Shaft drive TC... Why so few...
09-30-2014, 04:59 PM
#61
Its just a rotary damper, there are about 5 easy ways to do rotary damping, a wiper like the sachs or disks like I'm assuming the aweso's shocks have as they are round
09-30-2014, 05:28 PM
#62
Niznai, I think you are off the mark.
Torque steer comes from the spooling of mass in our cars longitudinally. Specifically all that matters is the mass moment of inertia of those parts (shaft and rotor, plus maybe a small gear or two), and how quickly the mass is accelerated or the rate of change of the RPM. The actual RPM does not matter, just how quickly it changes. These two directly influence torque steer... higher values mean more torque steer.
Now, a brushed motor has a greater amount of mass in the rotor and it is much farther away from the axis of rotation giving it a much much higher MMOI than a brushless rotor, which is lighter and more compact. Google MMOI if you are not following this.
And second, as for the acceleration of the parts. Assume two cars, one brushed, one brushless, that have very close to the same acceleration and top speed. Knowing brushed and brushless one knows the brushed car is geared higher than the brushless. Less torque but more RPMs. So the brushed cars rotor is going through more RPM change in the same amount of time as the BL.
All of this equates to brushed motors having much more torque steer than brushless because their parts have higher MMOI and higher rates of change of RPM.
Oh and I'd like to add I am building a TB04Pro2 I am pretty excited about.
Torque steer comes from the spooling of mass in our cars longitudinally. Specifically all that matters is the mass moment of inertia of those parts (shaft and rotor, plus maybe a small gear or two), and how quickly the mass is accelerated or the rate of change of the RPM. The actual RPM does not matter, just how quickly it changes. These two directly influence torque steer... higher values mean more torque steer.
Now, a brushed motor has a greater amount of mass in the rotor and it is much farther away from the axis of rotation giving it a much much higher MMOI than a brushless rotor, which is lighter and more compact. Google MMOI if you are not following this.
And second, as for the acceleration of the parts. Assume two cars, one brushed, one brushless, that have very close to the same acceleration and top speed. Knowing brushed and brushless one knows the brushed car is geared higher than the brushless. Less torque but more RPMs. So the brushed cars rotor is going through more RPM change in the same amount of time as the BL.
All of this equates to brushed motors having much more torque steer than brushless because their parts have higher MMOI and higher rates of change of RPM.
Oh and I'd like to add I am building a TB04Pro2 I am pretty excited about.
You're getting yourself entangled in irrelevant detail and are trying to be patronising using ignorance. Like I said, you need to convince me the momentum applied is greater and you fail on the same account as previous posters.
See Desert Rat's explanation a few posts back (after yours I am answering).
09-30-2014, 06:24 PM
#63
I hear the same thing said about torque steer in relation to the A700 by local racers.
The main reason I didn't buy the A700 is no local parts support and there is only one other local racer using one.
I have run the FT TC4 when there was no local part support and no one else running the car and it was a pain.
09-30-2014, 06:31 PM
#64
Yeaaah, no.
You're getting yourself entangled in irrelevant detail and are trying to be patronising using ignorance. Like I said, you need to convince me the momentum applied is greater and you fail on the same account as previous posters.
See Desert Rat's explanation a few posts back (after yours I am answering).
You're getting yourself entangled in irrelevant detail and are trying to be patronising using ignorance. Like I said, you need to convince me the momentum applied is greater and you fail on the same account as previous posters.
See Desert Rat's explanation a few posts back (after yours I am answering).
I'm looking forward to racing my shaft drive car soon!
09-30-2014, 06:50 PM
#65
Biggest thing is the R/C companies don't really test or build cars for spec, as we all know, all the top team drivers who test stuff run MOD.
really they look at two markets:
Bashers
and
MOD
Wins in MOD generate sales Win the worlds and you sell cars and you only do that in MOD so your car HAS to be best in MOD
really they look at two markets:
Bashers
and
MOD
Wins in MOD generate sales Win the worlds and you sell cars and you only do that in MOD so your car HAS to be best in MOD
A) Lack of talent
B) Lack of funds
C) if you are lucky enough to have either/both A&B, lack of others near by with A and or B to race against
09-30-2014, 07:03 PM
#66
How about a twin 380 brushless motor mounted front and rear that drives the differentials independently?
And an ESC to control both motors; like if you want more rear power or front or equal. Same with controlling the brake bias. Battery and electronics would be centered and no more belt or shaft. But you'll have 2 sets of spurs and pinions to deal with.
And an ESC to control both motors; like if you want more rear power or front or equal. Same with controlling the brake bias. Battery and electronics would be centered and no more belt or shaft. But you'll have 2 sets of spurs and pinions to deal with.
09-30-2014, 07:08 PM
#67
Racing and driving mod is an ego crusher, and perhaps not as fun on mainly small tracks
This is most likely why many able drivers shy away from this class
Mod 1/12th is a tire eating frenzy though
09-30-2014, 07:25 PM
#68
Tech Master
You need deep pockets to stay competitive in stock classes where motor/esc/batt of the month come and go. In a class where you need to squeeze every bit of RPM out of that blinky motor, things get crazy. And if you are up against guys with deep pockets or connections, the average joe has no chance.
09-30-2014, 08:01 PM
#69
Mate you have this wrong.
Brushed motors had considerably more torque effects on the chassi than brushless motors.
As the main shaft rotates in the opposite direction to the rotor there is also some torque cancellation effects. How much comes down to gearing, rotor diameter and weight.
As it stands I think there will not be a large come back of shaft drive cars.
There still is too much stigma in regards to shaft drives and torque steer. The A700 has the best suspension IMO lowest CG yet many racers wont buy it due to the shaft drive.
Brushed motors had considerably more torque effects on the chassi than brushless motors.
As the main shaft rotates in the opposite direction to the rotor there is also some torque cancellation effects. How much comes down to gearing, rotor diameter and weight.
As it stands I think there will not be a large come back of shaft drive cars.
There still is too much stigma in regards to shaft drives and torque steer. The A700 has the best suspension IMO lowest CG yet many racers wont buy it due to the shaft drive.
The shaft and all the rotating mass does indeed oppose the motor but not in a way that cancels its torque. If anything, it amplifies the effect.
Do this.
Disconnect all driveline components from the motor and give throttle a squirt with the car on say four scales under the wheels. See the effect on the scales. Now connect everything (except the driveshafts to the wheels, god forbid) and do the same. When did you see the largest variation on the scales?
Repeat with a brushed motor.
Report back.
The Awesomatix is a highly accomplished design so outlandish people don't really understand therefore fear. That is the psyche of the mass. They're followers, not leaders. Awesomatix is a leader design by miles. Like many other revolutionary designs in their own time, it has limited success, mainly because of the above but also because the sign of our time is the PR campaign and Awesomatix doesn't have the money to obliterate everybody else in such a way (like say Coca Cola, MacDonald's or some such). Now who in their right mind would say McDonald's is a good restaurant? Well, that's why you don't have a girlfriend.
Unfortunately this means Awesomatix doesn't have the funds to get worldwide distribution and this is what kills it especially in marginal markets (one of which I belong to). I would love to try one, but would hate to have to order and wait for six weeks to get a C-hub or something.
If I were Awesomatix, I would try an approach to distribution like Dell. Ordering all online from one place for the whole world, contracts with a major postal carrier (or two) worldwide like EMS or DHL or somebody that would guarantee a decent delivery time for a competitive price I would support myself, and I would distribute everything out of some place like HK or Singapore. I am aware this would mean a considerable strain on my life, but I don't see it happening any other way.
09-30-2014, 08:19 PM
#70
Not even close.
The shaft and all the rotating mass does indeed oppose the motor but not in a way that cancels its torque. If anything, it amplifies the effect.
Do this.
Disconnect all driveline components from the motor and give throttle a squirt with the car on say four scales under the wheels. See the effect on the scales. Now connect everything (except the driveshafts to the wheels, god forbid) and do the same. When did you see the largest variation on the scales?
Repeat with a brushed motor.
Report back.
The Awesomatix is a highly accomplished design so outlandish people don't really understand therefore fear. That is the psyche of the mass. They're followers, not leaders. Awesomatix is a leader design by miles. Like many other revolutionary designs in their own time, it has limited success, mainly because of the above but also because the sign of our time is the PR campaign and Awesomatix doesn't have the money to obliterate everybody else in such a way (like say Coca Cola, MacDonald's or some such). Now who in their right mind would say McDonald's is a good restaurant? Well, that's why you don't have a girlfriend.
The shaft and all the rotating mass does indeed oppose the motor but not in a way that cancels its torque. If anything, it amplifies the effect.
Do this.
Disconnect all driveline components from the motor and give throttle a squirt with the car on say four scales under the wheels. See the effect on the scales. Now connect everything (except the driveshafts to the wheels, god forbid) and do the same. When did you see the largest variation on the scales?
Repeat with a brushed motor.
Report back.
The Awesomatix is a highly accomplished design so outlandish people don't really understand therefore fear. That is the psyche of the mass. They're followers, not leaders. Awesomatix is a leader design by miles. Like many other revolutionary designs in their own time, it has limited success, mainly because of the above but also because the sign of our time is the PR campaign and Awesomatix doesn't have the money to obliterate everybody else in such a way (like say Coca Cola, MacDonald's or some such). Now who in their right mind would say McDonald's is a good restaurant? Well, that's why you don't have a girlfriend.
You are not even close on all points above except AMX perhaps being too complicated for the masses.
09-30-2014, 08:31 PM
#71
How about a twin 380 brushless motor mounted front and rear that drives the differentials independently?
And an ESC to control both motors; like if you want more rear power or front or equal. Same with controlling the brake bias. Battery and electronics would be centered and no more belt or shaft. But you'll have 2 sets of spurs and pinions to deal with.
And an ESC to control both motors; like if you want more rear power or front or equal. Same with controlling the brake bias. Battery and electronics would be centered and no more belt or shaft. But you'll have 2 sets of spurs and pinions to deal with.
But I think it's the way things will ultimately head to albeit in a much more sophisticated manner.
I have commented elsewhere I think we'll end up in the (more or less) distant future with direct drive and four independent motors in the wheels. Think some really small, really powerful outrunner motors like those used in airplanes right now, with the stator part of the hub, and the rotor being the wheel axle. All the diff action will be handled by electronics. This will probably mean we'll end up with a battle of the software like everything else.
10-01-2014, 03:56 AM
#72
Rules forbid using more than one motor. Thats why there is no development in this direction. Otherwise having 4 smaller motors and a sophisticated esc would be the way to go.
The Awesomatix is a nice car. Its problems for the most drivers is its small setup window. Some very good german drivers returned back to their "normal" cars, because the Awesomatix needs a lot of setup work if you change the racetrack and it was not faster than a "normal" car. Once you head to the next track it is not competitive anymore. Then you have to invest a lot of time to make it work again. Its other problem is fragility.
I for myself think it is not a better car. They just did things different...
The Awesomatix is a nice car. Its problems for the most drivers is its small setup window. Some very good german drivers returned back to their "normal" cars, because the Awesomatix needs a lot of setup work if you change the racetrack and it was not faster than a "normal" car. Once you head to the next track it is not competitive anymore. Then you have to invest a lot of time to make it work again. Its other problem is fragility.
I for myself think it is not a better car. They just did things different...
10-01-2014, 07:17 AM
#74
Unfortunately this means Awesomatix doesn't have the funds to get worldwide distribution and this is what kills it especially in marginal markets (one of which I belong to). I would love to try one, but would hate to have to order and wait for six weeks to get a C-hub or something.
10-01-2014, 08:09 AM
#75
Ferarri did 2 powertrains in one of their cars. I think it's the FF (4WD). Gas engine drives the rear then an electric motor drives the front. It didn't need a center diff or transfer case.
I for one will buy a kit like that, with twin 380 size motors. No more belts or shafts, more centralized placement of electronics, potentially more balanced.
I for one will buy a kit like that, with twin 380 size motors. No more belts or shafts, more centralized placement of electronics, potentially more balanced.