate (Strega purchase?)
Konrad
Very Strong User
Actually Kyle was fighting a wandering aileron pot on his Spektrum TX. I think he would have done much better if he didn't have to fight that wondering aileron roll. Being at base "B", I did see that balloon issue at least 3/4 of the time, coming out of the turn with the "factory" out of rig stab.
Now that I have that "spoiler" under control I'll get back to assembling my yellow Strega. And from the lessons learned I hope to make my red and white one a much better ship.
Now that I have that "spoiler" under control I'll get back to assembling my yellow Strega. And from the lessons learned I hope to make my red and white one a much better ship.
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Doc James Hammond
Very Strong User
Its fast enough, though Kyle's will go better when he does the Tail incidence mod (Today)
If you look at the Video from Mike R - poor old Kyle was disappearing into the stratosphere on every turn.
Ballooning in other words. Incidence will do that for you on a racing model.
Cheers,
Doc.
If you look at the Video from Mike R - poor old Kyle was disappearing into the stratosphere on every turn.
Ballooning in other words. Incidence will do that for you on a racing model.
Cheers,
Doc.
Doc James Hammond
Very Strong User
Nice solution Konrad!
Doc.
Doc.
Konrad
Very Strong User
Thanks Doc.
All the best,
Konrad
P.S.
Where is the video posted?
I was surprised how well Kyle did with the Strega. While he had issues with his set up (radio and incidence) I don't think he was ever less than one leg behind. I actually expected the Strega to be lapped. It didn't happen!
All the best,
Konrad
P.S.
Where is the video posted?
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Konrad
Very Strong User
Correcting the OEM’s (RCRCM) misunderstand of the aerodynamics of this bird.
Well that proved to be more of an issue than I had hoped.
Because of the joiner offset the linear offset as measured at the LE is different between the left and right side for the same angular change.
Raising the leading edge approximately 1.5mm has caused the control horn to violate the bottom of the tail cone.
I chose to dremel out half the hole to allow the pins to move the needed amount. I then filled the left over voids with epoxy. Prior to doing this I waxed all the surfaces, other than the pin holes, to protect them from the epoxy. I also painted on mold release as an added level of protection. I really didn’t want to glue on the stabs.
I will say that the realigned stabs now have more purchase for the pins than what was found with the OEM setup.
All the best,
Konrad
Well that proved to be more of an issue than I had hoped.
Because of the joiner offset the linear offset as measured at the LE is different between the left and right side for the same angular change.
Raising the leading edge approximately 1.5mm has caused the control horn to violate the bottom of the tail cone.
I chose to dremel out half the hole to allow the pins to move the needed amount. I then filled the left over voids with epoxy. Prior to doing this I waxed all the surfaces, other than the pin holes, to protect them from the epoxy. I also painted on mold release as an added level of protection. I really didn’t want to glue on the stabs.
I will say that the realigned stabs now have more purchase for the pins than what was found with the OEM setup.
All the best,
Konrad
Doc James Hammond
Very Strong User
Great job Konrad - neat and tidy!
Doc.
Doc.
Konrad
Very Strong User
Well I just suffered another epoxy failure. I didn’t know epoxy had a shelf life, but expecting it to be reliable after 30 years might be pushing it. Well it took me the better part of this morning to clean up the mess. This might be a blessing in disguise as I was pushing this build to try to make it to the next F3F race at the slot on Sunday. I could probably still make for Sunday but only to maiden. It is a real bad idea to maiden and race at the same time!
I’m fitting the ballast tube. My Strega kits did not come with one. I’m using Aloft Hobbies 330mm thin wall carbon tubes (Lg Lead). I can add 1.040Kg of ballast using 5 copper couplers filled with lead. What I like about these carbon tubes is that one can using them as keel stiffeners. Far too often I see slope ships fail the fuselage just ahead of the wing or just behind the canopy opening. I fastened my tube with a thick mixture of epoxy (fresh) and Cabosil for the full length of the tube.
Now I’d like to ask were to you guys like to set the Center of Gravity on the Strega. I read 105 to 110 from the leading edge. As I often like the CofG further aft than most, I decided to place the ballast’s center of mass at the 115mm point aft of the LE. This will allow me to go that far aft with no trim changes as a ballast the model. But as in more likely allow me to shim the ballast forward to meet the trim CofG that I establish during flight testing.
With Aloft’s ballast tube this means that the rear edge of my ballast window in the tube will be about 3 aft of the of the canopy opening. It looks like the canopy opening has a large enough of a lip that this shouldn’t be a problem. I’ll wait until after I’ve flown my Yellow Strega before installing the ballast tube in my red and white Strega.
I will say that it is looking a bit tight in the fuselage, with the wing joiner, ballast tube, push rods and wing wiring. I hope the push rods keep clear and are free to move.
All the best,
Konrad
I’m fitting the ballast tube. My Strega kits did not come with one. I’m using Aloft Hobbies 330mm thin wall carbon tubes (Lg Lead). I can add 1.040Kg of ballast using 5 copper couplers filled with lead. What I like about these carbon tubes is that one can using them as keel stiffeners. Far too often I see slope ships fail the fuselage just ahead of the wing or just behind the canopy opening. I fastened my tube with a thick mixture of epoxy (fresh) and Cabosil for the full length of the tube.
Now I’d like to ask were to you guys like to set the Center of Gravity on the Strega. I read 105 to 110 from the leading edge. As I often like the CofG further aft than most, I decided to place the ballast’s center of mass at the 115mm point aft of the LE. This will allow me to go that far aft with no trim changes as a ballast the model. But as in more likely allow me to shim the ballast forward to meet the trim CofG that I establish during flight testing.
With Aloft’s ballast tube this means that the rear edge of my ballast window in the tube will be about 3 aft of the of the canopy opening. It looks like the canopy opening has a large enough of a lip that this shouldn’t be a problem. I’ll wait until after I’ve flown my Yellow Strega before installing the ballast tube in my red and white Strega.
I will say that it is looking a bit tight in the fuselage, with the wing joiner, ballast tube, push rods and wing wiring. I hope the push rods keep clear and are free to move.
All the best,
Konrad
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Doc James Hammond
Very Strong User
Shutting the gate after the horse has bolted, Konrad, but I would not use any epoxy more than a year old, and 6 months at most for producing models.
You think the Strega is tight? That was my first F3f model so I probably didn't lay it out as well as I could have done. The Redshift II is actually much smaller but hopefully well planned so that everything fits in well.
Hmm...
Cheers,
Doc.
Konrad
Very Strong User
Talking with chemists, they tell me if the container is sealed there really isn't a shelf life. Key word is sealed not just a cap over the end. Also any crystals that have formed need to dissolved (heated). But 30 years really is way outside any reasonable expectation. Many data sheets will list the self life as 99 months this is code for unlimited. No we aren't talking Egyptology time lines, but...
Yep, I'm concerned about drag on the push rods and wear on the wing wires. I'm happy to say that the large ballast tube did clear the joiner with a 1mm to spare. Fully ballasted I should be close to 60g per square decimeter.
Do you agree with the 105 to 110 balance point?
All the best,
Konrad
Yep, I'm concerned about drag on the push rods and wear on the wing wires. I'm happy to say that the large ballast tube did clear the joiner with a 1mm to spare. Fully ballasted I should be close to 60g per square decimeter.
Do you agree with the 105 to 110 balance point?
All the best,
Konrad
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Doc James Hammond
Very Strong User
Glad it worked out Konrad.
I'd get better advice for the CG - as I remember thats about right but its been a long time.
I know that Kyle P flies them pretty often. Maybe solicit his sage advice?
Cheers,
Doc.
Konrad
Very Strong User
Thanks. I'm just looking for set up values I'll fine tune to my thumbs during flight testing.
Konrad
Very Strong User
Well I found some space in the fuselage. Much to my surprise there is a tunnel formed by the wing joiner and the top of the fuselage that just barely allows all the wing wiring to pass. This keeps the wires free of the push rods. I also learned that RCRCM gives us a boss to butt glue the Multiplex connector to the outside of the fuselage. This saves space inside the fuselage. I also like that we are pushing the connector against the fuselage rather than relying on the glue bond alone. The wing side connector still relies on the glue bond alone.
I've also stress relieved to wing joiner pass through. We had a discussion about this here.
forum.alofthobbies.com
I did find a pinch point, in that with the large diameter ballast tube the rear wing alignment pin does bind the push rods! I’ll need to relieve these pins to allow free movement of the push rods.
As shown earlier I have used milled fiberglass and epoxy as a ballast stop. This is far from being enough to stop over a Kg of mass. I’ve incorporated the servo tray and all its contact area to help keep the ballast slugs from going through the front of the fuselage. I've also extended the servo tray aft to the wing LE to give side support. I’ve seen far too many fuselages buckle between the wing and the canopy. I’m hoping that tying the fuselage, servo tray and ballast tube will stiffen these long narrow fuselages to withstand my landings.
All the best,
Konrad
I've also stress relieved to wing joiner pass through. We had a discussion about this here.
Manufacturing/design flaws
I've been looking for an F3F trainer to learn how to fly the course and maybe something to fly at the ISR. [Read; pass (I hope) and not get mid aired]. Now I've noticed a persistent theme to all the used gliders I've been looking at. That is that all with huge wing joiner going through the...
forum.alofthobbies.com
I did find a pinch point, in that with the large diameter ballast tube the rear wing alignment pin does bind the push rods! I’ll need to relieve these pins to allow free movement of the push rods.
As shown earlier I have used milled fiberglass and epoxy as a ballast stop. This is far from being enough to stop over a Kg of mass. I’ve incorporated the servo tray and all its contact area to help keep the ballast slugs from going through the front of the fuselage. I've also extended the servo tray aft to the wing LE to give side support. I’ve seen far too many fuselages buckle between the wing and the canopy. I’m hoping that tying the fuselage, servo tray and ballast tube will stiffen these long narrow fuselages to withstand my landings.
All the best,
Konrad
Konrad
Very Strong User
Well this put another nail in the coffin of Strega! While cleaning off my epoxy finger prints I noticed something didn’t feel or sound correct with this wing. Yep, the top and bottom of the wing had separated. This was because there wasn’t much if any glue bead at the LE bonding the top and bottom together!
This is a different failure mode than what we saw with the Sanda mini Mach. In that failure we had a localized shock induced de-lamination of the top composite skin. Here with the RCRCM Strega we have to top and bottom of the wing separating!
forum.alofthobbies.com
I fear that this has put an end to any hope of getting this model ready for Sunday’s F3F race at the Slot!
If you guys take anything away from this thread it is DON’T BUY AN RCRCM PRODUCT! It just isn’t worth the cost or the time to correct the issues. The issues are systemic to the build. There is no point in trying to make a silk purse out of a sow’s ear!
Pissed off,
Konrad
P.S.
Full discloser time!
While prepping the wing for repair, I did find an ever so small an indication that there was impact damage to the LE. Still RCRCM should have provided a sufficient LE bead, as is there are spots where this bead is less than 1 mm thick. The impact damage doesn't show up on the camera, just yet. After the glue cures the impact point might show after I block sand the area.
This is a different failure mode than what we saw with the Sanda mini Mach. In that failure we had a localized shock induced de-lamination of the top composite skin. Here with the RCRCM Strega we have to top and bottom of the wing separating!
mini Mach (Sanda Models)
One of the benefits (or curses) of having Aloft Hobbies as my local hobby shop is that I get to go through customer returns. I went in to Aloft Hobbies looking for a 60” racer other than a Sunbird and walked out with a customer returned Sanda Mini Mach. I’m still in need of a good value 60”...
forum.alofthobbies.com
I fear that this has put an end to any hope of getting this model ready for Sunday’s F3F race at the Slot!
If you guys take anything away from this thread it is DON’T BUY AN RCRCM PRODUCT! It just isn’t worth the cost or the time to correct the issues. The issues are systemic to the build. There is no point in trying to make a silk purse out of a sow’s ear!
Pissed off,
Konrad
P.S.
Full discloser time!
While prepping the wing for repair, I did find an ever so small an indication that there was impact damage to the LE. Still RCRCM should have provided a sufficient LE bead, as is there are spots where this bead is less than 1 mm thick. The impact damage doesn't show up on the camera, just yet. After the glue cures the impact point might show after I block sand the area.
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Konrad
Very Strong User
LOL (read crying)
It will be the same type of repair as the mini Mach. But instead of thinning the epoxy to aid in the capillary action, I'll be thickening the epoxy with cabosil to build up the LE bead.
I see the link to the mini MACH didn't post, so here it is.
forum.alofthobbies.com
All the ebst,
Konard
It will be the same type of repair as the mini Mach. But instead of thinning the epoxy to aid in the capillary action, I'll be thickening the epoxy with cabosil to build up the LE bead.
I see the link to the mini MACH didn't post, so here it is.
mini Mach (Sanda Models)
One of the benefits (or curses) of having Aloft Hobbies as my local hobby shop is that I get to go through customer returns. I went in to Aloft Hobbies looking for a 60” racer other than a Sunbird and walked out with a customer returned Sanda Mini Mach. I’m still in need of a good value 60”...
forum.alofthobbies.com
All the ebst,
Konard
