GWS IPS gears with EDF50's High power C motor - RC Groups
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Nov 12, 2001, 11:27 AM
Houng-wen Lin
GWS4CEO's Avatar

GWS IPS gears with EDF50's High power C motor

Just have some good result of this crazy combination. This will make you fly full power only 4 cells 4.8V!

But since motor take nearly 20W power, GWS heat-sink will be a must! to protect you EDF50 motor alive.

Will post GWS datas ASAP on, and choice the better combinations to be GWS standard products soon.
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Nov 12, 2001, 02:44 PM
Registered User
mattk17's Avatar
Mr. Lin,
flying full power on only 4.8volts with the micro ducted fans sounds great. That would let us use higher powered batteries without adding too much weight.

Any word on the new A-10 warthog? I want to have my Christmas shopping done by December 1st and have been holding out for the A-10 but am running out of time.
Nov 13, 2001, 07:23 AM
Registered User
Bleriot's Avatar
HI ALL. What are the ramifications of this experiment? What is the Gear ratio? 5.86:1 (A)?? Does this mean that we get the same performance as the DXAC/9-7 combo at 4.8V instead of 7.2v+????? If so, then this is an EVENT! I'm sure, however, that I'll have no trouble frying this combo, especially if the solder connections to the armature/comm are not reworked with either hi temp solder or welded/staked. What are yor thoughts on this combo and any comments will be appreciated. Best Regards
Nov 15, 2001, 12:08 PM
Houng-wen Lin
GWS4CEO's Avatar
I read most of the test datas made is great!

GWS will rework magnet charge density to make IPS-LV ( Low Voltage for 4.8V ) as a standard products ASAP.

As we know the battery capacity incresed more than weight gain.
If we can use 4.8V 4 cells to get enough power out put, why should we use a 7.2V? Yet, you will save the battery cost too!

Aslo reduce BEC problem which come from Micro ESC. So many advantage to use LV system.

Sooner or later, GWS will develope how to use a sigle cell Li-ion battery to fly at 3.7V only. Cost down will improve the hard way of Li-ion battery still expensive!
Nov 15, 2001, 09:51 PM
Strange Plane Central
frankenfoamy's Avatar
The drop from 7.2 to 4 volts is likely to be more noticeable than the drop from 4.8 to 4 volts.

Say a BEC cuts out at 4 volts.
Some flyers still fly to the cut off.

The receiver may not work below 3-3.5 volts which could come up fast considering intermittant voltage drop during servo use.

What will we do to protect the receiver?
We probably still will need a BEC but it won't have to be as robust.
Nov 16, 2001, 05:39 AM
Houng-wen Lin
GWS4CEO's Avatar
Recivers can work under very low voltage if use a C-Mos device as GWS did.

Some of the old TTL Rx can not use low voltage. However, most new Rx should be OK, but distance reduced. Still enough for indoor!

We can use 4.8V with 3.3V BEC. save a lot of cost of battery!
Nov 16, 2001, 09:20 AM
Strange Plane Central
frankenfoamy's Avatar
Good to know.
How low a voltage can the GWS sub-micro receiver function at?
Nov 16, 2001, 10:44 AM
Houng-wen Lin
GWS4CEO's Avatar
All GWS RXs should be still working even down under 3V, even 2V.
But, the receiving sensitive will reduced. I need to check with the exactly figure under links with euipments get the correct datas to reply you.

GWS is on the way to design a new system of RC standard at 3~3.3V ( one cell Li-ion with BEC ). There not thing wrong with traditional 5V. But when Li-ion battery price, cost-performance becoming more attractive, why shouldn't we go to get along with this advantage?

With this concept in my mine, that why GWS keep design many new stuffs at Low Voltage operation! Safe and Save!
Nov 16, 2001, 11:21 AM
Registered User
Mr. Lin, once again you are showing us why GWS is on the cutting edge of e-flight. Low voltage is a real key to small, lightweight slowflyers. While all of the surplus Li-ion cell phone packs that many of us have been buying are 7.2V packs with 2 cells, the latest cell phones, which are smaller, lighter and more efficient, all operate on 3.6V, 1-cell packs. I believe that 3.6V Li-ion packs are becoming the new standard for small electronic devices. As these become more common, the cost of these Li-ion packs will continue to come down even as their performance continues to improve. Looking ahead a year or two, I believe that many of us will be flying small, lightweight slowflyers powered by 3.6V Li-Ion packs. I expect that many if not most of these aircraft and their electronics will be produced by GWS because of your great vision in seeing these trends developing.
Nov 16, 2001, 10:49 PM
Houng-wen Lin
GWS4CEO's Avatar
All GWS Rx already build in regulator 3.3V ( GWS has 3V regulator for PG-03 Piezo gyro ). Technically said, you can use sigle cell Li-ion to fly. But all servo need to redesign for getting better power out put at 3V. But need to design match gear drive at low current not to make Li-ion battery's Vcc drop too much.

Trandtional servo will fall to sleep under 3.5V, but GWS is working on a new circuit for 2.8V ( Sorry Pico servo is too small to put this new PCB into her case! )

C-mos circuit can even operated at 2V, but high frequency RF end will get very bad performance, since dynamic range become poor. So, we'd better keep it use a 3~3.3V regulator for Rx.
Nov 17, 2001, 10:39 AM
Houng-wen Lin
GWS4CEO's Avatar
Just started a new thred to talk about

GWS next concpt: a single cell Li-ion battery RC system.

We keep this part for: GWS IPS gears with EDF50's High power C motor.

Nov 18, 2001, 10:48 AM
Registered User
Mr. Lin,

Do you think that this low voltage system will eventually work its way into bigger elctric flight? Such as, Speed 400 and more powerfull outdoor flight? if it could then we could possibly start seeing close to GLOW performance out cheaper speed 400 motors etc...

I guess my main question is do you think this would be applicable in the future to bigger electrics?
Nov 18, 2001, 05:34 PM
Houng-wen Lin
GWS4CEO's Avatar
GWS offer this LV system for small indoor application to save those who is using 9.6V 8cells 50mah. How much this will cost you? While todays Li-ion battery one sigle cell of 3.7V 1.2~2Ah cost you less than that, give you more ennergy and weight light.

For speed 400, you can pay for AA, SC... good capacity and cost performance OK with Ni-cd or Mi-H. Not a time to use Li-ion for Big airplane yet! But you can see battery vendors have great improvement from time to time, a SC size pack from 1.2ah up to latest 3ah, wasn't that a great deal?
Nov 18, 2001, 06:22 PM
Registered User
Bleriot's Avatar
Hello GWS4CEO when will GWS make this IPS combination for sale to distributors? Thank You Best Regards
Nov 18, 2001, 06:52 PM
Registered User
Ben Lanterman's Avatar

Receiver Question


I have lost the papers that came with the receiver. It is the GWR-4P. I have about 10 feet of range antenna down and about 100 feet antenna out. I need to send it in but cannot find where to send it in the US. Any help will be appreciated.

I still love the Tiger Moth. I take off from my driveway, go between the temporary construction dumpster and a tree and over to an empty lot. After 20 minutes of aerobatics the landing is the reverse. The handling qualities are without fault. Give your designers a raise.