stunthanger.com

Building Tips and technical articles. => Building techniques => Topic started by: kevin king on March 12, 2022, 04:32:07 PM

Title: Carl Goldberg P40 Warhawk
Post by: kevin king on March 12, 2022, 04:32:07 PM
Strange i haven't seen any post about this kit. It was the first or second 'large' plane i built in my youth some 40 years ago. Anyone familiar with it? 
Title: Re: Carl Goldberg P40 Warhawk
Post by: gene poremba on March 12, 2022, 05:31:31 PM

 I built one years ago, possibly when it came out. I had a Mc Coy35 on it. The plane could be built as a C/L model or R/C model. I still have a complete kit.....Gene
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 12, 2022, 09:53:32 PM
Strange i haven't seen any post about this kit. It was the first or second 'large' plane i built in my youth some 40 years ago. Anyone familiar with it?

 A neat simple design that first caught my eye years ago with a photo of a very nicely done one in Dick Sarpolus' C/L book "Flying Around". I imagine it would perform about identically to the Goldberg "Shoestring", essentially the same plane except the P-40 wing has a straight leading edge compared to the slight sweep of the Shoestring L/E. I've built a few of the Shoestrings and enjoyed them all, just an honest fun airplane to fly. I've got two NIB P-40 kits on the shelf and really hope to dig into one someday.
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 14, 2022, 04:39:50 AM
Seeing the kit box brings back nice memories. might have to add that to my build list.
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 14, 2022, 04:41:42 AM
A neat simple design that first caught my eye years ago with a photo of a very nicely done one in Dick Sarpolus' C/L book "Flying Around". I imagine it would perform about identically to the Goldberg "Shoestring", essentially the same plane except the P-40 wing has a straight leading edge compared to the slight sweep of the Shoestring L/E. I've built a few of the Shoestrings and enjoyed them all, just an honest fun airplane to fly. I've got two NIB P-40 kits on the shelf and really hope to dig into one someday.
I guess you wouldnt want to part with one of your P40 Kits?
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 14, 2022, 07:53:11 PM
I guess you wouldnt want to part with one of your P40 Kits?

 Sent you a PM.
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 15, 2022, 06:43:49 PM

 Kevin, please check your PM.
Title: Re: Carl Goldberg P40 Warhawk
Post by: BillP on March 16, 2022, 09:16:21 AM
Was this the same as the "Black Tiger" featured in MAN or FM yrs back? Just curious.
Title: Re: Carl Goldberg P40 Warhawk
Post by: Dan McEntee on March 16, 2022, 02:17:30 PM
Was this the same as the "Black Tiger" featured in MAN or FM yrs back? Just curious.

    No, this is a profile model.
    Type at you later,
  Dan McEntee
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 16, 2022, 06:56:41 PM
Was this the same as the "Black Tiger" featured in MAN or FM yrs back? Just curious.

 Nope, totally different design.
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 16, 2022, 06:57:46 PM

 Kevin, shipping info is in your PM.
Title: Re: Carl Goldberg P40 Warhawk
Post by: BillP on March 17, 2022, 07:04:27 AM
My mistake on the name. Not the Black Tiger but how about the Nov 62 MAN article by Gatto...P40 combat profile with 43" ws for 19-35 engines?
Title: Re: Carl Goldberg P40 Warhawk
Post by: Dan McEntee on March 17, 2022, 08:23:25 AM
My mistake on the name. Not the Black Tiger but how about the Nov 62 MAN article by Gatto...P40 combat profile with 43" ws for 19-35 engines?

    I would need to pull the kit plans and compare to the magazine plan, but from what I can remember, that may be a possibility. That design was by Paul Del Gatto, I think is the full name. Worth a trip to the files to check out.
  Type at you later,
   Dan McEntee
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 17, 2022, 05:10:03 PM
No Flappers
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 17, 2022, 05:45:52 PM

 This is the Paul DelGatto design, it's own animal and not related to the Goldberg kit...

 https://freercplans.com/plan-p-40-1725.htm
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 17, 2022, 06:50:59 PM
 I got as far as framing up the wing for mine, somewhere around 10 years ago. It's still hanging in my shop, I pulled it down just now for these photos.

 I don't recall what the kit plan dictates, but I re-spaced my ribs for more wing area/span, shown here in the attached photos. This of course required starting with new L/E and T/E stock and pre-notching accordingly for the ribs. I went with 2-1/2" spacing for ribs R-1 through R-7. Spacing between R-7 and R-8 is 2". Spacing between R-8 and R-9 is 2-1/4". There is 1/2" between the two R-9's at center. This yields 39-1/2" between the tip ribs, R-1 to R-1. I forget what the overall span with the finished built up wingtips added came out to. I added shear webs as well, not part of the original design.
 I planned to stretch the fuse too but couldn't find the pattern/template I made to show here. I planned cutting a new 1/2" thick fuse which is why I spaced the two center wing ribs at that dimension. I think I'd planned an extra 2-1/2" or 3" in overall length, simply tracing the kit outline while retaining the designed fuse height and stab position at the fin/rudder line. With these mods I would also make up a new stab and elevator with 2" to 3" more overall span.
 Doing all of this doesn't really make it a "Goldberg" P-40 anymore but I think the model would present and fly even better than the original. Either way it's done, it would be a great, fun, Sport/Stunt model.  y1
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 17, 2022, 07:09:11 PM
You can download or see the plans here for free. They also have the ribs formers and tips.
https://outerzone.co.uk/plan_details.asp?ID=5127

Strange when you look at the photo of the P40 on there the eye is way out of location.
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 17, 2022, 07:18:21 PM
I got as far as framing up the wing for mine, somewhere around 10 years ago. It's still hanging in my shop, I pulled it down just now for these photos.

 I don't recall what the kit plan dictates, but I re-spaced my ribs for more wing area/span, shown here in the attached photos. This of course required starting with new L/E and T/E stock and pre-notching accordingly for the ribs. I went with 2-1/2" spacing for ribs R-1 through R-7. Spacing between R-7 and R-8 is 2". Spacing between R-8 and R-9 is 2-1/4". There is 1/2" between the two R-9's at center. This yields 39-1/2" between the tip ribs, R-1 to R-1. I forget what the overall span with the finished built up wingtips added came out to. I added shear webs as well, not part of the original design.
 I planned to stretch the fuse too but couldn't find the pattern/template I made to show here. I planned cutting a new 1/2" thick fuse which is why I spaced the two center wing ribs at that dimension. I think I'd planned an extra 2-1/2" or 3" in overall length, simply tracing the kit outline while retaining the designed fuse height and stab position at the fin/rudder line. With these mods I would also make up a new stab and elevator with 2" to 3" more overall span.
 Doing all of this doesn't really make it a "Goldberg" P-40 anymore but I think the model would present and fly even better than the original. Either way it's done, it would be a great, fun, Sport/Stunt model.  y1
What engine you planning on using? Are you going to add a cheek cowl?
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 17, 2022, 07:51:19 PM
 Not sure when/if I'll get back to it.  If so no cheek cowl but would do a full tripler over the inboard nose section, power would be an FP .35 or .40.
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 17, 2022, 08:45:12 PM
  The rest of the story on my framed up wing, and why this P-40 never got finished...

 I had planned on also adding a bit of diehedral, since the wing is mounted slightly below the fuse center line. Plus, I just thought it would look cool.
 I started by carefully blocking each of the tip ribs up 3/4' inch. Keep in mind these ribs are also tapered vertically from center to tip. I meticulously went through the whole assembly process, centering the ribs vertically to both the L/E and T/E sections that were pinned down and never realized THE MISTAKE. I glued up the entire thing and then pulled it off the board. Um, WTF? It was only then that I discovered I had boffed the entire thing. I had glued the all the ribs to the blocked up T/E perfectly and following the diehedral as planned but somehow went brain dead along the way and had kept the L/E unblocked and parallel with the board. I ended up with a very nicely built junk wing, good for nothing but a shop ornament. Sigh.
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 18, 2022, 02:48:33 AM
I know the feeling Warbird. I botched up my Vector 40 wing awhile back but fortunately a friend  jumped in and got it straight as an arrow. 😁 
Title: Re: Carl Goldberg P40 Warhawk
Post by: gene poremba on March 18, 2022, 03:42:00 AM

 Kevin, i'd really be interested in following a thread on building the Goldberg P-40 once you get to putting it together. It just might light a fire under me to build mine!.....Gene
Title: Re: Carl Goldberg P40 Warhawk
Post by: kevin king on March 18, 2022, 11:06:38 AM
Could do Gene. It would be awhile as i have alot of of planes to build before i get to the Goldberg P-40

Kevin
Title: Re: Carl Goldberg P40 Warhawk
Post by: wwwarbird on March 18, 2022, 07:53:08 PM
Kevin, i'd really be interested in following a thread on building the Goldberg P-40 once you get to putting it together. It just might light a fire under me to build mine!.....Gene

 Me too.  y1
Title: Re: Carl Goldberg P40 Warhawk
Post by: Balsa Butcher on March 18, 2022, 08:24:11 PM
I built one about 30 years ago. As stated, could be built as R/C or C/L. I believe it was Carl Goldberg's answer to the Sterling F6F Hellcat which came out a little earlier and also could be built as an R/C or C/L. I remeber it as a good looking model but not a great flier. The Goldberg Shoestring/Buster/Cosmic Wind designs all flew better.  8)