scubaozy

I just have ordered one and now considering the engine options. Engines in my radar are OS GT22, GT33, GF30, GF40 and DLE 30 with pitts muffler. Obviously four stroke engines are quite pricy, I have to see whether I can justify it. Nevertheless, I found an offer with a minimal price difference between GF30 and 40, so bigger one could make sense if it fits into the cowl. I saw a video of Macchi and GT22 seems to be more than enough engine for it. There is a very nice scale 18x8x3 prop from biela and I think it would look just scale on macchi. I guess GT33 or DLE30 would be able to turn it efficiently. What is your opinion about engine choices?

sparky4lawndart

My Feedback: (10)

Congrats on finding one... I sold my spare kit some time ago... I cant find another for a decent price. I've been running my with a DLE30 and the Biela 3 blade prop for 2 years now. works great! Just be careful about running flat out for extended flights.

paladin

My Feedback: (9)

Good luck!

I'm hoping to get back to mine.

Be where of the rudder/ tail wheel stearing post. Mine had two problems there:

The tailwheel post comes up through two trunion mounts that are already mounted in the plane. Thosse trunions are two small and i had to take over .030inches off the tailwheel post to make it fit apropriatly. But then the control bracket was loose. I fixed that with some shoe goo. I hope it holds up

at the top of the tail wheel post an "l" bracket is inserted to control the rudder. It (the "l" bracket did not fit in the hole) i figured it was the plating they had on the "l" bracket causing the problem but it still did not fit after removing the plating and reshaping the tip. Ended up redrilling the hole.

Joe

scubaozy

Thanks, I read in your previous posts that you are using 16x10x3 Biela, I think it is a little small to be scale, in that case I'd rather go for 2 blader. I am wondering whether os gt 33 would be able to turn 18x10x3, which would be probably perfect scale size.

scubaozy

I have the plane finally delivered. Quite impressed with the looks. Quality seems to be average, perhaps less than a Seagull. I have found quite few areas where I need to glue or reinforce again. Covering looks good, hope it will hold out as well as it looks. I have noticed that retract supplied are different than I have seen in various forums. In general, they are made from blue aluminum. Mine came with normal alu color. I am wondering whether I have an improved version of the retracts. I initially thought of tossing the stock retracts away and putting in a pair of e-flite 60-120 85 degree retracts. I am wondering these retracts are worth of trying, although I find electric retracts much more practical. One other thing I noticed was that my pilot was not glued in, I had expected that it was already fixed into the cockpit.
I still consider the engine options, it seems that OS 4 stroke engines will have the mufflers getting out of the cowl in a not so stylish manner. I will look around for a 26cc or go for GT22 I guess.

paladin

My Feedback: (9)

Those are defiantly not the factory retract I have. Did you test them to see if they hold air?

Joe

scubaozy

Thanks for the feedback, I will test them in the weekend, I need to figure out first how they work .

paladin

My Feedback: (9)

The cylinder has two barbs on either end. When you put air to a barb it pushes the piston inside away from it.

To test for leaks you need an air source with a pressure gage. Pump one barb up to 60psi and let it sit, it should hold that pressure for 10 minutes, then do the other side. If any of the four barbs does not hold a moderate pressure for 10 minutes they will give you trouble and you have a really nice talking piece.

You can use a tire pump in a pinch. Get a needle for pumping up footballs, basketballs, etc.. Slip one end of a 10-12in (40-50cm) peace of the air tubing they gave you with the Macchi200 over the needle. Secure it with a few zip ties or twist ties. Slip the threaded end of the needle into the tire air pump and cam it in snuggly. Test it by clamping the other end with vice-grips or something and pumping it up. Be careful cause if the pressure gets to high the hose will come off the needle with prejudice. If it holds air you are ready to test by slipping the free end over the barbs on the retracts.

I hope they hold air for you! Mine did not.

Joe

scubaozy

Thanks for the instructions, these are my first air retracts, helped a lot. Yesterday evening I finally had a glance at the instructions and found that my retracts are indeed new version. I have quickly put the system together and used a bicycle pump to pressure the system. It worked ok, actuator was/is a little stiff but other than that I did not have any problems. I left the system under pressure whole night and I could cycle the retracts 4-5 times in the morning, I guess it is not leaking (I don't have a pressure gauge, so I can't exactly tell how much air is in). I hope it will remain airtight with the engine running. I guess I will give a try to the stock retracts, I can always switch back to electrics later if I find a showstopper bug.

paladin

My Feedback: (9)

five retracts after all night is excellent! but that is just one side, you need to do a similar test with the piston on the other side.

the test i go through for new retracts in the plane is charge to 80psi, set for at least 10 minutes, and 4-6 cycles and they are good to go. you exceeded the time and still hit the cycles target. that's good to me, just make sure the other side is =.


for the oil to use:

IDK if you can charge your own Air conditioning (AC) there. but on the chance you can, go to the local auto parts store and buy the oil they sell for adding to the AC unit. it is in a sealed aerosol can. To open it I drive a nail through the bottom of a plastic/ paper cup with the pointy end in the cup. Put the oil can in a tuperwear container to ketch the oil. Place the nail cup assembly over the seal so the cup covers most of the can. hit the nail with a hammer, it does not take much and the can will start to spit oil. It will hit the cup and rundown it into the tuperwear container.

The oil will bubble/foam when it comes out because it has a seal conditioner in it. You cant keep it sealed in once the can is open, and you don’t need it on new retracts that hold air so let it outgas and then bottle it. I pull the line off the tank to the valve and fill about 4 inches of line with oil, reattach and work the gear till the oils is gon from the line.

Should you develop a leak you want to use the oil while it is still foaming and it will fix minor tears, or nicks in the seals.

I realize you will probably not need to do this for a season or two, the seals should have been greased at the factory. But you have it for when you need it.

Joe

scubaozy

I am progressing with my build. I went with OS gt 22 as I have very good experience with it and it did fit fully into the cowl. I think I will have to make a small hole for the exhaust pipe only. In the weekend, I put the wings on and tucked everything into the cowl to see how it will balance and it seems to be close enough. I am using heavier 17x8 apc to help it to balance. I also tested the retracts as I have the wings first time on and it seems air retracts don't have the steam to push the retract doors in. I am tempted to remove the springs fully. Is there any other fix for this?

NoFlaps

My Feedback: (131)

Stock BHM retracts don't have a-lot of umph...You could try using lithium grease around the seals and dble check all line connections to ensure maximum pressure, minimum air loss, but regarding the springs, you could use subber bans that don't have as much tension as the springs. This could make closing easier.

scubaozy

I guess you are trying to say rubber band ;-)

scubaozy

I finally managed to maiden yesterday with success. I had OS GT22 running on the ground about 15 minutes, leaned out the factory needle settings and it was running reliably, a bit rich but reliable. I had it balanced with about 150 g weight on the motor mount. Retracts are keeping the pressure however, retract doors are always on the way and often retracts are getting stuck without fully getting into wheel wells. So, I decided that I will not use the retracts during the maiden until I sort it out.
The plane took off quickly, I gained some altitude and noticed that up elevator was need, and gave 5-6 ticks up and it was flying straight. I had the aileron throws conservatively set, so, it flew quite docile. After 5 minutes into the flight, I was already doing some mild acrobatics. I have 2 stages set for the flaps and used only 1 level and there was no ballooning. It landed absolutely perfect in a scale fashion.
I flew altogether 3 times 15 minute flights without pushing the engine too hard. All three landings were as reported above, scale and easy with flaps. There was a little wind, so I can see myself using flaps in fully down position in windfree days.
Engine had good power, it was not overpowered but I could do long steep climbs. I think I can have potentially near hovering once the engine is broken in. I have used 17x8 APC prop, I chose APC over wooden props because I need the weight in the nose, so, it worked out well.
Today, I have re-adjusted the retracts, they seem to work now at home but I guess you know the drill I guess, once you are at the field, with some magical reason they stop working. I will try out the stock retracts a bit longer, if I don't get it right, I will probably go for lado retracts. It seems this is a good flyer, probably, the investment will pay off.
Good day to all!

paladin

My Feedback: (9)

congrats on the maiden!

I seam to always do maidens gear down. its kinda funny cause I was taught to keep it simple stupid on maiden. flaps and retracts just add more complexity, but they change the entire landing process for the better so I use them when I can on maiden. I'm 1 for two last year.

now that my work room is back above 0defrees F I'm back working on mine. fuse is done, should not take long for wings.

Joe

Joe

scubaozy

Thanks. I have found an interesting blog which I could read through google translate. Blogger installed the flaps inside the wing, which looks like a great idea. I already had the wing done when I read this, if you consider doing it, it is here.

paladin

My Feedback: (9)

this one is set up pretty we for doing that. the holes in the aft spar are already there. you will need a control horn that goes forward of the hinge point and still clears the aft spar. also when putting the flap servo or making linkage adjustments the servo will only lift out of the wing by enough to remove the servo output arm and pop it off to get into the linkage. so all linkage adjustments require taking the output arm off the servo.


if its the first time you'll try it. it is worth the effort because you will learn a great deal and that is what ARF's are for. for me I will consider it when this gets recovered 4-10 years down the road and it gets a more scale like rebuild, if it lives that long. would also consider the ailerons, I think the control horn is on top of them on the real plane. that would mean doubling the aft spar and then making a notch in it for the clevis to clear.


fun fun


Joe

paladin

My Feedback: (9)

fitted the cowl. need to add back up battery pack to motor side of firewall and fuse is complete.

Joe

scubaozy

I am a little frustrated with mine for the time being. Retract mounts are made of very inadequate ply and mount on the right wing broke after a normal landing. I repaired it and after 6- 7 landings, this time the other mount broke; this time a little worse then the first incident. The landings were not hard. Now, I need to redesign the mount for the left wing. I suggest you soak the mounts with slow curing epoxy to strengthen it.

paladin

My Feedback: (9)

ya, that's the last thing I plan to tackle. I noticed the mounts are pretty thin. standard operating procedure for me is to remove the front mount and make new rib braces from marine ply then the new front brace is maple. then I fill the entire bay with the foam they put in boats so they will not sink. then carve away just what I need to fit the retracts. if the aft mount is week enough (2x 1/8 lt ply) ill put some 1/4x1/2 pine under it so the screws hit it.


light ply is a poor material for landing gear bearing points!

I was hoping to avoid all that work but I'm glad you wrote in cause now I know its needed.

Joe

paladin

My Feedback: (9)

going back to the retract thing did you have any ground handling issues. if im going to tweek the lg mounting blocks should I add any forward rake?

Joe

scubaozy

I have nosed it over twice and one was during taxi on our not-so-even grass field. The second time was in landing, it nosed over and tumbled resulting in cracks in canopy. It is just like any other warbird, it will punish when not careful. I think it is a good idea to add forward rake. Having said that, I think a small amount without disturbing scale appearance will suffice.

paladin

My Feedback: (9)

Ok, that is what i figured. What i will probubly do then is mount some maple under the existing lg mounts with epoxy. Cut away the factory mount just under the ears of my lg leaving the maple to mount to. Then i can shim between the maple and the lg to get the rake i want. Would like the wheel axiles onder the leading edge but that may look bad so will have to play with it.

Joe

scubaozy

I am working on fixing the retract mounts, distracted by good weather. Meanwhile, I have noticed that oleo legs are extremely stiff, I have to put on enormous pressure to get them working. I think these will never absorb the impact, hence, all the energy will end up on the retract mounts. Anyone has a fix for this?

paladin

My Feedback: (9)

try this:

take the oleo out and the wheel off. put one end on a bathroom scale and lean on the other end till they retract, telescope in. what does the scale read?

if they are set up for your model that should weight aprox 13# it should take about 10 to 20# to retract the oleo's. obviously the optimal number would be 13#, that would be 2G to make them go all the way in. of coarse I say this with no actual experience in that matter other than being an ME and when I pick up the tail of my plane to walk it back to the pits I can hear the oleos slamming against the stops as the wheels hit bumps.

Joe