q8cub

The reason I am asking this question is because I have an sd model YAK 50cc with DA-50 engine. The guy who sold me the model had put weight at the tip of the cowel of 195 grams.

A guy at the flying field who owns the same model but with DL-50 engine did not add any weight at the nose. He flew my plane and did a hover and told me it seemed harder than his model in keeping it in a hover. He said he could put his model in a hover with almost no inputs. He thought I was doing a good job keeping it in a hover which boosted my confidence since I am only trying to start with 3d.

He adviced me to take off some of the weight at the nose and maybe take it all out. When I talked to the guy who sold me the model, he told me he added the weight because the DA-50 is light and maybe 200 grams lighter than the DL-50.


Back to my question: What is the weight of the DA-50 and the DL-50. Do they have the same weight?

Thanks in advance!

JoeAirPort

My Feedback: (41)

Same exact weight. 3 pounds bare with spark plug. I weighed them. Weight of muffler used may add/subtract a few ounces.

q8cub

Thanks.

I corrected the added weight above: it is 195 grams.

The weight is glued to the cowel and I tried to take it off with no success.

Do you think an extra 195 grams at the tip of the nose would make 3d much harder? And by the way, I checked the CG and it is within the recommended range by the manual. The manual, however, suggests it could be moved slightly back after model is trimmed.

daveopam

My Feedback: (9)

I would balance it without the cowl and see where you are at. If it is close to the range, take a Dremel tool and grind the weight out of it. When the cowl is back on it should move the CG back up a little. You could also grind the weight out a little at a time. Take some out, fly it, then take a little more out.

David

JoeAirPort

My Feedback: (41)

That's a lot of extra weight. I'd do what Dave mentioned. Or you could just Dremmel it all out and just shift batt's forward if necessary. If your buddy's balances fine so will yours. That's pretty much a standard engine for that plane (DA/DL-50). The thing that makes a difference is the muffler. The stock DL muffler is 3.4 ounces. A Slimline wrap-around pitts is around 9 ounces. Compare your muffler weight and your buddies. Spinner too. If all things are similar you should be able to place your batts where his are, with the cowling weight dremmeled out.

Do a flying CG test. Get the plane flying straight and level inverted at 1/2 to 3/4 throttle. Let off the elevator stick. What does it do? If it dives suddenly, it's nose heavy. If it loses altitude gradually, it's good. If it climbs it's tail heavy. Some people like it to go straight and not lose or gain altitude. You can also do this test inverted in a 45 degree upline. I'm used to doing it straight and level.

Revy

My Feedback: (1)

The flying differences is the CG factor. Nose heavy aircraft are tougher to keep in a hover. The "locked in" feel of your buddies is because he has his tailheavy or CG moved back. Dremel the lead out as instructed, I'd start by removing it all and then play with the batteries location to find yer sweetspot. My $0.02.

q8cub

Thanks guys for the feedback. It was of great help.

I finally was able today to take off 75 grams using nail polish remover to undo the epoxy. There were two groups of weights: one at the top tip and another at the bottom tip of the cowel- 75 grams top and 120 grams bottom.

A pro 3d flier who tested my model, adviced me to do it in steps- 30-50 grams at a time. I did a 75 grams as a first step. I could say I would like to have the model that is somewhere between a precise flying 3d machine (slightly nose heavy) and an easy hovering one (tail heavy).

I will try this and see how it goes.

q8cub

Status report:

Tested with 75 grams taken off two flights today. Wind speed was 18-20 km/hour. The same guy who tested it before taking off the weights tested it today and said it performed better. He could hover it close to the ground but asked me to take more weights off and see how it goes.

I will try to do more tests in a less windy day within the next two days.