Thread Tools
Feb 06, 2015, 08:07 PM
Play that funky music right
kenh3497's Avatar
Thread OP
I have a 91AC I planned to use. THANKS for the heads up. I think the prototype may have been a "balsa" airplane and not a plywood plane like the production model. No wonder it is heavy. As for an engine..... I have an old Saito 120 (big block) and a YS 120 NC. The NC may be a bit much I'm surprised the 91AC didn't fly the plane as it is supposed to swing the same prop as other 120's What prop are you using in the 125 and about what RPM is it running?

Ken
Sign up now
to remove ads between posts
Feb 07, 2015, 04:28 AM
Registered User
It could be that the YS91 wasn't fully run in, I was running 20% nitro with a 15x8 pro which gave around 8600 rpm. It just felt underpowered all the time and the Saito was a drop in replacement, and lighter.

The 125 runs on 10% with 16x6 prop and when fully run in gives 9600-9800 rpm - I've used APC and Vess props - the latter being much lighter.

On another subject - I hated the interplane struts - as designed they would be difficult to fit and adjust. So I made small extensions to the ribs and made up struts out of carbon tube with left and right hand couplers and clevis at each end.

I can post some pictures but don't want to hog your thread!
Last edited by ogg2000; Feb 07, 2015 at 08:04 AM.
Feb 07, 2015, 07:19 AM
Play that funky music right
kenh3497's Avatar
Thread OP
Post away ogg! I'll stick my foot in my mouth and say many of us here don't mind others posting their "fixes" on the same model. IMO these forums are about learning new things and seeing how others do things. Almost like an afternoon in the shop with a bunch of guys talking about what ever comes to mind. If we go off subject so be it. We'll drift back to the airplane at hand sooner or later

I plan to use some 1/2" streamlined tube attached with 4-40 bolts to an aluminum plate screw to the rib. It will be important to get all the incidence set up first as the tube will be a "tight" fit over it's mating stub in the wing.

Yes please do post your solution.

Ken
Feb 07, 2015, 07:57 AM
Registered User
Here are some pictures of it finished with YS91 just before maiden flight. The cowl and spats are now painted blue - turns out there's a Mazda blue that exactly matches the metallic blue Monokote. Only phone pictures - it's currently in winter storage. The colour scheme was chosen in 1997 when I bought the Monokote, I've since bought some more while on business in the US.

I used 9-10kgcm servos except throttle. If I were building again or can be bothered I'd replace the single elevator servo with dual arrangement - the single servo is in the aft fuze with a Y made from 3 carbon rods. It works OK, but short direct links would be better.

Dave
Last edited by ogg2000; Feb 07, 2015 at 08:03 AM.
Feb 08, 2015, 11:29 AM
Play that funky music right
kenh3497's Avatar
Thread OP
Thanks for the photos Dave. Nice looking Bucker. I think I'm going to go forward with the 91 AC installation. I like to tinker so if an engine change is necessary in the future, so be it.

Ken
Feb 08, 2015, 03:44 PM
Registered User
I'd be interested to see how the YS91 works for you.

It was a no-brainer for me to try the Saito 125, I already had it, it was drop in and I knew it was well run in and reliable. It was never going to be less powerful than the 91.

Actually I stalled the plane and did lot's of damage, including big repairs to the Saito... new cylinder, ring and bearings, because the crash tore the exhaust out. I've now mounted the exhaust closer and inside the cowl.


Dave
Last edited by ogg2000; Feb 08, 2015 at 03:50 PM.
Feb 13, 2015, 06:07 PM
Registered User
Nice to see another Goldberg Bucker taking shape! I built mine and flew it in May 1996. Fabric covered and painted in the box art scheme. Power was a Saito 1.50 and a blast to fly. I still have the plane (and a NIB kit), but it needs to be restored. Good luck with your Bucker, you're gonna love it!

R
Feb 13, 2015, 09:15 PM
sturmovik
barron's Avatar
Great flying plane I had one with a saito 150 also.
Feb 21, 2016, 05:07 PM
Play that funky music right
kenh3497's Avatar
Thread OP

Here we go again......


The biggest reason I stopped construction of the Bucker was the canopy. I wanted a functional opening canopy. After three failed attempts I gave up and stopped the build. This coincided with the onset of summer with predictable results.

I started to work on the Bucker again a couple weeks ago figuring I would get everything done but the canopy while waiting for a solution to magically appear.

Well I have found a solution and it was just a refinement of a failed attempt. My first attempt was to use some pinned control surface hinges. I knew I needed to get the hinge point outside the canopy for the hinge to be successful. The second attempt was an offset hinge (gear door) which also failed as I was not able to find anything to suit and the attempt to build something didn't work out due to the shape of the canopy and the small hinges I built. Thirdly was the purchase of some piano hinge from a gentleman here on RCG. While this would have worked the hinge was just to small to make work like I wanted it to. Fussy ain't I

So last week I was in Hobby Lobby and spied some hinges that were the perfect size. With my 40% coupon, I paid all of $1.27 with tax.

Today I was looking through my balsa scraps and I found an unusual shape and it dawned on me that was the missing piece to the puzzle. Stood up on edge it looked like half a house cut down through the middle at the peak of the roof. I found a piece of bass wood and cut the shape on my band saw. It didn't turn out perfect but good enough and it works.

I discovered I will need to shim the front bottom part of the hinge to get the best fit due to a slight compound curve of the deck. If push comes to shove I can always stick a 2 X 4 in the hinge line and "finesse" the hinge into submission. That's a trick I learned from an "old timer" at the auto dealer I used to work at. He did the tweaking of doors, hood and trunk lids on new cars. He used the 2 x 4 quite often

I'll mount the third/center hinge and fix the holes and excess cut outs for the old hinges. The screws that attached the decking to the fuse will be mimicked on the canopy hinge. I think it will be strong enough to be able to not use any glue in the assembly.

Now on to prepping everything for covering and paint. I'm using Monocote and will be painting all the fiberglass to match the Monocote. It will be white with red and possibly another trim color.

Ken
Feb 21, 2016, 05:11 PM
Play that funky music right
kenh3497's Avatar
Thread OP
Almost forgot..... Canopy latch..... Still thinking about that one but I think I have a solution for that A 1/4 turn handle connected to an old servo horn with rods to the front and back of the canopy much like a possible full scale solution. Probably get stuck on that one also

Ken
Feb 21, 2016, 08:36 PM
Play that funky music right
kenh3497's Avatar
Thread OP

An A.R.C.


with the emphasis on ALMOST.

I still have the top ailerons to do the final fit on and then ding repair with mounting the aileron servos and a throttle servo. Then cover and paint. The darn thing is getting "heavy" though I have no clue how much it weighs. There are about 70 screws holding on the front deck and canopy. All installed so I can remove then and harden the threads with CA. Maybe it's the screws that a weighing it down??????

95% done with 95% left to do

Ken
Mar 11, 2016, 08:53 AM
Play that funky music right
kenh3497's Avatar
Thread OP
Bits and pieces for the canopy latch. Just in case you're wondering, the big lug of the handle DOES get cut off.

Ken
Mar 11, 2016, 01:22 PM
Registered User
Looks good Ken. Are you using the stock plastic parts or glass parts? I think with the wing area you have at 10 lbs with your 120 it would fly very well with good power. With the.91, I would aim for.8.5 lbs. Have you decided on a color.scheme?
Mar 11, 2016, 02:06 PM
Play that funky music right
kenh3497's Avatar
Thread OP
Quote:
Originally Posted by exf3bguy
Looks good Ken. Are you using the stock plastic parts or glass parts? I think with the wing area you have at 10 lbs with your 120 it would fly very well with good power. With the.91, I would aim for.8.5 lbs. Have you decided on a color.scheme?
Glass parts with the clear from the stock parts for the bubble.

White base color is as far as I am because I had that on hand. I have red, orange and a little yellow on hand for trim color.

Ken
Mar 11, 2016, 05:29 PM
Registered User
Just caught your thread; love my CG Jungie, best airplane I fly. MVVS 26cc power plant. Will do almost unlimited vertical. To bad they don't make the kit anymore. see one pop up every once in a while.


Quick Reply
Message:

Thread Tools