800mZero

My Feedback: (2)

guys please describe this binding during rotating? ZDO you mean there is play from side to side?

jet22b

I just found out I do have side play on both wheels. Maybe this is what SR is talking about???

Sonny
aka
jet22b

paracanary

[link]http://www.rcgroups.com/forums/showpost.php?p=13955945&postcount=1326[/link]

My struts got sloppy after a number of flights resulting in nose overs. I found I could tighten the struts wobble by replacing the elbow pins in the anti torque linkage with a 2 mm screw whcih can be tightened down to a very slop free joint. Easy to install by sharpening the end of the screw. Also put some grease on the axle. The axles bends very easily causing the tire to rub on the strut when the landings are a little more than gentile. The axles should be hardened and not soft metal.

Pit-Viper 1

My Feedback: (12)

I have done this mod on almost all my ARF warbirds. It does help tremendously, but you do not want the retract to be cock-eyed on the mount. If you don't get it flush you will have problems down the road I guarantee it. I usually remove the block and sand it down to the angle I need then re-epoxy it in. You don't need to go that route though. Just add spacers under the aft of the retract, as 172amd suggested, until you get the wheel where you want, then sand a piece of ply to the height and lenght you need and install under both rails. You may need to glue 2 pieces together to get the height you need. Don't use regular balsa though as it will compress and your retracts will become loose. This is an easy fix and well worth the time to do it right.

Shane

CH Ignitions

My Feedback: (11)

I will like to ask all of you if by any chance come across the Merlin V12 engine darawings that was the P51 powerplant.I search the net and could not find the drawings.

Thank you
Adrian

jet22b

Adrian;

Check out this link below to see if it help!
http://www.bluebird-electric.net/rol...lin_engine.htm

Sonny
aka
jet22b

CH Ignitions

My Feedback: (11)

Sonny,

Thank You,
I went to this site and all over the place. I can not find the actual drawings. It is a place:

http://dynamotive.netfirms.com/merlin/

and this is 1/4 scale

a 1/5 scale:

http://www.enginehistory.org/merlin_xx.htm


I did buy a engine manual where it shows a lot of details... but I am not good @ CAD I will have to learn it first take some clases.

Thae actual engine is real complex I will like to scale down and Simplifie. with a block lenght no more than 7inch and all 10inch.

If any one interested in team up I will be more than happy.

Thank you all
Adrian

Speedracer2112

I found a couple of things. First, as you stated, the elbow pins are too weak (RED ARROW). One was broken and the other was loose. I have a rivit press so I fixed them that way. As soon as I can I will use screws and nuts like you did. Both axels were bent also just like you said. Next, as RodanAZ found, I also found the solder joints broken at the strut ( between blue arrows. So I soldered two of them back together. Next I found the horns they are using to hold them straight were bent in at every joint (BLUE ARROWS). The metal is weak as all heck. I put a piece of aluminum tubing in the joint to add strength to hold the horns apart. (YELLOW ARROWS) Its almost like they forgot to add these. I wish I had brass in that size but I didnt. I will switch that out also. I put them in very tight to hold the horns apart. Im going to buy some brass bar and solder it in place there too.

Last, to take stress off of the joints I filled my tires with foam inserts to make them stiff and roll/turn better/easier.

The struts are very disappointing. I see alot of maintence there over time.

SR

Speedracer2112

Pick up the tail of the plane and have the nose down 30 degrees. Roll it back and forth. Watch the wheels and feel for resistance. Now roll it back and forth with the tail wheel on the ground. If you see no rotation sideways and do not feel any resistance, then you are fine. Mine was rotating enough to hit the strut which locked the wheel flipping the planes nose into the ground.

I hope this helps.

SR

Speedracer2112

Last thing.

My plane weighs 12.2 Pounds !!!!!! OMG!!

SR

tony-howard

My Feedback: (224)

Adrian

Another source might be one of the Merlins for plastic models. You'd have to develop your own plans by measuring from the model - there are some serious looking Merlins out there. I'm not sure which ones - try some of the plastic model forums.

Just a thought.

Pit-Viper 1

My Feedback: (12)

Here is a link to some serious modeling/craftsmanship of a P51 and Corsair. Don't think it pertains to your needs much but makes for some very good reading. This absolutely amazing modeling. Well worth a read.

[link]http://www.craftsmanshipmuseum.com/park.htm[/link]



Shane

800mZero

My Feedback: (2)

speed racerthanks for the update with arrows and such I will be looking at mine tonight.


Got in some out door photos this weekend.

bradyb

Thanks for the additional R&D this weekend Gentlemen.

If we're going to have issues with the gear why don’t we just secure the gear and make the struts solid? Drilling through the strut while adding a screw and lock nut would work well while not being permanent. If there's no give in the gear is the plane going to be bouncing around or worse pushing the mounting blocks through the wings?

Any Robart struts that will fit?

RodanAZ

Looks great Zero!!

Are you planning to fly it with a two blade prop first? I had intended to go to a 4 blade prop, but have found (the hard way) that a large prop on this plane ends up in the ground a lot... I'm running an 18" prop, and it's very close to the ground when the plane is up on the mains. Added to the tendency this thing has to nose over, and there's not much room for error. I decided it simply wasn't worth the expense to put a four blade prop on.

bradyb

Yeah I don't think Zero should ever fly his plane, it looks too good.

800mZero

My Feedback: (2)

You dont know how much this is crossing my mind eek

I am lucky enough to fly off of fields of well maintained well manicured, well watered golf green grass, I am going to try and fly it with the 4 blader if I can....

bradyb

Okay I ordered number two. Hopefully she will be here sooner then late April.

Please Horizon, please speed up that availability date!!!

Speedracer2112

I'm pretty sure I can beef up the gear to my skill level and a 12.2 pound plane but I have a lot of tools at my disposal also. I'll post photos of the upgrade and try to just use a sodering ironto do the repairs. Who has the most flights on this thread? Why is this just showing up? RodanAZ stated early on that he had a failure but no other complaints of toe in. I have about 10-12 landings.

I've been looking at the Top Flite model also. I Dont think it has as many issues but it has been out a little longer.

Well I'm out for the next two weeks. No flying or building.

Have Some Fun Guys

SR

bradyb

Zero
I would use at least a two blade if you can. I'm so glad I hadn't yet installed my tony exhaust before my plane's maiden.

If it helps you feel better, I taxied mine all over the place and and it always rolled nicely. I actually brought mine into work just to spend a lunch hour doing some high speed taxi tests in our large empty parking lot.

Be careful Man!

jet22b

Hey Zero;
I may have to come to your field!!! Best kept grass in the world!!!

Well spent yesterday in the workshop going over my P-51 to find why the tail would not stay on the ground during ground taxi test with full up elevator. First thing I did was to move the CG from 4 5/8" to 4 7/8". To move the CG, I added 4oz of weight in the tail. Now she at the CG the manual call for. I did check and found that SR was right on the gear. Both left and right wheel was rubbing the struts. On my way to the local hobby shop to pick some wheels that will be a nice fit. I hope the weather will be go for this coming weekend so I can try her again!!!

Zero, that is one beautiful P-51. You did a very sweet job!!! I am thinking of buying one more when they are back in-stock and doing it in the 332nd Fighter Group color, ( red tail for the Tuskegee Airmen. )
Hope you have a good first flight and please post how is fly with the 4 blade prop!!!
Have a great week everyone!!!

Sonny
aka
jet22b

RodanAZ

I have around 30 flights on mine. The soldering on both struts eventually failed, and I definitely have some 'variable' toe-in from the inherent looseness of the strut/scissor design. Some good ideas have been posted on dealing with this, and I'll probably work to address the problem. I don't end up all the way on the nose all that often, and most of those have been caused by gear issues.

I think the nose over tendency comes more from the angle of the gear (wheels are too far back), and the down trim needed for level flight (the incidence thing discussed several pages back). Also, I'm running an 18" prop, which is scale, but still large for this size plane, and the gear is not correspondingly tall. When rolling on the mains, my prop is very close to the ground, and a very minor mistake will require a new prop. I have been working on this, and on one of my flap switch positions I set up a "take off" setting, which consists of only a very slight flap deflection, but takes out my elevator down trim. After take off, I switch to the flaps up position, and get my down trim back for normal flight. You have to be very careful applying takeoff power as well... if you goose it, it will go over on the nose...

And for info, I fly off a paved runway...

Zero, if I were you, I would at least fly it with a 2 blade prop until you get used to the plane. Those Zingers are pricey....

flylower

Wrong thread....

Speedracer2112

Worst case.

You can buy just the parts and retro fit.

http://www.robart.com/RoboStruts/440_series.aspx

SR

jet22b

I just wish they had went Robart Struts at first. The arf may have cost a bit more, but people would still buy. Well for now I will go with the stock set, but, I know soon I will have to retro fit with these!!!

Sonny
aka
jet22b