The 24 year itch
12-24-2014, 12:43 AM
#151
If you have some thin rubber footings strips between the two metal surfaces perhaps this would reduce some stress on the bolt heads. You could use
a short section of shrink tube over the bolts to keep things snug in the mounting holes and reduce metal to metal contact.
The cox props could stay bagged up with a spritz of water in the bag to keep a moisture conditioned environment in theory might help prolong use.
a short section of shrink tube over the bolts to keep things snug in the mounting holes and reduce metal to metal contact.
The cox props could stay bagged up with a spritz of water in the bag to keep a moisture conditioned environment in theory might help prolong use.
12-24-2014, 07:24 AM
#152
Bugger!!! At least the engine remained attached.
I've had a number of older COX props that developed stress cracks running chordwise on the blades. Bending the blade will usually generate a lot more cracks or snap the blade off altogether --- either way, they hit the trash bin. I'm voting for shedding a blade, either from the cowl coming loose or stress. I would think if the prop had been intact when the engine rotated into the fuselage, you would have had more cuts in the fuselage side. Maybe a screw vibrated out, but three should have been sufficient to retain the engine. OTOH, with a blade gone, a stout firewall and solid mounts, something had to go.
I've had a number of older COX props that developed stress cracks running chordwise on the blades. Bending the blade will usually generate a lot more cracks or snap the blade off altogether --- either way, they hit the trash bin. I'm voting for shedding a blade, either from the cowl coming loose or stress. I would think if the prop had been intact when the engine rotated into the fuselage, you would have had more cuts in the fuselage side. Maybe a screw vibrated out, but three should have been sufficient to retain the engine. OTOH, with a blade gone, a stout firewall and solid mounts, something had to go.
12-24-2014, 10:23 AM
#153
PS, a coffee can lid might make a good mounting pad..?
3M makes a "barrier tape" that is used between dissimilar metals, or to keep any combo of metals from chafing.
I didn't see any black streaks after the "Day One" teardown though.
Boiling the nylon props is supposed to rejuvenate them, but I'm not sure if the Cox "rubber" props fall into the same category. Boiling won't repair cracks of course. In all my years, I've never seen a Cox rubber 5 x 3 voluntarily lose a blade in flight, but there's always a first time.
Andrew, I think the prop lost a blade before slicing into the fuselage. It was still spinning because there is a finely arched slit in the wood that enters aft of where you see the prop resting in the photo. Too bad I wasn't "On The Ball" and had good zoom video of this SNAFU..!
3M makes a "barrier tape" that is used between dissimilar metals, or to keep any combo of metals from chafing.
I didn't see any black streaks after the "Day One" teardown though.
Boiling the nylon props is supposed to rejuvenate them, but I'm not sure if the Cox "rubber" props fall into the same category. Boiling won't repair cracks of course. In all my years, I've never seen a Cox rubber 5 x 3 voluntarily lose a blade in flight, but there's always a first time.
Andrew, I think the prop lost a blade before slicing into the fuselage. It was still spinning because there is a finely arched slit in the wood that enters aft of where you see the prop resting in the photo. Too bad I wasn't "On The Ball" and had good zoom video of this SNAFU..!
12-24-2014, 11:38 AM
#154
Have you found the cowl yet? That may shed some light on the cause. I'm waiting to see a picture of all the pieces all laid out in sequence in a hanger like a proper FAA investigation. Which means you also need to find the other half of the prop. Until then I'm suggesting we ground all AME powered pacers until we get to the bottom of this. 
12-24-2014, 12:05 PM
#155
I have a wide rubber roll of dense thin rubber non stick by 3M ment for high voltage rap insulation held with 3M electrical tape. The stuff works great to isolate metal to metal contact, helps dampen vibrations / shock. The coffee can lids are made to be popped on and off so at least it has retention but not true rubber like the 3M will help all the same.
12-24-2014, 12:09 PM
#157
LOL..!
I was saying the same thing to myself, that the Pacer was never intended to reach speeds in excess of 70 mph and to declare this program grounded, or at least left as "unmanned" status until further review.
If I had put a pilot in the cockpit this would have just added to the misery.
Today is too miserable to be out there tramping around looking for the canopy. If there was a pilot involved, I might have "sucked it up" and forced myself to be out there looking for the little head.
There was a stiff breeze yesterday that could have blown the cowl 100 feet down wind from where it came loose even though the plane was only 50 feet high when it happened.
I was saying the same thing to myself, that the Pacer was never intended to reach speeds in excess of 70 mph and to declare this program grounded, or at least left as "unmanned" status until further review.
If I had put a pilot in the cockpit this would have just added to the misery.
Today is too miserable to be out there tramping around looking for the canopy. If there was a pilot involved, I might have "sucked it up" and forced myself to be out there looking for the little head.
There was a stiff breeze yesterday that could have blown the cowl 100 feet down wind from where it came loose even though the plane was only 50 feet high when it happened.
12-24-2014, 12:21 PM
#158
I was able to grind slots across the broken screws with a Dremel cutoff wheel and back the broken pieces out.
If they were Locktited in, it would have required heat for sure. The threads seem kind of sloppy, but I double checked my pilot drill and I actually used one size smaller than what is called for ..[I used a #51 instead of a #50].
After cleaning the mounting holes in the case, I greased some new #2-56 screws and started them into the mount holes of the engine, then used a toothpick to dab JB Weld into the over sized mounting holes of the engine. The last step was to run the srews in just finger tight, scrape away the excess glue that squeezed out and now just wait for it to cure.
The prop blade that is still intact has a well worn groove near the hub from using an electric starter. I wasn't hearing the typical "fuzzy" sound you get from a failing prop or of a loose engine during any of the flights, though.
If they were Locktited in, it would have required heat for sure. The threads seem kind of sloppy, but I double checked my pilot drill and I actually used one size smaller than what is called for ..[I used a #51 instead of a #50].
After cleaning the mounting holes in the case, I greased some new #2-56 screws and started them into the mount holes of the engine, then used a toothpick to dab JB Weld into the over sized mounting holes of the engine. The last step was to run the srews in just finger tight, scrape away the excess glue that squeezed out and now just wait for it to cure.
The prop blade that is still intact has a well worn groove near the hub from using an electric starter. I wasn't hearing the typical "fuzzy" sound you get from a failing prop or of a loose engine during any of the flights, though.
12-24-2014, 12:29 PM
#159
What is going to happen is 2 days from now someone will release a fuzzy cell phone video showing a small projectile headed for the nose of the Pacer moments before the "Cowl eating AME incident." MJD will deny having any bottle rockets opperating in the area. Aspeed will post a toll both ticket proving he was indeed in CA at the time of the incident. Pond Skipper will release radar tracking of a small projectile originating from the grassy knoll on the south west corner of your field. Finally, Kim Jung will deny any involvement but will reiterate that "Individuals sympathetic to the his most supreme being had already threatened a major event in the Washington area" so no-one should be surprised. He will of course, be willing to participate in a joint investigation to get to the bottom of this.
12-24-2014, 03:19 PM
#161
Photo #2 shows an old OS .15 NVA hanging off the side of the carb. These NVAs make great remote NVAs. The OS .10 NVA is actually a better fit where space is tight.
That's what is shown mounted to the plane now. The 2 open lines are the CC pressure and they are waiting for me to join them with an "In & Out" fitting. The coupling simplifies refueling.
This Enya .11 is kind of "clapped out"..but it's my only .10 sized engine that's still ambulatory. I used to run it on a little "Pattern Bat" flying wing type thing that would stay locked into a flying saucer like hovering spin while screaming away with a 5.7 x 3 prop. I used to wonder if Mr. Enya would have been proud to see his little engine used like that...or angry.....!
12-25-2014, 12:41 AM
#163
12-25-2014, 06:49 AM
#164
That's a nice tip on a VA..thanks..!
Dan lives about 1/2 hour south of me and he comes up to fly C/L often. He was the columnist for several different categories of RC engine powered things dating back to when the news stand was packed with various magazines.
I might be mistaken, but I think this is the lightest .049 ever.
Dan lives about 1/2 hour south of me and he comes up to fly C/L often. He was the columnist for several different categories of RC engine powered things dating back to when the news stand was packed with various magazines.
I might be mistaken, but I think this is the lightest .049 ever.
12-25-2014, 11:00 AM
#165
Yea its the first generation but has potential adjustable piston/timing if willing to fuss with it.
George Aldrich described VA Mk. II .049 as follows:
I have just received the new VA Mk. II .049, and it is LIGHT YEARS better than the old Mk. I. It's advertised in the latest Flying Models. It still has the adjustable piston/timing feature and the one I received had timing for C.L. Combat. I would advise ordering it with the piston Loctited and the timing set for 150 deg. of exhaust timing, as the 160 deg. mine had is too high for our prop sizes. These engines aren't designed to EVER swing a 6 x 3, but really come alive on a 5.5 x 2, or 5.5 x 2.5 ! The quality rivals that of a Shuriken on this new engine ! At $69.95, it a "keeper" !
George Aldrich described VA Mk. II .049 as follows:
I have just received the new VA Mk. II .049, and it is LIGHT YEARS better than the old Mk. I. It's advertised in the latest Flying Models. It still has the adjustable piston/timing feature and the one I received had timing for C.L. Combat. I would advise ordering it with the piston Loctited and the timing set for 150 deg. of exhaust timing, as the 160 deg. mine had is too high for our prop sizes. These engines aren't designed to EVER swing a 6 x 3, but really come alive on a 5.5 x 2, or 5.5 x 2.5 ! The quality rivals that of a Shuriken on this new engine ! At $69.95, it a "keeper" !
12-25-2014, 11:01 AM
#166
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The Space Hopper is close but the VA nudges it by about 2 grams as I recall. I weighed them in a few months ago because I was not sure which was lighter. Actually I think I'll go dig them out now to confirm..
Oh yeah.. Merry Christmas to all! And if you don't do Christmas.. well then, cheers!
Oh yeah.. Merry Christmas to all! And if you don't do Christmas.. well then, cheers!
12-25-2014, 11:04 AM
#167
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That's a nice tip on a VA..thanks..!
Dan lives about 1/2 hour south of me and he comes up to fly C/L often. He was the columnist for several different categories of RC engine powered things dating back to when the news stand was packed with various magazines.
I might be mistaken, but I think this is the lightest .049 ever.
Dan lives about 1/2 hour south of me and he comes up to fly C/L often. He was the columnist for several different categories of RC engine powered things dating back to when the news stand was packed with various magazines.
I might be mistaken, but I think this is the lightest .049 ever.
12-25-2014, 11:24 AM
#168
I may own the lightest .049 engine after my last effort added a grinded down spinner / vintage thin walled TD cylinder and of course ground down all the fins.
Should stay cool as long as its not over loaded.
Should stay cool as long as its not over loaded.
12-25-2014, 11:53 AM
#169
MJD, I'm committed to running what I've got with .049 engines, so don't be bashful about bidding on the VA.
The VA II still had rod problems run as combat engines.
Dan's next door neighbor, Jeff Rein came up with a superior rod that he made out of round stock that shifted the predictable failure point up to the crank pin. He sold a lot of these rods while the VA was still a hot item.
For running with conservative props, these engines are just fine, especially if the price is right.
PS, that's pretty light for an engine with a bunch of steel parts..!
Meery Xmas to you all.
The VA II still had rod problems run as combat engines.
Dan's next door neighbor, Jeff Rein came up with a superior rod that he made out of round stock that shifted the predictable failure point up to the crank pin. He sold a lot of these rods while the VA was still a hot item.
For running with conservative props, these engines are just fine, especially if the price is right.
PS, that's pretty light for an engine with a bunch of steel parts..!
Meery Xmas to you all.
12-25-2014, 02:29 PM
#170
The VA MkII feels much better than the MkI. In terms of power the difference isn't very different to a regular Norvel .049, to me, but the handling is much nicer. Very easy to handstart and throttles well to.
I'm intending to use mine in a SWR instead of the Norvel I first had in mind for it;
I'm intending to use mine in a SWR instead of the Norvel I first had in mind for it;
12-25-2014, 03:43 PM
#171
That VA will get a nice work out on a fast plane.
Here is what my .11 powered Pacer looks like after 2 flights....err, 1.5 flights.
I could not believe my eyes, it was like "deja vu all over again" [a famous Yogi Berra quote].
The culprit this time was using really light wood and getting carried away with sanding the fuselage to a pretty shape. This balsa was SIG's lightest...so soft that even with a new blade it tended to tear instead of slice when cut across grain.
I think it will be a relatively easy repair with some fiberglass cloth.
The first flight was with a 7x3 and it was painfully slow. The model flew just fine, but I doubt it got up to 40 mph.
The second flight was with a Cox 7 x 3.5 that I cut down to 6.5. This really pulled the plane nicely and I'd love to have more of these props. The plane really handles great, has a sporty roll rate and it has an "effortless" quality like the big pattern planes have.
Truthfully, it's a much nicer experience than flying the .061 version was [so far].
So, I can't make any jokes about junky ARFs or Harbor Freight cheap junk until I clean up my act.
I'll review the video[s] and see if anything is fit to be uploaded later. I was swearing a little bit after the firewall popped loose, so that part will need to be censored.
12-25-2014, 04:44 PM
#172
http://youtu.be/NSeuj1cjWs8
[editted to fix bad link]
Here is the thrilling SNAFU.
It looks like the ZOOM needs to be backed off some to keep the plane in view better.
Not much to see at the end, it was cut a split second before the Eff Word was blurted out.
Not so much in anger, but in amazement that I let the same thing happen twice in a row.
Here is the thrilling SNAFU.
It looks like the ZOOM needs to be backed off some to keep the plane in view better.
Not much to see at the end, it was cut a split second before the Eff Word was blurted out.
Not so much in anger, but in amazement that I let the same thing happen twice in a row.
Last edited by combatpigg; 12-25-2014 at 06:07 PM.
12-25-2014, 08:32 PM
#175
Back when I was doing stupid stuff like putting 15's and 25's on 1/2a planes I got in the habit of running square stock on the inside of the firewall all the way around and just never stopped doing it. That way if I got carried away with the sanding, my motor still landed at the same time my plane did.