RFX features questions

technoid

Well-known member
Is this a problem with the brakes??? I get the same "glued in place" aircraft behavior when I hold full down elevator and apply throttle, (that I expect) as to when the aircraft sticks after applying and releasing the brakes during taxi maneuvers.
Your biplanes that I fly do not have brakes and they taxi perfectly.
I've been wondering for a while if it has something to do with the tire size so after your mentioned the Great Lakes Biplanes didn't do it I looked at both tire sized.

Great Lakes Biplane Tire Size Main Gear Tire Size

X: 1.26
Y: 5.29
Z: 5.29

T-28 Trojan Nose Tire Size

X: 1.0
Y: 3.47
Z: 3.47

T-28 Trojan Wing Tire Size

X: 1.01
Y: 3.9
Z: 3.9

I don't know if that's an issue but the tire size on the Biplane is quite a bit larger. I think I'll do a test build with larger tires and see what happens. Of course the brakes might be an issue too but often when the plane is first loaded it's stuck, so no brakes applied yet. (unless the problem is there are brakes in the physics even if never applied)
 
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asj5547

Well-known member
Yes the T-28C is stationary on load, if rolling resistance is set 30% - 100% range, but if rolling resistance is set to 1% - 30% range it rolls freely on initial load, yet the brakes grip and the nose wheel steers (seems to have normal amount of traction).?
I have imported G4.5 models with brakes, trike landing gear and no collision mesh and they work okay, A-6 Intruder for example.
I do not have a solution for this problem, just hope the supplied info will help to trigger the thought buds.
Oh yes, the runway stripes cannot be turned off so it's not a wheel catching in a stripe sink hole, I can only remove the entire runway decal.
 
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technoid

Well-known member
Yes the T-28C is stationary on load, if rolling resistance is set 30% - 100% range, but if rolling resistance is set to 1% it rolls freely on initial load, yet the brakes grip and the nose wheel steers (seems to have normal amount of traction).?
I have imported G4.5 models with brakes, trike landing gear and no collision mesh and they work okay, A-6 Intruder for example.
I do not have a solution for this problem, just hope the supplied info will help to trigger the thought buds.
I just did a test build with a 1.25 x 4.75 front tire and 1.25 x 5.00 wing tires and had the same problem. Then I went back to the RF-X editor and set all brakes to 0% and also set the brake servo to none. After saving the changes and reloading RF-X it did the same thing, one time I was even able to increase the throttle slowly and break off the nose gear.

SO.. enough is enough I'm going back to what I think is the best build, which is my last change to the tire collision mesh and release it that way. I don't know what the problem is and I've worked on it enough. The plane is fine in RF-X except for this problem AND the fact the Canopy can hardly be seen but is very visible, even more than I want it to be in RF-8. I may even lower the Canopy opacity so it looks the best in RF-8 and add comments in the Release Notes about these two issues and people can change the Canopy opacity in the CS TGA file Alpha Layer to fix it in RF-X. It would be nice if the same build is fine for both RF-8 and RF-X but it doesn't appear that's possible. I'll probably give an Alpha Channel Value in the Release notes to make the Canopy look right in RF-X. Bummer but I want to release the plane and I've done all I can at this point.

Thanks for all your help on this it's been a big help to me. I just don't want to change the rolling resistance but that would be some good information to pass along in the release notes too. I don't know what I've done wrong but it's probably something simple, the NexStar in RF-X is a Trike too and it works fine.
 
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technoid

Well-known member
Okay in a last ditch effort to fix the sticking problem I looked at the landing gear on several planes including the Great Lakes Trainer and the built-in NexStar. The common thing was they were using 'springy' gear of some sort, spring flat aluminum or springy scale retracts. When I first started flying Wright Island like several others mentioned it was Very Bouncy on Landing so I changed the landing gear on the T-28 to round steel to get rid of the bouncing, but then you had to put up with the extra noise on landing.. which was a small price to pay for no bouncing. SO.. I just changed the T-28 nose and wing gear to springy scale retracts with a 100% (default) strength factor and Walla.. the Sticking went away.

SO.. asj5547 will you change both your Nose and Wing gear to Springy Scale Retracts and make sure the Strength for the springy scale retracts is set to the Default 100% and let me know how it works for you, but I expect it will work the same and get rid of the Sticky problem but add back the Bouncy problem.

Again thanks for your help on this!
 

asj5547

Well-known member
Okay in a last ditch effort to fix the sticking problem I looked at the landing gear on several planes including the Great Lakes Trainer and the built-in NexStar. The common thing was they were using 'springy' gear of some sort, spring flat aluminum or springy scale retracts. When I first started flying Wright Island like several others mentioned it was Very Bouncy on Landing so I changed the landing gear on the T-28 to round steel to get rid of the bouncing, but then you had to put up with the extra noise on landing.. which was a small price to pay for no bouncing. SO.. I just changed the T-28 nose and wing gear to springy scale retracts with a 100% (default) strength factor and Walla.. the Sticking went away.

SO.. asj5547 will you change both your Nose and Wing gear to Springy Scale Retracts and make sure the Strength for the springy scale retracts is set to the Default 100% and let me know how it works for you, but I expect it will work the same and get rid of the Sticky problem but add back the Bouncy problem.

Again thanks for your help on this!
Scale retracts or springy scale retracts work good, and for some strange reason I can now alter the graph points on the brakes for more stopping power.:)
Will do a lot if taxiing and landings today to confirm solution.
 

technoid

Well-known member
Scale retracts or springy scale retracts work good, and for some strange reason I can now alter the graph points on the brakes for more stopping power.:)
Will do a lot if taxiing and landings today to confirm solution.
It's good to hear you don't have to use springy retracts I'm going to try that out right now. SO.. Which is your preference, Springy Retracts or Retracts? I guess it boils down to do you want to bounce on landing or hear the thud.
 

asj5547

Well-known member
It's good to hear you don't have to use springy retracts I'm going to try that out right now. SO.. Which is your preference, Springy Retracts or Retracts? I guess it boils down to do you want to bounce on landing or hear the thud.
Problem with scale retracts, had plane stick twice when turning.
Springy scale retracts have worked good so far, will keep testing.
If you want to see something funny, load the T-28C with springy round steel, the undercarriage legs act really wobbly and then the plane breaks apart.
 

technoid

Well-known member
Problem with scale retracts, had plane stick twice when turning.
Springy scale retracts have worked good so far, will keep testing.
If you want to see something funny, load the T-28C with springy round steel, the undercarriage legs act really wobbly and then the plane breaks apart.
Yeah I tested the scale retracts and found the same thing, but springy retracts works fine in RF-8 and RF-X so I'm going with them. I also tested springy round and seen that too. Try setting the strength setting for springy retracts to min and max values, the min sinks into the surface and sometimes far enough to stop the prop. Setting it to max gives you a real nice dance. SO.. I'll set it to the default 100. Again thanks for your help on this. I think I'm done testing it in RF-X and will go with what I've found.
 

asj5547

Well-known member
Yeah I tested the scale retracts and found the same thing, but springy retracts works fine in RF-8 and RF-X so I'm going with them. I also tested springy round and seen that too. Try setting the strength setting for springy retracts to min and max values, the min sinks into the surface and sometimes far enough to stop the prop. Setting it to max gives you a real nice dance. SO.. I'll set it to the default 100. Again thanks for your help on this. I think I'm done testing it in RF-X and will go with what I've found.
Springy Scale Retracts still working good, the aircraft has great ground handling.
I made a couple of adjustments to the landing gear default settings, set front gear to 300% stiffness, set main gear to 20% stiffness and changed rubber tires to pneumatic tires, (just my crazy settings) although the defaults work okay.
You must be very proud of the T-28 Trojan it is an incredible model.
Thank you for sharing it.
 

technoid

Well-known member
Springy Scale Retracts still working good, the aircraft has great ground handling.
I made a couple of adjustments to the landing gear default settings, set front gear to 300% stiffness, set main gear to 20% stiffness and changed rubber tires to pneumatic tires, (just my crazy settings) although the defaults work okay.
You must be very proud of the T-28 Trojan it is an incredible model.
Thank you for sharing it.
Thanks for the info and yeah I'm definitely happy with the way the T-28 is turning out. When I lowered the front gear stiffness the gear started sinking into the runway and at 0% it sunk enough into the runway the prop would strike it and the engine would die, but I didn't try 20% just 0% to see what it would do.
 

Bill Stuntz

Member
That sounds weird! How can softer gear cause it to sink into the runway??? Is the gear leg (limp spaghetti?) collapsing, or is it the tire that sinks into the runway?
 
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technoid

Well-known member
That sounds weird! How can softer gear cause it to sink into the runway??? Is the gear leg (limp spaghetti?) collapsing, or is it the tire that sinks into the runway?
Springy gear makes the gear compress so I think the bottom part compressed enough to make the prop strike. But I didn't look super close.
 

asj5547

Well-known member
That sounds weird! How can softer gear cause it to sink into the runway??? Is the gear leg (limp spaghetti?) collapsing, or is it the tire that sinks into the runway?
"stiffness " setting relates to spring compression, low setting will allow the landing gear spring to become very "soft" and lower the aircraft ground ride height, an increased stiffness setting will result in a very strong spring on the landing gear, acting more like a rigid construction.
You can get away with soft settings on the mains (trike gear) and firmer on front gear, too soft on front will allow the nose to dip on harsh landing or hard braking, causing the prop to touch the ground and kill the engine.
 
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