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Tamiya mini cooper

Old 04-24-2015, 02:30 PM
  #23476  
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I don't have the extensive experience with the 21.5 motors as I do with the Silvercans. So far, have only run the Reedy Sonic, Thunderpower, Killshot, Speed Passion, Novak Ballistic, Schuur, and one other, whose name escapes me at the moment. In very case, to be competitive, you had to set the timing so the motors were coming off the track at 170 or better. If your motors are coming off "cool", 150 or less, your timing or your gearing was off.

Sometimes, just a degree or two, made a significant difference in performance. The reason a motor is coming off cool is that you are not "working" it and the motor is loafing. Yes, you will get much longer motor life, but you will also get your ass handed to you when racing with someone who knows what he is doing.

I don't run on postage stamp sized tracks, but have run on a fairly small carpet track. My guess is that it is about the same size as the one Monkey racing is on and some of the carpet tracks in the USA are. Assuming this to be true, the Reedy Sonic, for example, won't give you much till you go to 50 degrees or more advance. Your motor should come off fairly warm.

Sorry Sak----, have never run on a track that's super small, so don't really know for sure that this would hold true there.

As far as throttle curves go, I've never seen much of a need for complicated throttle curves, especially on a Mini. On occasion, you will need to feather the throttle on corner entry if your car is stepping out, but I usually don't modulate throttle thru a corner. On a large track like the Tamiya USA track, you will drive the throttle, but just don't see that happening on a small track. Those, for the most part, are point and shoot tracks and require a little different technique.

Incidentally, a properly set up Silvercan, is no match for a properly set up 21.5. On most racks, except for the really small tracks, 10 sec or less lap times, you will see lap time differentials of more than a second.

Last edited by Granpa; 04-24-2015 at 02:37 PM. Reason: Addition
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Old 04-24-2015, 02:38 PM
  #23477  
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Is anyone shimming the gap between the rear hex and the bearing in the rear upright? Mine has a ton of play.
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Old 04-24-2015, 02:43 PM
  #23478  
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Originally Posted by bmxcrx
Is anyone shimming the gap between the rear hex and the bearing in the rear upright? Mine has a ton of play.
Yes. Use a 0.3mm shim. Don't use much more than that, especially with the stock plastic hub. It is very easy to over do it and wind up with a little drag.
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Old 04-24-2015, 02:59 PM
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Hi Granpa- Thanks for the insight. I may need to get another ESC because when I advance the timing more than 8-10 increments on Sonic, the ESC (TBLE02S) gets pretty hot.

Do you all run a fan on the ESC while running brushless with aggressive timing?

Gearing wise, I am running the 20teeth as 18 and 16 were just too slow..!
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Old 04-24-2015, 03:37 PM
  #23480  
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Originally Posted by sakadachi
Hi Granpa- Thanks for the insight. I may need to get another ESC because when I advance the timing more than 8-10 increments on Sonic, the ESC (TBLE02S) gets pretty hot.

Do you all run a fan on the ESC while running brushless with aggressive timing?

Gearing wise, I am running the 20teeth as 18 and 16 were just too slow..!
So far have not had to run a fan on the esc. However, I do run a R1 Wurks fan on the motor. So far the R1 is the best fan that I've ever used. As you know, I've been away for a number of months so don't have a particular esc suggestion. Presently, I'm using a KO Propo 350 BLZ, but they've been discontinued. I believe they were a little sensitive to heat,but in a Mini, that never seemed to be a problem. I do know that a few of the guys were using the Juststock and had no issues.

Gearing with the amount of advance you're running, won't be an issue. With the amount of experience you have, I'm not the one to advise you on how to match the gearing to the motor. I've only been doing this stuff for 15 years or so. Most of my R/C was with helicopters and boats.
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Old 04-24-2015, 03:57 PM
  #23481  
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Originally Posted by Granpa
Yes. Use a 0.3mm shim. Don't use much more than that, especially with the stock plastic hub. It is very easy to over do it and wind up with a little drag.
Thanks!
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Old 04-24-2015, 04:08 PM
  #23482  
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Originally Posted by Granpa
So far have not had to run a fan on the esc. However, I do run a R1 Wurks fan on the motor. So far the R1 is the best fan that I've ever used. As you know, I've been away for a number of months so don't have a particular esc suggestion. Presently, I'm using a KO Propo 350 BLZ, but they've been discontinued. I believe they were a little sensitive to heat,but in a Mini, that never seemed to be a problem. I do know that a few of the guys were using the Juststock and had no issues.

Gearing with the amount of advance you're running, won't be an issue. With the amount of experience you have, I'm not the one to advise you on how to match the gearing to the motor. I've only been doing this stuff for 15 years or so. Most of my R/C was with helicopters and boats.
Thanks for the advise. Your reference is good for my benchmarking. Okay if your motor is warm with a fan blowing on it, then my motor is definitely running too cold then. I will advance the timing more and see how well the TBLE02S can hold up. My silver cans get hot enough that I can't keep my fingers on them, so my cars do get quite a beating in my tiny track.

I will check out the Juststock ESC. Also, if anyone can recommend me a decent ESC to run with my Reedy Sonic 21.5t, please advise! I do not need the best as I will not be racing. I just want a reliable one that is known to work well with the Sonic, spec class.
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Old 04-24-2015, 04:24 PM
  #23483  
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Originally Posted by sakadachi
I see. Does that mean I should be running a Reedy ESC because I am running a Reedy motor? ie: Would that sync better to each other?

I noticed a lot of manufacturers sell motor and ESC as a package.
Originally Posted by sakadachi
I will advance the timing more and see how well the TBLE02S can hold up... I will check out the Juststock ESC. Also, if anyone can recommend me a decent ESC to run with my Reedy Sonic 21.5t, please advise!
Sensored brushless motors and ESCs are compatible across brands, thanks to ROAR rules. There's no need to buy anything else if you are having fun with what you already have.

You probably don't need to advance the motor timing much (or at all) given the small track you have, and no impetus to keep up with faster cars. Cool motors live nice long lives! There's nothing wrong with that.

The drive frequency is adjustable on many ESCs, both brushed and brushless. Running a higher frequency makes the throttle response soft on the low end, much like using exponential curves on the transmitter. If the brushless drive frequency is higher than the brushed frequency, this could be the lack of sensitivity you are feeling at low throttle. If your ESC has adjustable drive frequency, play around with it to see how it affects the response.
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Old 04-24-2015, 04:34 PM
  #23484  
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Originally Posted by howardcano
Sensored brushless motors and ESCs are compatible across brands, thanks to ROAR rules. There's no need to buy anything else if you are having fun with what you already have.

You probably don't need to advance the motor timing much (or at all) given the small track you have, and no impetus to keep up with faster cars. Cool motors live nice long lives! There's nothing wrong with that.

The drive frequency is adjustable on many ESCs, both brushed and brushless. Running a higher frequency makes the throttle response soft on the low end, much like using exponential curves on the transmitter. If the brushless drive frequency is higher than the brushed frequency, this could be the lack of sensitivity you are feeling at low throttle. If your ESC has adjustable drive frequency, play around with it to see how it affects the response.
Thanks for the info and advise! Unfortunately the TBLE02S does not appear to offer adjustment for the drive frequency so I guess I will need to compensate with the throttle curve I have. I'm going to be running more laps tonight and will decide what I need to do next. Perhaps I may need to retard the timing a hair to compensate for the flat sensitivity by adding some torque. Hummmm..
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Old 04-24-2015, 04:43 PM
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Originally Posted by sakadachi
Thanks for the info and advise! Unfortunately the TBLE02S does not appear to offer adjustment for the drive frequency so I guess I will need to compensate with the throttle curve I have. I'm going to be running more laps tonight and will decide what I need to do next. Perhaps I may need to retard the timing a hair to compensate for the flat sensitivity by adding some torque. Hummmm..
I think your best bet, given that you are running the largest pinion, is to set the timing to give a reasonable top speed, and use the transmitter expo to tailor the response... just as you are doing now. There aren't any adverse effects from using throttle expo; that's just a matter of preference.

If you aren't racing and need more top speed, then consider going to a 17.5 motor. When set to the same kV rating as a 21.5, it will be much more efficient, so it will run cooler and give more run time. The disadvantage is it has gobs of torque, which will be overkill for a FWD Mini... and your ESC may not be rated for it.

EDIT: There are a few brushless ESCs that have adjustable current limiting. That will reduce the excess torque AND make the motor even more efficient.

SON OF EDIT: It would be more cost effective to stick with the ESC you have, along with the Sonic 21.5 set to low timing, and see if you can get a high-speed gear set for your car. Hopefully the other guys will inform us if such a thing is available.

Last edited by howardcano; 04-24-2015 at 05:08 PM.
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Old 04-25-2015, 03:14 AM
  #23486  
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http://www.ebay.co.uk/itm/Super-Spee.../281668958103? This is the fast gear set we use in the UK, much better than the 3racing set. Afaik they are made by RW Racing. We also tend to use the HPI Racing 20t motor which is faster than 21.5t brushless. This is of course for Mini Mod, for Mini stock the guys run HPI 27t. A few guys at my local club run 17.5t brushless I can keep up with all but one using the HPI 20t.
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Old 04-25-2015, 07:12 AM
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Originally Posted by howardcano
I think your best bet, given that you are running the largest pinion, is to set the timing to give a reasonable top speed, and use the transmitter expo to tailor the response... just as you are doing now. There aren't any adverse effects from using throttle expo; that's just a matter of preference.

If you aren't racing and need more top speed, then consider going to a 17.5 motor. When set to the same kV rating as a 21.5, it will be much more efficient, so it will run cooler and give more run time. The disadvantage is it has gobs of torque, which will be overkill for a FWD Mini... and your ESC may not be rated for it.

EDIT: There are a few brushless ESCs that have adjustable current limiting. That will reduce the excess torque AND make the motor even more efficient.

SON OF EDIT: It would be more cost effective to stick with the ESC you have, along with the Sonic 21.5 set to low timing, and see if you can get a high-speed gear set for your car. Hopefully the other guys will inform us if such a thing is available.
Howardcano- Thanks again on your comments and recommendations. Besides the 2 motors' differences in torque delivery (between 21.5t and silver can) I think I need to re-learn how to drive using the 21.5t.

Last night I tweaked the throttle curve a little more on my radio by a few increments and the rest of the evening put on my test mule body and just drove for a few hours. I crashed many times which is unusual for me as I rarely scrape my cars while driving my own track. I need to familiarize myself to the completely different feel, especially off-throttle and how to release or not to release throttle completely. Just feels very different.

But as you said, I am having fun with my cars so I guess my current setup is fine for my purpose.

Originally Posted by BILKO1
http://www.ebay.co.uk/itm/Super-Spee.../281668958103? This is the fast gear set we use in the UK, much better than the 3racing set. Afaik they are made by RW Racing. We also tend to use the HPI Racing 20t motor which is faster than 21.5t brushless. This is of course for Mini Mod, for Mini stock the guys run HPI 27t. A few guys at my local club run 17.5t brushless I can keep up with all but one using the HPI 20t.
Thanks, BILKO1. That's great info, thanks for posting.

Until I lay down ozite this summer, I think I am pretty much at the limit of adhesion with my FWD's at the moment in my basement track even with the advanced 21.5t I have. I can go so much faster with my M-Four without crashing..!



Started off this morning fixing my bodies I crashed last night. I only run Rover Mini bodies so the headlamp decal needed fixing.. dang wish I could buy just the headlight decals!!
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Old 04-27-2015, 01:49 PM
  #23488  
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alright call me what you will but Im pressed for time
What do you guys use to lock up your gear diffs in the 03's???
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Old 04-27-2015, 01:59 PM
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Originally Posted by KA2AEV
alright call me what you will but Im pressed for time
What do you guys use to lock up your gear diffs in the 03's???
Bits of fuel tubing, putty, glue, spool inserts - they all work.

Here's an idea for a diff that I knew was going to make a comeback someday. Torque converter!

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Old 04-27-2015, 02:07 PM
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Originally Posted by monkeyracing
Bits of fuel tubing, putty, glue, spool inserts - they all work.

Here's an idea for a diff that I knew was going to make a comeback someday. Torque converter!

Ohhhhhhh Daddy Like

Thanks Jim
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