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Jun 07, 2005, 08:49 AM
LJH
LJH
Moths do not fly inverted
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.40 Size Trainer on a Brushed Astro 05?


My Brother has a Generic .40 size trainer , I believe the Tower Hobbies one, and we would like to electrify it. I have an old brushed geared Astro 05. The motor I have does not have any designations on it as to what turn 05 it is but the previous owner has it marked with a 7. I just counted the teeth on the straight cut gears and it looks it is 2.21:1. Wondering if you guy think this will work OK. I have both 10 and 12 cells CP2400 packs that I am planning on useing. Looking at the Astro web site they show a 7 turn 05 but with 2.4:1 box on it and they are showing somewhere over 400W with a 12X8 which I would think could flying this plane OK. I have done a bit of research here and all indicators seem to show this will work OK but I have very little experience with the Astro 05 so looking for some guidence here.

Cheers,
Jim
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Jun 07, 2005, 09:06 AM
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I say go for it. Should work fine. I have a Great Planes cub (76" w/s) with an old astro cobalt 15 on it, geared 2.6:1, spinning a 13x10. Works great. Of course I built it, and left out quite a bit of unneeded ply to lighten it, but the setup your talking about should be fine.
Jun 07, 2005, 09:35 AM
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Jim
I've run an Astro 035 G on 10 cells for around 6 or 7 years with no ill effects, in sports aerobatic models. Motor's still on its original brushes too.

The amp limit for these motors - the 05 and 035 - is 30A. I allowed a full power, fresh pack setting of 31 - 32A but nothing more. However, I was using a 3.7:1 ratio box - the "Superbox" with the 'standard' box 13T pinion.

Using your ten cell pack, and whatever prop comes out at 30A-ish flat out, you should be okay, though you might find that the prop size is on the low side. Springing for an Astro "Superbox" at higher ratio would allow for a better size of prop, but would involve you in spending and swapping push-on pinions, which might not excite you overmuch.

With a Superbox, the 05 might even live with your 12 cell packs. As a 40 sized glow trainer is likely to be a hefty beast after electrocution, this could make flying a more pleasant experience.

Hope that helps

Dereck
Jun 07, 2005, 09:41 AM
Registered User

Astro brushed motors are still good


I have an Astro 05 brushed motor in a Seniorita that flies quite well. I would say that you might think it does not have enough power. I am using a SuperBox, old 13x6 Top Fight prop and a 3s1p Polyquest 4400 mah pack. It glides and thermals quite well but doesn't fly like the typical .40 sized trainer. If you want that you might consider an Astro 15 or 25 on 14 or 16 cells. That was the original power in this plane. Back then it weighed 96 ounces. It now weighs 69 ounces. I like the new configuration much better but it is more like an Old Timer. I haven't been able to wear out an Astro motor either. I have replaced 2 sets of brushes in the 10 years of this plane. I like the Seniorita so much that I have 2.
Jun 07, 2005, 10:29 AM
LJH
LJH
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Thanks Guys, This is going to be a total "on the cheap" conversion useing what I have laying around collecting dust. I will give it a go and see what happens and let you guys know.

Cheers,
Jim
Jun 10, 2005, 02:52 AM
Ay up it's warped
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I flew my Flair Piper Cub on 10cells 10x7 prop quite happily on the Astro.
http://www.flairproducts.co.uk/Aircr...ainers/Cub.htm


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