MarkShapiro

My Feedback: (52)

Sam, brazing is a special type of welding that using a tig weld machine (I believe). If you have a local welding shop anywhere near you, they will do it for very cheap. A couple years ago I built a custom exhaust for a Yellow Spitfire I was builidng. Took it to the welder already dry assembled. He brazed the whole thing up for me; about $20.00! JB weld will not work either.

fw190d9

My Feedback: (1)

If you are using copper, you need to braze it with a silver brazing rod and a torch. you dont need a tig welder. JB weld and regular silver solder will not work at all. Check home depot for brazing rods that work on copper
E.

BobH

My Feedback: (2)

You'll need a torch and you can buy the from Home Depot as well. Brazing requires a higher temp than does solder so the torch you buy will specify that it's intended for brazing etc.

samparfitt

My Feedback: (43)

Thanks, guys for the input.
Several years ago I bought a two part torch kit that has an oxygen bottle that says it's for brazing.
Now, I'll go to HD and get some rod and any needed special flux.

pappy35

This is a little technical but might be of help. Also do a search there for 'soldering' to get an idea of the differences.

[link=http://en.wikipedia.org/wiki/Brazing]Wikipedia Brazing Article[/link]

mr sopwith

if you use Bernzomatic Oxygen Torch Kit, you may need 2 or 3 oxygen cylinders for that job.
Try to weld it quickly.

How about 3/4" EMT Conduit ? you can bend it with a klein conduit bender....I'm not sure.

JeffH

My Feedback: (43)

I have been told that the brazing/soldering? rod used in refridgeration can handle exhaust heat. The rods are copper nickle or something like that? I do know that the compressed refridgerant gets HOT!!!

samparfitt

My Feedback: (43)

Thanks guys for all the input: I'll check all of them out.

============

Assembly (cont)

Finished up the cockpit.
I made a paper template for the 'dash' and then cut out the plastic dash.
I screwed everything together.
On the gunsite, I drilled a hole in the instrument panel and then put two screws through the dowel from the top of the fuse. The two sets of toggles panels were screwed to the dash from the bottom of the dash. I then screwed the dash to the top of the fuse and then screwed on the front wind shield. I bought some brown ribbon at the local art store and secured the seat to the vertical rails with the ribbon. I used some 1/4" diameter dowels and pushed those into the bottom of the rails that hold the seat, drilled holes in the floor and inserted the dowels into the holes to keep the rails in one spot. The back of the rails were screwed, using the ribbon, to the back bulkhead.
The sliding canopy was installed and connected to the sliding rods in the side brass rails.
After checking the cockpit for operating correctly, I installed the wings to the fuse and sat her on her feet.
Last, I installed the engine, connecting up all the wires, lines and linkages.
After fueling, I had to put the choke on, the throttle to full and then used a starter to get the engine to pop (manual turning was not good enough to get the fuel to pump into the carb).
I then put the throttle to low and manually started the engine. It took about 3-4 of these routines before there was finally enough fuel in the lines for the engine to continue to run.
My solo 3-blade 32" was set to a 12 pitch.
The engine idles nicely at about 800 RPM'S.
I can only get the engine up to 2200 RPM's at around 60 percent throttle: after that, she just slows down.
My test sheet from the factory says: 800/4300 rpms.
Temperatures were all about 240 degrees for all five cylinders so all are 'popping'.
I put the chain saw oil on the rockers per the moki thread.
My buddy thinks she's too lean and I need to richen the high end. I'll work on that tomorrow.
(my old camera sent 'south' on me, I bought a new cannon and I'm spending time learning about it).

The video only shows the moki 250 in idle:
http://www.youtube.com/watch?v=1WYcl2GPKvY

DJ

My Feedback: (5)

Sam
Sounds great, can't wait to see her fly.
I got my pilot today, looks good but no May West to be had. Fast service on getting the pilot in. The size looks good.

DJ

samparfitt

My Feedback: (43)

DJ,
thanks,
please show pilot.

===========
Transport ("IT's never BIG enough!)

I screwed the ramps (31 5/8" center to center) to the trailer and rolled her in.
I'll have to take the prop off for her to fit when the P-61 is also in the trailer.
(still got to figure out how to stabilize the wings in transit while attached)

samparfitt

My Feedback: (43)

Moki PM:

I was able to tighten all the exhaust nuts by about a 1/4 turn, each.
The H needle is at about 1.7: specs says 1 3/4; I'll try 1.8, tomorrow.

warks62

My Feedback: (140)

Hey Sam, don't remember if you had done this or not. On the one that I am helping with we purchased the engine from Vogelsang. Super nice guy to deal with and has been very willing to help us with information. He highly recomended that we use the electric fuel pump. So when the Moki was ordered from him we ordered the fuel pump and Turbolator intake defusor (I think that was what it was called). When we were running the engine a couple of weeks a go to start the breakin, the engine was not getting much over 2000 RPM's and I realized that in the excitment of starting it the first time we had forgot the pump was not on so I hit the switch and then it would rev right up. Also it appears to help with starting. I am guessing that since the fuel is pumped up to the carb as soon as the switch is turned on that there is an instant fuel supply. Had read this in the Moki forum also about the fuel pump and seems to be a really good accessory. Anyway if you have it already then this was not needed but thought it might help.

DJ

My Feedback: (5)

Sam
A shot of the pilot
DJ

samparfitt

My Feedback: (43)

Engine rpm's:
First I want to try the high needle and the prop pitch.
I'm using 1/8" tubing and maybe that's restricting flow, especially the T in the line is a little smaller.

==========
Wing pump:

The pump makers in Germany replied.
They said to watch what baby oil used as some has very poor lubricating qualities as the oil also lubricates the pump.
They recommended Castrol Carelube biotech HVX but I contacted Castrol and they don't have that product in the USA but recommended HTG and referred me to a distributor in my state. Unfortunately, this stuff is only sold in large quantities (meaning it doesn't come in quarts).
The pump maker also said to check for any dirt in the oil, insure the control valve moves the full distance and to insure no air or leaks are in the system.

samparfitt

My Feedback: (43)

engine testing:

(also posted on the 'moki' thread)

Initial moki 250 engine testing:
Yesterday, I was only getting 2000 rpm's and hope some possible solutions will be posted on getting a lot closer to the specs of 4300 rpm's.

This morning, I've been running the engine using a solo 32" 3-blade (paddle blades) at 12 pitch (units = 9.5).
Specs say about 1.5 for H and L.
Mine was L=0.9 and H=1.7
I changed L to 1.5 and the engine was much easier to start (no starter needed this time as was necessary, yesterday).
The engine has easy access to adjust the needles while running so I moved L to 1.7 (idle went down so I increased trim) to maintain about 800 rpms.
The rpm still went to around 2100 ( so I moved the 'H' up as well as down about an 1/8 turn to get more rpm's but on the lean side, rpm's went down at around 1900 and no change on the rich side.
Using 1/8" tubing with a T having a 3/32" ID and tank on CG of comparf F4U.
Fuel line routes out the top of the fire wall and then to the bottom of the carb when the inlet is located. Ignition is mounted inside the fuse.
All cylinders are firing with temperatures from 210-240 degrees.

samparfitt

My Feedback: (43)

Engine test (cont)

Reducing the pitch 'did it'.
I dialed in a 10 pitch (8 1/4 on the dial) and now get 800/4130.
Since the factory test sheet had 4300 on a 2-blade, I'll stick with the 4100 for the 3-blade.
The engine is extremely easy to start: choke on, ignition on and flip a few times until she 'spits': Choke off and a few more flips and she's running. I haven't had any kickbacks but I wear a glove since I'm unfamiliar with 5 cylinders 'habits'. It doesn't take much to start the engine and the start is quick (and you don't think it is going to start).
Cylinders head readings were also good: 210 for top cylinders and 180/190 for bottom (they cool down fast as I checked the top cylinders first, and after checking the bottom cylinders, the top ones were also down to 195).

Test 02 video:
interesting: putting the choke on to stop the engine takes a few seconds.
http://www.youtube.com/watch?v=v5JFXI8MfdI

Solo props:
fyi:
pic 1/2:
Make sure you read the instructions for tightening the 12 bolts and prop shaft because the 'logical' method is incorrect: The prop shaft needs to be tightened first on the engine and then the twelve #6 bolts around the hub, repeating this sequence until all are tight. The prop shaft gets tightened first to insure that the two hub halves are 'square' to each other (equal gap on all sides between the props). The sequence I used on the #6 bolts was the two center bolts on each side was first tightened on all sides and then the two outer bolts on all sides until all was firm. I then repeated and tightened the prop shaft (which is loose after the 12 bolts are tightened). This process is continued until all is firm. (don't over do it as there should always be a gap between the two hubs: if there isn't a gap, it means the props are not making firm contact with the hub and must be replaced)

ps: also posted on the 'moki' thread.

samparfitt

My Feedback: (43)

Scott Prossen just called me and my results aren't logical and we have no explanation.
A change of pitch of two shouldn't produce such dramatic results as the prop pitch was the only change made with no adjustment of the needles. Scott said his solo zero point was not zero so possibly I really had a 16 pitch instead of 12 (the side view did look large as can be seen in the first test run video).

samparfitt

My Feedback: (43)

Post engine run PM:
A lot more work with a moki:
oil rockers and push rods.
tighten exhaust retaining nuts (about 1/8-1/4 turn).
tighten solo props 12 #6 bolts and prop shaft nut.
insure all wires and lines are clear of exhaust ring.

samparfitt

My Feedback: (43)

Pilot painted.

So happy getting the engine to run that I forgot that I painted the vailly pilot. Had to cut off the bottom of his legs and re-attach the feet near the knees, used 10 buck paint set from craft store and some hot glue gun to hold him together. Not bad, for now!
mmmm...kind of looks like Greg...after a hangover!

oh yes, my large numbered decals came in last week and 86 was put on the side of the fuse.

samparfitt

My Feedback: (43)

Looks like they now have a painted version out for four grand (about 300 more for the paint job).
ARF version only with folding wings.
(the picture almost makes it look like a 'profile' fuse!)

samparfitt

My Feedback: (43)

Scott had a few other good points:
Keep the fuel tank as close to the fire wall as possible to keep the tube run as short as possible to the carb.
For gas, I usually put the tank over the CG but on a plane this large, a little extra fuel weight on take off isn't going to affect it's flying characteristics.
If you're having miss-fires in the air, he's finding his 4200 ma, 4 cell seems to cure the problem.

uncljoe

My Feedback: (8)

It appears they still have Big holes in the wing area(where we have crafted that hatch that covers it)

samparfitt

My Feedback: (43)

IN TRANSIT WING STABILIZER

Some 2" thick foam seems to work.
They don't flop around.
Some bungees hooked along the wing covers seem to hold the foam on.
Will have to give it a 'drive' test.

uncljoe

My Feedback: (8)

That pink foam just might be the ticket.
Joe

didiwatt

My Feedback: (38)

Sam:
Have you crafted anything to secure the main retracts while transporting and moving the plane around. Eventually, the air will bleed out and there is no locking mechanism. I used a short piece of aluminum channel that fit over one side of the scissors and then clamped it so there is no way they can collapse. I also learned that when you move the airplane on the ground, without the channel locks, always pull the plane backwards as the gear cannot collapse that way. I was pushing my plane forward and struct a concrete edge, both gear collapsed and all four doors where pulled off, all in a nanosecond. Duh!!!!!!!!!
LOL
Paul