1/12 forum
Help? Finally getting going in 1/12 after a slow start.
Xray x12, spool, 17.5 motor. I want to go down to 48p gears for simplicity and durability. Will be running on high grip carpet. Can anyone give me a good starting point for gearing and/or gear ratios? Good all around spur size to start with?
Thanks in advance for the opinions!
Xray x12, spool, 17.5 motor. I want to go down to 48p gears for simplicity and durability. Will be running on high grip carpet. Can anyone give me a good starting point for gearing and/or gear ratios? Good all around spur size to start with?
Thanks in advance for the opinions!
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Hi guys,
Quick question, how much timing do you usually set for the 17.5 and 13.5 motors?
Comparable to 2S or do you set it differently?
Recently got a motor analyser and I noticed I set my motor to 10,5A current draw but thats with 2S off course.
Thanks,
Dirk
Quick question, how much timing do you usually set for the 17.5 and 13.5 motors?
Comparable to 2S or do you set it differently?
Recently got a motor analyser and I noticed I set my motor to 10,5A current draw but thats with 2S off course.
Thanks,
Dirk
I use a SkyRC 2S for my initial setting, looking for between 4.5 and 5 amps. On some motors that happens at 42 degrees and on others it takes closer to 50 degrees. SkyRC testers are ok, but are tested without load on the motor. It is a good way to get a quick starting point or make a quick adjustment at the track. Inertia dynos help to see real differences in motors and timing settings. I use both, so the SkyRC between 4.5 and 5 amps is usually close to where each motor ends up on the Mini-Pro dyno. The Mini-Pro provides evidence on how to gear two motors differently (4.5 to 5 amps on an X-Factor will produce a different torque curve than a R1 Shorty) and which motors are slightly better than others.
Last edited by MC Hamilton; 09-25-2024 at 09:29 AM.
Tech Master
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From: Spokane, WA
FYI - SMC is back in the 1S battery game: https://www.smc-racing.com/index.php...product_id=832
It looks like Danny is comparing this new one to the Tekin 7400 and 8500. Based on how my Tekin 7400 performed against other batteries, this new SMC should be amazing.
It looks like Danny is comparing this new one to the Tekin 7400 and 8500. Based on how my Tekin 7400 performed against other batteries, this new SMC should be amazing.
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From: Belgium
Was that tested on a SkyRC 2s type of tester? If so, 10.5 amps is way high for a 17.5. Cut that in half. You're going to get two different answers from the community. Some are setting 17.5s around 40 degrees of timing. The 40 theory being that the motor will have more torque. Others will say closer to 50 degrees - the thinking being that these motors have so much torque anyway that you don't lose anything by cranking more amps into them and getting more overall RPMs.
I use a SkyRC 2S for my initial setting, looking for between 4.5 and 5 amps. On some motors that happens at 42 degrees and on others it takes closer to 50 degrees. SkyRC testers are ok, but are tested without load on the motor. It is a good way to get a quick starting point or make a quick adjustment at the track. Inertia dynos help to see real differences in motors and timing settings. I use both, so the SkyRC between 4.5 and 5 amps is usually close to where each motor ends up on the Mini-Pro dyno. The Mini-Pro provides evidence on how to gear two motors differently (4.5 to 5 amps on an X-Factor will produce a different torque curve than a R1 Shorty) and which motors are slightly better than others.
I use a SkyRC 2S for my initial setting, looking for between 4.5 and 5 amps. On some motors that happens at 42 degrees and on others it takes closer to 50 degrees. SkyRC testers are ok, but are tested without load on the motor. It is a good way to get a quick starting point or make a quick adjustment at the track. Inertia dynos help to see real differences in motors and timing settings. I use both, so the SkyRC between 4.5 and 5 amps is usually close to where each motor ends up on the Mini-Pro dyno. The Mini-Pro provides evidence on how to gear two motors differently (4.5 to 5 amps on an X-Factor will produce a different torque curve than a R1 Shorty) and which motors are slightly better than others.
Its an old 13.5t Motiv motor tested on a hobbywing tunalyzer. The 10 amps was at 55 degrees timing, I went back to 50 degrees where it draws around 6A.
I know I played with it last year and ended at the 55 setting.
I'll try to gear higher then.
Thanks for the info!
That's a good free wheel tester. The challenge that I saw with the free wheel testers is that cranking more timing kept producing better KV (torque) and better RPMs. Timing was like an addictive drug, the downside wasn't easily seen. When I put any motors over 5.5 amps, they looked great on the free wheel tester, but just seemed to generate extra heat and not really faster lap times when put under load in the car.
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From: Belgium
Correct idd, going to plot the curves of timing vs rpm and current to see if I can spot a point where inefficiency really gets a lot worse.
Why I asked the question was that idd, I read and always hear the guys with an analyser always talk about the magic 6A or more recently idd 3-4A setting.
If running the analyser at 1S will obviously result in lower current while freewheeling. So I was wondering if I had to compensate for that so it'll pull 3-4A at 1S.
That being said, my motors in 1/12th usually run fairly cold and I havent found a way to get some temperature in them. Throw on too much gearing and the car becomes sluggish at the timing I mostly use (50-55 degrees). Maybe I need to try a lower timing and gear a lot higher (driving on a moderately large, flowing track at this moment).
Why I asked the question was that idd, I read and always hear the guys with an analyser always talk about the magic 6A or more recently idd 3-4A setting.
If running the analyser at 1S will obviously result in lower current while freewheeling. So I was wondering if I had to compensate for that so it'll pull 3-4A at 1S.
That being said, my motors in 1/12th usually run fairly cold and I havent found a way to get some temperature in them. Throw on too much gearing and the car becomes sluggish at the timing I mostly use (50-55 degrees). Maybe I need to try a lower timing and gear a lot higher (driving on a moderately large, flowing track at this moment).
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I have a motor that pulls close to 11 amps on the dyno, but the car accelerates like a stabbed rat and it doesn't overheat.
Got it out to the track- unprepped asphalt.
car was a bit of a handful especially in my rusty hands but got a rhythm down.
Only problem is the car does not want to stay straight, usually favoring the left, then it suddenly behaves then starts doing it again.
Links, shocks and center pivot all smooth, servo locked down an saver and tie-rods play free- ball diff good.
I'm starting to wonder if it is the shit-vox servo. (CRC CK25 chassis)
car was a bit of a handful especially in my rusty hands but got a rhythm down.
Only problem is the car does not want to stay straight, usually favoring the left, then it suddenly behaves then starts doing it again.
Links, shocks and center pivot all smooth, servo locked down an saver and tie-rods play free- ball diff good.
I'm starting to wonder if it is the shit-vox servo. (CRC CK25 chassis)
Joined: Sep 2014
Posts: 2,030
Got it out to the track- unprepped asphalt.
car was a bit of a handful especially in my rusty hands but got a rhythm down.
Only problem is the car does not want to stay straight, usually favoring the left, then it suddenly behaves then starts doing it again.
Links, shocks and center pivot all smooth, servo locked down an saver and tie-rods play free- ball diff good.
I'm starting to wonder if it is the shit-vox servo. (CRC CK25 chassis)
car was a bit of a handful especially in my rusty hands but got a rhythm down.
Only problem is the car does not want to stay straight, usually favoring the left, then it suddenly behaves then starts doing it again.
Links, shocks and center pivot all smooth, servo locked down an saver and tie-rods play free- ball diff good.
I'm starting to wonder if it is the shit-vox servo. (CRC CK25 chassis)
1. Is the track banked at all, causing the favoring the left, if not...
2. Make sure your toe is straight...whether you have some toe out or have it set to zero.
3. I see alot of people running ball diffs on asphalt and not straight axle. So either ball or gear diff.
4. Make sure car is tweak free and tweaked



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