THE BLUE MAX - John Stennard

Looking for a 'bigger than normal' model for electric power I came across the Global Models Blue Max. This is sold in the UK by YT International. The Blue Max is a 'vintage Eindecker' style model of 1700mm (67") wingspan, and is designed for a .40-.46 2 stroke or .52 4 stroke with an AUW of around 2.5 Kg (5.5lb).

I wanted to use an electric power unit that would give enough power from 2 x 7 or 8 cell standard packs. I did not want to have to use larger packs. John Emms of Puffin Models was consulted and he was confident that a standard MM 24/12 or 24/16 brushed motor with a 3:1 gearbox would give the required power output. A test with the 3:1 geared 24/16 and an APC 14" x 7E showed that around 300+ Watts were available with 14 or 16 cells. On 16 cells the
RPM was around 6000. 3000 mAh NiMH cells were used for the tests using a Jeti 450 ESC.

The excellent quality of this ARTF model made it a pleasure to assemble, and the conversion to E-power was very easy. I may have 'over engineered' the motor mount but a 14" prop at power encourages one to ensure the mounting is a secure and solid fixture! 

The final AUW is 3kg and the Blue max has flown with both the 24/12 and 24/16 motors. The 24/12 can only be used with a maximum of 14 cells and a 12" prop. This motor flew the Blue Max adequately, but is probably best suited to a 2-2.5kg size of model. The performance is better with the 24/16-16 cells-14" prop combo, and this gives a very short take off run and 8 minute plus flights.

I think the performance using electric power is very appropriate for the type of model. A sprightly takeoff, stable and pleasant handling characteristics in flight and easy landings make it a lovely aircraft to fly.

I think my objectives of getting a 'large' electric model in the air, using coupled standard packs, has been very successful. Other than electric gliders my largest model to date has been the Multiplex Cargo. In fact the Blue Max has very similar flight characteristics. The 24/16 motor and excellent quality indrive gearbox from Puffin Models costs around £70. I think this represents a very good value for money power system for the Blue Max, and any model of the 2-3kg size.

Would it be better with a brushless motor? As a regular user of brushless motors and AXI motors in particular, I am sure it would, but of course at a price. When the new larger version of the direct drive AXI arrives I will be able to give it a try and see how it compares.

Send mail to steve.south@blueyonder.co.uk with questions or comments about this web site.
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Last modified: 22-04-04