thom25

Sorry,
Yes I did build the model, I did the covering. I don't own any ARF's. I currently have ten planes that I built flyable, like an Aeromaster, a Simla, Bel Air .60 bipe, Robin Hood .25, Big Lazy Bee, Bristol M1, P.47, Brewster Buffalo, Something Extra, Stuka. I am working on a Faiery Fantome.
Regarding the Spring Air retracts: I purchased them in 1980 for a Royal FW-190 that I have yet to build. There is no model number on them. They measure 3 5/16" x 1 1/8" x 1 1/2" with anodized gold frames, using 3/16" coiled struts that I bent up. The struts put the wheels as shown on the US60 plans.
I hope that helps. BTW what Brotherhood number would I be?
Thom

rickbrad

My Feedback: (30)

Thom,

Someone will grab the next number and republish the list, or you can just read the thread backwards until you reach the most recent list and put the number in your signature, etc..

rglgatortail

My Feedback: (7)

Thanks Thom I appreciate your info. Yeah go back to the last post I made and look for the last number issued and put the next number in your signature and I will then update the list and dont forget to message me that you got that number so I dont miss it like I have done before.

KaP2011

My Feedback: (17)

The most recent list is one page back and the next in line is 138

thom25

Robert,
Thanks I am in.
Ultra Sport Brotherhood #138

rglgatortail

My Feedback: (7)

Your in thom25.

1. Ken Isaac - RCKen
2. Mike Buzzeo - Minnflyer
3. Alex7403
4. Dash008
5. AH1G
6. tschuy
7. MILDBILL-RCU
8. Box car
9. Top Gunn
10. SeaJay
11. Crash Campbell
12. SKYHI1
13. ChuckW
14. RhyanO
15. landeck
16. Ilikebipes
17. airbusdrvr
18. Insanemoondoggie
19. daisy shoot
20. prgonzalez
21. BelAirBob
22. hrrcflyer
23. rastus1
24. tony0707
25. *JCB*
26. Redback
27. bigugly
28. MetallicaJunkie
29. Gordie M
30. Jim_Purcha
31. rcsws
32. jeffsend
33. fireman7875
34. 72
35. ser00
36. Oly
37. cpeisher
38. donzhere
39. SKYHI1
40. kbarko
41. pgilbert
42. rambler53
43. rcjets_63
44. dschroeder
45. Quikturn
46. blueapplepaste
47. green river rc
48. SushiSeeker
49. VCScott
50. FallDownGoBoom
51. ccp10
52. Deadeye
53. Eganwp
54. carlosponti
55. Navy18
56. MineBurg
57. Cdallas2
58. loopyrc
59. Sled
60. Bernard
61. jrbmoto
62. Bubba153
63. Alfredbmor
64. FentonFlyer
65. Sneakywrist
66. BLW
67. smkrcflyer
68. gabarber
69. Amishwarlord
70. JPMacG
71. kamakazie frank
72. RussianFlyer
73. RoyR
74. Red Jeepster
75. Fallingleaf
76. Yukonflier
77. rcjim000
78. goonybird1
79. rglgatortail
80. Latebreaker
81. Tango juliet
82. Saito18
83. hafidy
84. RR24
85. mechdrew
86. siko_flyer
87. Kit
88. n7188u
89. gerryndennis
90. JNorton
91. misterv
92. Mustangman40
93. OntAeronut
94. proptop
95. scottrc
96. scirocco14
97. pt19 flyer
98. Doug47
99. b.bixel
100! bikerbc
101. weezle
102. Mtthwacrss
103. matadco
104. rickbrad
105. GaryHarris
106. Roary m
107. P47Tbolt
108. jp boud
109. arrdee
110. KaP2011
111. HFrank
112. custombuiltrc
113. jquid
114. dasquirrelisme
115. KC10Chief
116. _Tommy D
117. Do328jet
118. sirzepp
119. mrshea
120. AJsToyz
121. svenska3
122. I FLY
123. turnscrew
124. SteveW
125. Super08
126. ma_mulcahy
127. digital_trucker
128. ARTP47
129. us020140
130. Profiled
131. kgibson4
132. r/coldie
133. Tubthumper
134. JH313
135. TWIN FLYER
136. Fliegerboy
137. Doug Robinson
138. thom25

Yak13

My Feedback: (17)

I think I can be a member now. I got a US40 in a trade. Liked is so much I got an old US1000.
The 40 has an OS 40 w pipe & retracts. It is zooming at almost 100mph!
The 1000 I fitted with a Magnum 180 four stroke. Still needs some tuning as it flies much slower than the little 40.

COUNT ME IN

Ed

jrf

My Feedback: (551)

Yak13:

Be aware that large airplanes appear to be flying slower than they actually are. With a clean airplane like the US1000, your airspeed in level flight will be just a couple of mph faster than static rpm times prop pitch. (Divided by 1000) So if your 180 will turn a 10 pitch prop at 9000 rpm on the ground, your US1000 will be doing a bit over 90 in the air.

But speed is not everything. The higher pitch prop you use, the longer your takeoff runs will be and the weaker your vertical pull. I have found that a top speed of 75 - 80 mph is a compromise that gives you good speed and still allows BIG loops and high stall turns.

Jim

Zor

Hi Jim,

Let me see what I can reason out of your statement.
Let us assume that "doing a bit over 90 in the air" is 92 mph.

Let us convert 92 mph to inches ___we have 92 x 5280 (feet per mile) x 12 (inches per foot) = 5,829,120 inches per hour.

That means 5,829,120 dvide by 60 minutes in an hour gives us 97,152 inches per minute.

At 9,000 rpm each rpm would correspond to a forward movement of 10.79 inches.

The way I see that is the propeller is pulling the model at 92 mph with a negative angle of attack of the prop blades.

Now I can believe in miracles or I do not know simple maths.

Zor

jrf

My Feedback: (551)

Zor:

I am neither a scientist nor a mathematician, but I can assure you that "rule of thumb" is very close to reality. The answers it provides match several published nemonics and have been verified by myself and others many times by radar gun.

Perhaps the math is not as simple as you assume. You might want to consider the fact that the prop will unload in the air.

Jim

landeck

My Feedback: (1)

Zor, remember that the prop unwinds in the air, i.e. RPM increases. The increase in RPM can be anywhere from 500 to 1,500 or more RPM. The resulting RPM will be more than what a straight pitch/RPM needed for 92 MPH because of inefficiencies in the prop.

Zor

Hi Jim,

Yes I know that a prop unloads in the air but I do not know by how many rpm and even that will vary with the speed.

You no doubt noticed I used 92 because you had written "a coupleof mph faster".

I made the calculations just for the fun of figuring things out .

Props diameters and pitch are selected to load the engine to its constant rated horsepower and result in its best (highest) thrust to torque ratio. That determines the angle of attack for a fixed pitch prop.

In different words ___With a specific engine capable of delivering a maximum constant horsepower installed on a specific airplane the resulting cruising speed should result with an angle of attack of the prop blades that has the best thrust and a minimum torque requirement.

It is sometime referred to as the prop having best efficiency.

I am just trying to explain my understanding.

I can see things better in my mind than I can convert it into written text.

Zor

Zor

Yes landeck,

It would be interesting to have some postings from fellows with telemetry and an rpm feedback.

Zor

landeck

My Feedback: (1)

Zor, I agree.

Bruce

Gordie M

Hey Guys,

Back into the brotherhood with my new US60 / OS75AX all finished as per pics below. Sorry about the photo quality, I just used my phone camera

Cheers

Gordie

box car

Very nice, thats a real good looking plane, good job.

landeck

My Feedback: (1)

Very good looking plane. What prop are you using with the OS 75 AX?

Bruce

KaP2011

My Feedback: (17)

What is your AUW and how does it fly with the .75? It looks really good.

Mine is very near completion but I keep setting it aside because I can't decide on an engine. This week I'm leaning toward a Saito 1.00. I have went from an OS .75AX to an OS .95AX to an OS FS95 to a Super Tigre G90. I just can't decide. I want to have very good verticle. I would like to have a 1 to 1 power ratio, or maybe a little more. I traded the Super Tigre off so it's out of the picture. I already have the Saito 1.00, but I'm going to buy a new engine before the end of Sept. (even if I don't need it)so I have to decide soon.

What are the suggestions from the gallery?

Twin_Flyer

My Feedback: (4)

looks amazing Gordie!

I think Im pretty good with monocoat, but always have a problem comming up with a scheme.

Yours is amazing!

Bill S.

hrrcflyer

Hello Gordie,

I have to agree with Twin Flier. That is one of the best looking Ultrasport's I've seen........

David

VCScott

Nice!!!

thom25

Hi KaP2011 ,
I have an US60.(See post #1819 and 1822) I am running an OS .75AX with an APC 14X8 prop, Omega 15%. Lots of speed and vertical. Try it you will like it.
Thom

Gordie M

Thanks for the nice comments guys!

AUW is around 8lbs. Based on my previous US with same engine I anticipated nose heavy, so moved the servos back a bit during the build, bought a macs muffler and planned a wood prop. Wouldn't you know it, tail heavy in that configuration!!! So back to stock muffler and APC prop - it balanced perfectly. I know I could strip 5ozs out by moving the battery forward and going back to macs + wood prop. It's also over-servoed with high torque digi's at 2.2oz each, so there is 2+ozs weight saving there if you use more appropreiate sized servos.

Mods are fully sheeted wings + twin aileron servos mountedunder hatches in each wing.

Prop: 13x6 or 13x7. I tried the 14 inch props on the previous US / 75AX. Personally I think thats too much prop for the 75AX and causes a vibration in the mid range.. The US is not overly fast in level flight with a 13x6 but the thick wing doesn't help straight line speed anyway. Vertical isout of sight upon the other hand....

Covering is Ultracote: Orange (its a bit see-thru) + Pearl White (really hard to use - almost as bad as Silver) + Carbon fibre black + Silver and Pearl Blue stripes.

Will take some more pics using a good camera the carbon fibre black looks really cool close up

Cheers,

Gordie

KaP2011

My Feedback: (17)

Thanks for the info Gordie. I expect mine will come in close to that weight as well as I've done all the Minnflyer mods. plus adding eflite retracts. I've got an Extra 300 that weights 7.5# with a Tower .75 on it and I'm not too impressed with the Tower engine just yet. I believe it is just getting to the fully broken in stage so it may get better.

If anyone could educate me on how to figure the power to weight ratio I would be greatfull.

Zor

Divide the weight into the power.

Examples ___

Power 1 HP
Weight 1 lb
Ratio is 1 HP per lb.

Power 3 HP
Weight 8 lbs
Ratio 3 divide by 8 is 0.375 which is 3/8 of a horse power per pound of weight.

Zor