The Refurbishing of an Alley Cat
11-05-2010, 03:46 PM
#1
Thread Starter
The Refurbishing of an Alley Cat
The Alley Cat was a seventies era sport/pattern plane that many older fliers will recall.
http://pages.suddenlink.net/arlyn/alleycat1.html
http://pages.suddenlink.net/arlyn/alleycat1.html
11-08-2010, 09:25 PM
#3
Thread Starter
RE: The Refurbishing of an Alley Cat
Engine, tank and radio gear all fitted and the plane is grossly tail heavy needing six ounces of lead in the engine compartment just to hold the nose wheel down. Probably another two to balance. I could probably save that two by moving the servos forward but that would mean all linkages reworked. Evidently it is due to the automotive paint finish.
11-09-2010, 12:13 PM
#4
Thread Starter
RE: The Refurbishing of an Alley Cat
I was a bit disheartened last night with the discovery that 8-10 oz of lead were needed to balance. This morning however after running the numbers they don't look that bad at 23.3 oz sq ft, a reasonable number.
11-09-2010, 10:19 PM
#6
Thread Starter
RE: The Refurbishing of an Alley Cat
No work on her today... I had my grand son with me. Flight will be a week or so off. Plans are to do the touch up paint tomorrow and I normally wait a week to clear coat. The canopy repair can be done during that week.
At the field today, I talked with my friend who passed the plane to me and he was at a loss about the needed weight... saying that he didn't recall needing any weight. Another friend said he had the plan and would supply the CG.
Power will be a HB .40 PDP. Total weight is going to be somewhere around 6.25 lbs. I've never flown the HB .40 in a plane, having taken it out of a helicopter I had many many years ago. It tachs 13,200 (13.400 leaned to top) with a MAS 10x6 though I might check tomorrow for an APC 10x7.
At the field today, I talked with my friend who passed the plane to me and he was at a loss about the needed weight... saying that he didn't recall needing any weight. Another friend said he had the plan and would supply the CG.
Power will be a HB .40 PDP. Total weight is going to be somewhere around 6.25 lbs. I've never flown the HB .40 in a plane, having taken it out of a helicopter I had many many years ago. It tachs 13,200 (13.400 leaned to top) with a MAS 10x6 though I might check tomorrow for an APC 10x7.
11-21-2010, 12:16 PM
#7
Thread Starter
RE: The Refurbishing of an Alley Cat
After a week for the touch up paint to dry, clear coating was done so is ready to fly once some more lead is acquired. The final weight outcome was not good. I could tell initially that it would need 8oz but the actual nose weight needed is 12 oz... that is huge for a .40 size plane. AUW will be 6lbs 10oz dry. The plane has 616 sq in for a loading of 25 oz sq. ft.
It should be in the air next weekend but I've heard our weather is about to take a turn.
It should be in the air next weekend but I've heard our weather is about to take a turn.
11-21-2010, 09:14 PM
#9
Thread Starter
RE: The Refurbishing of an Alley Cat
I looked at that this afternoon and have a 600 mah pack that might go under the fuel tank without fouling the nose wheel steering arm. And, it looks like the servos would reposition fully forward in the wing cavity. That would help a lot but it will take some effort to get there. One issue is rails to mount a servo tray... the tank is almost the full width of the plane, which doesn't leave much room for rails... but I'll take a second look at it.
I don't remember that far back whether there were any balance issues on my Alley Cat. I do remember that I'd lightened the elevator and rudder by tapering them. I've a feeling that the greater issue is the auto paint.
I don't remember that far back whether there were any balance issues on my Alley Cat. I do remember that I'd lightened the elevator and rudder by tapering them. I've a feeling that the greater issue is the auto paint.
11-22-2010, 07:00 AM
#10
My Feedback: (2)
RE: The Refurbishing of an Alley Cat
A friend of mine found that out about the Auto Paint on his Citabria... he got it from a friend who had finished it that way - a bit heavy handed. He's going to do a recover job this winter and he estimates that he will save about a pound of weight (of course, his plane is twice the size of yours).
Another thought would be if you could rig a pull-pull system for the rudder? You could save the weight of the pushrod in the tail - not much, but something, if you ever decide to go the 'recover' route.
Bob
Another thought would be if you could rig a pull-pull system for the rudder? You could save the weight of the pushrod in the tail - not much, but something, if you ever decide to go the 'recover' route.
Bob
11-22-2010, 07:28 AM
#11
Thread Starter
RE: The Refurbishing of an Alley Cat
The Alley Cat has generous stabalizer surfaces, perhaps one of the reasons it flew so well but they provide a lot of surface for paint and extra tail weight if the paint is too heavy.
Sleeping on it last night and especially after yesterday's flying session where I was the only one at the field... flying my Ultra Stick Lite into blustery 12-15 winds, it occurred to me that the extra weight might make it a better windy day flier and most of my hanger are lightly loaded and more suited to gentle air. The HB .40 is a strong motor and the thought of getting the old covering off doesn't excite me. I believe it is a polyspan doped on as evidenced around the wing cavity.
I hear you on the Citabria... a gentleman at the field recently finished a large one powered with an OS 160 twin and had painted it... it flew but barely. I used to have good luck painting years ago using poly and dope base with K&B epoxy finish. The epoxy paint covered very well so it didn't take a heavy coat.
Sleeping on it last night and especially after yesterday's flying session where I was the only one at the field... flying my Ultra Stick Lite into blustery 12-15 winds, it occurred to me that the extra weight might make it a better windy day flier and most of my hanger are lightly loaded and more suited to gentle air. The HB .40 is a strong motor and the thought of getting the old covering off doesn't excite me. I believe it is a polyspan doped on as evidenced around the wing cavity.
I hear you on the Citabria... a gentleman at the field recently finished a large one powered with an OS 160 twin and had painted it... it flew but barely. I used to have good luck painting years ago using poly and dope base with K&B epoxy finish. The epoxy paint covered very well so it didn't take a heavy coat.
11-22-2010, 08:09 PM
#12
My Feedback: (2)
RE: The Refurbishing of an Alley Cat
Yup, I hear you about the higher wing loading and the penetration.
One other area my buddy had good luck in was when he changed over from standard ignition to EI. I know that you're only running a HB 40, but tell your friend about this - he might be interested. My friend with the Citabria saved about two pounds of weight (literally) by switching over to EI. The old ignition stuff that he took off his engine weighed 26 ounces. The new one weighed in at 10 oz.
Just a thought,
Bob
One other area my buddy had good luck in was when he changed over from standard ignition to EI. I know that you're only running a HB 40, but tell your friend about this - he might be interested. My friend with the Citabria saved about two pounds of weight (literally) by switching over to EI. The old ignition stuff that he took off his engine weighed 26 ounces. The new one weighed in at 10 oz.
Just a thought,
Bob
12-31-2010, 08:20 PM
#13
Thread Starter
RE: The Refurbishing of an Alley Cat
The old Alley Cat got a flight today. It was windy and not great flying weather but a couple of buddies were at the field so we put it in the air. It was quicker than I remember or perhaps the HB-40 is significantly more powerful than the Enya 40 on mine. It is the first trike gear plane in twenty five years but that was no issue. It needed left and up trims so power was reduced to make trimming easier. The ailerons have minimal throw but proved adequate for decent roll speed.
It was put through some loops, rolls, Cuban eights, stall turns, Immelman, inverted and as remembered.... it handled aerobatics well. The one thing not tried was spins... mine would go into a flat spin easily and wasn't real easy sometimes to get out and because of the wind and grey cloudy skies they were left for another day. I'd like to do an in flight CG first anyway as it had felt slightly snappy with giving hard elevator. The landing also acted slightly tail heavy with a little ballooning as it slowed... but that could have been ground effect winds. Will just have to test again on a less blustery day to be sure.
The single surprise was how well it went uphill with the extra 12 ounces. It now weighs 6lb 6oz and goes uphill very smartly, whereas I'd expected the vertical performance to be doggy because of the extra weight. The HB-40 PDP (Perry Directional Porting) had never been in a plane before as I'd purchased it and installed it in an American Revolution helicopter, though it didn't get run much there. It's power surprised me. I'm not into fast anymore so don't know how much enjoyment I'll get from the plane.... but it was a hoot to fly an Alley Cat again.
It was put through some loops, rolls, Cuban eights, stall turns, Immelman, inverted and as remembered.... it handled aerobatics well. The one thing not tried was spins... mine would go into a flat spin easily and wasn't real easy sometimes to get out and because of the wind and grey cloudy skies they were left for another day. I'd like to do an in flight CG first anyway as it had felt slightly snappy with giving hard elevator. The landing also acted slightly tail heavy with a little ballooning as it slowed... but that could have been ground effect winds. Will just have to test again on a less blustery day to be sure.
The single surprise was how well it went uphill with the extra 12 ounces. It now weighs 6lb 6oz and goes uphill very smartly, whereas I'd expected the vertical performance to be doggy because of the extra weight. The HB-40 PDP (Perry Directional Porting) had never been in a plane before as I'd purchased it and installed it in an American Revolution helicopter, though it didn't get run much there. It's power surprised me. I'm not into fast anymore so don't know how much enjoyment I'll get from the plane.... but it was a hoot to fly an Alley Cat again.
