E-power for Burrito - AXI 4120/18 or 4130/16
04-18-2006, 10:04 AM
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E-power for Burrito - AXI 4120/18 or 4130/16
I'm so confused
. It seems like both AXI motors will provide the 750W I'm looking for. If I use the same batteries in either set-up (a pair of PQ 4000mAh 12C for 6S1P) , the weight penalty of using the 4130/16 would only be ~ 3-4oz. The benefit of the 4130/16 seems to be that I could run larger props at a low amperage (I would like to remain below 48A), therefore providing flexibility for use on most 40-60 size models.
What works better on these profiles, smaller prop at high rpm or larger prop at low rpm? Does anyone have any experience with both of these? I would appreciate your feedback.
Thanks in advance,
Tony
. It seems like both AXI motors will provide the 750W I'm looking for. If I use the same batteries in either set-up (a pair of PQ 4000mAh 12C for 6S1P) , the weight penalty of using the 4130/16 would only be ~ 3-4oz. The benefit of the 4130/16 seems to be that I could run larger props at a low amperage (I would like to remain below 48A), therefore providing flexibility for use on most 40-60 size models. What works better on these profiles, smaller prop at high rpm or larger prop at low rpm? Does anyone have any experience with both of these? I would appreciate your feedback.
Thanks in advance,
Tony
04-18-2006, 12:56 PM
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RE: E-power for Burrito - AXI 4120/18 or 4130/16
Here is a layman's answer, and engineer tends to confuse the subject so much that if you feel mixed up now, wait until later.
General layman's rule.
1. Figure the RPMs that you want, or use the prop size that Axi recommends. The prop speed is a product of the volts. The volts to the motor are determined by the lipos in series.
2. OK, now you have RPM, the bigger the prop size, the more amps required. The more amps required is satisfied by batteries in parallel. Youn can get the RPM with small amp batteries in series, however, they won't run the motor for long, and will be strained or ruined. The discharge rate is important.
In summary, putting a smaller prop size on the motor will not necessarily increase the RPMs, it will lower the amps drained. A good start would be to use the manufacturers recommended prop size matched to the suggested lipos in series. Test it, feel for heat, time the duration of the run at varied speeds, and add more batteries in parallel to provide more amps for duration and cooling. After you do this you can try different props or try other setups. In any case you will be starting with something that works, go from there.
Al
General layman's rule.
1. Figure the RPMs that you want, or use the prop size that Axi recommends. The prop speed is a product of the volts. The volts to the motor are determined by the lipos in series.
2. OK, now you have RPM, the bigger the prop size, the more amps required. The more amps required is satisfied by batteries in parallel. Youn can get the RPM with small amp batteries in series, however, they won't run the motor for long, and will be strained or ruined. The discharge rate is important.
In summary, putting a smaller prop size on the motor will not necessarily increase the RPMs, it will lower the amps drained. A good start would be to use the manufacturers recommended prop size matched to the suggested lipos in series. Test it, feel for heat, time the duration of the run at varied speeds, and add more batteries in parallel to provide more amps for duration and cooling. After you do this you can try different props or try other setups. In any case you will be starting with something that works, go from there.
Al
04-18-2006, 04:33 PM
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RE: E-power for Burrito - AXI 4120/18 or 4130/16
I'm starting to lean towards the 4130/16. Here is a reply I found for a 5lb. 3D Airplane Conversion:
From Greg Covey, electrics moderator, dated 1-27-2005.
For a 5lb 3D plane, use a power system that can deliver around 150 watts per pound (or 150w/lb).
This means that you need a motor that can handle at least 5 x 150w or 750 watts.
Using and outrunner like an AXI 4130/16 motor can provide this power for a good cost value. The outrunner motor is also maintenance free as there is no gearbox to lubricate or pinion gear to worry about slipping.
A 20 cell NiCd or NiMH setup with a 14x7 or 15x7 APC e-prop is a good starting point. The combination AXI 4130/16 motor and Jeti 77-amp Opto ESC (PM413016C) can be purchased at Hobby Lobby for only $329. This is less than half your $700 budget.
I would start out with two 10-cell battery packs, and, if you like the result, switch to two 3-cell Lithium packs.
Good luck!
From Greg Covey, electrics moderator, dated 1-27-2005.
For a 5lb 3D plane, use a power system that can deliver around 150 watts per pound (or 150w/lb).
This means that you need a motor that can handle at least 5 x 150w or 750 watts.
Using and outrunner like an AXI 4130/16 motor can provide this power for a good cost value. The outrunner motor is also maintenance free as there is no gearbox to lubricate or pinion gear to worry about slipping.
A 20 cell NiCd or NiMH setup with a 14x7 or 15x7 APC e-prop is a good starting point. The combination AXI 4130/16 motor and Jeti 77-amp Opto ESC (PM413016C) can be purchased at Hobby Lobby for only $329. This is less than half your $700 budget.
I would start out with two 10-cell battery packs, and, if you like the result, switch to two 3-cell Lithium packs.
Good luck!
