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Old Mar 30, 2009, 06:28 AM
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How many planes is too many?
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Australia, VIC, Melbourne
Joined Aug 2007
4,018 Posts
I couldn't resist

I have a new EPP plane to try! It's a Hokusei Ultima EPP BX and appears to be a new design by the respected Japanese manufacturer Hokusei that is based on the Ultima SOV.

I bought 2 Ultima BX kits from in China. This is a new website operated by the owner of, which is where I bought all of my previous Hokusei planes from. wattaplane is still active but bestvaluerc has a few advantages. It offers planes from several manufacturers, so for example you can mix TechOne planes and Hokusei planes in a single order. bestvaluerc has more postage options that can reduce the postage cost considerably.

Here's a link to the plane on the Hokusei website: Scroll down to see photos and video links. The first video features some impressive flying and shows that this plane can do fantastic rolling harriers.

I've studied web photos and videos of the Ultima SOV and Ultima BX and I've noticed some differences. The Ultima BX is smaller and lighter. It has a very tall fuselage that I expect will make it a fantastic knife edging plane. It appears to have a relatively short fuselage but this might be an illusion caused by the tall fuselage as when I placed the fuselage and rudder beside the wing they looked about the same length. Looking at the design of the plane I suspect that it'll be more of a pattern 3D plane like the Hokusei Primus Z, but I've been surprised a few times by the characteristics of some planes that weren't obvious just by studying the airframe design.

Unlike the Primus Z, the Ultima BX has a flat plate foam sheet on the bottom of the fuselage. I suspect this is what the BX in its name indicates. All the BX planes on the Hokusei site have this feature. Does this make a difference? Well I believe it leads to a fuselage that is more resistant to tail twist. The planes that I own with a flat plate on the bottom of the fuselage definately twist less than those I own without it, though I don't have many planes without it so it might be related to other design aspects.

Here are a few photos to get things started. I'll post more photos once I start the build.

EDIT: I've started the build.

I've glued the main wing on but I haven't attached the ailerons yet. I've also glued the horizontal stabiliser on and hinged the elevator. So far this kit is building in the traditional Hokusei way, so it should be a simple and fast build.

The control surfaces consist of a thin layer of Depron sandwiched between sheets of EPP. In the areas where the CA hinges are placed there is no Depron. Be careful when gluing in the hinges that you don't let your CA run too far or it will eat the Depron a little. Consider using foam safe CA instead if you're worried about this.

This combination of Depron sandwiched between EPP has proven to be very durable on my other Hokusei kits. It seems to have the durability of straight EPP but benefits from the stiffness of Derpon within. CF is still used in appropraite areas for extra rigidity.

Here are some progress photos. I forgot to take a photo of the very tall fuselage. Maybe next time.
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Last edited by groovejet; Jan 30, 2010 at 10:03 AM. Reason: Merged original content of post #1 with post #2
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