Goldberg Super Decathlon

[Smash McCrash]

Been looking at this model for a long time. Finally found a deal locally that I couldn't refuse. LNIB for $200. Don't know what power system to use. I have 2 options... 6S or 8S. Hyperion motors, 4025-16 or 4035-14, either will spin a 15-16" prop and get the power down. 6S will get me about 1000-1100W and the 8S will get me to the 1500W area. The plane is said to weigh about 9lbs rtf, so either option will give me copious power. :D The decision will be whether or not the lighter setup will need additional nose weight for balance.

So, I am looking for someone who has built one that can comment on the CG issue with the setup that they have used (and details on that would be appreciated as well.) I will get some pix as the build goes.

Mike

[Smash McCrash]

Well, I made the decision. 8S it is. I think the extra overhead in power will be welcome, besides, thats why the left stick moves up and down, right?

Ordered a high torque servo for the rudder yesterday, and started a little bit of assembly. Going out of order as compared to the manual, but, thats what we do.

Setup will be:

Hyperion 4035/14
Castle Phoenix 85HV
2×4S Zippy-H 4000
AR9000 w/2 satellites
DS821's
DS8411 for rudder
4 cell NiMh for radio
Planning on a 16×10 or 17×8 to start.
16×10 pulls 53A for 1600W
Haven't run the 17×8, don't have one. :D

Mike

[Smash McCrash]

Been doing some slow work. Wings are almost ready. Changing the CA hinges to Robart Hinge Points. Got all the holes drilled, and the ailo's are hinged. Need to add the control horns, and the wings will be done. All of the servos are mounted, the receiver and satellites are in, and the motor and ESC are in as well. Had to machine some standoffs for the motor, 2.7"×½" dia aluminum rod center drilled. I like the size of this model, its easy to get most of your arm into it if needed. I am thinking of leaving the forward windows out to get to the batteries/radio switch, but I am not sure. Maybe I can make one of them removable with magnets or something...

Mike

[navee8or]

s.m. Could you please post some pictures please? When you are doing a build it's great but the build would be a lot more interesting and informative with pictures. Myself personaly it gives me a better idea of the size of the parts in relation to the other parts also it gives me a better idea of the quality and workmanship that the company making the kits puts into their product. This is just my suggestion and by no means is it a criticism of the information that you take upon yourself to pass on. Thank you for your post and keep up the good job. navee8or

[Smash McCrash]

There didn't seem to be much interest in this project, so I wasn't shooting pix. I do have a lot of the work done, but, I will work on getting some pix this evening. I have only 1 real complaint so far, the wing was larger than the saddle. I had to sand the lip at the trailing edge on the fuse to get it to sit down on the fuse correctly. Other than that, the plane has been a simple build, with the conversion being the only thinking I had to do.

Mike

[navee8or]

S.Mc. Thank you for your response. I my self have built several cg kits as well as two of the ultimate arfs. I have no complaints on any of them. I do feel that you will find the flying qualities just as good. navee8or

[Smash McCrash]

Here's the pix as of sundown last night. I did a lot of little things last night after the pix, so I am getting closer to maiden. I am still trying to think of a way to make the side windows hinged so I can get at the interior with the wing on. Maybe I just need to put hinges on the top, and magnets on the bottom and see how it works. Would make a great hatch... :D

Mike

[rodsmith123]

My conversion of this plane. Nice flyer, but I got bored with it and sold it after 5 flights.

http://www.rcgroups.com/forums/showthread.php?p=9465620&highlight=super+decathlon#post9465620

[Smash McCrash]

Well, she's done. Replaced the plastic clevises with metal and did a screw on front window for arming access. I also made a removable battery plate. 2 4-40 screws hold the back down with a hold down in the front. Should be able to remove the whole plate for recharging at the field without removing the wing.

AUW: 11.25#
Power: 1600W (140W/lb)
Loading: 26 oz/ft²

Should be a decent flyer!

[wollins]

Beautiful plane Smash! I see you're using the back mount type Hyperion motor ... are you using a collet type prop adaptor or one of the regular bolt on types that is usually used with their regular motors? (when backmounting)

Colin.

[Smash McCrash]

Using a collet. I know some people that don't trust them at these power levels, but, I haven't had a problem, and I am using some "special" adapters. I wish they were still in production, but, the company seems to have gone out of business. Sierra Hobby made some adapters called Perfect Prop Adapters. They had a keyways on the back of the tapered prop washer that keys from the collet fit into and locked them together. Because they lock together, you can get a tighten them down real easy with a wrench and small screwdriver. There are bolt on prop adapters available, but you would have to take off the fan on the motor to use one. I don't think there would be a problem with overheating, but, cooler is better, right? The big advantage to the larger Hyperion backmount specific motors is the large "can" bearing that you get, and the retaining ring on the back is not a wheel collar affair, but a thick washer that is bolted to the end of the shaft. Much more secure than the wheel collars that rely on two smallish set screws to hold them on.

Mike

[wollins]

Cooler IS better! :D BTW, I've never seen one of their "backmount specific motors" in person so was just wondering if they can also accomodate the bolt on prop adaptors ... or are they built to only take the collet types?

Colin.

[Smash McCrash]

The motors come with a fan mounted to the "front" of the motor with the same screws that would hold on the prop adapter. These can be removed and the bolt on adapter take its place. My brother just finished a Wild Hare Baby Extra using the same motor/controller/cell count as I have in the Decathlon, but has 5000mAh packs, and a 17×8 prop and is using the bolt on adapter.

Mike