DIY discussion - Increasing power to the G25 & G27 wheels

[angor 7]

Hi,

I'm new to this forum and I've reached it searching "increase speed G25".

 

I've change the pinion of the motors, replacing 10thoot with 20thoot.

Result is a failure in calibration, probably because the software count too low pulse from the encoder.

 

So, I so I tried to remove the encoder from the engine and I mounted it to the main gear by a pinion 10 teeth, so that the encoder would provide still the same number of pulses.
But it did not work: the wheel behaves as if it does not have the transducer connected.

I then noticed that the transducer, as it is done, does not provide direction of rotation, but only on the extent of rotation.

Usually encoder to give angle and direction must have 2 couple of emitter-receiver.

 

So, I think that the card reads the direction of rotation as a signal from the engine (there are radio-controlled cars systems that read the engine speed by measuring the voltage while spinning) and that this should correspond to the one that reads the optical encoder.

Maybe later I send some pictures to show what I did.

I hope I have given some ideas for someone

PS: sorry for the google-english

[Tberg 2]

I will then, be back in 3-4 weeks.

[angor 7]

surprise!

I simply swap position of encorde and then in work!

 

see here

http://www.youtube.com/watch?v=aJ1LAI22WC8

 

Only upgrade is 20T pinion instead 10T.

 

obviously, now FFB is halt that before was.

 

Now, I try supply 36V instead 24V to have a bit more strength.

I will monitoring temperatures.

 

[Tberg 2]

surprise!

I simply swap position of encorde and then in work!

 

see here

http://www.youtube.com/watch?v=aJ1LAI22WC8

 

Only upgrade is 20T pinion instead 10T.

 

obviously, now FFB is halt that before was.

 

Now, I try supply 36V instead 24V to have a bit more strength.

I will monitoring temperatures.

Be careful, you're adding 225% more power than stock by going to 36V, and if the ffb is halfed, you're probably even at higher power.

The mosfets may take it, but maybe not the currentlimiting resistors and onboard fuse.

So temperature is not safe to monitor only.

Good luck

[angor 7]

I read somewhere that mosfet and diode are safe until 50V, so seem only temperature must be the most important factor.

 

My idea is to start with about 30%, then monitoring temperature and FFB....if is all right after 30-40 min of drifting, switch to 40% and so on.

 

I need only some fans and a dissipator over the mosfet.

 

PS: 36V is "only" 150% than 24V

[Tberg 2]

Yes you're right, but I ment power as in watt, not voltage. 150% voltage is 225% watts over the same resistance, in theory. Obviously neither voltage nor power will be constantly at max, but you need to calculate with it.

Trust me, you need to pay attention to the the surrounding resistors as well.

Post your results, looking forward to them. I won't be working on this the next couple of weeks, will follow the thread though.

[angor 7]

Ok, I forgot power=volt x ampere....so, power is V^2.

 

However, I tried to control the temperature of various components during use and it seems that only in the highlighted area there is heating.

 

Instead, it seems that engines are the most stressed component: after 30 minutes they are about 50°C.

I don't realize why: most people say they are the less stressed in the original configuration.

 

 

[Tberg 2]

Put RC heatsinks and fans on them and try again. How's the ffb?

As with the parts, I've only looked at the pcb, haven't tested or measured anything yet.

Keep posting results

[simul8r 114]

surprise!

I simply swap position of encorde and then in work!

 

see here

http://www.youtube.com/watch?v=aJ1LAI22WC8

 

Only upgrade is 20T pinion instead 10T.

 

obviously, now FFB is halt that before was.

 

Now, I try supply 36V instead 24V to have a bit more strength.

I will monitoring temperatures.

 

Angor, can you elaborate more as to what you changed on your G25 wheel that made it respond as shown on the video.  Was it the sprocket gears on the motors, was it the main large sprocket on the wheel itself or was it the plastic pinion gear front of and below the gear housing that rests on the plastic slide bar? Can you show us photo of the part or parts you changed?

 

Thanks.

[simul8r 114]

Put RC heatsinks and fans on them and try again. How's the ffb?

As with the parts, I've only looked at the pcb, haven't tested or measured anything yet.

Keep posting results

 

I'm currently at that point as we speak.  Here, are the following things I've done to my G27:

 

1) I have changed the encoder wheel from the fragile Logitech plastic one to the bronze wheel I ordered from Thailand.

2) I've added a high velocity 70mm fan directly over the pcb, right above the mosfets (loud but affective)

3) I've knocked out holes from front of my G27 wheel @ at the housing grill section for fresh air in.

4) I've added RC motor heat sinks to both motors and slapped on some Artec5 heat sink paste between that and the motors.

5) Added springs to either side of the lower plastic slide bar below the gear housing in hopes it will help the wheel center.

6) Added that adaptor rated 26vdc @ 2.5a mentioned earlier.

 

The result is a bit better especially with the new adaptor but still desiring more power if possible.

[angor 7]

double post

[angor 7]

sure. pinion are fitted on the motor and I have to shift motors.
see photo.
I need also some drilling grinding and build a support for encoder.

 

Really, are only two changes, though for them need a bit of work.

1) replacement of the pinion gears
original pinion has 10 tooth, fitting a 20 tooth doubles the speed of the wheel and the force is halfed
Since the new pinions has a diameter twice, you must move the engines, milling slots and so on

2) displacement encoder
having changed the pinions, motors half of the rounds and this does not allow proper calibration (the drivers think that the wheel stops halfway)
So, I made ​​a stand for the encoder that rotate at the same motor speed with the 10 original teeth pinions.
I don't know why, but It is important that the encoder is the same side of the engine: towards the interior of G25.


In this way the steering wheel has doubled, or even more, the speed.

 

WARNING: FFB is half. It 'great for drift, not so much fun for normal driving.

[Tberg 2]

Very Nice simul8r and angor!

 

 

 

I found the G25 motor datasheet.

 

There's also excellent options for RC heatsinks with fans, 540 motorsize as the G25 motor is, like this one.

 

I'm busy all week, then off for 1 week skiing, but after that I'll look into the electronics around the DC supply, resistors, fets etc.

[angor 7]

I think 36Volt is too high....so, I think to use some diode to lower the tension, connecting them in serial mode.

 

Firts I'll try with 15 diode, will give a reduction of about 10V. So I'll have about 26-27V input G25. If will be all ok, I'll remove 1 or 2 diode, elevating supply at 28-29 and so on.

 

I'll post the results.

bye

[angor 7]

So, G25 motors seems to have only 3W... 

 

Now, I have a BIG temptation:

http://www.ebay.it/itm/2-Unite-Electric-E-Scooter-Motors-24-Volt-120-Watt-16-Th-Belt-Sprocket-120w-24v-/171207365485?pt=LH_DefaultDomain_0&hash=item27dcc1136d

 

LOL....120W instead 3W....

 

No no no.....I thinks it's better walking step by step....

[angor 7]

News.

 

I've bought a 36V power supply (like this ) and LM7824 (limiter tension to 24V) and some diodes to lower output tension.

 

My original supply is about 23,5V.

 

Whit those stuff, I try to supply G25 with 24-26-28-30V.

Until 26V, there are no overheating of motors nor components respect oem supply.

 

28 and 30V required some cooling (actually, a simple fan direct to the board), but after 30 minutes of drift seems to be all ok. Speed increase about 20-25%, so I think actually my G25 is 3x faster respect original pinions and supply. I think for 30-40 bucks is a good goal.

 

Probably I'll try to go more over (not 36V, but 32-33), but first I need to create a small heatsink for IC.

[angor 7]

Today I try to go over 30V, but finally I have some failures.

 

at 33V the power supply goes on protection

at 36V the G25 doesn't work at all.

 

So, I think about 33V is the maximum for original electronic.

 

But, at "only" 30V I've got this

speed

speed

 

I think motor and IC that drive them can go more over 30V, but need to modify the PCB to divide electronics supply to motor supply.

And is more over my capacity.

 

Now has nearly the same torque as the original and I think at least a triple speed.
It would be nice to try that torque would have with the original pinion 10 teeth.

I think that anyone who is looking only for torque, could achieve a great result with a 30V power supply (or one like the kodak 36, 7824 and a 10 diodes) and a fan. For a total of 30 Euros.

Obviously, anyone who wanted to try do so at your own risk. I'm not responsible for any damage that may occur.

[simul8r 114]

Good work angor.  I'm surprised you took it as far as you did.  After reading your last entry I went ahead and bought a cheap power supply rated 28vdc @ 1.8 amps from ebay.  Looking forward to see what it does to the wheel.

 

Regards.

[angor 7]

Remember to give it some cooling: actually my G25 is without the cover and a fan just over the pcb.

[Tberg 2]

Good work angor, but mind that your G25 is not working past 33V probably because 1.6A is not enough to drive the FFB.

 

I will probably go for this supply, rated up to 9.7 amps:

http://www.parts-express.com/36-vdc-97a-350w-regulated-switching-power-supply--320-3141

 

I hope I can be helpful in the electronics, getting it past 33-36V without shutdown.

 

I'm off to France, skiing, same place as Schumi hit his head 

[simul8r 114]

Tberg, isn't 9.7 amps extreme?  The original Logitech power source is rated 1.75 and I can't imagine pushing more than 4 times that without frying something on the board.  Can I ask how you came about that much to experiment with?

[Tberg 2]

Tberg, isn't 9.7 amps extreme? The original Logitech power source is rated 1.75 and I can't imagine pushing more than 4 times that without frying something on the board. Can I ask how you came about that much to experiment with?

Very simple, it's the only one in that voltagerange I want for testing. Having 9,7A is indeed an extreme, but it's just headroom. The G25 under my planned test will hardly pull more than 3A spikes at max. The motors are rated 2,7A so they better be proper cooled when running beyond that, not to mention the mosfets.

Quick reference: 24V/1.75A = 13,7 ohms at max current. Fictive non-practical ffb/wheel-resistance, but just for theory. Go to 36V, and: 36V/13,7ohms = 2,63A. Just under the motors max rating. Beyond that, you'd better cool everything and probably get new parts/mosfets to control the current and not burn anything.

Anyway, you could get this suply at 3.3A:

http://www.parts-express.com/48-vdc-33a-150w-regulated-switching-power-supply--320-3142

but the voltage range is just too much I think. And, going that high, you'd probably exeed 3.3A anyway if the G25 was ever modded to take it.

Parts-express supplies are by far the most costefficient I can find anywhere.

[angor 7]

Good work angor, but mind that your G25 is not working past 33V probably because 1.6A is not enough to drive the FFB.

 

I will probably go for this supply, rated up to 9.7 amps:

http://www.parts-express.com/36-vdc-97a-350w-regulated-switching-power-supply--320-3141

 

I hope I can be helpful in the electronics, getting it past 33-36V without shutdown.

 

 

 

I'm off to France, skiing, same place as Schumi hit his head 

 

 

No, I'm sure it wasn't for Ampere: when FFB is not used, G25 use very low power (0,1-0,3A).

 

So, I think nothing change using even a 1000A supply

 

My opinion is a better and safer idea don't go over 30V with original electronic.

 

Good luck for your skiing....

[simul8r 114]

No, I'm sure it wasn't for Ampere: when FFB is not used, G25 use very low power (0,1-0,3A).

 

So, I think nothing change using even a 1000A supply

 

My opinion is a better and safer idea don't go over 30V with original electronic.

 

Good luck for your skiing....

 

I think Tberg may have confirmed what I discovered in my previous tests using other power supplies.  I currently have 4 power units of which includes the original Logitech G27's.  Here is what I found based on how the wheel felt during operation (sim racing).

 

24 vdc ~ 1.75a.............standard torque

24 vdc ~ 2.1a...............same to slight torque increase

26 vdc ~ 2.5a...............noticeable torque increase (currently in use with my wheel)

28 vdc ~ 1.5a...............same as standard but then looses torque completely in the middle of a turn and then regains afterwards

 

As of now, I'm waiting on 2 other units from ebay to arrive and they are.....

 

28 vdc ~ 1.8a

32 vdc ~ 2.5a

 

Yeah......I have a sickness for power supplies and I need help!

[rfernandes 21]

"Yeah......I have a sickness for power supplies and I need help!"

 

loOL!!