1/2A RC speed - such a popular pasttime
03-19-2014, 08:10 AM
#51
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- cut a parting plate to match the silhouette
- fixture plate flush with centerline of fuselage (plywood, modelling clay)
- fill gap between plate and fuselage
- wax whole assembly
- PVA
- layup first half
- remove parting plate
- touch up release coats if necessary
- lay up second half of mold
then..
- finally, make the bloody cowl
- maybe sometime in the future make another one, maybe not..
This is a silly amount of work for a one-off, but if the piped version ever materializes, or I get the .061 FIRE version of this engine, maybe another will need to be built. 2nd one ought to go a bit quicker..!
And it is good practice - I have lots of experience with adhesives and resins, but pretty much a beginner on patterns and molds. It requires patience, which is not my strongest point.
- fixture plate flush with centerline of fuselage (plywood, modelling clay)
- fill gap between plate and fuselage
- wax whole assembly
- PVA
- layup first half
- remove parting plate
- touch up release coats if necessary
- lay up second half of mold
then..
- finally, make the bloody cowl
- maybe sometime in the future make another one, maybe not..
This is a silly amount of work for a one-off, but if the piped version ever materializes, or I get the .061 FIRE version of this engine, maybe another will need to be built. 2nd one ought to go a bit quicker..!
And it is good practice - I have lots of experience with adhesives and resins, but pretty much a beginner on patterns and molds. It requires patience, which is not my strongest point.
03-19-2014, 10:02 AM
#52
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If this turns out fast and interesting enough, then I might be inspired to go ahead with scratch building a dedicated 1/2A speed model. But this guy isn't too far off what it needs to be, so other than the obsessive project the cowl turned into, it is a quick and easy project.
I don't have a feel for how much cleaner this might be than the 25" jobbie I built a couple of years ago for the .061, or CP's v-tail quickie, or other similar models. But I have to think it is by design/nature, so I am optimistic.
If I EVER get my laser behaving (almost there!! much progress..) then I can cut airfoil plywood or G10 root and tip templates for sanding SWR wings to real airfoil profiles. I figured out what I want to do also.. I will cut two for each end, with identical locating screw holes, but the first set will be maybe 25 thou oversize, because as I sand I will hit the template. So I'll rough it out with the first set, then finish with the second. We'll see, might not be a great idea.
I don't have a feel for how much cleaner this might be than the 25" jobbie I built a couple of years ago for the .061, or CP's v-tail quickie, or other similar models. But I have to think it is by design/nature, so I am optimistic.
If I EVER get my laser behaving (almost there!! much progress..) then I can cut airfoil plywood or G10 root and tip templates for sanding SWR wings to real airfoil profiles. I figured out what I want to do also.. I will cut two for each end, with identical locating screw holes, but the first set will be maybe 25 thou oversize, because as I sand I will hit the template. So I'll rough it out with the first set, then finish with the second. We'll see, might not be a great idea.
03-19-2014, 11:45 AM
#54
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It's a GWeike 300mm x 500mm 60w system. Entry level, but as far as Chinese lasers go they have a good reputation apart from the usual comments about documentation. The guy who was cutting my Demon kits before only used 50w and got the job done.
By rotating the Demon ribs at an angle, I was able to nest the entire 1/8" plywood part set onto one 300x500mm piece of 1/8" ply, and with efficient usage. Now if I could only cut one..
BTW I tried punching holes through Formica.. nah, need more power or it will take forever.
By rotating the Demon ribs at an angle, I was able to nest the entire 1/8" plywood part set onto one 300x500mm piece of 1/8" ply, and with efficient usage. Now if I could only cut one..
BTW I tried punching holes through Formica.. nah, need more power or it will take forever.
03-19-2014, 01:41 PM
#55
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You know what I think is funny? This project is really just a fun thing I am doing for kicks, it won't change my life or anyone else's, and I don't expect more than about three people to really give a crap. But it seems to me the least active threads on this forum are the threads that are actually about "extreme speed", rather than dropping a .61 in a .46 ARF and assuming a national speed record is in sight. But I guess "extreme" is from the point of view of the builder rather than the status quo, isn't it?
Admittedly this is definitely a niche segment of the sport, although who doesn't want to put pedal to the metal at some point..
Admittedly this is definitely a niche segment of the sport, although who doesn't want to put pedal to the metal at some point..
03-19-2014, 03:07 PM
#56
If you throw in the guys who race RC Pylon, then there is still quite a lot of interest in RC Speed.
The guys who REALLY feel like a dying pack of dynosaurs are the C/L Speedsters, C/L Carrier Event, and C/L Racers.
The C/L Combat guys sort of fall into the "Extreme Speed" category and they are still going strong on a global FAI level.
C/L Carrier is kind of silly to watch [my opinion] but it is also pretty awesome to see the demonstration between slow speed and high speed performance. Picture a .15 sized scale model Corsair with a Nelson .36 on 60 foot lines. The leadout position is somehow adjustable in-flight so that the leadoouts shift aft to cause the plane to yaw / bank away from the pilot for max line tension during slow speed laps, then shift back to a forward location to make the nose of the plane track tangent to the line of flight for the high speed laps. There is also an arrestor hook that deploys when the pilot is ready to land. So when you look these models over up close, they would make Rube Goldberg drool.
The guys who REALLY feel like a dying pack of dynosaurs are the C/L Speedsters, C/L Carrier Event, and C/L Racers.
The C/L Combat guys sort of fall into the "Extreme Speed" category and they are still going strong on a global FAI level.
C/L Carrier is kind of silly to watch [my opinion] but it is also pretty awesome to see the demonstration between slow speed and high speed performance. Picture a .15 sized scale model Corsair with a Nelson .36 on 60 foot lines. The leadout position is somehow adjustable in-flight so that the leadoouts shift aft to cause the plane to yaw / bank away from the pilot for max line tension during slow speed laps, then shift back to a forward location to make the nose of the plane track tangent to the line of flight for the high speed laps. There is also an arrestor hook that deploys when the pilot is ready to land. So when you look these models over up close, they would make Rube Goldberg drool.
03-19-2014, 04:10 PM
#58
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I only recently had the bright idea to look for a CL carrier video on YouTube, man they do slow them thangs down don't they!
https://www.youtube.com/watch?v=yVURyH1d-O0
Copious amounts of nitromethane..
https://www.youtube.com/watch?v=yVURyH1d-O0
Copious amounts of nitromethane..
03-19-2014, 04:40 PM
#59
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It may be telling that the difference between a kickass pylon racer and a straight line speedster on the same engine is not all that much. Look at the MB Profi .40 powered F3 speed models by F3D (approaching 240mph I believe) and an FAI pylon model on the same engine esp. with a prop change. Not much.
This thing will be lighter than the EP version so it ought to turn on a dime and keep moving. Apparently it's pretty maneuverable, never saw one fly myself. I was shocked at how tight the 25" .061 jobbie would turn and I think it is up to about 12oz now.
03-19-2014, 04:44 PM
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Oh yeah, I just remembered why I actually dialed into the forum in the first place just now..
Before getting to work on the parting plate and mold, I peeled off all the masking I had on there for a last chance to admire the pattern in its raw state (and tape the wing in to go vroom vroom..).
Before getting to work on the parting plate and mold, I peeled off all the masking I had on there for a last chance to admire the pattern in its raw state (and tape the wing in to go vroom vroom..).
03-19-2014, 07:16 PM
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When I ordered it I asked how fast they have been pushed, and they suggested to around the 200 mark, but that they did not recommend this. The hottest motor package they would endorse was a 175-ish setup IIRC. It is so easy to overpower a lekkie, just call up the order desk.. "hi, I want to order one FQU2 pylon racer. Yes, red please. And I'll take the 200mph motor package, and throw in an extra prop. Thanks."
I need to get hold of them again and see what examples they have, i.e. this many watts did this. Should be able to make a crude estimate of speed potential, maybe, with that.
No worries about it being rigid enough for the worst that the 1/2A or 1cc engine world can throw at it. For a .15 will go up a notch with a slightly larger model with a wing proven to 200+.
I need to get hold of them again and see what examples they have, i.e. this many watts did this. Should be able to make a crude estimate of speed potential, maybe, with that.
No worries about it being rigid enough for the worst that the 1/2A or 1cc engine world can throw at it. For a .15 will go up a notch with a slightly larger model with a wing proven to 200+.
03-19-2014, 08:25 PM
#64
I don't know if you remember the "GZ .061 SPECIAL"..but it was the first SWR I did for 1/2A RC. It had the look of a 747 fuselage and the outlet for the exhaust was just a slit in the belly. Flat bottom airfoil carved into 1/4" thick balsa slab. IIRC, it was also kind of heavy for it's size.
I swear that thing did 160 mph, but that was before I was clocking flights from promising planes. This was with a 4.2 x 4 prop that hit 42,000 on a ground check. It was also with a compression / nitro combo that averaged 3 or 4 good runs in between piston / liner / head button changes. It roasted the silicone pipe seals on every run. The glow plugs were just black holes after every run, no element and the plugs leaked compression enough to let the prop freewheel on the glide home.
This is what I remember what 160 mph was like with 1/2A power...but my point of reference was running 160 mph Q-500s with Nelson .40 entry level engines. I think the G&Z SPECIAL would have blown the doors off a Nelson powered Q-500 from a standing start and possibly for an entire heat.
BTW...I used a 1.25" tall control horn [measured to the hole] on that plane...and most other SWRs for pitch control. After the maiden flight of this plane I went home and simply glued a piece of 1/16" ply to the side of the original control horn that was way too short and scurried right back to the field ASAP. The improvement was like night and day, the plane behaved more like a 747 now and was no sweat at all to fly. IIRC, I used the inner hole on the servo arm and the total throw from center was about 1/16". This would have been with a 25% CG.
I swear that thing did 160 mph, but that was before I was clocking flights from promising planes. This was with a 4.2 x 4 prop that hit 42,000 on a ground check. It was also with a compression / nitro combo that averaged 3 or 4 good runs in between piston / liner / head button changes. It roasted the silicone pipe seals on every run. The glow plugs were just black holes after every run, no element and the plugs leaked compression enough to let the prop freewheel on the glide home.
This is what I remember what 160 mph was like with 1/2A power...but my point of reference was running 160 mph Q-500s with Nelson .40 entry level engines. I think the G&Z SPECIAL would have blown the doors off a Nelson powered Q-500 from a standing start and possibly for an entire heat.
BTW...I used a 1.25" tall control horn [measured to the hole] on that plane...and most other SWRs for pitch control. After the maiden flight of this plane I went home and simply glued a piece of 1/16" ply to the side of the original control horn that was way too short and scurried right back to the field ASAP. The improvement was like night and day, the plane behaved more like a 747 now and was no sweat at all to fly. IIRC, I used the inner hole on the servo arm and the total throw from center was about 1/16". This would have been with a 25% CG.
03-19-2014, 09:36 PM
#66
http://www.rcuniverse.com/forum/1-2-...ml#post3852798
I'm still looking, but I found some funny stuff here............
There was a video posted at RCU called "1/2 A NW Pylon Racing" or something close to that.
Nothing at JooToobe.
I'm still looking, but I found some funny stuff here............
There was a video posted at RCU called "1/2 A NW Pylon Racing" or something close to that.
Nothing at JooToobe.
Last edited by combatpigg; 03-19-2014 at 09:50 PM.
03-19-2014, 11:47 PM
#67
http://www.rcuniverse.com/forum/1-2-...a-express.html
I completely forgot about this plane. I do not even remember flying it after seeing this thread.
still looking for the "G&Z Express"..or "G&Z Special"...............
I completely forgot about this plane. I do not even remember flying it after seeing this thread.
still looking for the "G&Z Express"..or "G&Z Special"...............
03-20-2014, 06:52 AM
#68
I spent a couple of hours looking for the GZ video. Couldn't find it, but this looks interesting. 2008? http://www.youtube.com/watch?v=Wl7w3smOTS4
03-20-2014, 07:39 AM
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I remember that video from when it was posted - that looks like SERIOUS fun.
The Boomerang ought to hold it's own in that group. Not sure about the pilot but the airplane for sure. I don't think there is any 1/2A pylon in Canada, barely Q500 and EF-1.
The Boomerang ought to hold it's own in that group. Not sure about the pilot but the airplane for sure. I don't think there is any 1/2A pylon in Canada, barely Q500 and EF-1.
03-20-2014, 08:46 AM
#71
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I hope you got side-tracked working on your proof of concept model, as opposed to work or chores.
Most of my RCU posting is done at work. About every 2 hours I close my daybook, grab a cuppa, and dick around for 5-10 minutes to chill out. Of course if something really interesting is going on I'll sneak a peek now and again from my desk, elapsed time about 10 seconds to check for updates.
Most of my RCU posting is done at work. About every 2 hours I close my daybook, grab a cuppa, and dick around for 5-10 minutes to chill out. Of course if something really interesting is going on I'll sneak a peek now and again from my desk, elapsed time about 10 seconds to check for updates.
03-20-2014, 10:16 AM
#72
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I wish it were to work on my plane but unfortunately it wasn't. Today however that has been my major focus, playing around with servo locations to try to balance it a bit better.
03-20-2014, 11:53 AM
#73
I spent a couple of hours looking for the GZ video. Couldn't find it, but this looks interesting. 2008? http://www.youtube.com/watch?v=Wl7w3smOTS4
I've got coffee cans full of VAs, AMEs, Coxes, Big Migs, APs, etc...but I keep just 1 Cyclon [with no spare parts] that runs like a Rolex. It is money far better spent if you are commited to USING IT A LOT, YEAR AFTER YEAR.
03-20-2014, 08:29 PM
#75
Speaking of "quaint but fun".......I just tried to find a video about 1/2A .049 Mouse Racing and struck out.
I think 3 up at a time is the most I've ever seen flying a heat..and 3 looks pretty insane.
http://www.rcuniverse.com/forum/1-2-...-gz-delta.html
I'm getting closer to finding the G&Z video......
I think 3 up at a time is the most I've ever seen flying a heat..and 3 looks pretty insane.
http://www.rcuniverse.com/forum/1-2-...-gz-delta.html
I'm getting closer to finding the G&Z video......
Last edited by combatpigg; 03-20-2014 at 08:34 PM.
