The 24 year itch
#126
Sounds like it flew as expected. I would still try the 5.7X3. That should give you more speed and still all the thrust you need. I've never liked the 6X3 on anything other than a trainer. Plus they tend to kill rpms on an AME by getting them out of the range that their porting is set for.
As far as a SWR, I've lopped 2" off each wing (4" total), gone to a 9% airfoil (I'm thinking RG 14 maybe) but kept the long tail moment.That helps a lot with the roll speed as well as overall speed. I still stayed with a built up wing as you can get pretty wide between ribs and still stay strong and light. I have yet to snap one even on some landings that would have killed the pilot for sure.
The 074 would probably help the vertical a lot on the one you have and running a 6.3X4 helps the speed too. In any event it came out nice.
As far as a SWR, I've lopped 2" off each wing (4" total), gone to a 9% airfoil (I'm thinking RG 14 maybe) but kept the long tail moment.That helps a lot with the roll speed as well as overall speed. I still stayed with a built up wing as you can get pretty wide between ribs and still stay strong and light. I have yet to snap one even on some landings that would have killed the pilot for sure.
The 074 would probably help the vertical a lot on the one you have and running a 6.3X4 helps the speed too. In any event it came out nice.
#128
Thanks..!
Unless I am able to get my point across to the manager of the local airport that there are way too many full scale planes flying below 500 feet over this field, I don't get many chances to savor a nice, stretched out climb. Today I spotted at least a few different planes about 150 feet over head. I ought to use the video cam to zoom in on the action. I'm not sure if you need a tripod or not.
I've got a few 1/2 A engines to exercise yet, plus an order of 5.7 x 3 props due any day.
As for building too light for 1/2 A`...if the plane is tough enough to handle my clumsy handling in the garage and at the field, the safest place for the plane is in the sky. I was on that train of thought today after watching this plane zoom around at full throttle. It probably would have been OK to use a balsa spar instead of the full depth Douglas Fir. Something like 1/8" hard balsa, basically the same size as this Dug Fir spar is.
Any way, after seeing .049 - .061 planes in action I can't help but think that they are all "over built". The Cyclon type engines can really dish out some punishment and I've yet to see a wing folded by any of them. I've seen a 1/4" thick balsa wing [with a hardwood spar] flex.
The lowest powered wing explosion I've ever seen was a OS .15 popping a 36 inch, balsa sparred plane that I threw together just to see how skimpy you can go. It flew several times before it went POP, too.
Unless I am able to get my point across to the manager of the local airport that there are way too many full scale planes flying below 500 feet over this field, I don't get many chances to savor a nice, stretched out climb. Today I spotted at least a few different planes about 150 feet over head. I ought to use the video cam to zoom in on the action. I'm not sure if you need a tripod or not.
I've got a few 1/2 A engines to exercise yet, plus an order of 5.7 x 3 props due any day.
As for building too light for 1/2 A`...if the plane is tough enough to handle my clumsy handling in the garage and at the field, the safest place for the plane is in the sky. I was on that train of thought today after watching this plane zoom around at full throttle. It probably would have been OK to use a balsa spar instead of the full depth Douglas Fir. Something like 1/8" hard balsa, basically the same size as this Dug Fir spar is.
Any way, after seeing .049 - .061 planes in action I can't help but think that they are all "over built". The Cyclon type engines can really dish out some punishment and I've yet to see a wing folded by any of them. I've seen a 1/4" thick balsa wing [with a hardwood spar] flex.
The lowest powered wing explosion I've ever seen was a OS .15 popping a 36 inch, balsa sparred plane that I threw together just to see how skimpy you can go. It flew several times before it went POP, too.
#129
MJD, I was trying to visualize a Cyclon in there. I think if a 1/2" thick plywood disk was used between the backplate and the firewall it would fit.
I'd rather just make this plane something to run a .074 / 7 x 3 or 6 x 4 with and build something similar but smaller for the Cyclon.
The place to start is by finding a hot looking canopy that is similar to this one, but smaller. Then design the rest of the plane around the canopy.
I'd rather just make this plane something to run a .074 / 7 x 3 or 6 x 4 with and build something similar but smaller for the Cyclon.
The place to start is by finding a hot looking canopy that is similar to this one, but smaller. Then design the rest of the plane around the canopy.
#130
Congradulations CP for getting your birdie in the air and many flights on the first day! What sort of run time was the .061 giving you on 1oz of fuel?
Sounds like a 5.5 x 3.5 might be worth trying there is such a prop
Master Airscrew RC Model G/F 3 Series MA0635 6 x 3.5 Airplane Propeller PP668 could be trimmed down.
http://www.rcecho.com/Master-Airscre...Propeller.html
http://www.ebay.com/itm/Master-Airsc...item4619a7a83d
Sounds like a 5.5 x 3.5 might be worth trying there is such a prop
Master Airscrew RC Model G/F 3 Series MA0635 6 x 3.5 Airplane Propeller PP668 could be trimmed down.
http://www.rcecho.com/Master-Airscre...Propeller.html
http://www.ebay.com/itm/Master-Airsc...item4619a7a83d
Last edited by Pond Skipper; 12-22-2014 at 09:45 PM.
#131
Thanks PS..!
This tank isn't a full, honest oz. and the .061 AME slurps it up too fast. If this was a fast plane, then a 90 second flight that captures several good passes on video is good enough, but for a plane like this that you just want to kick back and play with it really needs a 2 oz tank.
I don't know exactly how long the flights were, but with a 5 x 3 prop 2:30 would be my guess. Maybe 3 minutes with a 6 x 3...?
This tank isn't a full, honest oz. and the .061 AME slurps it up too fast. If this was a fast plane, then a 90 second flight that captures several good passes on video is good enough, but for a plane like this that you just want to kick back and play with it really needs a 2 oz tank.
I don't know exactly how long the flights were, but with a 5 x 3 prop 2:30 would be my guess. Maybe 3 minutes with a 6 x 3...?
#133
Yep....gotta find a nice canopy, like a F-16 in some oddball scale.. I'd build the wing with some dihedral.
Keep the thrust line low.
I'd like to stay with a high aspect wing [7:1] but [for example] 28 x 4 sounds kind of scary.
I'd also upgrade to the lipo battery for no other reason but to save space inside the plane.
Those 2/3 AAA nimh packs never gave the service that I hoped for.
Keep the thrust line low.
I'd like to stay with a high aspect wing [7:1] but [for example] 28 x 4 sounds kind of scary.
I'd also upgrade to the lipo battery for no other reason but to save space inside the plane.
Those 2/3 AAA nimh packs never gave the service that I hoped for.
#138
If these are available in 2/3 AAA, then 1.2 ozs for a battery pack and 500 mah isn't too bad of an option for a Cyclon powered project.
I don't remember where I bought it, but it might have been from Common Sense RC or special order through Tower's order assistance operator..
I see that Just Engines in England carries ASP engines and parts, but the cost is pretty high.
Hobby Partz and Nitro Planes look like the same outfit. I wonder why they need 2 separate identities..?
Are they always in a state of "OOS...?"
#140
That's good news. I'll start paying better attention to what is cooking with the new cells.
You never know what a new day will bring. I put a 2 oz Hayes tank in the plane. There was plenty of room to pack in some foam. The 2 oz tank doesn't weigh much more than the 1 oz tank.
The first flight was going very well. The 5 x 3 was singing on the AME. The model seemed just as lively as yesterday and everything was just going great until a big POP sound was heard and I saw chunks leaving the front end of the plane while it was doing a level pass.
It looked from a distance like the cowl and engine were missing, but the plane didn't seem tail heavy when it glided in to land.
Upon closer inspection the two #2-56 screws in the upper mount are missing, the two lower screws have broken and the cowl was ripped off the nose. All three cowl screws are still tight.
My aim on the helmet cam was off, so that was no help when I tried to replay the scene with the hope of retracing where the cowl might have landed.
Right now is as good a time as any to find the cowl since the grass is so short.
#141
Hobby partz, nitroplanes, heli... and the car one are the same company, I think just to separate each interest area. They likely buy a shipping container full when the last one is sold out, so the poor sellers drag it out a long time. The .06, .46 and blue head .15 always seem to go fast when the new order comes.
#143
Ya, I got the first AP .15 and blue head ASP .15 a few years ago, and thought I would get another AP .15 and .06 at the same time to save shipping. ($10 to Canada if over $50) I gave up after a while and ended up with a crappy used .06, and another .15 from H King for a few pennies cheaper when I ordered some other crap. Only dealt with each place once so far. No problems like some other people whine about.
#144
Sorry to see the cowl eating engine. Do you think the cowl contacted the engine, causing the bolt shear, or bolt shear then motor ate the cowl? In any event good choice to safty wire the motor on with high quality fuel line. At least as a backup in case the prop arresting nose cone doesn't catch the engine on the first shot. I think the nylon mounts have a bit more give to them. Other than a radial mount I've never used metal mounts on anything under a 40.Probably has more to do with being too lazy to make them than any scientific study.
#145
I'm with holding some forensic evidence, so here is everything I know.
This morning I took off the cowl and the engine and found that 1 of the grade [?] black cocket head screw heads had broke off.
The mount holes in the AME's case are "wallowed out" and could contribute to this problem, putting an uneven load on the little bolt heads.
I used blue Locktite on the threads on the first install, but I didn't re-locktite them today.
The engine seems to run smooth,even though the mount beams are kind of long.
It's possible that the cowl mounting holes failed and triggered the whole mess.
I have a Nelson FAI .40 engine that has caused the cowl retaining screws to melt / burn the fiberglass after a 2 minute run.
It's even possible that the prop lost a blade, then triggered a chain reaction. It's a very old rubber Cox prop that has who knows how many crashes.
I think finding a broken bolt head from "Day #1", then having this happen points to the sloppy holes in the AME's mount lugs.
It might be possible to "pot" the mount holes with JB Weld while the bolts are greased and threaded into the mount.
i sure was happy to see the engine still hanging from the side of the plane.
This morning I took off the cowl and the engine and found that 1 of the grade [?] black cocket head screw heads had broke off.
The mount holes in the AME's case are "wallowed out" and could contribute to this problem, putting an uneven load on the little bolt heads.
I used blue Locktite on the threads on the first install, but I didn't re-locktite them today.
The engine seems to run smooth,even though the mount beams are kind of long.
It's possible that the cowl mounting holes failed and triggered the whole mess.
I have a Nelson FAI .40 engine that has caused the cowl retaining screws to melt / burn the fiberglass after a 2 minute run.
It's even possible that the prop lost a blade, then triggered a chain reaction. It's a very old rubber Cox prop that has who knows how many crashes.
I think finding a broken bolt head from "Day #1", then having this happen points to the sloppy holes in the AME's mount lugs.
It might be possible to "pot" the mount holes with JB Weld while the bolts are greased and threaded into the mount.
i sure was happy to see the engine still hanging from the side of the plane.
#146
You should be making good power with that nelson plug. I wonder if the wee cox prop was flexing aiding to the bolt head shearing.
I would think 3 bolts should have held the engine with 2oz tank your over 17oz in the air added load so going with thrown a blade chain reaction scenario.
I would think 3 bolts should have held the engine with 2oz tank your over 17oz in the air added load so going with thrown a blade chain reaction scenario.
#147
Most of the time I steer away from using machine screws this small unless they are long enough for nyloc nuts. In this case, the front screws need to be kept short for the cowl to fit.
Even with nylon mounts I prefer sheetmetal screws over machine thread.
I'll be looking closer at the old pile of props and tossing any that deserve to be given the old heave ho.
My 5.7 x 3 's came from Omni Models. They charged for 10 but shipped 12. That's a pretty good way to foster good customer relations and loyalty. So now I'll spend time looking at their inventory, where before I never paid them any mind.
The Nelson plugs never work loose..! The plug expands the head adapter slightly when you cinch it down. For some reason I believe that the Norvel plugs are a little more powerful on an AME than the Nelson, but not enough to be an issue here. The fastest guy I raced against always used the Norvel plugs, but there could have been other factors at play that he never talked about........
Even with nylon mounts I prefer sheetmetal screws over machine thread.
I'll be looking closer at the old pile of props and tossing any that deserve to be given the old heave ho.
My 5.7 x 3 's came from Omni Models. They charged for 10 but shipped 12. That's a pretty good way to foster good customer relations and loyalty. So now I'll spend time looking at their inventory, where before I never paid them any mind.
The Nelson plugs never work loose..! The plug expands the head adapter slightly when you cinch it down. For some reason I believe that the Norvel plugs are a little more powerful on an AME than the Nelson, but not enough to be an issue here. The fastest guy I raced against always used the Norvel plugs, but there could have been other factors at play that he never talked about........
#148
So you think the machine head screws are more brittle? I have snapped off many a allen head type sheet metal screw but never a fine threaded bolt that I can recall. For sure the over sized holes on the engines mounting tabs didn't help the metal mount to metal engine interface would load the machine heads more less forgiveness while the engine is running or the older dried out prop is flexing under loads. All the same you have some APC's now and this will rule out the cox prop in the next round of flights.
Last edited by Pond Skipper; 12-23-2014 at 10:20 PM.
#149
I noted a AP .061 had better compression with the norvel head over the nelson plug but the nelson plug felt like it had more compression with the norvel engine over the stock. Perhaps a few shims would leg out the rpm some more.
#150
The sheetmetal screws can break or back out of wood, but I still like them better than blind nuts and machine thread screws for most RC engine mounting, .40 and under..
For aluminum mounts [like these DIY type], it's really important to have the beams perfectly in line with each other and to test flip the prop as you torque the engine down and I made sure to check that.
I'm pretty sure with some attention to detail this problem will go away and I'll still be able to stand behind my belief that it is not necessary to balance 1/2 A props...!
Until I'm sure the problem is "licked" it might be smart to tie the engine to the plane, or always bring a blood hound to the field.
For aluminum mounts [like these DIY type], it's really important to have the beams perfectly in line with each other and to test flip the prop as you torque the engine down and I made sure to check that.
I'm pretty sure with some attention to detail this problem will go away and I'll still be able to stand behind my belief that it is not necessary to balance 1/2 A props...!
Until I'm sure the problem is "licked" it might be smart to tie the engine to the plane, or always bring a blood hound to the field.
Last edited by combatpigg; 12-23-2014 at 11:23 PM.