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Classic Designs => Classic Planes => Topic started by: Skip Chernoff on March 28, 2017, 07:19:56 PM

Title: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on March 28, 2017, 07:19:56 PM
Here is my recently recovered and no more hunting Palmer Thunderbird 1. Monokote finish,OS 32,7mm venturi,tongue muffler,5oz uniflow using muffler pressure,Enya NVA.Weight is 48.5 oz. 63' .015 lines Reyco Handle. Fuel is my homebrew 5%Nitro 23% oil 50/50. Prop ia10.5x4.5 APC. Engine is run on a wet two cycle. Lap times are 5.2 She's flying great now.....PhillySkip
Title: Re: PhillySkip's Thunderbird 1
Post by: C.T. Schaefer on March 29, 2017, 05:35:38 AM
Handsome ship..... Skip.  Hope to see it this season!   TS
Title: Re: PhillySkip's Thunderbird 1
Post by: john e. holliday on March 29, 2017, 10:59:43 AM
Looks great.  May have to build another one as I had one years ago before I knew there was a stunt pattern.  A Veco kit before laser cutting was thought of. 
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on March 30, 2017, 06:58:13 AM
Thanks guys, I'm waiting for a decent day to get a base color coat on a redone Ares and some other stuff. I'm loving this stuff,,,can you tell??? Cheers,Skip
Title: Re: PhillySkip's Thunderbird 1
Post by: Target on March 30, 2017, 07:24:53 AM
What did you have to do to stop hunting?
Looks great!
Title: Re: PhillySkip's Thunderbird 1
Post by: Randy Powell on March 30, 2017, 09:13:27 AM
Nice plane.
Title: Re: PhillySkip's Thunderbird 1
Post by: Glenn (Gravitywell) Reach on March 30, 2017, 12:33:53 PM
That's a very pretty and hip ship Skip.  Couldn't resist, sorry. H^^
Title: Re: PhillySkip's Thunderbird 1
Post by: rustler on March 30, 2017, 03:09:10 PM
A Mk. II T'brd. with upright motor? Nice.
Interested to hear what stopped the hunting.
Title: Re: PhillySkip's Thunderbird 1
Post by: john e. holliday on March 30, 2017, 04:52:59 PM
I think he said it was the first version of the Thunderbird which is what I had many, many years ago.  When I first started flying it, it would hunt a little until I got several flight on it.  I think the controls were too tight on mine.   But, what did I know back then other than I thought it was one beautiful design.   Did have Mr. Meriwether's Thunderbird II that was a completely different plane even thought you could see the Thunderbird lineage.
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on March 30, 2017, 10:22:21 PM
I discovered that a "cross brace" running chord wise placed over the lead outs near the last inboard rib caused binding of the controls under tension. With the plane sitting on the ground you could operate the controls and they felt great,but once flying with tension on the lines she would hunt badly. It took me at least 50 trim flights to discover this.  I recovered her with the Monokote and and she lost almost 6oz in weight. The OS32 I'm flying her with does just fine. Not a typical stunt run, but more than enough power to do the pattern and look good doing it....PhillySkip
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on March 30, 2017, 10:28:55 PM
Here's another photo.....
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on July 07, 2017, 11:26:39 AM
Just for the record I removed the OS 32 and installed a Tower Hobbies ABC 40. She flies with more authority now especially on windy days.
Title: Re: PhillySkip's Thunderbird 1
Post by: john e. holliday on July 08, 2017, 11:27:46 AM
That should do the trick.  My first Thunderbird was built fro the original kit back in 1963 and was powered with Fox 35 Stunt.  Gene Dunham put it through the AMA pattern just to show me it would do it.   Tried to restore it a few years ago and it gave up the ghost as all the Ambroid joints had come apart as well as the silk covering.  I now have Marvin "Big Iron" Denny's kit that he built several planes from with all his notes and templates.   Need to make room in the shop to start on it.  But, I still need to finish the ones I have in finishing stage now.   But, flying season is here and I need to get out more.
Title: Re: PhillySkip's Thunderbird 1
Post by: Target on July 08, 2017, 03:09:08 PM
Just for the record I removed the OS 32 and installed a Tower Hobbies ABC 40. She flies with more authority now especially on windy days.
I wonder about what percentage of that has to do with the (I assume) CG shift?
Are you (again, I assume) running a bigger prop also?

Good info to share as I have been thinking a lot about how much less or more thrust effects flight qualities.

Glad it's working good for you, regardless of the reason.

R,
Chris
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on July 08, 2017, 06:54:12 PM
Chris I actually used the same prop for both engines. The prop is a 10.5x4.5 APC. With the OS32 I ran it on a wet 2 cycle at a very constant speed. The Tower Hobbies mill is set up for a 4 2 4 break. Having the engine break makes flying it more enjoyable for me. One thing I will mention is that the OS 32 engine is very powerful for it's size, probably has more HP than most plain bearing 40s we commonly use in stunt.
Title: Re: PhillySkip's Thunderbird 1
Post by: Avaiojet on July 08, 2017, 08:07:25 PM
Skip,

WOW! You did a great job with that T-Bird.

Congratulations.

CB
Title: Re: PhillySkip's Thunderbird 1
Post by: Target on July 08, 2017, 08:16:24 PM
Thanks,  for the info,  Skip. The reply is of great interest to me with my recent post about an engine for the Tom Dixon Stiletto kit i have.
Some suggested a more 2-2-2 style power plant,  but so  far i have only flown the 4-2-4 break style.
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on July 09, 2017, 05:23:05 AM
Thanks Charles.It took a lot of trial and error,but she's flying nicely now.
Title: Re: PhillySkip's Thunderbird 1
Post by: Avaiojet on July 09, 2017, 09:31:16 AM
Thanks Charles.It took a lot of trial and error,but she's flying nicely now.

Skip,

Loosing that 6oz was magic. I gotta build lighter.

CB
Title: Re: PhillySkip's Thunderbird 1
Post by: Randy Powell on July 10, 2017, 01:33:39 PM
Nice plane, Skip.
Title: Re: PhillySkip's Thunderbird 1
Post by: Steve Helmick on August 09, 2017, 08:39:05 PM
A Mk. II T'brd. with upright motor? Nice.
Interested to hear what stopped the hunting.

Yes, I was also thinking that the wing is a Mk.II/'59/'60 blunter shape tips and not the more elliptical/pointy tips of the first Veco T-Bird. Puzzling. Regardless, good on PhillySkip for finding the problem and making it fly right.  H^^ Steve
Title: Re: PhillySkip's Thunderbird 1
Post by: Joseph Patterson on August 11, 2017, 06:27:14 AM
    Thanks Skip for posting. It looks great. A few of these have flown at DVIII contests and they were great fliers. We have raffled some off at our contests. I've always wanted to build that one. I like the dark fuse. and the bright wings-nice.
          Doug
Title: Re: PhillySkip's Thunderbird 1
Post by: Skip Chernoff on August 11, 2017, 03:07:43 PM
It's funny,that plane has gone thru so many changes. For the record, that wing is not the correct TB#1 wing. The original builder admitted to warping the kit wing and scratch building a new one with  a constant chord (no taper towards the tip) If you look at the pics carefully you can pic that up. When I got it she was covered in Coverite and I put on about 5 coats of clear Brodak's dope to fuel proof it. Weight was 54 oz. The Fox 35 flew it in slo-motion. I then put an OS 32 in it which put out waaay more power than the Fox,but it still didn't feel right. At present it has a Tower Hobbies 40 and is Monokote covered. It's flying very nicely now. I fly it on 61' lines eye to eye.

Around the time I got this plane I also got a TBII by the same builder. Again Coverite /Clear Dope finish, La 40 engine. Just my opinion but the TBII was a better flyer than this one especially in the wind. Unfortunately no one told me that I needed more than 4 oz of fuel with this plane to complete the pattern and I ran out of gas directly overhead and creamed it! I'd build another one,one day,but not from a kit........Skip