U Can Do 3D
06-07-2003 | 04:46 AM
#1176
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From: Morgantown,
WV
U Can Do 3D
As seanychen mentioned most people seem to go with the 91FX for 2 stroke power. Others have used the ST90(as you can see in Dave McDonald's video). I've even heard that some people were able to fit an OS 1.08 on a UCD.
Other than that I don't hear much about big 2 strokes in UCD's. Mostly Saito 100's, YS 91, Mag 91, and TT91 4 strokes.
Other than that I don't hear much about big 2 strokes in UCD's. Mostly Saito 100's, YS 91, Mag 91, and TT91 4 strokes.
Originally posted by obi1
Thanks Coolmarlin , but being cost conscious , what 2s (if any ) would give me full 3d capability
Thanks Coolmarlin , but being cost conscious , what 2s (if any ) would give me full 3d capability
06-07-2003 | 05:53 AM
#1177
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Originally posted by Dave McDonald
It's not much, but here's a video of my UCD powered by a ST 90 with MCP, APC 15x4w.. (10 meg so allow enough time to load)
http://www.eldonmo.com/video/ucando1.htm
It's not much, but here's a video of my UCD powered by a ST 90 with MCP, APC 15x4w.. (10 meg so allow enough time to load)
http://www.eldonmo.com/video/ucando1.htm
06-07-2003 | 11:43 AM
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From: Edison, NJ
U Can Do 3D
Originally posted by Jack Lewis
I'm about to mount my Saito 100 in my UCD and noticed there is no built-in right thrust. Has anyone noticed if any right thrust is needed and how much?
I'm about to mount my Saito 100 in my UCD and noticed there is no built-in right thrust. Has anyone noticed if any right thrust is needed and how much?
The instruction manual notes that the center line is offset to the left side to accommodate for right thrust. There should also be 2 degrees of right thrust built into the firewall but on my model the thrust line was dead center and the firewall mounted square. To fix this I put 2 washers behind the motor mount on the left side and shifted visually the motor mount to allow the motor to exit through the center of the cowl. The pictures above show this in detail.
http://www.rcuniverse.com/reviews.ph...ew&reviewid=44
06-07-2003 | 03:06 PM
#1179
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From: Milan, Tennessee
Darn
Mostly Saito 100's, YS 91, Mag 91, and TT91 4 strokes.
I've got a OS 91 Surpass (pumped) that I was going to use cause It was just sitting around. Now I'm confused
06-07-2003 | 03:25 PM
#1180
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rajul,
IMHO, the sound level on the video doesn't accurately capture the sound of the ST 90 w/MCP. The video has a loud drumming sound that's hardly noticable in real life.
The other plane you're hearing (and sometimes seeing) is my nephew's UCD, which is powered by a TT Pro 61. His UCD is fairly quiet, but the camera makes it sound like he's got a DA-150 in there.
IMHO, the sound level on the video doesn't accurately capture the sound of the ST 90 w/MCP. The video has a loud drumming sound that's hardly noticable in real life.
The other plane you're hearing (and sometimes seeing) is my nephew's UCD, which is powered by a TT Pro 61. His UCD is fairly quiet, but the camera makes it sound like he's got a DA-150 in there.
06-07-2003 | 03:49 PM
#1182
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U Can Do 3D
rajul,
I only did the flying. Crash99 owns and operated the video camera, then created and posted the videos of my UCD.
The next time I see Crash99, I'll mention the unrealistic sound in the video. Maybe the audio can be adjusted in the video editing program, but I really don't know since I've never messed with creating videos on my PC.
I only did the flying. Crash99 owns and operated the video camera, then created and posted the videos of my UCD.
The next time I see Crash99, I'll mention the unrealistic sound in the video. Maybe the audio can be adjusted in the video editing program, but I really don't know since I've never messed with creating videos on my PC.
06-07-2003 | 04:15 PM
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From: Rockport, TX
U Can Do 3D
The instruction manual notes that the center line is offset to the left side to accommodate for right thrust. There should also be 2 degrees of right thrust built into the firewall but on my model the thrust line was dead center and the firewall mounted square. To fix this I put 2 washers behind the motor mount on the left side and shifted visually the motor mount to allow the motor to exit through the center of the cowl. The pictures above show this in detail.
Thanks for the info! I measured my firewall and it is also square to the sides of the fuselage and the engine mount lines on the firewall were aslo dead center, not offset to the side.
06-08-2003 | 11:17 PM
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From: Rockport, TX
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I e-mailed Great Planes about the discrepency between the manual showing the engine mounted with right-thrust and the actual firewall not having any right-thrust built into it. Here is the reply I recieved:
Thank you for your recent email.
In response to your question regarding right-thrust on the U-Can-Do, there should be no right-thrust .
Thank you for your recent email.
In response to your question regarding right-thrust on the U-Can-Do, there should be no right-thrust .
06-09-2003 | 12:48 AM
#1187
U Can Do 3D
I had to add right thrust to mine. Like someone else said, two small washers or one large fender type washer should do it about right, depending on engine and prop combo.
Adding right thrust made a huge difference on mine (verticals and hovering especially, as you'd expect.)
JS
Adding right thrust made a huge difference on mine (verticals and hovering especially, as you'd expect.)
JS
06-09-2003 | 06:29 PM
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From: Edison, NJ
Did it help?
Originally posted by stevezero
Waterfall= outside loop within a fuselength, rotating around the trailing edge of the wing. Fast servos help, but you need servo torque, and alot of servo throw. The farther back the CG, the easier to waterfall and spin with.
I didnt beef up my firewall, but i did glue as much as i could.
I put tail wires made out of .047 wire with soldered ring connectors. I needed the tailweight anyway, might as well make it functional. I drilled and tapped thru the vertical fin, and the outer trailing edge of the stab(thru the ca hinge), and ran 1 inch pieces of 4/40 threaded rod thru. Some aluminum washers, and aluminum nuts with a drop of loctite to hold them in place. On the bottom of the fuse, I mounted the lower wires to the rear servo mount screws on my rudder servo. I put the rudder servo under the fuse to run pull-pull.
If needed, Ill do the same to the leading edge of the stab, but I dont think that would be necessary.
Dont have a soft mount, but may put some rubber washers between the firewall and mount, to give me the right thrust and some vibration damping.
I'm not running a Saito, and am using 15% nitro.
Stock wheels should suffice, even turnin a 16 inch prop, youll have plenty of clearance. If you fly off of grass, or are really weight conscious, dont install the wheelpants. They add 3-4 oz of weight.
I ran my antenna inside the fuse, and dumped it out at the rear of the fuse. I am going to do a serious range test to check for interference before going up, and will relocate it to the top if needed.
Heres a pic of the tail. Notice the rudder servo, pull pulls, large arms, sealed hingelines, sullivan tailwheel, and the tail wires.
Waterfall= outside loop within a fuselength, rotating around the trailing edge of the wing. Fast servos help, but you need servo torque, and alot of servo throw. The farther back the CG, the easier to waterfall and spin with.
I didnt beef up my firewall, but i did glue as much as i could.
I put tail wires made out of .047 wire with soldered ring connectors. I needed the tailweight anyway, might as well make it functional. I drilled and tapped thru the vertical fin, and the outer trailing edge of the stab(thru the ca hinge), and ran 1 inch pieces of 4/40 threaded rod thru. Some aluminum washers, and aluminum nuts with a drop of loctite to hold them in place. On the bottom of the fuse, I mounted the lower wires to the rear servo mount screws on my rudder servo. I put the rudder servo under the fuse to run pull-pull.
If needed, Ill do the same to the leading edge of the stab, but I dont think that would be necessary.
Dont have a soft mount, but may put some rubber washers between the firewall and mount, to give me the right thrust and some vibration damping.
I'm not running a Saito, and am using 15% nitro.
Stock wheels should suffice, even turnin a 16 inch prop, youll have plenty of clearance. If you fly off of grass, or are really weight conscious, dont install the wheelpants. They add 3-4 oz of weight.
I ran my antenna inside the fuse, and dumped it out at the rear of the fuse. I am going to do a serious range test to check for interference before going up, and will relocate it to the top if needed.
Heres a pic of the tail. Notice the rudder servo, pull pulls, large arms, sealed hingelines, sullivan tailwheel, and the tail wires.
06-09-2003 | 08:03 PM
#1189
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ZG77_OzZ, I agree with all of it. I don't feel the need for the wires on the tail but when you need the weight, make it functional as he said. I don't recall how his rudder servo was but mine is mounted on bottom of fuse with pull-pull. I prefer that over stock setup. I'm real happy with the Sullivan tailwheel as well. I have not strengthened firewall or gear mount as yet. I figure I'll wait till it has a problem. I have watched two UCD's tear out gear on mildly rough landings.
Later,,,basmntdweller
Later,,,basmntdweller
06-09-2003 | 08:24 PM
#1190
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From: Greensboro, NC
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I would definately recommend the tail wires. Keeps everything stiff. I also like the location of the pull pull, keeps the rudder nice and tight as well, and does centralize a small amount of weight.
I am running a saito now (a 1.50 even), and I'm turning a 17 inch prop on it, and still have plenty of prop clearance. I would definately recommend threadlockin everything on the plane, including the servo horn screws (on metal output shaft servos). I had an aileron horn come off after a blender, but was able to land without incident.
I am running a saito now (a 1.50 even
), and I'm turning a 17 inch prop on it, and still have plenty of prop clearance. I would definately recommend threadlockin everything on the plane, including the servo horn screws (on metal output shaft servos). I had an aileron horn come off after a blender, but was able to land without incident.
06-10-2003 | 12:06 PM
#1193
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From: Edison, NJ
What do you all think about
The du-bro engine mount that get rid of vibration?
Du-Bro RC Motor Mount for 1.20 to 1.50 4-Stroke Eng.& 1.20 to 1.80 2-Cycle Engines (QTY/PKG: 1 Set )
Du-Bro's patented designed Motor Mounts are very effective in reducing airframe vibration and greatly reduce fatigue on the entire airframe. They are a totally captive mount that cannot debond and break free.
Du-Bro RC Motor Mount for 1.20 to 1.50 4-Stroke Eng.& 1.20 to 1.80 2-Cycle Engines (QTY/PKG: 1 Set )
Du-Bro's patented designed Motor Mounts are very effective in reducing airframe vibration and greatly reduce fatigue on the entire airframe. They are a totally captive mount that cannot debond and break free.
06-10-2003 | 12:40 PM
#1194
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From: Greensboro, NC
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Too much weight on the dubro mount. There are better systems that can be done much cheaper.
What were you looking for part numbers for? The tail wires I made out of stuff I had on hand (music wire, radio shack solder ring connectors, and a piece of 4/40 threaded rod/ washers/nuts). The pull pull system was made from fishing tackle supplies (60 lb nylon coated stainless steel fishing leader, the proper size crimps), and some dubro threaded links for pull/pull. I looped directly through the servo horn and crimped, and looped through the threaded links.
If you want to soft mount an engine, try the mount they have listed at www.piedmontmodels.com. It uses neoprene well nuts and a dave brown 120fs mount. We used a mount similar to that on my dr jeckyll pattern plane, and it really cuts down on the vibration. Cool thing is, if you change engines, you can just swap out the DB mount. I didnt want to go through all the hassle on the ucd, so I went with the stock mount.
What were you looking for part numbers for? The tail wires I made out of stuff I had on hand (music wire, radio shack solder ring connectors, and a piece of 4/40 threaded rod/ washers/nuts). The pull pull system was made from fishing tackle supplies (60 lb nylon coated stainless steel fishing leader, the proper size crimps), and some dubro threaded links for pull/pull. I looped directly through the servo horn and crimped, and looped through the threaded links.
If you want to soft mount an engine, try the mount they have listed at www.piedmontmodels.com. It uses neoprene well nuts and a dave brown 120fs mount. We used a mount similar to that on my dr jeckyll pattern plane, and it really cuts down on the vibration. Cool thing is, if you change engines, you can just swap out the DB mount. I didnt want to go through all the hassle on the ucd, so I went with the stock mount.
06-10-2003 | 04:04 PM
#1196
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From: Edison, NJ
120 bucks wow
What else is out there?http://www.piedmontmodels.com./hydemount.htm
Sorry I guess I forgot to put up the link..
Sorry I guess I forgot to put up the link..
06-10-2003 | 06:20 PM
#1197
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From: Greensboro, NC
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OK I think you just lost me. I'm not sure where you got the 120 bucks. I made my mount for about $8.00 worth of material, including the dave brown mount. The neoprene well nuts are a bit difficult to track down (my neighbor who helped with the mount had some in his shop) I didnt use the fuel tubing as in the piedmont mount, just have the well nuts in 1/4" holes, and a 10/32 hex head nut to hold the mount to the nuts. Washers are added as necessary for right/down thrust. 4 6/32's to hold the engine to the mount. I'll try to snap a pic of the mount on my pattern plane to show you how its done (since the engine is out of it). It is much simpler than it sounds.
06-11-2003 | 12:13 AM
#1198
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Originally posted by coomarlin
I've run into another potential snag. I bought some Dubro dafety lock clevis for the control horn end of my linkages and some Dubro Ball links for the servo end. When I got home I realize that only 1 end of my sullivan 4-40 pushrods were threaded. Both the clevis and ball link are self tapping.
I've run into another potential snag. I bought some Dubro dafety lock clevis for the control horn end of my linkages and some Dubro Ball links for the servo end. When I got home I realize that only 1 end of my sullivan 4-40 pushrods were threaded. Both the clevis and ball link are self tapping.
