66-stang

My Feedback: (3)

Well I finally got all my parts. So the wife is off to Chicago with my daughter and my son is at the in-laws. So tomorrow I will try and get her done. Also have a Skywriter smoke system I might install. Can't wait to fly this one. I had a DP Ultimate and really like it.

kwhite.6

I had a great day yesterday! I never could get the engine to run like I wanted it to but it is way stronger than the Fuji I had on it. I think I still need to lean it out more but I didn't want to go to lean with only 1.5 gallons thru it. It idles good, transitions good and I got the top end right but it's got a rough spot in the mid range. I've been doing some reading and best I can tell is that it's still rich. It took me about 2 gallons to get the Fuji figured out but I got it finally. I need to make a screwdriver with a small tube over the end so I can turn it with the engine running. Anybody got any suggestions?

bubbagates

My Feedback: (32)

The first thing I will say is you should never tune a gas engine while it's running. Just make small 1/8th to 1/16th inch turns, it really does not take that long

Now that I have that out of the way, what I do for rear mounted carbs is go to Lowes/Home Depot and buy a two pieces of brass tube just big enough to get your screwdriver through, now mount them so that the tube ends are right in front of the needles. and out the side of the cowl. I'll see if I can did up my pics of my Da85 install that I did this on.

twn

When I first started flying my ulti/dl50 it didn't have much power. I first felt let down but after 4 gallons and minor tuning I'm getting 7100 on the ground and still a little rich and my vertical is getting really good. Not quite to the crazy point but my buddies tell me after another gallon or 2 and I switch to 100% synthetic it will be a rocket. Oh and after I toss out the burn in prop, zinger pro 22-8 and get a xoar...

kwhite.6, if u think it has power now just wait untill you have 4-5 gallons thru her... OMG! But do yer self a favor and use an ashless oil for the first 5 gallons of fuel. If you are already using synthetic it will take forever to burn in. My IMAC buddies tell me to use Castrol TC-W3 Ashless. It will decrease your rpm by about 100 from synthetic. It did for me. Again my IMAC buddies tell me it is making the engine work harder and burn in faster. I'm getting 7100 on ashless. One more gallon and I switch to 100% synthetic and grab a new prop. 2-3 more weeks for the snow to leave and then it is play time!!!

chuck l

My Feedback: (17)

I have the DL50 on my Ultimate and vertical is insane even with a JTec muffler. Unfortunately, I've had a few dead sticks recently mainly do to dirt in the carb. I was just filtering the fuel from the gas can, but obviously that wasn't enough. There is a filter from the tank to the carb, plus a "crap" filter on the tank vent line now. However, I've had two dead sticks since, one because the engine still wasn't tuned back in, that happened on final approach so no big deal, just landed a little short. The other one was really scary with only speculation on the cause. I was trying a blender from way up high and the plane snapped really, really violently into a fat spin. Coming out of the flat spin, the motor was dead. (Don't do that maneuver if you are using the stock wing joiner!!!) All we could figure out was because of the long down line, the engine ran out of gas. With the violence of the snap, I must have had some throttle in it, which used up the gas or so the speculation goes. But then the engine restarted on the second flip, so that sort of counters the running out of fuel speculation.

Anyway, the Ultimate is a great plane, no pun intended.

Chuck

bubbagates

My Feedback: (32)

Chuck,

Just a hint, it's not uncommon to have a blender, KE spin or other extremely violent maneuver kill the engine, especially gas because the G forces can pull the fuel away from the carb/clunk, this bipe is especially violent in rotational maneuvers as it winds up pretty darn fast.

Something I always do is set my idle up a bit higher, usually about 300 rpm right after takeoff and leave it there, that will prevent that. On my 9303 I sent up a switch using a mix to do it for me but just raise your idle trim up a couple of clicks will work just as well. I find the switch must easier for me, less chance of pulling the idle back too far

In either case, do not forget to turn the switch off or lower the idle back down to land

chuck l

My Feedback: (17)

Bill

I have a switch set for a high idle also, but I wouldn't swear to having it on at the time the engine died. I will become more disciplined on using it. Thanks for the comment, point well taken.

Chuck

bubbagates

My Feedback: (32)

Chuck,

After re-reading your post and knowing how tight this plane winds up, I'd say the G's were enough to pull the fuel away, especially if you did this well into the flight so that the fuel load was getting low. During "normal" downlines and such ()if there is such a thing ), the fuel moves to the back of the tank so that would not likely cause it to shut down but a sudden and violent change into another maneuver could.

The problem with using an idle up switch shows up right here, sometimes because of the switch, the engine pulls the fuel from the line faster than it would normally and it only takes a couple of milli-seconds with the clunk out of the fuel to get a big enough "air pocket" in the line

I've started using clunks with filters on them as they hold a very small amount of fuel which pretty much eliminates this issue. I use the pick-up clunks that B&B Specialities sells for their fuel tanks. Haven't had that problem since on any plane I use them on.

http://www.bennettbuilt.com/page5.htm

Aircraft International also sells clunks like this

http://www.aircraftinternational.com/

Look under Accessories -> Fuel and Smoke

highfly24

We have one with a DL 50 on it. The chinese version of the DA 50. It runs great, just a little vibration. It does 3D Awsome. You would love it i think. Here is a picture of mine.

bubbagates

My Feedback: (32)

love the extra striping [sm=thumbs_up.gif]

highfly24

Thank you. It looks great in the air and low to the ground!

iflywhenican

My Feedback: (1)

Bill.....WELCOME back to the fold....

OldFart1

Well, I'm in the final stages of gathering all the "little things" before starting my build. The Princess asked me over the weekend "when are you going to start on that biplane I got you FOR CHRISTMAS"??

Seeing as the dachshund is a bit grumpy about sharing his bed, I've been happily contributing to the economy at lunch - lots of stuff ordered. I have a few questions though:

I'm going to run aluminum servo arms. My notes indicate that 1.25" is correct for the tail, but I didn't note the ailerons - 1.25" or 1"?

Do the Hangar 9 titanium pushrods take a standard threaded link on either end? I'm planning ball at the servo and DuBro 818's at the horn, unless it needs one end reverse threaded (TBM indicates this on their website) (Edit - I found a big picture of these so I think I've answered my own question - standard looks to be what they need)

The build:
ZDZ50NG
HS645's (ailerons)
HD-9150's (tail)
DuBro HD hinges
GP Extra 330S landing gear

chuck l

My Feedback: (17)

I need to buy two additional servos because of another plane I'm putting together. I want to put a HS7955TG on rudder of both my Ultimate and the new plane. With the juggling of servos, I would end up with a HS5945 on one aileron and a HS5985 on the other three ailerons. These are the spec's on the servos at 6 volts:

HS5945 - 181oz-in - .13seconds
HS5985 - 172oz-in - .13seconds

Does anyone see a problem with doing this? Both servos are much larger than the recommended servos, plus the ailerons aren't all that big, relatively speaking.

Chuck

bubbagates

My Feedback: (32)

Chuck,

Torque will be fine but you need to worry about the servo speed. I'm not sure what both of them are but if they do not match then the plane will roll all sorts of weird and you would not be able to do much about it

chuck l

My Feedback: (17)

Bill,

Thanks for the reply, as listed by Hitec the speeds are the same. I can also adjust the speed with either my radio X9303 or with the programmer.

Chuck

bubbagates

My Feedback: (32)

NP Chuck,

Those are good servos, you can't go wrong with them, especially on this plane

Inyosi

I have recently heard of "bluebird" does anybody know anything about them

kwhite.6

I carried my Ultimate out today and had my first dead stick. Actually every time was a dead stick landing. My Fuji wasn't as strong but after a whole year and about six gallons of gas, it never cut off. I'm going to try a pressure tube going inside the fuse to see if that will help. The only thing I changed this time was putting the spinner on and I'm thinking maybe it's changing the pressure inside the cowl. Every time I flew a knife edge from one end to the other, it would cut off. I tried richening it and leaning it, but it didn't help. Anybody got any other suggestions?

iflywhenican

My Feedback: (1)

Yep...If it is a DL-50, change the carb to the next size larger Walbro or either modify the main jets in the stock one. A pressure tube inside the cowl will not stop it from cutting off. A friend of mine had the same problems untill he went with a larger carb.

kwhite.6

Yes it's a DL50 so what kind of modification do I need to do? I can't find any information on it. Thanks.

skorman

My Feedback: (3)

My Ultimate is powered by a DL50 with 2 gallons through it and I've not had one dead stick...yet.

bubbagates

My Feedback: (32)

Sorry but this does not sound like a carb problem at all. I'd agree on the pressure tube though it's a bit unusual, but not unheard of, for a spinner to change cowl pressure. KE is the give away here. I'd be curious to hear if it happens in KE both ways, just to be sure.

In my experience, most guys flying DA50's that have the mid-range problems usually take the stock carbs from a DL50 which solves that problem

twn

I'm also using a dl50 and I have about 4 gallons of fuel thru her without any dead sticks. But the worst I've done are hard vertical climbs, loops and flatspins. I'm also still running a bit rich...

I should add, I'm using a felt (filtered) clunk that I got from the local saw shop.

JoeAirPort

My Feedback: (41)

I have this same problem on my DL-50. I did tap the vent hole for 8-32 and installed an 8-32 barbed fitting with red lock tite. I used tygon and plumbed it into the fuse. It really improved it but I still hear a change in mixture in knife edge left to right (but not the other direction). It's totally tolerable but I would prefer to improve it if I can. I think that the carb can be affected by in-cowl pressure changes and/or turbulants. It's affected in two places: the metering diaphragm vent hole, and the air inlet to the carb. Like I said the vent plumbed into the fuse totally helped but the air inlet is still seeing pressure and or turbulants at certain attitudes (knife edge only). You probably have to make some changes to the cowling like I do. I'm working on what those changes are right now. So far my plan is to either change the air inlet or outlet areas. My air inlet area is too big, wider than the engine jug on the outer part of the cowling. I'd prefer to block that more rather than chop up the bottom of my cowling.

Someone also suggested trying a velocity stack for this.