Advise required

[Andy Freeman]

Long time lurker and reader of much seasned advise now requires some more specific guidance.

I have a hankering to build a model of the 600 size. I dont want an ARTF and I would like it to run on 8 sub C cells.

 So far i have thought about the BVR 45 inch Tucano or  galaxy models aerojet 540. I know many people know the Tucano but does anyone know much about the areojet? 

My reasons for wanting to run on nicad are twofold. They are cheap and i fly at what must be the windiest patch on the planet! so a little extra weight is no bad thing at times.

for a motor i was thinking AXI 2820/10 or equivalent from my local shop (ie this).

A bit of advise would be great.thanks in advance.

Andy 

[Tim Mackey]

Hi Andy, and welcome. I had a Galaxy aerojet many years ago,when buggy motors and cells were all that was available to us leccy flight enthusiasts - it flew very well indeed and would even thermal on a good day I often contemplate getting another I liked it so much.

Although it goes against my religion to "endorse" old technology nickel cells, you make a valid argument for them so I will proffer my .02 P worth.

As budget motors go, this will fit the bill for the models you mention but I feel the claimed maximum wattage is a little optimistic considering they recommend maximum 3s Lipo ( 10V under load ) and max current is only 25A - that equals 250 Watts absolute max.

The AXI is happy on 10 cells ( nickel !! ) which gives 12V PLUS it happy up to 40A maximum, which means more like 400watts potentially.

There are plenty of other alternative motors which would do fine, just look for one which will swing the prop size you intend to use - 8 -10 X 6/7 ?? - and is happy at around 100 watts per pound of AUW.

Fitting an inrunner may prove easier due to the confined nose space ?  

[Andy Freeman]

Thanks for the reply Timbo.

Working on the 100 Watts per Pound rule it should suffice I think.

You say a 3S LiPo gives 10v under load, i can see that. You then go on to say that 10 cells NiMh gives 12v+. Is that under load ? I suppose i shall get the meter out and play.

I really am going to have to get a multimeter that will handle more than 20A DC or a Wattmeter...

[Tim Mackey]

You are right to pick me up on that Andy.... 10 nickel cells may show less than full 12V under load, but if they are quality high capacity cells, then in my experience they do hold up better than some Lipo packs. 10 freshly charged nickel cells will probably show around 14V off load, and drop to around 11.5 - 12V depending on the load and quality of the cells as stated. Remember the nominal voltage of 3s Lipo is only 11.1V and when  freshly charged is only 12.4 - 12.6V

[Andy Freeman]

So. working from that, prior to me getting a chance to play with the meter.

You could say 8 cell NiMh would "probably" give 9v under load. (generalisation i know) where 3S LiPo would give 10v.

I really think I am going to have to re visit NiMh cells. All the E flying I have done has been with 400 sized stuff with LiPo and 4/5 AA NiMh.

As I mentioned earlier i feel the need for sonething a bit bigger to cope with the wind. I really am sensing this is the way to go. Esp. as i hate spending what little money i have.