Building an Ultimate 10-300 – Gallery
Languishing for many years in the back of a cupboard in my hobby room I had a Carl Goldberg Ultimate 10-300 kit. At the beginning of 2016, as the aeromodelling bug began to bite again after many years of absence, I decided to set about building this lovely aircraft. This was the second time that I would build this kit, I first built one somewhere back in the 90’s and flew it for many enjoyable hours. The original was powered by a OS120 four stroke, but this time I decided to convert the model to electric power. After some research I settled on a RimFire 1.20 50-65-450 Brushless Outrunner Motor controlled by a Graupner ESC with a 6S Lipo battery.
The following photo gallery documents the various stages of building this model. I ended up making quite a few modification to the model, some reflecting updates in technology, such as using four small servos in the wings, and others flowing from the use of electric power. One of the trickiest problems was figuring out how to install and remove a large 6S battery pack without having to remove the wings. This was accomplished by building two access hatches in the side of the model that, with some fiddling, allow the battery pack to be removed. I also remembered from by first Ultimate that the standard piano wire gear was too weak, as were the ABS spats. So I replaced the gear with a carbon fibre Extra 300l style that fitted perfectly and also bought some suitable glass fibre spats from the same supplier.
The original model is supplied with old style “transfer” trim stickers which I never liked and is pretty difficult to handle and not very robust. So I scanned the transfer stickers onto my computer, Photoshopped them and printed new versions on more robust and easier to handle material, with the benefit that if I ever need to recover part of the model, I’ll easily be able to print new stickers.
The following photo gallery documents various stages of building process. The problem with investing so much time and effort into such a model is that it becomes rather emotionally valuable. Therefore I tend to be quite conservative about flying it!
13th september 2018 (2:21 pm)
Hello! Can you tell me a bit more about your motor/esc and battery combination? What prop size are you using and what sort of flight times are you seeing?
I’m starting a project along those same lines – with a Goldberg Extra 300. I can see a rimfire motor in your photos – is that a RimFire 1.20?
13th november 2018 (9:51 pm)
Hi Cliff, sorry for the slow response. I’ve not had much hobby time recently. I had a problem with the Rimfire 1.20 during testing (see pic) so ended up putting a Roxxy 5065/07 motor in it, driving a 17×8 prop. The ESC is a Graupner T100 with a 6S 6000mah Lipo. This package gives excellent results, with the capability to hold a vertical line further than I can see… I get about 10 mins flight time with this setup.
I got the Rimfire fixed and that went into the GP Sequence, where it has been entirely reliable. Let me know if there’s anything else I can help you with.