Originally Posted by binaryclock

Today I figured I'd maiden Beast #2 since Beast #1 had a sticky servo and badly messed up my wings and minor damage to my fuselage a few weeks ago.

I put the batteries in where I normally put them just under the top fuselage section back from the removable hatch and sent her on her way. I almost lost it.. it seemed extremely tail heavy and all she wanted to do was climb like crazy. I brought her down without problem and decided to set the battery to the front about a 1/2 inch more. Sent her back up - still wants to climb and seems tail heavy! Brought her back down and put the battery almost maximum to the front. Sent her back up and she flew okay with a few sticks of down elevator (like 3 or 4.) My #1 Beast isn't as touchy with battery placement. I can put it near the front, or way back and she still flies level with a one or two ticks of elevator trim. However this #2 Beast (never crashed and new out of the box) seems to be extremely touchy with battery placement.

Any ideas what it could be? I'll post the maiden flight in a bit so you guys can see. I've got like 200+ flights on #1 Beast so I've got experience with the air frame. But #2 Beast porpoised so badly I really had to get control of her.

You didn't say but it sounds like you have not physically checked the CG? It doesn't really matter where the battery goes, it is where the actual CG point is on the wing. Maybe someone left something in the model that shouldn't be there.

Originally Posted by WSEN

You didn't say but it sounds like you have not physically checked the CG? It doesn't really matter where the battery goes, it is where the actual CG point is on the wing. Maybe someone left something in the model that shouldn't be there.

Yeah I never check the CG of my models (which is really dumb on my part.) I just put them up there and see what I like. If I had a big 1400mm+ model I would of for sure CG test it without question. From this point on I'll be cg testing all models now.

Tonight I'll be making an ad-hoc CG tester. A maiden on a tail heavy beast would of been disaster for a new person flying it. I have the experience to know how to handle it, but it was still a bit scary not knowing it was going to happen that bad. Movie will be up in about 15 minutes of the tail heavy maiden.

Double post, sorry. Can't delete.

Guess I may as well put here that I added my #2 Beast Maiden video a few posts back.

Originally Posted by binaryclock

Yeah I never check the CG of my models (which is really dumb on my part.) I just put them up there and see what I like. If I had a big 1400mm+ model I would of for sure CG test it without question. From this point on I'll be cg testing all models now.

Tonight I'll be making an ad-hoc CG tester. A maiden on a tail heavy beast would of been disaster for a new person flying it. I have the experience to know how to handle it, but it was still a bit scary not knowing it was going to happen that bad. Movie will be up in about 15 minutes of the tail heavy maiden.

Tell me about it, on my maiden I got away with it because the battery was flush with the holder, session two the battery was under the cowel almost 3/4 inch back........that was horible.

Originally Posted by WSEN

You didn't say but it sounds like you have not physically checked the CG? It doesn't really matter where the battery goes, it is where the actual CG point is on the wing. Maybe someone left something in the model that shouldn't be there.

Wsen I have built a plane balancer (bent coat hangar in a vice) will that be sensitve enough? to get a good CG and I must do it upside down right?

Originally Posted by RTF Thumper

Tell me about it, on my maiden I got away with it because the battery was flush with the holder, session two the battery was under the cowel almost 3/4 inch back........that was horible.

Weird thing is I can place the battery where ever I want on Beast #1 and it flies pretty much straight and true. Maybe that's because there is so much glue on the thing that the weight of the battery becomes less of a deciding factor of the CG. But a brand spanking new Beast wants the battery up front.

I wish I had a good scale so I could weigh my train wreck-wings #1 Beast vs the NIB Beast #2.

Originally Posted by RTF Thumper

Wsen I have built a plane balancer (bent coat hangar in a vice) will that be sensitve enough? to get a good CG and I must do it upside down right?

Correct. Upside down. I put a very small black mark at the suggested CG point, which on mine is just about in the middle of the gold strip just before it makes its curve aft. Sort of cumbersome working around the flying wires, but the coat hangar trick works fairly good for me.

Most of my batteries (stock 120, 160 nanos, 190 and 210 miniaviations) end up being behind the cowl opening.

I just did a quick test with finger nails and battery placement, 0 diffrence and my plane only showed tail heavy with no battery. Must have been unseen crash damage that caused the radical flight issues in session two. then repair went well and bang all is good.

Originally Posted by RTF Thumper

Wsen I have built a plane balancer (bent coat hangar in a vice) will that be sensitve enough? to get a good CG and I must do it upside down right?

Got a link on how to bend it properly?

Naw just bent a big V wide enough to clear 1/3 each side then forward 3 inches then up 1/2 inch

Originally Posted by binaryclock

Got a link on how to bend it properly?

https://www.rcgroups.com/forums/show...r#post19091983

Don't know if I would trust this guy though. He lives in a small bush village in AK that has no take-out places to get foam plates to repair elevators.

Originally Posted by binaryclock

Got a link on how to bend it properly?

Here is a pic

Now I want more fly time, 5 min is just not enough. It goes by in a blink while I'm trying to get stunts right. Used a minute or two of a battery checking the diffrence of flight control movement last night with D/R and Expo. flew the battery today and found LVC at 4 min 20 seconds well got the pulse and no power. that was 4:20 of WOT and rollllllllllllllls lol

My replacement Beast arrived today. Everything was aligned perfectly. I relocated the control rods to my preferred horn positions & mechanically adjusted the trims. I went to the field for the maiden. Lined up, poured on the coals, and let 'er rip. Didn't even need any trim. Beast #4 flies as well as, or better than, Beasts 1-3. I am a happy camper...

Joel

Originally Posted by RTF Thumper

Now I want more fly time, 5 min is just not enough. It goes by in a blink while I'm trying to get stunts right. Used a minute or two of a battery checking the diffrence of flight control movement last night with D/R and Expo. flew the battery today and found LVC at 4 min 20 seconds well got the pulse and no power. that was 4:20 of WOT and rollllllllllllllls lol

I forget... you using the stock battery? If so, time to UPGRADE!