RE: Goldberg Ultimate Biplane Engine  
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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 9:03:44 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		Alfred, have you run the 120ax with your ultimate yet?

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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 9:49:41 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		IN addition to the above, is there any preference on hinges? The CA hinges that come with the kit look fine but I will install probably with epoxy just to be sure.

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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 12:08:34 PM   
huggins



Posts: 351
Joined: 3/28/2003
From: Greentown, IN, USA
Status: offline
quote:

ORIGINAL: fallingleaf

IN addition to the above, is there any preference on hinges? The CA hinges that come with the kit look fine but I will install probably with epoxy just to be sure.


I hope that you are not saying that you are going to install the CA hinges with epoxy. Bad idea. CA hinges will work fine on a 120 size airplane. If you want to go to a pinned hing and use epoxy, that is fine too. But, don't install CA hinges with epoxy. If I misunderstood your intent, I apologize.

Mike


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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 12:49:12 PM   
Ed Cregger



Posts: 7736
Joined: 1/31/2002
From: Ringgold, GA, USA
Status: offline
quote:

ORIGINAL: fallingleaf

IN addition to the above, is there any preference on hinges? The CA hinges that come with the kit look fine but I will install probably with epoxy just to be sure.






Do not install CA hinges with epoxy! There's nothing wrong with CA hinges, as long as you meticulously follow the instructions and the hinges are from a reputable manufacturer, such as Goldberg.


Ed Cregger


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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 5:47:19 PM   
alfredbmor



Posts: 1127
Joined: 6/1/2005
From: El Paso, TX, USA
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quote:

ORIGINAL: fallingleaf

Alfred, have you run the 120ax with your ultimate yet?


I received the engine last Friday and I am still amazed about its size. It has a very short head in comparison with the Magnum 1.20 FS. Looks almost like a 60 size engine. I like the muffler which can be rotated and it will fit fine in my already cut cowling, maybe it will need a little extra work.
I planned to run in the engine this week but I have been dealing with some other projects (Fuel tank of a Venus 40 and a Dynaflite SE5A Build) that have taken a good amount of my free time.
Meanwhile I have taken some measurements and happily found that I do not have to make new holes at the firewall and even at the engine mount because the OS 120 AX have exactly the same bolt pattern that my Magnum does, I think it is because my Magnum is a copy of the OS 1.20 FS.
The difference here is that the OS 120 AX is shorter from its back plate to its front than my Magnum which is significantly longer meaning that I will have to shim the engine mount with plywood. The second job to do will be rerouting the throttle pushrod accordingly.
The fact that I have to perform those tasks before attaching the new engine in my Ultimate is why it has taken longer.
I was thinking on my bench mount to break in the engine but at the end it will take more time to do those changes so I prefer to make the changes on my Ultimate and bolt the new engine and break in mounted on the Ultimate.
I will let you know any advance, hopefully this weekend I’ll get it installed.

As per the CA hinges, they work flawlessly just be sure to drill a hole at the center of the slot of each hinge to let the CA run into the hinge and have a good grab. Anyway they have to be checked after a dozen flights. I have seen a couple of CG Ultimate hinge failures at my field with not bad result till now but they easily could be otherwise.

Let us know when you start your build.


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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 10:05:50 PM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		My bad regarding the hinges! I think I was confused at the time of writting that post. Will only use CA with the hinges which I am sure will be fine. As it stands I will not be using much of the stock hardware supplied with the kit, so it would be nice to use at least the hinges which look pretty good! I am thinking that I may do away with the 2-56 or 4-40 control rods supplied with the kit as well, and go with carbon fibre. Collectively they do weigh quite alot...will check on price first though!

That all sounds great Alfred. Yes I too was surprised at the size of the engine, its about the same size as my 61fx! Look forward to hearing how you get on with it! I ordered the pitts muffler for it but I think I will be going with the stock muffler....I think there is less chance of complications if I just use the stock muffler from what I have read in other forums. I just hope it doesnt bulge out the bottom of the cowl too much but from what you have said it shouldn't be too bad! I may get one o those extended cowl done by fibreglass specialties to make it a little less noticeable. How are you planning on installing the fuel lines? Will you have an overflow? I am thinking of using a filler valve on the carburetor line as this will stop fuel spilling into the muffler when filling (shuts off to the muffler when filling). Usually it is mounted on the fuel line but this way I wont have to owrry about fuel seeping into the muffler. Either that ora check value on the carb line!

I will post my build once I get started, probably on this thread to make it easier. At least then It is a complete documentation from prior to ordering the kit right through to the end!

Thanks all once again

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RE: Goldberg Ultimate Biplane Engine - 5/8/2008 11:53:59 PM   
alfredbmor



Posts: 1127
Joined: 6/1/2005
From: El Paso, TX, USA
Status: offline 		I had a normal three line tank set up when using the Magnum 1.20, one line for filling the tank, one to muffler and one to carb. With the OS 120 AX maybe I will have to ad a "T" and a check valve, because the line to the muffler will be hidden and I do not like to spit any fuel on the ground. I will use a "T" in the line to the muffler so I will be able to discharge the overflow to an additional tank that I always carry in my tool box for that purpose. The check valve will be connected on the same muffler line and will allow me to avoid spitting fuel over the muffler when refueling. Also the check valve improves the pressure inside the tank which is fine for any aerobatic set up.
I will post dome pictures when ever it'll be done.


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RE: Goldberg Ultimate Biplane Engine - 5/9/2008 9:05:40 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		Okay so begineth the build of the Goldberg Ultimate Biplane! I know there are a few other good build threads out there so I don't want to boar everyone, but I will document my build anyways as i think it is a neat idea and enjoy people giving their input as I go. Plus I got a lot of enjoyment reading other build threads so I am sure others do too!

Ironically I was home sick today so began my build Most of the shots are self explanatory. The shop is in the garage, nothing fancy by a long shot but its fine for my needs. I took the obligatory shot of the box including engine (O.S 120ax) and the 15x10 zinger prop I have for it. I plan on breaking in the engine with this prop and then going to a 16x8. Having said that, if it runs good I will just stick with it! You can see I already have my stock of monokote...too much for the plane I think but better to be safe than sorry. Those who are patient will get to see what I do with the colours....I haven't a clue yet but I have matching sapphire blue lustrekote so the cowl and wheel pants will be that colour (highly rare to find that stuff now in New Zealand).

I completed the entire tail assembly in the afternoon working solidly from 2.30pm to 7pm. The only parts that didn't fit too well were the laser cut rudder corners and centre piece of the tail plane. Not an issue however as the leading and trailing edges lined up good and that’s what matters the most. Some of the balsa stock was a little on the soft (grain) side, however there were some harder pieces so I selectively placed those on high stress points like hinge areas. All in all very easy thus far and certainly no problems as yet!

I will hinge and give the surfaces their final sanding at a later stage closer to assembly. In the past I have found that sanding up at an early stage inevitably leads to dents from the parts lying around! Either way I like to leave my hinge work till last (in this case before I glue the tail assembly to the fuse. I will most likely glue the hinges PRIOR to covering so that I can seal the control surfaces with the same piece of monokote – just my preferred method!

Oh, you can also see that I have installed ply gussetts in the tail plane. These are no stock and are the platforms for my flying wire/tail wire – whatever they are called! I was unsure of where to put this in the fin so will install the 5/16” ply gussett once I have the tail plane assembled on the fuse. This will give me the flexability to get the alignment and appearance I want.

Okay I hope that was interesting. Next up....wings!



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RE: Goldberg Ultimate Biplane Engine - 5/9/2008 9:07:32 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		Ah crud...here is the shop pic!

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RE: Goldberg Ultimate Biplane Engine - 5/9/2008 4:24:47 PM   
alfredbmor



Posts: 1127
Joined: 6/1/2005
From: El Paso, TX, USA
Status: offline 		Great to see those pictures of a bunch of wood becoming a nice biplane.
I hope you feel better.


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RE: Goldberg Ultimate Biplane Engine - 5/10/2008 6:16:07 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		I spent a little time this afternoon just sanding up the leading edge of the stab/fin and what not. I was going to start the bottom wing but realised that the interplane strut tabs on the wing ribs have posed a problem for some builders in terms of strength in the past, so I am curious if anyone out there has modified these and if so how?

I don't like the fact that there is a wing lightening hole on the rib just below where the tab projects out of the rib. This makes the area of ply holding the tab to the rib very small compared to if the hole wasn't there. In any case I don't like that AND the use of lite ply...I can flex it quite easily with my hands even

So I am thinking of making a new set of ribs either from 1/8" aircraft ply (in laymans terms multi-laminate ply from what I gather!) without the hole there, or just glassing over these ribs. Any suggestions?...If I glass I will have to wait until I can buy some fiberglass though WOuld

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RE: Goldberg Ultimate Biplane Engine - 5/10/2008 10:17:13 PM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline 		Having slept on it, I think I will use some good 1/16 ply and laminate this either side of each interplane strut rib with the grain going vertical. This cross grain pattern should add alot of strength when glue with super 6 hour-setting araldite epoxy I don't think I can be bothered with glass on something this small and this way it will be far easier to cover as opposed to paint.

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RE: Goldberg Ultimate Biplane Engine - 5/11/2008 8:17:30 AM   
fallingleaf



Posts: 150
Joined: 4/14/2008
From: Auckland, NEW ZEALAND
Status: offline
quote:

ORIGINAL: alfredbmor

Great to see those pictures of a bunch of wood becoming a nice biplane.
I hope you feel better.



Thanks for the kind thoughts Alfredo!

Traced out my 1/16" ply doublers today, cut them out (which took a long time) and epoxied one either side of each original rib to form a sandwich. This should provide alot more strength in this area and reduce the torsional flexing that is present in the stock ribs. I saw someone had used 1/8" ply in the same manner but I would have had to buy some. 1/8" would make a pretty thick tab I think and with the super strength epoxy I feel it should be sufficient. They better not break when I fly!!!


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