Ultimate 120 (oz6958)


Ultimate 120 (oz6958) by Doc Mathews from RCMplans 1993 - plan thumbnail

About this Plan

Ultimate 120 (Ultimate 4-120). Radio control sport model. This is a plan that details how to modify a kit.

Quote: "The Ace R/C 4-120 bipe has been called the most 'bashed' kit ever. That well may be, and the reasons are pretty obvious: the design is completely straightforward, it seems to fly well regardless of how it is changed, and it builds quickly and straight.

When the flood of Ultimate Bipe kits and designs hit a few years ago I, like so many others, was attracted to this awesome biplane. After checking through the various available models it suddenly hit me 'why not rework the aesthetics of the 4-120 bipe kit to resemble an Ultimate?'

A few hours spent at the drafting table playing with a pencil on some Clearprint taped over the original kit drawings, convinced me still another 'bashing' was well within the realm of practicality. I then cut out the required new pieces and conned master craftsman John Walker into building from my drawings.

A month or so later the model was delivered and flown. John has actually had other modelers accuse him of 'putting them on' when he tells them our Ultimate 120 is a modified Ace kit. So what we have here are some really simple modifications to a stock 4-120 bipe kit, resulting in a big model that bears enough resemblance to an Ultimate bipe to be instantly recognizable.

This 'bashing' utilizes nearly everything in the kit while retaining the nearly idiot proof cabane mounting jig and other really neat features of the original concept.

This project was drawn up with no intent of publication, but while flying mine over the last two years a surprising number of modelers have asked for copies of my drawings. There are now at least four other Ultimate 120's flying that I know of, all with enthusiastic reports. So, I've decided to share the project with you..."

Supplementary file notes



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Ultimate 120 (oz6958) by Doc Mathews from RCMplans 1993 - model pic


Ultimate 120 (oz6958) by Doc Mathews from RCMplans 1993 - pic 003.jpg
Ultimate 120 (oz6958) by Doc Mathews from RCMplans 1993 - pic 004.jpg

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User comments

There is no wing rib templete in plans
dvines - 13/10/2016
Good point. The subject of this article and plan is the modification (kit-bashing) of the Ace kit, so I guess they assumed anyone starting the project would have the full set of ribs beside them, in the kit box. But it's a fair point. Does anyone out there have a drawing of the rib template we can add to this plan? Thanks.
SteveWMD - 13/10/2016
The 4-120 Bipe from Ace is an enlarged version of the 4-40 Bipe plan on OZ. Any competent builder should be able to enlarge those ribs to the correct size, at least close enough.
DougSmith - 13/10/2016
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Download File(s):
  • Ultimate 120 (oz6958)
  • Plan File Filesize: 711KB Filename: Ultimate_120-RCM-1155_oz6958.pdf
  • Supplement Filesize: 1728KB Filename: Ultimate_120-RCM-1155_oz6958_article.pdf
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