Motor for Radio Princess

[Ray Farrimond]

As per title can anyone recommend a motor esc combination for the Radio Princess that was a free plan in Nov 1988 Radio Modeller. The plane was 56" wingspan and for 1.5 - 2cc engines. I am nearly at the point in building this where I need to decide on the motor etc. The original with an OS15 and 3 channel radio weighed 2 1/2 LB.

Thanks in advance for any help.

Ray

[Denis Watkins]

Save me the job Ray, of looking at the 4max site, where there is a list of similar models and set ups.

We ballpark requirements at 100 watts per lb

So that's 250w. The OS is rated max at 500w, but would not achieve that

Sports models will cruise around on as little as 50w per lb

[ken anderson.]

hello ray..have a look here it'll give you and idea re size and prices etc...I've highlighted a possible contender for you......good price as well..... you wont need a lot of power for your model

ken Anderson...ne...1.... power dept.

[Ray Farrimond]

Hi Denis, I looked at the 4max site but at the motors didn`t think to look at similar models will remember that for any more I do. Still trying to get my head round electric having only done ic before.

Hi Ken, thank you for that. Not really looked at the BRC site before but it looks like that is just what I need.

Ray

[kc]

I have a BRC(Robotbirds) BL2217/9 in two different models

1. Electra ( Vic Smeed design ) which is a 3 channel vintage model of 52 inch span and about 4 pounds Uses the 2217/9 with a 3S2200 Lipo and 10 by 7 APC electric prop with 30 amp ESC. Flys in a slow vintage manner.This could be considered similar to your Radio Princess especially if the weight is more than the 2.5 pounds suggested. So this motor or equivalent would suit.

2. A Mini Frantic which is a small aerobatic model of about 40 inch span. weighs a couple of poiunds and goes like stink. Same setup 2217/9 with 3s2200 10 by 7 APC electric and 30amp ESC.

 

So a few 3S200 lipos are used for these models and others. That means same lipos can be used for different types of model depending on weather, mood et. Minimises expense, maximises number of flight per day.    3S2000 are popular and cheap so a good size to standardise on.

 

Note the 2217/9 has a different spec to 2217/8 and the Kv ( revs per 1 volt ) differs a fair bit and therefore uses different size props or only 2 cells -7.4 compared to 11.1 volts - for that reason. So buy the motor with correct last digit (suffix.) for your purpose.

I presume you have the Radio Princess article? If not let me know - it's in my collection I think.

Edited By kc on 11/07/2017 13:03:26

[Ray Farrimond]

Hi kc, thanks for the info. I am slowly learning about these motors and will get there sooner or later. I managed to get hold of a copy of the mag that the Radio Princess came in. Over the years I managed to keep all my plans but lost the mags so am building them back up as I need them.

Ray