If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
Doodles...
"Richard Lamb" wrote in message
... But then there is the gas load (!) Wet wing between the spars (no clue how much gas that is, but that's all you get). If it will cruise at 80 shp and consumption is 1.3#/shp @ sea level, you get 17 gph. That's got to decrease a bunch at altitude, doesn't it? 50-60 gallons ought to do it. And yes, it backs up real well. At least on the ground. Pick it up by the tailwheel and drag it around like a little red wagon. You could paint "Beta mode" on the wagon, I guess. I was thinking of the geometry of reverse thrust on a full-swivel tailwheel. Talk about a ground loop! Rich "I *hate* the smell of kerosene in the morning" S. |
#12
|
|||
|
|||
Doodles...
"Rich S." wrote: snip\ I can't see any scale or measurements on your sketches. Maybe I need better glasses. Rich S. http://home.earthlink.net/~cavelamb/!L-ONE-A4-A.JPG there is a reference dimension under the fuselage = 48" and a little lower just above the frames is a foot/inch scale. that help? |
#13
|
|||
|
|||
It looks like a Midget Mustang. The MM-1 span is 18.5 ft 66 sq ft and 16.5 long and anywhere between 650-780 empty or more. If it can be built under 500lbs empty with a light engine VW or 912 it sould be bullet.
Jim Williams Quote:
|
#14
|
|||
|
|||
Doodles...
"Richard Lamb" wrote in message
... there is a reference dimension under the fuselage = 48" and a little lower just above the frames is a foot/inch scale. that help? Got it! Rich S. |
#15
|
|||
|
|||
Doodles...
"Rich S." wrote: "Richard Lamb" wrote in message ... there is a reference dimension under the fuselage = 48" and a little lower just above the frames is a foot/inch scale. that help? Got it! Rich S.. Great! Now, your assignment, should you choose to accept it, is to draw up a reeeeeaaaaaaly light weight retract system for it bg. Gear mounts on front side of the main spar (sorry, no tricycles) 5x5 wheels with MacGreary rubber, band brakes with cables? or hydraulic actuation. If need be (and it will), we'll rework the root using that 15% Ribblet airfoil (get all the buzz-words in!) or a 23012/15 (nil CP travel - important in such a tiny package) and add a P-51 style planform to provide room for the wheels. now we're too cool... Some other minor wing concerns: At stall speeds, the root chord still has an RN (Reynolds Number) of at least 3 million. But the tips, being shorter, show barely 2 million. So what does that imply? Well, for one, many of the fancy airfoils get pretty lame below three meg. Which might result in: Sloppy aileron control at low speeds at best? Or even a TIP stall - i,e: a nice fun wing drop at the break (or before???) Looking for an airfoil that performs well at these low RN led me to the old NACA 4 digit 2312. It is considered a turbulent airfoil, rather than a laminar type. But it ought to hold on a little better when slow. Which means that the rib patterns would be a pure-D beast to loft, were if not for a little CAD magic. The more ribs (assuming they fit right) and the thicker the skin the better we can hold the desired airfoil shape - but both mean _heavier_. The dreaded C word - (compromise), Oh golly, well, that at least scratches the surface.... |
#16
|
|||
|
|||
Doodles...
"Richard Lamb" wrote in message
... Now, your assignment, should you choose to accept it, is to draw up a reeeeeaaaaaaly light weight retract system for it bg. Moi? (In my best Miss Piggy voice). I'm a retarded firefighter - no engineer fer sure. The Emeraude uses the 23012 and I'll bet the Zephyr does as well. Add a bit of washout to soften the stall. I would 86 the idea of retracts and go with an RV-type gear off the engine mount. No spar reinforcement needed, you can keep the fuselage on the wheels when the wing(s) is/are removed, & other weight-saving advantages. JMHO Rich S. |
#17
|
|||
|
|||
Doodles...
"Rich S." wrote: "Richard Lamb" wrote in message ... Now, your assignment, should you choose to accept it, is to draw up a reeeeeaaaaaaly light weight retract system for it bg. Moi? (In my best Miss Piggy voice). I'm a retarded firefighter - no engineer fer sure. The Emeraude uses the 23012 and I'll bet the Zephyr does as well. Add a bit of washout to soften the stall. I would 86 the idea of retracts and go with an RV-type gear off the engine mount. No spar reinforcement needed, you can keep the fuselage on the wheels when the wing(s) is/are removed, & other weight-saving advantages. JMHO Rich S. Damn! But it worked for Huckleberry Finn! Oh well, the extended roots don't really fit anyway. The wing on the Zephyr looked long and narrow (higher aspect ratio due to a pretty short chord). I didn't download his plug-in to get a look at the rest of the stuff. 3 meg on a land line? Not today. But it is an interesting design. I've always rigged my parasol wings flat - no washout. The thing is so lightly loaded it doesn't really stall anyway. But I agree that this wing, with the tiny tip chords should probably have a bit of twist in it. Even if it does cost some top end speed. And you touched on one of the issues I still have with this one. Landing gear attached to the wings can be very inconvenient if a wing needs to be removed. So we start looking at a 3 piece wing. Center section and removable outer wing panels with the gear mounted on the center section. Sounds like a better idea. But consider how much that complicates the wing structure! (damned C word anyway!) We would need about a foot of center section sticking out from the fuselage for the gear mounts. (I don't want any of that in the cockpit area - in case of a gear failure. Don't want any failed structure coming into the cockpit (i.e.: pilot). ) So, while I agree that it would be a lot more convenient to have the plane on the gear when the wings are removed, I'm not sure that the extra weight and complication would be worth it on such a small ship. BTW, this is the one place where Bruce had problems too. His first try failed rather early (just widened the stance some). I know he fixed it, but haven't heard how well it's standing up (no pun intended). Lastly, unfortunately, RV style off the engine mount (which olde timers still call Wittman-style gear) won't work here because we don't have 1) room behind the engine, or 2) an engine mount! Yes, I have one sketched in. But more likely, for a VW engine, the engine mount is nothing more that 4 aluminum spacers just long enough to keep the flywheel and rear exhaust stacks to get clear of the firewall. Something I hear a long time ago, and have come to believe - "Better is the mortal enemy of good". Richard are we having fun yet? |
#18
|
|||
|
|||
Doodles...
Jim Williams wrote: It looks like a Midget Mustang. The MM-1 span is 18.5 ft 66 sq ft and 16.5 long and anywhere between 650-780 empty or more. If it can be built under 500lbs empty with a light engine VW or 912 it sould be bullet. Jim Williams Long was a true artist! And the MM-1 is his masterpiece. BTW, have you ever seen the original MM-1 gear arrangement? The legs are flat aluminum leaf type but the bolt to a weldiment that has a torque tube running thru the front spar back to the rear spar. The torque tube has two concentric tubes, welded together at the rear end - thus doubling the effective length. An interesting solution to a thorny problem... Richard |
#19
|
|||
|
|||
Richard,
What software did you use to design the aircraft? The aircraft looks pretty damn good. Jim Williams UOTE=Richard Lamb]Well, since you asked... this one is a 76 sq. ft wing which is not the exact right wing for this plane, but the worksheet was already done-so...what. No idea how the columns will hold up on the net, but ..... it's worth a try... The spar caps are 1-1/5" X 1/8" 6061 with 1-1/2" x 1/8" 6061 straps layered to the indicated (interpreted) thickness. Bruce bolted his spar, which produced a very straight spar assembly. Hammering big rivets into small structures will invariably induce some distortion. We are doing is a beam spar rather than a proper box, so the sheer web dimension should be doubled. And? No promise that any of this is close to correct... ================================================== ====================== X-Wing SPAR Build .58 R.Lamb 2001 Project Name L-One V Run time: 01-10-2006 at 10:43:10 Wing Span [ft] 17.00 Root Chord [ft] 5.00 Wing Area [sqft] 76.50 Tip Chord [ft] 4.00 Chord thickness [%] 12.00 Mean Chord [ft] 4.50 Gross Wgt [lb] 888.00 Aspect Ratio [#] 3.78 Lift (Vs) [lb] 888.00 Wing Loading [lb/sqft] 11.61 V(min) [mph] 59.04 Max CL [#] 1.30 Load Factor [G's] 4.00 Spar Width [inches] 1.50 Cap Compression [psi] 66,000 Shear Web [psi] 10,000 Thickness [% of Chord] 12 Sta W.STA. AIR LOAD SHEAR MOM FTLB num FT PPF LB FT.LB 1 0.000 232.000 1776.000 7268.000 2 0.850 236.000 1580.000 5842.000 3 1.700 241.000 1389.000 4580.000 4 2.550 246.000 1201.000 3479.000 5 3.400 250.000 1018.000 2536.000 6 4.250 255.000 838.000 1747.000 7 5.100 260.000 663.000 1109.000 8 5.950 264.000 491.000 618.000 9 6.800 269.000 323.000 272.000 10 7.650 273.000 159.000 67.000 11 8.500 278.000 0.000 -1.000 Spar weight parameters: Sta W.Sta. SPAR HGT CAP THK WEB THK num FT IN IN IN 1 0.000 5.760 0.306 0.031 2 0.850 5.645 0.251 0.028 3 1.700 5.530 0.201 0.025 4 2.550 5.414 0.156 0.022 5 3.400 5.299 0.116 0.019 6 4.250 5.184 0.082 0.016 7 5.100 5.069 0.053 0.013 8 5.950 4.954 0.030 0.010 9 6.800 4.838 0.014 0.007 10 7.650 4.723 0.003 0.003 11 8.500 4.608 -0.000 0.000 Shear web thickness is for a box type spar. For single web, double it. ================================================== ======================[/quote] |
#20
|
|||
|
|||
Richard,
What software did you use to design the aircraft? The aircraft looks pretty damn good. Jim Williams UOTE=Richard Lamb]Well, since you asked... this one is a 76 sq. ft wing which is not the exact right wing for this plane, but the worksheet was already done-so...what. No idea how the columns will hold up on the net, but ..... it's worth a try... The spar caps are 1-1/5" X 1/8" 6061 with 1-1/2" x 1/8" 6061 straps layered to the indicated (interpreted) thickness. Bruce bolted his spar, which produced a very straight spar assembly. Hammering big rivets into small structures will invariably induce some distortion. We are doing is a beam spar rather than a proper box, so the sheer web dimension should be doubled. And? No promise that any of this is close to correct... ================================================== ====================== X-Wing SPAR Build .58 R.Lamb 2001 Project Name L-One V Run time: 01-10-2006 at 10:43:10 Wing Span [ft] 17.00 Root Chord [ft] 5.00 Wing Area [sqft] 76.50 Tip Chord [ft] 4.00 Chord thickness [%] 12.00 Mean Chord [ft] 4.50 Gross Wgt [lb] 888.00 Aspect Ratio [#] 3.78 Lift (Vs) [lb] 888.00 Wing Loading [lb/sqft] 11.61 V(min) [mph] 59.04 Max CL [#] 1.30 Load Factor [G's] 4.00 Spar Width [inches] 1.50 Cap Compression [psi] 66,000 Shear Web [psi] 10,000 Thickness [% of Chord] 12 Sta W.STA. AIR LOAD SHEAR MOM FTLB num FT PPF LB FT.LB 1 0.000 232.000 1776.000 7268.000 2 0.850 236.000 1580.000 5842.000 3 1.700 241.000 1389.000 4580.000 4 2.550 246.000 1201.000 3479.000 5 3.400 250.000 1018.000 2536.000 6 4.250 255.000 838.000 1747.000 7 5.100 260.000 663.000 1109.000 8 5.950 264.000 491.000 618.000 9 6.800 269.000 323.000 272.000 10 7.650 273.000 159.000 67.000 11 8.500 278.000 0.000 -1.000 Spar weight parameters: Sta W.Sta. SPAR HGT CAP THK WEB THK num FT IN IN IN 1 0.000 5.760 0.306 0.031 2 0.850 5.645 0.251 0.028 3 1.700 5.530 0.201 0.025 4 2.550 5.414 0.156 0.022 5 3.400 5.299 0.116 0.019 6 4.250 5.184 0.082 0.016 7 5.100 5.069 0.053 0.013 8 5.950 4.954 0.030 0.010 9 6.800 4.838 0.014 0.007 10 7.650 4.723 0.003 0.003 11 8.500 4.608 -0.000 0.000 Shear web thickness is for a box type spar. For single web, double it. ================================================== ======================[/quote][/quote] |
Thread Tools | |
Display Modes | |
|
|