WACO YMF
RE: WACO YMF
WacoDream,not sure about all the different sizes you get quoted when ordering these small screws and bolts that we use but I do know that what I used are called 1 gauge, 0 gauge only came in slot head and 2 gauge looked a little large.
tmac.
tmac.
RE: WACO YMF
Nut, your model must have a higher stance than mine,I think a 34 inch prop would have ground clearance problems. ( I'm running a DA 150.)
tmac.
tmac.
RE: WACO YMF
When she is up on her mains on a take-off run the prop is just above the grass.
I will not buy another 34" prop as the ground clearance is close. My next prop will be a 32x12 Xoar. The 34x10 prop on there does look good and it is like putting the brakes on when you chop the throttle. It did take a bit of the top end speed off but I really like the sound of the blade tips ripping the air when you pour the throttle to it. We do not have to worry about noise where we fly.
Later!!
Anthony
I will not buy another 34" prop as the ground clearance is close. My next prop will be a 32x12 Xoar. The 34x10 prop on there does look good and it is like putting the brakes on when you chop the throttle. It did take a bit of the top end speed off but I really like the sound of the blade tips ripping the air when you pour the throttle to it. We do not have to worry about noise where we fly.
Later!!
Anthony
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RE: WACO YMF
Bill, Mike, Tmac,
first of all Happy Birthday to you I hope it is still ok even it is some days late.
I have checked the photos of the Waco and Bill you are right the airfoil does not steepen on the upper side but comes up from the lower side. We are going to change this, but it will take some time to change the parts as it is not only the upper center wing to change but also the root ribs of the outer wing panels have to be altered and test built before first delivery. If you don't tell judges will not realize this. I didn't know this since now and all judges I had to show my Wacos did not find out. It depends of course what you are going to show them. From the three or five view dwgs. you will not find out only from photographs which directly show the upper wing section. Even on your photo, bill one had to enlarge it to really see the how the airfoil of the center wing is shaped.
Tmac nice model. I will try to simulate the metal sheets on my next Waco with ABS plastic. I wonder if this is lighter in weight than Alu.
Peter Waco Brotherhood #170
first of all Happy Birthday to you I hope it is still ok even it is some days late.
I have checked the photos of the Waco and Bill you are right the airfoil does not steepen on the upper side but comes up from the lower side. We are going to change this, but it will take some time to change the parts as it is not only the upper center wing to change but also the root ribs of the outer wing panels have to be altered and test built before first delivery. If you don't tell judges will not realize this. I didn't know this since now and all judges I had to show my Wacos did not find out. It depends of course what you are going to show them. From the three or five view dwgs. you will not find out only from photographs which directly show the upper wing section. Even on your photo, bill one had to enlarge it to really see the how the airfoil of the center wing is shaped.
Tmac nice model. I will try to simulate the metal sheets on my next Waco with ABS plastic. I wonder if this is lighter in weight than Alu.
Peter Waco Brotherhood #170
RE: WACO YMF
FMBB, If you are going to add the panels to your kit when you make the change to the center wing profile, you might look at adding the aerodynamic balancer to the rudder so as to represent the latter model ymf3 and the current Super.
tmac.
tmac.
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RE: WACO YMF
Barth 1/3 YMF
Tmac,
Your tip on Tnuts worked fine. Don't know which version kit you have, but I noticed the 1/2 sq (approx) stringer running along bottom from firewall back goes right through the landing gear spring support pin. Did you whack off the stringer and frame around it on both sides of pin?
Thanks,
Mike Hopkins
Waco Brotherhood # 132
Tmac,
Your tip on Tnuts worked fine. Don't know which version kit you have, but I noticed the 1/2 sq (approx) stringer running along bottom from firewall back goes right through the landing gear spring support pin. Did you whack off the stringer and frame around it on both sides of pin?
Thanks,
Mike Hopkins
Waco Brotherhood # 132
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RE: WACO YMF
ORIGINAL: hopkimf
Barth 1/3 YMF
Tmac,
Your tip on Tnuts worked fine. Don't know which version kit you have, but I noticed the 1/2 sq (approx) stringer running along bottom from firewall back goes right through the landing gear spring support pin. Did you whack off the stringer and frame around it on both sides of pin?
Thanks,
Mike Hopkins
Waco Brotherhood # 132
Barth 1/3 YMF
Tmac,
Your tip on Tnuts worked fine. Don't know which version kit you have, but I noticed the 1/2 sq (approx) stringer running along bottom from firewall back goes right through the landing gear spring support pin. Did you whack off the stringer and frame around it on both sides of pin?
Thanks,
Mike Hopkins
Waco Brotherhood # 132
RE: WACO YMF
hopkimf I did not like the sprung undercarriage with the fairing being attached to the fuselage. I saw a full scale big radial pits with a solid undercarriage so I thought why not on a model? I cut the spreader wire at the fuselage attachment point, silversolderd ends on them and attached them to the fuselage as per the full scale. I will post a couple of photos and you may be able to see what I am getting at. This is a solid mount with out any spring in the center.
tmac
tmac
RE: WACO YMF
ORIGINAL: tmac48
hopkimf I did not like the sprung undercarriage with the fairing being attached to the fuselage. I saw a full scale big radial pits with a solid undercarriage so I thought why not on a model? I cut the spreader wire at the fuselage attachment point, silversolderd ends on them and attached them to the fuselage as per the full scale. I will post a couple of photos and you may be able to see what I am getting at. This is a solid mount with out any spring in the center.
tmac
hopkimf I did not like the sprung undercarriage with the fairing being attached to the fuselage. I saw a full scale big radial pits with a solid undercarriage so I thought why not on a model? I cut the spreader wire at the fuselage attachment point, silversolderd ends on them and attached them to the fuselage as per the full scale. I will post a couple of photos and you may be able to see what I am getting at. This is a solid mount with out any spring in the center.
tmac
Banned
RE: WACO YMF
tmac48
I sure hope you got REAL squishy wheels. I think the full size wheels were spring hung inside the spats, so that they could give a little, but I cannot prove it.
Les
I sure hope you got REAL squishy wheels. I think the full size wheels were spring hung inside the spats, so that they could give a little, but I cannot prove it.
Les
RE: WACO YMF
Guys you didn't read my post correctly. I did not say that the Waco had solid suspension, that was a full scale big pits with a radial engine from a DC 3. I have flown a 33% comp arf Yak with solid suspension, my flying buddy has 40% Yak and 40% pits all with solid suspension, I'am sure that I will not have any problems with the Waco,we will soon find out when I get this thing finished.
tmac.
tmac.
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RE: WACO YMF
Tmac,
I understand. From your pictures I see you have the later kit with more scale like fairings. The limit of gear spread on landing must be the point where the spring hits its solid length. Calculate the force to flatten the spring. Is a reasonable load the plane could cause on landing? If so you could work back to calculate the angular movement of gear legs, etc. I know, it sounds like I'm going off the deep end. The full scale Waco looks to have the fairing rigid to fuse. There must be some means to keep it from flexing. Maybe it's fixed at top and just guided at wheel pants?
I'm not a big fan of making it rigid. It's going to be real stiff. The full scale Cessna I fly has a solid steel bar for the mains, but it is a single bar and it deflects under load.
Maybe someone else with the same issue will chime in here.
Regards,
Mike Hopkins
Waco Brotherhood # 132
I understand. From your pictures I see you have the later kit with more scale like fairings. The limit of gear spread on landing must be the point where the spring hits its solid length. Calculate the force to flatten the spring. Is a reasonable load the plane could cause on landing? If so you could work back to calculate the angular movement of gear legs, etc. I know, it sounds like I'm going off the deep end. The full scale Waco looks to have the fairing rigid to fuse. There must be some means to keep it from flexing. Maybe it's fixed at top and just guided at wheel pants?
I'm not a big fan of making it rigid. It's going to be real stiff. The full scale Cessna I fly has a solid steel bar for the mains, but it is a single bar and it deflects under load.
Maybe someone else with the same issue will chime in here.
Regards,
Mike Hopkins
Waco Brotherhood # 132
Banned
RE: WACO YMF
OK. IF this thing uploaded, this is what I found.
Les
Son of a gun. It worked. If you look closely at the left spat, you can see the vertical reliefs where the axle can move up and down.
Les
Les
Son of a gun. It worked. If you look closely at the left spat, you can see the vertical reliefs where the axle can move up and down.
Les
Banned
RE: WACO YMF
RE: WACO YMF
hopkimf, please do not let me determine how you set up the suspension, Peter Barth would know better than me it is just that I do not like it. There's more to consider than what you may think,please consider a landing with more weight on one wheel, the way the spring now works lets all the travel to be transferred to on one leg and I do not believe that you can allow for that amount of movement on the fairings. Yes the full size Waco has oleo struts and I did make an attempt at making them , you can also purchase them but they run into about 700$
tmac
tmac
RE: WACO YMF
Les,
If you are talking about the 2 narrow dark strips (there are 6 total around the fairing, 3 on the inside and 3 on the outside) on the leg they are stainless steel wear strips to keep the fairing and pant from wearing on each other. There are not any relief slots, just relief cut outs to allow the secondary struts to attach, the inner strut is bolted to the upper main strut and only pivots at that point (and at the mid point on the fuselage). The main strut has an oleo in it that is splined internally to keep the wheel from twisting. The rear strut is also attached to the upper main strut and fuselage and only pivots as well. I think I know, I took the pictures of NC 14081 and have talked with the mechanics and other members of the American Waco Club that are restoring their Waco's.
P1 - Close up of the inside area
P2 - Close up of the outside
P3 - Main Struts from a YKS (right main on top, left main on bottom)
P4 - Attachment to YKS, slightly different arrangement but same principle, secondary struts are solid and only pivot at the attachment point.
If you are talking about the 2 narrow dark strips (there are 6 total around the fairing, 3 on the inside and 3 on the outside) on the leg they are stainless steel wear strips to keep the fairing and pant from wearing on each other. There are not any relief slots, just relief cut outs to allow the secondary struts to attach, the inner strut is bolted to the upper main strut and only pivots at that point (and at the mid point on the fuselage). The main strut has an oleo in it that is splined internally to keep the wheel from twisting. The rear strut is also attached to the upper main strut and fuselage and only pivots as well. I think I know, I took the pictures of NC 14081 and have talked with the mechanics and other members of the American Waco Club that are restoring their Waco's.
P1 - Close up of the inside area
P2 - Close up of the outside
P3 - Main Struts from a YKS (right main on top, left main on bottom)
P4 - Attachment to YKS, slightly different arrangement but same principle, secondary struts are solid and only pivot at the attachment point.
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RE: WACO YMF
ORIGINAL: tmac48
hopkimf, please do not let me determine how you set up the suspension, Peter Barth would know better than me it is just that I do not like it. There's more to consider than what you may think,please consider a landing with more weight on one wheel, the way the spring now works lets all the travel to be transferred to on one leg and I do not believe that you can allow for that amount of movement on the fairings. Yes the full size Waco has oleo struts and I did make an attempt at making them , you can also purchase them but they run into about 700$
tmac
hopkimf, please do not let me determine how you set up the suspension, Peter Barth would know better than me it is just that I do not like it. There's more to consider than what you may think,please consider a landing with more weight on one wheel, the way the spring now works lets all the travel to be transferred to on one leg and I do not believe that you can allow for that amount of movement on the fairings. Yes the full size Waco has oleo struts and I did make an attempt at making them , you can also purchase them but they run into about 700$
tmac
Don't worry, you won't determine how I set up the suspension. I realize one wheel landings happen often and impose greater load. If you create a free body diagram of the suspension, it's statically indeterminate as made. But if you replace the spring to bent wire connection with a pin, break the bent wire into two with pins at each end, you can solve it. Assume you land on left wheel. That force creates a moment in the axle leg that's resisted by the grooved wood blocks. The axle leg wants to deflect, but is resisted by the small wire which pulls the spring down, putting the small wire in tension. The spring is pulling up on its axis. Draw a sketch. Spring force up, wire force down along its axis. It looks like an upside down Y with one lower leg missing. You need another component to match the force of the one wire. That's the other wire pulling and trying to pull the other axle leg too. So it really doesn't all go to one side.
Regards,
Mike Hopkins
Waco Brotherhood #132
RE: WACO YMF
I think this will be the final front screen, a few more screws and it is done. Thought I would use stainless steel ties for the fuel lines but the are not very satisfactory so I will go back to making them from strips of alloy,anyway it was worth the try.
tmac.
tmac.
RE: WACO YMF
Peter, I have not tried to weigh the model yet, next time I have it all assembled I will try to get her on the scales,my guess is close to 25 kgs.
tmac.
tmac.
RE: WACO YMF
Peter I have just weighed the fuselage with center section and all radio gear except receiver and battery and it comes out at 17kgs. Would be interested in how that compares to your model minus the wings.
Regards tmac.
Regards tmac.