Aloft Forums
Welcome to Aloft Forums. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
4 meter scratch build - Glass schedule / reinforcement questions
- Thread starter thenated0g
- Start date
thenated0g
Moderator
@Wayne @Doc J Yes its a copy of the Ridge rat. I started a thread over in flitetest on how i really loved the ridge rat and the ninja but have had you and others say its not the best flyer anymore so i decided to do a copy in fiberglass (GlassRat) and change the airfoil. @bracesport liked what i was doing and had just got into sloping so he started his version. We have kind of been building sideby side. He went with carbon over foam fuselage and trying the 3d print wing stuff i went purely fiberglass. I just put the tail feathers on mine
Konrad
Very Strong User
This is what I think of when I hear the name Ridge Rat
Let's not forget the Cheetah and Super Cheetah. As I recal these had a plastic baseball bat like fuselage.
Let's not forget the Cheetah and Super Cheetah. As I recal these had a plastic baseball bat like fuselage.
Last edited:
Konrad
Very Strong User
thenated0g
Moderator
yeah @Konrad that's exactly the one i copied. Here's the balsa plans i based it off of:
outerzone.co.uk
I left the tail feathers dimensions and placement and distance between the trailing edge of the main wing and the tail feathers all the same. The only thing i really did was change the airfoil to mh32 and some minor adjustments to fuselage shape as i was sanding it.
Oz : Ridge Rat plan - free download
outerzone.co.uk
I left the tail feathers dimensions and placement and distance between the trailing edge of the main wing and the tail feathers all the same. The only thing i really did was change the airfoil to mh32 and some minor adjustments to fuselage shape as i was sanding it.
Nate - Looking forward to borrowing the sticks on this one at Sunset. 
I think the MH32 will work great for the Rat. Should have better performance but a cool vintage look. Well done.
Just a thought, my buddy would pop on a canopy from a P-51 to give the Rat a little better look. He would usually pop some sort of toy under it for a pilot figure.
I think the MH32 will work great for the Rat. Should have better performance but a cool vintage look. Well done.Just a thought, my buddy would pop on a canopy from a P-51 to give the Rat a little better look. He would usually pop some sort of toy under it for a pilot figure.
thenated0g
Moderator
heading to parkflyerplastics.com right now........
thenated0g
Moderator
Any thoughts on this as a way to slow down a big plank?
Konrad
Very Strong User
I like center of gravity shift towards being more “tail heavy” in landing mode. Or if you have flaps, mixing in “crow” just like a normal ship. Note that the balance between both the flap and aileron/spoiler is a bit more critical. I hate the classic spoilers as these suck!
Doc J
Very Strong User
Tried it Nate - not effective - it just makes the model into a big, soggy, (but still too fast) sponge.
CG change works, but again it tends to have adverse effects on the landing controllability.
Go for normal flaps etc, its a bit tricky at first to get the ratio between the elevons (down) and the ailerons (up) right, but its simple and it works.
By the way I have tried elevons up and ailerons down but it takes it a bit twitchy.
Cheers,
Doc.
Konrad
Very Strong User
I had a Klingberg Wing 100 that had variable center of gravity. I don’t recall any adverse flight characteristic with the CofG being aft in the landing pattern. In fact I find that the only thing worse than being tail heavy is being nose heavy. With the CofG being forward the nose would drop prematurely. Meaning that one couldn’t lock in the glide slope. With the result being that landing speeds were far too fast with the subsequent damage from landing too fast. Now what surprised me was that in landing mode (slow flight) I didn’t need to cut down on the aileron throw.* The only Gotcha I recall with the variable CofG was the need to use a servo with a large gear train. I recall using sail and/or retract servos.
What adverse control response should one look out for when moving the CofG aft (narrowing the static margin of stability)on landing? I’m not talking about divergent flight where we would need gyros for flight stability.
* Normally as the CofG is moved aft one needs to cutdown on the control movement. With the CofG moved aft in landing mode this wasn’t required as the aft CofG is only used at low speed. This meant that as the speed built up and the wing started to feel too responsive to the control, it was time to move the CofG forward.
What adverse control response should one look out for when moving the CofG aft (narrowing the static margin of stability)on landing? I’m not talking about divergent flight where we would need gyros for flight stability.
* Normally as the CofG is moved aft one needs to cutdown on the control movement. With the CofG moved aft in landing mode this wasn’t required as the aft CofG is only used at low speed. This meant that as the speed built up and the wing started to feel too responsive to the control, it was time to move the CofG forward.
Last edited:
Doc J
Very Strong User
I gave it up pretty much for the reasons you outline Konrad.
- Its adding another system to the mix.
- Needs a big servo and some serious hardware/weight to work - I used a huge battery and a moving tray.
- It was pretty hard to tune, and I don't think I ever got the mix of CG and appropriate control settings dialled.
- "Kinda" works with a swept wing configuration but the nearer you get to a plank where the MAC and CG are not too far away from each other, the worse it is.
- If I moved the CG back even the tiniest bit too far, the ailerons completely lost authority.
- It was really hard to recover to normal flight if you want to do a go-around.
I think al lot depends on the planform of the wing.
Cheers,
Doc.
Konrad
Very Strong User
Yep, coming up with a durable system was an issue back in the day. But with the drive system we have with electrical retracts much of those issue might be behind us.
As I recall the mixing wasn't too much of a head ache even with my late 80's Ace MicroPro 8000. With today's programable radios like those running Open TX it should be a snap!
But crow/butterfly is the main configuration to be using to slow down a wing or even a traditional sailplane.
As I recall the mixing wasn't too much of a head ache even with my late 80's Ace MicroPro 8000. With today's programable radios like those running Open TX it should be a snap!
But crow/butterfly is the main configuration to be using to slow down a wing or even a traditional sailplane.
I have seen all sorts of silly things like the split rudders, split ailerons, huge canopies that popped up from the fuselage.. I have never seen a setup that I thought worked well on a plank or even a twisty wing. Seems the best to can try for on a plank is a hyper stall, but never heard of anyone doing this with a larger model, usually smaller than 40" span.
I think the best option is to build strong and fly out as much energy as you can and then "place" the plane into a soft bush. That seemed to be much more reliable than anything else I have seen tested.
On twisty wing planes, if you have a rudder and some side profile to the fuselage you can play with crabbing to the wind as much as you can handle to burn off energy. I think this is probably the best bet to kill energy on these planes. Basically hold a ton of rudder and use the elevator and wing roll to keep the plane level and on course. This uses the sides of the fuselage as a speed break.
I have seen one winderon built with flaps. It upset some of the twisty wing guys but made great sense. This was on a very FAST twisty wing plane that had a ton of weight. The addition of flaps should have allowed the plane last a lot longer.
gp49
Very Strong User
How about something similar to this?
www.rcgroups.com
Pitcheron/wingeron brakes using new technology - RC Groups
Discussion Pitcheron/wingeron brakes using new technology Slope Soaring
thenated0g
Moderator
Posted a wanted add on rcgroups for broken fuselages.
thenated0g
Moderator
Guy offered me a xplorer fj3 fuselage, broke just behind the wing saddle, for cost of shipping. So that should save me a bunch of time, although i was looking forward to making 2 part molds. Guess i could still try making a mold of it once its done being repaired/modded.
thenated0g
Moderator
yeah its not the exact shape i want, but it will save me some time and, as the wings are removable, i can make another fuselage when i want.
