Goldberg Skylark 70  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       


Airworld BAe Hawk - RTF
Seller:  rambat1
Details:   $23,000.00   |  8/17/2008   |  Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> RC Airplanes >> Kit Building >> Kit Manufacturer Direct Support Forum >> Great Planes, TopFlite, Duraplane, US Aircore >> Goldberg Skylark 70
Page: [1]

Login
Message << Older Topic   Newer Topic >>
Goldberg Skylark 70 - 3/10/2008 1:26:10 PM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		I am hoping that this forum includes Goldberg as Goldberg is now part of Great Planes and I hope I can get some help here.

I have a new Skylark 70 ARF. I bought it last week and have been slowly working on it to get it completed.

I ran into an interesting problem that I hope can be resolved. When I put the tank together, and placed it in the fuselage, I figured that the hole in the firewall would be where the tank neck goes then I secure the tank in it's place with whatever I wish.

Well, when I put the tank in, I noticed that it was a tad tall. See the picture and maybe you can understand what I am talking about.

Any help would be certainly appreciated.

Edited to add more pictures. One picture is a drawing the other two are screen captures from the manual. You can see the tank fitting as I described, the other is with the hatch cover closed. I cannot close the hatch cover because, when the tank is placed as shown, it is to high.

CGr.

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by CGRetired -- 3/10/2008 2:24:55 PM >

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!
       Post #: 1

RE: Goldberg Skylark 70 - 3/10/2008 6:42:20 PM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		Added information: I got a reply from Goldberg about this. Their suggestion is:

quote:

> Thank you for your recent email.
>
> I liked you diagram, it was really helpful! I would recommend using a dremel sanding drum attachment to elongate the fire wall hole so as to accommodate a lower fuel tank location.
>


I am not exactly sure I want to be dremel sanding a larger hole to accomodate a fuel tank location change.

If the fuselage is wrong, then I think I should get a new fuselage. If the tank is wrong, likewise.

I don't want to make an elongaged hole in the fuselage because that would present a problem with contamination from fuel and oil from the engine, or dirt or whatever, coming in through the larger hole and into areas of the fuselage that I don't particularly want to get contaminated.

The retail price on this ARF is $179.00 and should be right. I paid a little less because I had a gift cert for the LHS, however, that does not take away from the fact that the model may not be right, and should be corrected.

Does that make sense to you guys?

Opinions please!!!

CGr.

< Message edited by CGRetired -- 3/10/2008 6:44:26 PM >

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!

(in reply to CGRetired)
       Post #: 2

RE: Goldberg Skylark 70 - 3/11/2008 2:33:13 AM   
rjp


 

Posts: 7
Joined: 8/19/2007
From: Portsmouth, VA, USA
Status: offline 		CGr,

I ran into the same problem with my Skylark 70. I solved it by fabricating another former for the tank neck. I also added an additional former under the fuel tank as well. The picture I’ve provided is a poor example. I’m in the process of strengthening the nose gear after a hard landing, thus my fuel tank is removed. I’ll try to take a better photo and send it along later.

Rick

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to CGRetired)
       Post #: 3

RE: Goldberg Skylark 70 - 3/11/2008 11:04:13 AM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		Hi Rick.

Ok. That's pretty much what I did last evening. I ended up enlarging the firewall hole by elongaging it then pushed the tank back with a former frame made with 1/4" hardwood. The tank is now lowered by almost a half inch from the factory location. This is not a difficult process, but not what I had expected from Goldberg. They tend to give heavy (especially tail heavy) models, my Tiger 120 required 1 pound of lead weight in the nose to make the CG.. but otherwise, it was a well constructed and strong plane. And flys well.

I must say that the Protege was a simple build and required absolutely no additional weight to make the CG. And I used the OS 75 AX on that one, and love to fly it.

Their quality control is a tad short on this one, that's for sure. It does not take away from the plane, just a little bit of disappointment on something that I should not have to mess with during the build (for you purists... assembly..) process.

They also did not supply the screws to hold the hatch cover down. I have to go to the hardware store and see if they have something that is that small, yet long enough to pass through the hatch cover and into the firewall braces that I installed. Always something.

But, all else looks pretty good. I will know more in the next couple of evenings, I should have it done by the weekend.

Thanks for your help and suggestions. Please DO place the picture of the second former (tank support) you installed. I have to do that and would like to see how you did your.

CGr (Dick).

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!

(in reply to rjp)
       Post #: 4

RE: Goldberg Skylark 70 - 3/13/2008 2:17:12 PM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		I finished it last evening. Other than that enlarged hole in the firewall, it came out pretty nice.

One other issue. A quick check of the CG showed me that I will need to add some nose weight to make it balance. Maybe up to about 10 ounces. I am not happy with that at all.

Rick.. did you have to add weight to make it balance? What engine are you using?

CGr.

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!

(in reply to CGRetired)
       Post #: 5

RE: Goldberg Skylark 70 - 3/13/2008 4:58:21 PM   
rjp


 

Posts: 7
Joined: 8/19/2007
From: Portsmouth, VA, USA
Status: offline 		CGr,

I used the OS 75AX. However, I replaced the stock power box muffler with a performance specialities tuned pipe. As a result I placed approximately 4 oz under the engine to make her balance. Had I kept the stock power box I would have had to use additional weight. I also place 1/4 once in the left wing tip at the CG line to balance in the lateral direction.

Rick

(in reply to CGRetired)
       Post #: 6

RE: Goldberg Skylark 70 - 3/13/2008 6:48:07 PM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		Hi Rick.

Ah..ok. Minnflyer said he needed about 6 ounces to make his CG. He put his under the engine mount (that break-away mount and the rails where there is room. Darn.. I have to remove the engine to do that.. but will... I know I will need some weight so I will do that and epoxy them in place.

A tuned pipe eh? I imagine that really made the thing perform. Did you really think you needed it? That OS 75 sure pulls the Protege around, and they are somewhat the same size. I guess you did because you used it, eh? Not questioning your choice, just curious.

Ok.. thanks again for the input. I did take your lead and put a 'shelf' under the tank and wedged the tank in there with that model foam rubber on the bottom, rear, and top (under that cover). The hatch cover now closes nicely.

CGr.

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!

(in reply to rjp)
       Post #: 7

RE: Goldberg Skylark 70 - 3/14/2008 1:15:02 AM   
rjp


 

Posts: 7
Joined: 8/19/2007
From: Portsmouth, VA, USA
Status: offline 		Dick,

The OS 75 AX doesn’t need a pipe, it has more than enough thrust right out of the box. I bought and installed the ultrathrust more out of curiosity (my first engine modification). With the ultrathrust installed the 13 x 6 APC prop turns 13,000 rpm at a flank bell. It gives the Skylark an amazing vertical climb rate and low altitude passes are really fun. However, the boys at the field are complaining of hearing loss in the pit area during preflight needle valve adjustments….lol

Rick

(in reply to CGRetired)
       Post #: 8

RE: Goldberg Skylark 70 - 3/17/2008 6:16:32 PM   
CGRetired



Posts: 4144
Joined: 9/14/2004
From: Galloway, NJ, USA
Status: offline 		Ha... I imagine!!! Thanks for the reply. Yeah, that thing ought to pull the Skylark around just fine.. I am sooo anxious to get that thing out to the field!!! Waiting for wind to die down a tad.

Dick.

_____________________________

Skylark 70 - OS 75 AX; Venus II - OS 1.20 AX; Tiger 120 - OS 1.20 AX; Protege - OS .75 AX. Airtronics - Spektrum. AMA 705964. Semper Paratus!

(in reply to rjp)
       Post #: 9

RE: Goldberg Skylark 70 - 3/21/2008 5:39:33 PM   
Bax


 

Posts: 12221
Joined: 4/26/2002
From: Champaign, IL, USA
Status: online 		We're closing this thread. This is not a discussion forum, but one for support. If you wish to have a discussion, it should be in the General Kit Building area, not the support area. This is where people can ask questions of the manufacturer and get help from them.

Thanks.

_____________________________

Bill Baxter, Manager Hobby Services/Futaba Service/North America
3002 N. Apollo Dr. Ste. 1 Champaign, IL 61822 USA
Service Phone: 217 398-0007
Email: hobbyservices@hobbico.com

(in reply to CGRetired)
       Post #: 10

Page:   [1]
All Forums >> RC Airplanes >> Kit Building >> Kit Manufacturer Direct Support Forum >> Great Planes, TopFlite, Duraplane, US Aircore >> Goldberg Skylark 70
Page: [1]





Jump to:


Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Member Video Posts | RCU Video Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC,