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Post by James Calland on Dec 17, 2008 17:20:28 GMT
Hi All,
So i have managed to get my grubby hands on a tc5 and i have been setting up today. Now the gearing as i have not been racing at the track my gearing has always been high final ratio of around 6/7 so i had nice strong acceleration. But obviously now i am starting to get into the club schene i have been told that the ratio needs to be around the 3-4 mark. So i have a speed passion esc and a losi 17.5t brushless and the internal ratio of the tc5 is 2.0:1 so i used a 60t spur and 38t pinion to give me an overall ratio of 3.16 which speaking to a few of you guys is about right. But i went to run the car today and honestly the car would not go faster than walking pace with there being no acceleration to speak of.
What am i doing wrong?
Now i have changed the gearing to 83/26 and now the car moves a little faster than walking pace but still rubbish. I guess its something really simple and its just not clicking with me and i know there is something wrong coz when i was at bashley outdoor track last weekend the cars were zooming around with great acceleration.
Please help.
Rega5rds
james
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Post by mattsedgley on Dec 17, 2008 18:01:34 GMT
Ah! James you should have made yourself known to us, we'd have taken a look at your car. The best thing to do is to bring it along tonight (indoors memorial hall) and speak to one of the guys on the stage, they'll point you in the right direction or bring it down on Sunday.. 3.14 is low.. I started at 4 and worked down.. cooking the motor is always a risk when you're new (I've done it myself) If your local to NM you're welcome to PM me i might be able to give you a hand at some other time ;-) I'm no expert.. only been going 6months.. still many hands and all that.. Matt  |
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Post by James Calland on Dec 17, 2008 19:56:47 GMT
Hi Matt thanks for that, i will make myself more known on sunday-im the one driving the grey mini. But it just seems very wierd coz i mean i set it today at a final ratio of 6.38 but still as mentioned above its just a bit faster than walking pace. I guess this means i need to increase my final gear ratio maybe to something around the 8 or 9 mark.
Regards
James
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Post by mattsedgley on Dec 17, 2008 22:29:43 GMT
Ah I recall the mini!!
Think you spoke to Ruben?? - 3.14 is crazy low! Your other ratio leaves you in the high 6's I suggest you leave it as it is and pop down Sunday, I drive a deep red astra.
In all honesty it is probably a setup issue with your speedo.. although you never can be sure!
HIH
Matt
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Post by keitheroonie on Dec 17, 2008 22:34:53 GMT
James you'll need a final drive just below 4 to start, if the cars only doing walking pace at that then there's something else wrong, have you got the sensor lead connected from the motor to the speedo and have you checked you've got the phase rotation correct. the 3 motor wires should be connected, blue on A, yellow on B and orange on C. Bring it down Sunday if your still struggling, I'm the bloke in the white van  |
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Post by James Calland on Dec 17, 2008 22:41:15 GMT
ok i will bring it down sunday. thanks all tbh the motor and everythimg was ok speed wise in my tc4 but the other day i bought a new speed passion esc the one with the little program remoted and since then the motor doesnt seem to run high rpm's
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Post by lesbaldry on Dec 17, 2008 23:09:12 GMT
ok i will bring it down sunday. thanks all tbh the motor and everythimg was ok speed wise in my tc4 but the other day i bought a new speed passion esc the one with the little program remoted and since then the motor doesnt seem to run high rpm's James....17.5 brushless motors rev very low (aprox 20k free running) but have loads of torque hence the final drive ratio of 3.5/4.0.your gearing of 3.14 if the speedo is set correctly will give you good top end speed but less punch compared to a correct ratio for that motor of 3.5;1'ish(for our track) You say the car is very slow? I suspect "if your wireing is correct" the speedo profile is wrong...increasing the final drive to 8/9 as you quoted will only decrease the top end speed: ie lower gear =higher ratio The cars on Sunday were running 17.5's and even though they were running slow due to the track conditions you should expect a similar top speed from yours,aprox 25/30mph on the strait at our track. This is just my opinion but the speed passion ESC in my book is not the best for the money,the Nosram/LRP ISTC is by far more popular and a darn site easier to set up. Weather permiting..on Sunday if you come,have a chat to Rob Howett I believe he runs the speed passion..bring your set up sheet too...good luck! |
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Post by Simon Crabb on Dec 18, 2008 8:34:55 GMT
No, Rob runs a GM. Adam Smith or Liam Cuff both run Speed Passion.
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Post by mattsedgley on Dec 18, 2008 10:41:53 GMT
so does martin young
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Post by Simon Crabb on Dec 18, 2008 11:28:09 GMT
That's great: lots of support.
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Post by Martin S on Dec 18, 2008 12:38:18 GMT
This is just my opinion but the speed passion ESC in my book is not the best for the money,the Nosram/LRP ISTC is by far more popular and a darn site easier to set up. I beg to differ Les, the speed Passion ESC is a breeze a set up with its plug in card. No awkward counting of flashing lights reqd. Just tap the numbers in to the card and store to the ESC With a 17.5 and gearing about 3.5 with the punch turned up full and brake right down low, Adam easily acheived a damp 18 laps in 306sec on wet tyres. We can compare notes on Sunday if weather suitable. |
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Post by lesbaldry on Dec 18, 2008 13:43:05 GMT
[/quote] This is just MY OPINION but the speed passion ESC in my book is not the best for the money,the Nosram/LRP ISTC is by far more popular and a darn site easier to set up. [/quote]....  ....I know what I would rather use  |
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Post by yellowshark on Dec 18, 2008 14:37:11 GMT
This is just my opinion but the speed passion ESC in my book is not the best for the money,the Nosram/LRP ISTC is by far more popular and a darn site easier to set up. I beg to differ Les, the speed Passion ESC is a breeze a set up with its plug in card. No awkward counting of flashing lights reqd. Just tap the numbers in to the card and store to the ESC With a 17.5 and gearing about 3.5 with the punch turned up full and brake right down low, Adam easily acheived a damp 18 laps in 306sec on wet tyres. We can compare notes on Sunday if weather suitable. Martin do you use the low profile one or the more expensive bigger one? I heard the latter was a bit of a brick. The price of the cheaper one is attractive too! |
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Post by Martin S on Dec 18, 2008 15:30:53 GMT
Martin do you use the low profile one or the more expensive bigger one? I heard the latter was a bit of a brick. The price of the cheaper one is attractive too! The brick with the fan on top. It fits fine on the Cyclone We've got the LRP sphere & The Speed Passion Brick. Adam uses the brick out of preference. |
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Post by lesbaldry on Dec 18, 2008 16:37:42 GMT
I beg to differ Les, the speed Passion ESC is a breeze a set up with its plug in card. No awkward counting of flashing lights reqd. Just tap the numbers in to the card and store to the ESC With a 17.5 and gearing about 3.5 with the punch turned up full and brake right down low, Adam easily acheived a damp 18 laps in 306sec on wet tyres. We can compare notes on Sunday if weather suitable. Martin do you use the low profile one or the more expensive bigger one? I heard the latter was a bit of a brick. The price of the cheaper one is attractive too! Hmmm Pete asking questions about BL speedos Martin??...what ever next...brushless fitted to the 008...naaah! Word of caution Pete ..Its tight enough fitting the ISTC to the Xray,you will strugle with anything bigger |
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Post by Martin Young on Dec 18, 2008 17:16:54 GMT
Hi All, So i have managed to get my grubby hands on a tc5 and i have been setting up today. Now the gearing as i have not been racing at the track my gearing has always been high final ratio of around 6/7 so i had nice strong acceleration. But obviously now i am starting to get into the club schene i have been told that the ratio needs to be around the 3-4 mark. So i have a speed passion esc and a losi 17.5t brushless and the internal ratio of the tc5 is 2.0:1 so i used a 60t spur and 38t pinion to give me an overall ratio of 3.16 which speaking to a few of you guys is about right. But i went to run the car today and honestly the car would not go faster than walking pace with there being no acceleration to speak of. james Just an idea! Make sure the EPA on you transmitter for both the throttle and brake are set to 100% when you first set up the speedo. If the EPA are set highter or lower than this it can cause some strange results. As far as set up of the speedo, with a 17.5 I would start with the factory default, its a good starting place. Gearing I run 3.5 to 3.66 with the Nosram 17.5 motor. Don't know if this helps at all. |
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Post by James Calland on Dec 19, 2008 20:05:10 GMT
Hi all thanks for the comments. I have now fixed the problem lol. I had the controller set baackwards so the car was Erving at the reverse speed but forward hehe. Amature! But all fixed now and it's nice and nippy. I have the sp EEC with program card which is a breeze. Almost as easy to program as my mamba max on the comp. So I will be running it on Sunday weather permitting and I will bring down my completed application from.
Regard
James.
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Post by Reuben on Dec 19, 2008 20:39:08 GMT
rtm comes to mind how are you geared now? Ide suggest getting your gearing to at the lowest 3.7 to start with, otherwise you might cook the motor at 3.14.... glad to hear u got the speedo sorted though. |
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Post by James Calland on Dec 20, 2008 0:01:26 GMT
Rtm?? I have the gearing at 3.75. Which is 60/32.
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Post by keitheroonie on Dec 20, 2008 13:11:06 GMT
That doesn't sound too bad James, I recon you're ready to go now, see you tomorrow |
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Post by samuraiblade on Apr 19, 2009 11:36:15 GMT
for a 68t spur gear should i get a 40t pinion gear for the ratio i need? i think if my calculations are right that comes to 3.655 on a cyclone TC chassis as the formula is 68/40x2.15
i have a spur gear that says 48/68 on it , i guess that means its a 48dp 68 tooth gear? , the manual says i need to use a 64dp pinion , is that correct?
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Post by samuraiblade on Apr 19, 2009 11:52:54 GMT
wrong hypothosis |
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Post by samuraiblade on Apr 19, 2009 12:01:21 GMT
ok completely confusd now lol , other sites are talking about final ratio's of 6-7 , why do you guys go for such low ratios? i have a 100t 64dp spur gear in box , atm the car has a 68t 48dp spur , i just need to know what to run tbh.  problem is with the 68t spur which is 48dp , the best ratio i can acheive is 4.19 with a 35t pinion which is by far the biggest afaik for 48 tis all confusing hehe p.s i guess you run low ratios due to how short bashley track is , what you guys gonna run at calshot? ridicolously high ratio i guess? |
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Post by samuraiblade on Apr 19, 2009 13:10:47 GMT
ok i found a site that does up to 42t 48dp pinions , would you recommend i go for a 40t one?
heres my calculation , 68*40/2.16=3.67
also if the 17.5 losi im running has 13104rpm max , and the wheels are 65mm diameter the top speed will be 27.18mph according to gearchart.com if im doing it right?
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Post by TryHard on Apr 19, 2009 14:39:06 GMT
Hey Darren, Pop into Terry at Reality Racing, he has 48dp Spurs small enough and pinions big enough to get the correct ratio. I've got a 54 Spur, and a 43 Pinion in my box.. so there are smaller avaliable What you state there is correct in terms of ratio, that sounds about right for the Losi to start with, maybe want to go higher. So maybe get a selection of pinions. Maybe 42, 41 and 40 would be a good selection, with the 68 Spur. That gives a Final Drive ratio (FDR) range of 3.67 to 3.49, which should be enough to cover you to start with. As for running the ratio's so low, it's simpy because with the brushless motors, they have more torque than rpm, so need to be geared higher (lower FDR number) to acheive a good top speed... I now that some old 27t brushed motors could hit 27k RPM... Now as you loose winds on a brushless, the rev's come back, so you can start to gear lower (higher FDR)... it's not uncommon to hear on small tracks mod drivers with 3.5's being in the 10's on FDR... HiH Ed |
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Post by Jazzler on Apr 19, 2009 14:55:09 GMT
EDIT: Ed: you beat me to it.., Darren: What he said.. ;D
Hi Darren,
The fdr (final drive ratio) of 6 -7 you are reading about is probably for a brushed motor. Since you are running the losi brushless thats why you need to run a lower ratio, as the brushless motors have more torque but less rpm than a brushed motor and will need to be geared appropriately.
48dp gears are the way forward, they are easier to mesh than 64dp and although the manual states you should use a 64dp, the car is capable of running either type. (Stick with 48dp though).
Regarding your calculation, "68*40/2.16=3.67" sounds about right to me, check on gearchart.com to make sure though. You should be able to mesh a 68t spur and 40t pinion, but can't confirm it as I have not used that combo.
Be careful though, as you have to get gearing right, or you could blow the motor and/or esc. Its better to run a known safe ratio (As you are), then go lower one step at a time, while checking motor temperature so you don't overheat it. Until you get to a ratio and motor temp you are happy with (Under 70degrees C). But for indoor racing this will be a higher ratio. (We start at a ratio of 5.5 on the losi 17.5 indoor, which is safe, then work our way down)
Re, Calshot, I believe it will be a very low ratio that people will be running, to reach the highest speeds, but again I cant confirm this as I have not been, hopefully someone else will be able to confirm what you should be running.
You speed calculations are correct, however that doesn't take into account drag, wind resistance, vehicle weight, drive train resistance etc.. etc.. so... don't rely too much on that for a speed calculation. Its an estimate based on maximum possible performance in absolute ideal circumstances.
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Post by samuraiblade on Apr 19, 2009 16:36:29 GMT
well i picked up a load of spurs (48dp) from james too , 60,68,69,72,73,75,83 so i have them to juggle with too ive ordered a 38t and a 40t pinion , this will give me a nice range of ratios with the spurs i have |
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....I know what I would rather use 
