3W Bearcat with Moki 300
#301
#304
My Feedback: (7)
Made the spinner backplate out of many layers of vacuum bagged carbon. As you can see I drilled a million lightening holes. Before I did it was HEAVY. Glued and riveted mount points
for 3mm button head cap screws (on order).
Spinner is mounted and ready to run - minus burnt-orange paint.
for 3mm button head cap screws (on order).
Spinner is mounted and ready to run - minus burnt-orange paint.
#307
OMG I wish you all the luck you can get for this extremely demanding paint scheme.
A chap in Switzerland did this (99% sprayed, no decals) and it was a true challenge.
But a beauty in the air and on the ground, second to none.
Keep on the good work
Detlef
A chap in Switzerland did this (99% sprayed, no decals) and it was a true challenge.
But a beauty in the air and on the ground, second to none.
Keep on the good work
Detlef
#308
My Feedback: (7)
I think I know the guy you reference. His build made my build look like a monkey did it. I prayed there would be videos, but NO! Darn.
Made a mandrel so I could balance the backplate and then the spinner. It’s as well balanced as one can do without a dynamic balancer.
Made a mandrel so I could balance the backplate and then the spinner. It’s as well balanced as one can do without a dynamic balancer.
Last edited by mitchilito; 04-27-2020 at 02:24 PM.
#310
My Feedback: (7)
I was thinking of our friend Detlef as I took this opportunity to do a rough CG check. He expressed concern about my decision to put the two elevator servos and the rudder servo waaaaay back in the tail. However, my DC-7 cowl and giant spinner add SIGNIFICANT weight to the nose.
Anyway. As it sits in the pic below the CG is about 3 inches in front of the wing tube.
Hey - it finally looks like an airplane!!
Anyway. As it sits in the pic below the CG is about 3 inches in front of the wing tube.
Hey - it finally looks like an airplane!!
Last edited by mitchilito; 04-29-2020 at 12:12 PM.
#311
Hi Mitch,
the difference was that I was lacking the heavy spinner, AND I had a scale but not light-weight tail gear ( 420 gr complete with everything, including wheel etc).
I could NOT afford 2 servos in the tail.
Maybe our engine mount is comparable, then your pretty spinner way ahead of the CG counts a lot on the other side :-).
Then I would guess your cockpit area is a lot lighter than mine. The guy that had built my cockpit was pretty generous about weight, the entire take-out cockpit had 1050 gr. Not really slim.
Again- good work
the difference was that I was lacking the heavy spinner, AND I had a scale but not light-weight tail gear ( 420 gr complete with everything, including wheel etc).
I could NOT afford 2 servos in the tail.
Maybe our engine mount is comparable, then your pretty spinner way ahead of the CG counts a lot on the other side :-).
Then I would guess your cockpit area is a lot lighter than mine. The guy that had built my cockpit was pretty generous about weight, the entire take-out cockpit had 1050 gr. Not really slim.
Again- good work
Last edited by Detlef Kunkel; 04-29-2020 at 11:46 PM.
#312
My Feedback: (7)
That’s a good assessment, Detlef. But we won’t know until it’s done, right?! I can always move the heavy rudder servo up front etc. and my cockpit is going to be light indeed. I ordered the pilot bust yesterday, 100 grams and the instrument panel assembly, maybe 50 grams. It’s going to be very simple and light. “Stand off” scale for sure.
I was worried the stock canopy would be unsuitable for this Rare Bear version but after careful trimming I’m happy with it. Hard to tell much difference in these pics but this is the finished canopy trim:
Hard to believe John Penny could see out of that thing!!
I was worried the stock canopy would be unsuitable for this Rare Bear version but after careful trimming I’m happy with it. Hard to tell much difference in these pics but this is the finished canopy trim:
Hard to believe John Penny could see out of that thing!!
Last edited by mitchilito; 04-30-2020 at 03:24 AM.
#313
My Feedback: (7)
Brazed up the 2-into-1 today. Got the pre-fluxed rod from Vogelsang. Expensive but really easy and effective stuff. A little goes a long way so maybe it’s not so expensive - per use. . .
It’s a little scary brazing these pipes on. Once you braze them they are on for life. You have to destroy them to get them off! Better do it right the first time!!!
It’s a little scary brazing these pipes on. Once you braze them they are on for life. You have to destroy them to get them off! Better do it right the first time!!!
Last edited by mitchilito; 05-06-2020 at 02:34 PM.
#315
My Feedback: (7)
After drooling over Detlef’s big 28 mm gear actuating cylinders I couldn’t take it any more. We always knew my whimpy stock Century Jet cylinders would be marginal (22.4 mm) so I decided to see just how much bigger I could make my cylinders. Turns out MUCH bigger. My pistons are now 28.7mm! I will now have power to spare.
Stock cylinder on the right
This is what my blueprints look like. I know, pretty archaic ☺️
Stock cylinder on the right
This is what my blueprints look like. I know, pretty archaic ☺️
Last edited by mitchilito; 06-01-2020 at 02:27 PM.
#318
My Feedback: (7)
Breaking news!!!!
Now that I have finished every single thing that’s not painting I find that I’m unwilling to spend the next six months (or more) painting before I get to fly it. SO:
I’m going to put a quick “test” paint scheme on it. If and when I get it working well I will put on the final livery. This means I will be flying in a month or two - YAAAAYYYY!!
This will be the “test scheme”:
I’m going to put a quick “test” paint scheme on it. If and when I get it working well I will put on the final livery. This means I will be flying in a month or two - YAAAAYYYY!!
This will be the “test scheme”:
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perttime (06-09-2020)
#320
My Feedback: (7)
Just for fun I ran the numbers on my new gear cylinders:
original: .875 piston, 34 pounds of force@120psi
new cylinder: 1.0 piston, 94 pounds of force@120!!
Almost triple the force of the original cylinders. Amazing how that works.
original: .875 piston, 34 pounds of force@120psi
new cylinder: 1.0 piston, 94 pounds of force@120!!
Almost triple the force of the original cylinders. Amazing how that works.
Last edited by mitchilito; 06-11-2020 at 05:08 AM.
#321
Hi Mitch,
I bet you wont regret the big cylinders.
you would even appreciate them more if you had made your ( probably sad) experience with the smaller ones.
Very good work you show here :-)
I bet you wont regret the big cylinders.
you would even appreciate them more if you had made your ( probably sad) experience with the smaller ones.
Very good work you show here :-)
#323
My Feedback: (7)
Taking care of last minute details before paint: I finally got around to balancing the ailerons. This aircraft is FAMOUS for aileron flutter.
You can see the plugs to fill the holes I used to insert 2 ounces of epoxy/lead shot in each leading edge.
With my overbuilt landing gear and weighted ailerons the wings will be pretty heavy.
You can see the plugs to fill the holes I used to insert 2 ounces of epoxy/lead shot in each leading edge.
With my overbuilt landing gear and weighted ailerons the wings will be pretty heavy.
Last edited by mitchilito; 06-16-2020 at 04:33 AM.
#325
Nice Work Mitch.
I was not lazy either ( although pretty slow)
There are more than 2.5 years of project time and a few k€ on the table.
The middle one is mine, on the left Marios, on the right Chris (who wants to paint his I think silver).
The U/C is probably the most complex one I have built so far.
Let's leave out my old Cessna 337 RG and A-7 Corsair II (too long ago);
The 1/4 P-40 was already very complex, the Jeanie ( P-47 1/4,4) with its oil damping and air suspension, which was switched off for retraction (with shortening of the telescope) was also not trivial, including very close resemblance to the original (at that time also measured in Duxford). That was more work.
But the Bearcat U/Cs is even more complex in terms of its components and overall geometry, plus the task of making sure that the locking mechanism is bullet proof to withstand the loads.
We calculated thrust forces in the rigid strut beyond 175 kilos. The holding forces in the lock reach a quarter of a ton (!)
There is a reason why the latch is so elaborate and was made of chrome steel.
I (you can see it on the pictures) wanted to have a predetermined breaking point with this enormous leg length. You can see the separation in the upper leg head. Its presence has challenged the construction of the telescope enormously, concerning the remaining length for the large spring travel including 2 step spring and oil damping.
You can't see it from the outside, but inside there is not a single mm unused or just loitering around senselessly.
The space is so completely used that the leg needs an external breathing chamber towards the end of the travel (air connection with hose on top of the leg). The telescope itself has a remaining volume of ZERO at the top.
I was not lazy either ( although pretty slow)
There are more than 2.5 years of project time and a few k€ on the table.
The middle one is mine, on the left Marios, on the right Chris (who wants to paint his I think silver).
The U/C is probably the most complex one I have built so far.
Let's leave out my old Cessna 337 RG and A-7 Corsair II (too long ago);
The 1/4 P-40 was already very complex, the Jeanie ( P-47 1/4,4) with its oil damping and air suspension, which was switched off for retraction (with shortening of the telescope) was also not trivial, including very close resemblance to the original (at that time also measured in Duxford). That was more work.
But the Bearcat U/Cs is even more complex in terms of its components and overall geometry, plus the task of making sure that the locking mechanism is bullet proof to withstand the loads.
We calculated thrust forces in the rigid strut beyond 175 kilos. The holding forces in the lock reach a quarter of a ton (!)
There is a reason why the latch is so elaborate and was made of chrome steel.
I (you can see it on the pictures) wanted to have a predetermined breaking point with this enormous leg length. You can see the separation in the upper leg head. Its presence has challenged the construction of the telescope enormously, concerning the remaining length for the large spring travel including 2 step spring and oil damping.
You can't see it from the outside, but inside there is not a single mm unused or just loitering around senselessly.
The space is so completely used that the leg needs an external breathing chamber towards the end of the travel (air connection with hose on top of the leg). The telescope itself has a remaining volume of ZERO at the top.