3LikesTekin RX8 1/8 Scale Brushless ESC Thread
02-23-2010, 02:40 PM
#6766
5s 1700 on a tight track is way too much power. I was running that setup on a track with a 200 foot front straight and it was still a bit overpowered.
I would run the 1400kv motor on 5s to tame it down a bit and then gear for about 33-35 mph at most if the track is really small.
My motors rarely get above 130 degrees these days, but then can usually run up to 175 degrees safely. Anything more than that you are getting into the danger zone of demagnetizing the motor.
I would run the 1400kv motor on 5s to tame it down a bit and then gear for about 33-35 mph at most if the track is really small.
My motors rarely get above 130 degrees these days, but then can usually run up to 175 degrees safely. Anything more than that you are getting into the danger zone of demagnetizing the motor.
02-23-2010, 02:54 PM
#6767
How quickly people forget all of Castle's problems and the three major revisions it took to get the MMM mostly reliable. And they can still fail. Any ESC will fail given the amount of abuse they get in an 1/8th. This isn't a nice soft landing 1/10th buggy, these bricks fall from the sky 20 ft up and land hard and flat at full power. 
02-23-2010, 03:18 PM
#6768
Cheap, small, reliable: Pick any two.
02-23-2010, 03:31 PM
#6769
People pay $400-$500 bucks for nitro engines, they will pay it for a speed control.
I think Tekin/Castle could sell a few "race spec" ESCs and then maybe offer a cheaper one for the bashers on a budget.
02-24-2010, 05:41 AM
#6770
Tech Regular
hi there
i see at tower and amain that the tekin truggy 2000kv motor is on back order
so my question
i run 4s on the mugen truggy and would know if its a big difference in runtime, performance and temps, iff i run the buggy 2050 version on 4s in my truggy?
what would be the difference?
thank you
mihael
i see at tower and amain that the tekin truggy 2000kv motor is on back order
so my question
i run 4s on the mugen truggy and would know if its a big difference in runtime, performance and temps, iff i run the buggy 2050 version on 4s in my truggy?
what would be the difference?
thank you
mihael
02-24-2010, 05:59 AM
#6771
I used to run the Buggy 2050kv motor on my F8T Truggy. Temps are abt the same with the truggy motor but of course with the truggy motor, it will have more torque. As for runtime, I did not calculate tht.
02-24-2010, 08:10 AM
#6772
Well i must say after having my main and Spare ESC take a dump on me at the Nitro Pit this past weekend and not to mention i think the motor is pooched as well.....im not very happy....this isn't the first time...and im sure it wont be the last...But PLEASE Tekin....get this stuff Sorted.
Ty and or Randy ill be in Contact in the next couple days either by phone or E-mail.
Ty and or Randy ill be in Contact in the next couple days either by phone or E-mail.
02-26-2010, 12:47 PM
#6773
For you folks who are burning through a RX8 every month for six months straight:
1. Are you monitoring the temperatures of your motor and ESC?
2. Are you running a working fan with all blades operational on your ESC and motor?
3. Are you using the recommended maximum number of cells for your motor? For 2000kV, for example, it is only 4s.
4. Are you mounting the ESC directly to the chasis or on some foam tape? I would think that screwing it directly to the chasis may crack a solder joint on a really hard landing. Why not put a piece of dense foam beneath it and zip tie it down?
Example: 3M™ Extra-thick Multipurpose Mounting Tape 4008
5. Are you making the wires connecting the motor to the ESC long enough that there is ample room to bend when the chassis flexes?
6. Are you insulting the motor and ESC terminals with tape or heat shrink tubing so that they can't accidentally short out? I would be worried that some piece of debris or an allen wrench could momentarily touch and short the ESC.
Has anybody tried doing all of the above and still had numerous issues with the newer RX8 designs?? Things don't magically break unless they are subject to vibrations, shock or heat. If you keep the temperatures below 150 F, by monitoring them, and mount the ESC on a couple layers of thick foam double sided sticky tape, I don't see how you can fry so many so frequently. The one thing that can spell disaster for electronics are bad solder joints since they can crack, but I highly doubt Tekin hasn't double checked that.
Now, maybe the RX8 is too fragile, but more likely people just need to learn to be extra careful with 1/8th scale because of the speed and power, no? After all, how much better can either Castle or Tekin engineer these things for $300? 1/8th electric is still relatively new, so it wouldn't surprise me if there is some learning that we all need to do.
-Just my 2 cents
1. Are you monitoring the temperatures of your motor and ESC?
2. Are you running a working fan with all blades operational on your ESC and motor?
3. Are you using the recommended maximum number of cells for your motor? For 2000kV, for example, it is only 4s.
4. Are you mounting the ESC directly to the chasis or on some foam tape? I would think that screwing it directly to the chasis may crack a solder joint on a really hard landing. Why not put a piece of dense foam beneath it and zip tie it down?
Example: 3M™ Extra-thick Multipurpose Mounting Tape 4008
5. Are you making the wires connecting the motor to the ESC long enough that there is ample room to bend when the chassis flexes?
6. Are you insulting the motor and ESC terminals with tape or heat shrink tubing so that they can't accidentally short out? I would be worried that some piece of debris or an allen wrench could momentarily touch and short the ESC.
Has anybody tried doing all of the above and still had numerous issues with the newer RX8 designs?? Things don't magically break unless they are subject to vibrations, shock or heat. If you keep the temperatures below 150 F, by monitoring them, and mount the ESC on a couple layers of thick foam double sided sticky tape, I don't see how you can fry so many so frequently. The one thing that can spell disaster for electronics are bad solder joints since they can crack, but I highly doubt Tekin hasn't double checked that.
Now, maybe the RX8 is too fragile, but more likely people just need to learn to be extra careful with 1/8th scale because of the speed and power, no? After all, how much better can either Castle or Tekin engineer these things for $300? 1/8th electric is still relatively new, so it wouldn't surprise me if there is some learning that we all need to do.
-Just my 2 cents
02-26-2010, 01:25 PM
#6774
Been there done that with Tekin & castle.
Both companies have had to go thru the learning curve. Castle had a year head start and now are pretty reliable. Tekin is getting there.
Both companies have had to go thru the learning curve. Castle had a year head start and now are pretty reliable. Tekin is getting there.
Last edited by RBMike; 02-26-2010 at 04:17 PM.
02-26-2010, 01:50 PM
#6775
Great first post. No one here thought of any of that over the last year.
No offence but your 2 cents worth is worthless. Been there done that with Tekin & castle.
Both companies have had to go thru the learning curve. Castle had a year head start and now are pretty reliable. Tekin is getting there.
No offence but your 2 cents worth is worthless. Been there done that with Tekin & castle.
Both companies have had to go thru the learning curve. Castle had a year head start and now are pretty reliable. Tekin is getting there.
Not related to Tekin, but and one point when monsters were blowing up more frequently, Patrick pointed out that people who have problems, have them over and over agin each time they start with a fresh speed control. They are clearly doing something bad that others, some of whom are still running V1 monsters are not.
02-26-2010, 01:56 PM
#6776
I disagree that it is entirely worthless.
Not related to Tekin, but and one point when monsters were blowing up more frequently, Patrick pointed out that people who have problems, have them over and over agin each time they start with a fresh speed control. They are clearly doing something bad that others, some of whom are still running V1 monsters are not.
Not related to Tekin, but and one point when monsters were blowing up more frequently, Patrick pointed out that people who have problems, have them over and over agin each time they start with a fresh speed control. They are clearly doing something bad that others, some of whom are still running V1 monsters are not.
I have seen people do some ridiculous things with electronics. I've seen people wire the hot to the nuetral on AC circuits and then wonder why it blew up in their face when they turned it on. Just saying, somebody may be doing something that is causing the problem without realizing it. Now, that isn't to say Tekin and Castle shouldn't design these things to prevent that, but if the goal is to solve the problem, a little thinking might help.
If we can find a way to reduce the stress on the ESC/motor, than maybe it will get us through until they work out all of the bugs. After all, other than heat or shock/vibration, I don't see what could kill the ESC if they didn't make any stupid design errors. One problem that could happen would be if the temperature sensor detached from the MOSFETs and the heatsink also began to detach. Then the MOSFETs could fry without the thermal shutdown kicking in. Or maybe they put the sensor on the heatsink, which would be dumb. How securely is the heatsink attached to the MOSFETs?
One other thing is that MOSFETs are really sensitive to static electricity. If they didn't put some ESD diodes on the inputs, that could eventually cause flaky operation leading to failure. To prevent this you can wire up a "Tranzorb" diode across the battery input terminals.
02-26-2010, 02:03 PM
#6777
For you folks who are burning through a RX8 every month for six months straight:
1. Are you monitoring the temperatures of your motor and ESC?
answer : yes motor and esc "never" get anything above warm im actuly very happy with how cool this system runs
2. Are you running a working fan with all blades operational on your ESC and motor?
answer: yes working fan with all blades even though the only time the fan ever comes on is when you first power it up because like i said the system runs very cool
3. Are you using the recommended maximum number of cells for your motor? For 2000kV, for example, it is only 4s.
answer: im running a hyperion vx g3 35c 4s batteries with a 1900kv motor and the batteries dont get puffed or even warm for that matter
4. Are you mounting the ESC directly to the chasis or on some foam tape? I would think that screwing it directly to the chasis may crack a solder joint on a really hard landing. Why not put a piece of dense foam beneath it and zip tie it down?
Example: 3M™ Extra-thick Multipurpose Mounting Tape 4008
answer: im mounting my esc with several layers or squishy double sided tape so it has some give.... even though randy pike says it wont last any longer ether way and tekin says one layer is fine
5. Are you making the wires connecting the motor to the ESC long enough that there is ample room to bend when the chassis flexes?
answer: yes plenty of extra wire and wire is lightly secured so it dosn't bounce around on the bumps
6. Are you insulting the motor and ESC terminals with tape or heat shrink tubing so that they can't accidentally short out? I would be worried that some piece of debris or an allen wrench could momentarily touch and short the ESC.
answer: yes all thermals have heat shirk on them
Has anybody tried doing all of the above and still had numerous issues with the newer RX8 designs?? Things don't magically break unless they are subject to vibrations, shock or heat. If you keep the temperatures below 150 F, by monitoring them, and mount the ESC on a couple layers of thick foam double sided sticky tape, I don't see how you can fry so many so frequently. The one thing that can spell disaster for electronics are bad solder joints since they can crack, but I highly doubt Tekin hasn't double checked that.
Now, maybe the RX8 is too fragile, but more likely people just need to learn to be extra careful with 1/8th scale because of the speed and power, no? After all, how much better can either Castle or Tekin engineer these things for $300? 1/8th electric is still relatively new, so it wouldn't surprise me if there is some learning that we all need to do.
answer : i have done every thing i can think of to make my rx8 last as long as possible but it still breaks over and over. the car has never been run outside and bashed the only thing this car is ever used for is racing, and its raced on an indoor clay track made for 1/10 scales and the track has no big jumps heres a vid of the track im not in the vid but you can see its not like we are jumping 10 feet up and smashing down see for yourself where im running and see if its too much abuse for the rx8
http://www.youtube.com/watch?v=zWAlYXz923o
-Just my 2 cents
1. Are you monitoring the temperatures of your motor and ESC?
answer : yes motor and esc "never" get anything above warm im actuly very happy with how cool this system runs
2. Are you running a working fan with all blades operational on your ESC and motor?
answer: yes working fan with all blades even though the only time the fan ever comes on is when you first power it up because like i said the system runs very cool
3. Are you using the recommended maximum number of cells for your motor? For 2000kV, for example, it is only 4s.
answer: im running a hyperion vx g3 35c 4s batteries with a 1900kv motor and the batteries dont get puffed or even warm for that matter
4. Are you mounting the ESC directly to the chasis or on some foam tape? I would think that screwing it directly to the chasis may crack a solder joint on a really hard landing. Why not put a piece of dense foam beneath it and zip tie it down?
Example: 3M™ Extra-thick Multipurpose Mounting Tape 4008
answer: im mounting my esc with several layers or squishy double sided tape so it has some give.... even though randy pike says it wont last any longer ether way and tekin says one layer is fine
5. Are you making the wires connecting the motor to the ESC long enough that there is ample room to bend when the chassis flexes?
answer: yes plenty of extra wire and wire is lightly secured so it dosn't bounce around on the bumps
6. Are you insulting the motor and ESC terminals with tape or heat shrink tubing so that they can't accidentally short out? I would be worried that some piece of debris or an allen wrench could momentarily touch and short the ESC.
answer: yes all thermals have heat shirk on them
Has anybody tried doing all of the above and still had numerous issues with the newer RX8 designs?? Things don't magically break unless they are subject to vibrations, shock or heat. If you keep the temperatures below 150 F, by monitoring them, and mount the ESC on a couple layers of thick foam double sided sticky tape, I don't see how you can fry so many so frequently. The one thing that can spell disaster for electronics are bad solder joints since they can crack, but I highly doubt Tekin hasn't double checked that.
Now, maybe the RX8 is too fragile, but more likely people just need to learn to be extra careful with 1/8th scale because of the speed and power, no? After all, how much better can either Castle or Tekin engineer these things for $300? 1/8th electric is still relatively new, so it wouldn't surprise me if there is some learning that we all need to do.
answer : i have done every thing i can think of to make my rx8 last as long as possible but it still breaks over and over. the car has never been run outside and bashed the only thing this car is ever used for is racing, and its raced on an indoor clay track made for 1/10 scales and the track has no big jumps heres a vid of the track im not in the vid but you can see its not like we are jumping 10 feet up and smashing down see for yourself where im running and see if its too much abuse for the rx8
http://www.youtube.com/watch?v=zWAlYXz923o
-Just my 2 cents
i dont know what to say im using this rx8 on 4s with a 1900kv and im not hitting and huge jumps smashing down on the chassis or running outdside hitting curbs "THE ONLY WAY THIS CAR IS EVER USED IS LIKE IN THE ABOVE VIDEO"the esc and motor never ever have gotten hot not even very warm i dont even think the fan has ever come on at least its never been on when i come off the track.
answer: this rx8 esc has some connection issues inside the unit and it has nothing to do with the user or how its used period.
02-26-2010, 02:06 PM
#6778
funny how you should mention that my friend bought his rx8 at the same time i got mine and we race together use the exact same car and setup batteries everything.........his has never broke and his is the old first run version and mine is the newer one lol
02-26-2010, 02:07 PM
#6779
Obviously, its hard to know without being in the Tekin engineering room.
02-26-2010, 02:11 PM
#6780
I disagree that it is entirely worthless. There are people (me for one) who have run a whole season on a single, early production, RX8 with nary a hint of problems, Then there are people that have gone through 5 of them, getting a few minutes track time with each before the ESC gets croaked. Those two camps have got to be doing something different. Maybe some of the differences are what tetris pointed out.
Not related to Tekin, but and one point when monsters were blowing up more frequently, Patrick pointed out that people who have problems, have them over and over agin each time they start with a fresh speed control. They are clearly doing something bad that others, some of whom are still running V1 monsters are not.
Not related to Tekin, but and one point when monsters were blowing up more frequently, Patrick pointed out that people who have problems, have them over and over agin each time they start with a fresh speed control. They are clearly doing something bad that others, some of whom are still running V1 monsters are not.
I do think the failures have something to do with 1) hard braking during racing and 2) mounting.
I notice that you rarely see failures with speed runs, but mostly racers on the track. None of mine failed just running out in the street.
I have more buggy failures than in truggy and I think it is because the lower profile of the buggy has more frequent chassis slaps. My only truggy failures were when I had it mounted behind the battery. Once I went with the Tekno kit at the beginning of last year, I didn't have a single rx8 failure with it mounted at the front of the car and slightly raised.
My current two failed rx8's have been mounted behind the battery in the buggy and I did/do use anti vibration underneath. I have been considering going back to the RCPD top plate and mounting it elevated over the center diff to see if that helps any.