Unspinable Xtreme 3D (Ha!!)

11-04-2004

Aircraft: Kit built Balsacraft (Ripmax) Xtreme 3D. Mods: carbon undercarriage.

Okay, the other day I moved the CG back until it climbs inverted hands off, and climbs even more upright hands off and still the mutha won't snap or spin!!
The CG is about an inch behind the rearmost position given on the plan. What gives? I have about 40 degrees each way of elevator and plenty of rudder. I can get into a pretty pathetic inverted spin that I can flatten a bit with opposite aileron but its still nose down and spirals out with just a breath too much of the opposite. Positive snaps or spins don't even exist. Snaps are just a quick barrel roll and its obviously not stalled.

Next day I tried eight inch "toblerones" on the leading edge at the tips. If you don't know what these are they're just triangular strips that sharpen the leading edge. A sharp leading edge is known to induce stalling whereas a rounded leading edge is known to smooth the airflow and so help prevent stalling. Anyhow, this didn't make much difference either! So what now?

It doesn't want to do it and I can't make it, please help

adzam · 11-04-2004

lol wish i could help m8, but to be honest it`s beyond me

12-06-2004

Had to give up flying the Funtana due to lack of fuel (four stroke needs 50/50 synthetic/castor mix) till the next show (Weston Park on the 19th) so thought I'd have a bash with the Xtreme again (two stroke likes pure castor which I have plenty of).

Xtreme has a few problems with knife edge coupling so thought I'd fly it on a computer radio (FF6) to see if I could sort it out. Well, while setting it up I decided to increase the elevator and rudder throws by using the ATV (Adjustable Travel Volume) function. You can't get bigger servo arms in the fuz', not enough room. Rudder is till it's parallel to the elevator halves (about 40 degrees - 80 total) and elevator is a little more, say about 42 - 43 degrees for a total of around 85.

Now suddenly the damn thing will snap like a good 'un! CG still needs to go back further as a proper flat spin is still unobtainable, you just get a nose down version, similarly the knife edge spins, so I may modify it to have the elevator servo at the rear by the tail - this was an option on the plan but I ignored it like a t**t!!

Now if I could just trim off half a pound of weight I'd be onto something! Alternativly, I'll just have to save up for a Saito 72 or the new OS 70 Ultimate four strokes to replace the SC53 two stroke in it at the moment. One day, one day...

Anyway, the extra movement has enabled all the flick and spin stuff so I'm pretty happy even though this aircraft is now very dated as far as 3D flying is concerned. Well, I like flying it anyway...

T.W. · 17-11-2006

Wowbagger: Glad to read that you sorted your problem out. The Balsacraft Extreme 3D is my all-time favourite model. I built mine in 1999 and sold it after having 175 flights with it, and then it was taken off the market. If I'd known then, that all this time later I would still be trying to find a model which suits my flying style as well as the Extreme did, I would never have sold it. Is there any chance that you'll sell me a copy of your plan so that I can build a "replica" over the coming winter?

Tony

PS: Please!

adzam · 18-11-2006

hi tony, unfortunately Wowbagger is no longer a contributing member of the forum,if you look at the dates the posts are over 2 years old
hopefully someone else could help you out though, or point you in the right direction.

**wonwinglo** · 18-11-2006

T.W although I have lost Wowbaggers e-mail address,just leave a message here for him- http://www.fennisflyers.org.uk/ and ask for Gez.
That should put you in touch via his model flying club.

T.W. · 18-11-2006

Many thanks guys. I advertised for a copy of the plan on the BMFA website last night. This morning a guy 'phoned to say he's going to get a copy of his own plan and post it off to me on Monday. Doesn't come any better than this does it

Tony