Goinstraightup

My Feedback: (26)

I knew it was only a matter of time before this thread was revived again. Woohooo! About the only "plane" that I have that goes to the field with me every-time is my PBF.

Nice job Steve 108.

Radio Mixing: I like about 20 rudder throw with aileron input - but that is just a personal preference. It helps in hovers. It is kind of cheating, but you need to use the rudder control waayyy less that way. Usually when you are hovering you can just give it a tiny blip of aileron input and be right on course then. I like to run all the control throw I can get and about 25 to 30 % expo (soften center). I think when guys use more expo than that it actually hurts your control feel and it becomes mush. Just my opinion on that too, but I've flown buddies planes with 80 % expo and the feel is mushy and difficult.

By all means go to a 10X4 prop. Don't know what % nitro you are using, but at the very LEAST I would use 15% for good power and transition. I've found that the extra power from 15% is well worth the few bucks extra a can. Especially when blasting out of a hover.

One of your problems may be the weight of your side supports. The VTOL thing is very cool, but I've found that PBF's (and any plane you are trying to 3D) are very weight sensitive. I've also found that Coro is not very light. Coro for a PBF airframe is around 8 to 9 oz. Therefore I can probably safely say that you've added at the very least 4 oz. with the side supports - probably more like 5 or 6 oz.

Also, I flew a .40 FP (the forerunner to the LA) PBF for 14 months then built a .25 size PBF and used a lighter battery and tried to save weight all around. Well, I almost ended up saving a whole pound. The difference in the flight performance of the 2 PBF's was like night and day. The light .25 one flys soooooooo much better. To be quite outright honest, if you took your side supports off and put a .25 FP or LA on that "plane" with a 9X4 prop, you would be AMAZED at how nice it flew.

The VTOL thing is cool tho'. The trick is to make them as light as possible. Maybe if you still want to keep them, slap some lightening holes in them.

Jeff

Steve108

My Feedback: (36)

Thanks, I forgot to mention that I did remove the wing tips. 20% A/R mix right? Also, where would you recommend balancing a PBF for a beginner in 3D?

Steve

Goinstraightup

My Feedback: (26)

Yeah, 20% A/R. I like 5 3/4" from LE. I just remembered something too, on the .25 size PBF I saved a little over a half pound - not almost a pound as I mentioned earlier, but it still flew waaaayyy better.

You picked the PERFECT "plane" for learning 3D. The key to learning 3D is fearless LOW close in (within safety reason of course) flying. This way you can see what is going on with your "plane" and make the required inputs. A lot of people wonder why they can never get the hang of 3D, but for one they have wayyy too heavy a plane and for two they have too nice a plane that they are completely scared to bring it under 200 feet high.

Keep at it - the reward of PBF flying is totally worth it. When you get 2 or even more in the air at once you end up laughing so hard you can hardly fly - of course if you doink it, it doesn't matter anyway. Put on a new prop and go at it.

One other thing that I've found very valuable with PBF flying is Q-Tips. I keep a handful of Q-Tips in my flight box then when the inevitable doink comes along I like to swab the dirt out of my carb before the next fire up with the new prop. Heheee. Works great.

Good luck and keep us posted on how it goes.

Jeff

Steve108

My Feedback: (36)

Will do.

Thanks again,

Steve

magnumeng

My Feedback: (8)

I have built and flown two of these wonders.

1st - OS 32 w/stock Nexus exhaust 2 Futaba 3003's, 1 FMA 100 and a 1500 NiCd. Let me say this I found out that FULL power is for hovering only. Just above idle is all I needed to fly around. It has been retired and awaits a rebuild.

2nd - OS 32 w/Magnum 40 exhaust 2 Futaba 3003(Elevons) 1 Futaba 148(Rudder) 1 FMA 90(Throttle) 1500 NiCd Radio 9zWCII. This one flies great and boy did the rudder add a whole new flying window. My throws are Elevons 3" up/down about 50 degs. The throw for rudder is almost 90 degs in both directions. I have NO expo dialed in at all just alot of small movements to get it to fly nice and easy. There is NO low rates either.

These planes are a blast to fly. Everyone should have one. You can use left over radio gear that you have laying around. That is what I did.

Dave McDonald

My Feedback: (19)

Wow! This thread is nearly 3 years old, and it continues to produce more and more new generations of PBF flyers.

Goingstraightup has once again written some very good advice that should be mandatory reading for every new PBF pilot. Thanks Jeff!

To all of the past, present, and future PBF pilots, thank you for letting me know how much you are enjoying your PBFs! I never get tired of reading these.

UPTater

I mix a litle expo in also - just to make the mid range a little less responsive.
Makes her a little less twitchy when I need some stable harrier.

magnumeng

My Feedback: (8)

Dave

is ther such thing as to much elevator and aileron through? I have managed to get close to 80 deg movement in both directions. Have not test flown it yet with this new set up.

Dave McDonald

My Feedback: (19)

Personally, I tend to limit my control throws to around 45 to 50 degrees in one direction, and no more than 60 degrees unless I'm using coreless or digital servos. IMHO, once you get over 60 degrees of throw with standard servos, the loss of precision control around neutral isn't worth the extra throw.

Steve108

My Feedback: (36)

Bad news guys, today when I was trying to fly my PBF I dunked it in my pool cover. (Full of water) I ran the engine after draining it right away to clear the water and will test the electronics after giving them a few days to dry. It does work so much better with a 10 x 4 prop. Good news about crashing in a pool is you don't break your prop.

I won't give up.

Steve

UPTater

Make sure - give it a few extra days to dry.

Getting a Grish Tornado (Tempest series) prop is another way to not break a prop. It will bend back time after time - but eventually will crack enough that I worry about using it. So get 2 - that way you'll have one flying while wating for a replacement. Good news is - they're no more expensive than other props!
http://www.grishproducts.com

Steve108

My Feedback: (36)

I found that the cause of this crash was that I forgot to check my fuel clunk after previous crashes. I won't make that mistake again!

magnumeng

My Feedback: (8)

Took my Pizza Box out Saturday and fly it till my glow igniter went dead, about 10 flights. Broke 6 props and it is still flying. This is truly an outstanding way to learn how to hover and other 3D stunts. Got 6 more props for this saturday... can't wait.

Steve108

My Feedback: (36)

Good news, I tested the electronics today they worked fine. I flew it around my backyard and had one of those very succesful days. I felt like I was in control of the plane rather than having it control me. I actually got to perform 2 torque rolls for more than a few seconds. My fun had to end for today when the glowplug shot out of its hole. (It was just JB welded in.) Today I learned throttle and rudder control are key for 3D.[8D]

Steve108

My Feedback: (36)

Oh yea, when I order my new head I'm going to buy props. Would you reccommend going with a 10x4 or 11x3? Again I'm running a .40la with no pipe but will be adding an MCP soon.

Steve

Dave McDonald

My Feedback: (19)

MA 10x4 or 11x4 works OK.
APC 10x4 or 11x3 works good too, but are more fragile.

Steve108

My Feedback: (36)

My rudder is not sensitive enough for my liking. It is made the normal way as shown on plans with around 45 degrees of throw. I drew up a drop in replacement. Do you think it would work?

Steve

Dave McDonald

My Feedback: (19)

Yep, it'll work!

magnumeng

My Feedback: (8)

You can get about 85 deg of throw on your rudder easily. Mine has enough throw so the control horn touches the stationary part of the vertical stab. Just use a LARGE servo horn and a 1/2A size control horn. That will give you the extra responce you would want. Also don't put in any expo. The plane as it built in already with the flimzy control surfaces.

Goinstraightup

My Feedback: (26)

I agree with Mag on the no expo on rudder. I'm using a cheapo old JR computer radio on my PBF and it mixes the elevons good and puts expo on them, but doesn't even have expo on rudder so I've never had it. I've always liked the rudder response from that set up.

Dave,

Speaking of rudder control, your upholstery thread Pull Pull that amazes me. I flew my first PBF for 13 months and biffed it 100's of times. In all that time the Pull Pull never failed once and was in perfect condition to the end! On all my PBF's since I've never had a failure or one hint of Maint to the thread pull pull. Very nice!!

Jeff

what?

is it posible to put a supertiger 45 on a PBF???


Thanks

magnumeng

My Feedback: (8)

I am in the works of building my 3rd PBF and will be putting a Magnum 46(just collecting dust) on it. Just remember that full power is for pulling verticle or out of a hover. Not for just flying around.

Also, If you have ever tried flying a brick, then you will know what it is like to fly the PBF with NO power. I don't think that the slope fliers will be looking at these any time soon.

what?

plese let me know how yours flyes with the 46 on the plane.
I first wil have to finish my spa3dt and then will start on the PBF.


Thanks

AKsel

Dave McDonald

My Feedback: (19)

A ball bearing 40 to 46 size engine is way too heavy for a 24x24 PBF. It might work if you scale it up to about 28x28 or 30x30......but I've never personally tried that yet.

magnumeng

My Feedback: (8)

The weight of a OS 32 Helicopter engine is 10.23 w/o muffler. The weight of a Magnum 46 is 13.1 w/o muffler. The muffler is weight is about 4oz for either engine. Smaller battery or lighter servos should be able to make up the weight difference to keep it light.

3 oz would be easy to loose atleast my PBF that i fly.