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Tnx king
Junior Member
United Kingdom
331 Posts |
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grasshopper
Senior Member
1652 Posts |
 Posted - 10 October 2010 : 21:12:29
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Thanks for the link mate, been there, seen that - still clear as mud!
Having just refered to my SC10 manual, the recommendation for a 10.5 turn brushless is a 24 tooth pinion on an 87 spur giving an FDR of 9.42:1. Your suggested ratio will be good for the tight, twisty indoor circuit, but may leave you a bit lacking on top end speed outdoors, but what do I know?
I am slowly fitting a brushless set-up into my 'spare' for outdoor and have been wondering about ratios - my BL kit is classed as a 3600kv motor so will have to experiment as the book doesn't give kv equivalent info. |
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integrale1
Junior Member
Madagascar
410 Posts |
Posted - 10 October 2010 : 21:41:14
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| I run a 19 on my sc10 with a 10.5 setup on a standard spur gear.top speed is fine at west bridgefords larger track.but i was going to run a 20 on your track just to calm the power delivery down a bit.. |
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grasshopper
Senior Member
1652 Posts |
Posted - 10 October 2010 : 21:56:58
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having done a bit of delving, my 3600kV motor falls between a 10.5 and a 13.5 turn - so I'll start on the standard ratio and go from there.
I think that the 17 turn brushed motor fitted as standard is more than sufficient for indoors where we're currently racing.
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frecklychimp
Average Member
852 Posts |
Posted - 10 October 2010 : 23:13:17
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So what does the 'kV' rating mean then?
Mine is a 6.5T but rated at 7400 kV?! i take it this is not the rev range?
On the slash i went up to a 20/86 with a 2.71 final drive, kit is 18/86.
I thought you geared these things to temperature as well?
according to a gearing calculator my overall gearing was in good range for the motor, although it did seem to get a bit warm, although it had plenty of air flow as it was cartwheeling and doing backflips!
Does anyone have an idiots guide link to brushless info?
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grasshopper
Senior Member
1652 Posts |
Posted - 11 October 2010 : 11:08:37
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As far as I have ascertained. the 'kV'rating is revs/volt off load. So in your case 7400kV means on 7.2v off load it should spin at 53280rpm ! are you sure it wasn't 4700kV meaning 33840rpm which is a more reasonable figure for a car motor.
Haven't found an idiot's guide to brushless yet, but am still looking. |
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frecklychimp
Average Member
852 Posts |
Posted - 11 October 2010 : 13:47:33
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Ahhh, so you multiply the kV rating by the voltage load to get physical rpm...
Its definitely 7400kV, its got a little sticker on the motor and according to the manufacturers website the speed controller is rated at 100A!
The 3.5T motor that Fusion does is rated at 13300kV!
so with 7.4 LiPo's the rpm is 54760, oops.
tbh have never had an r/c car behave the way the Slash did with this set up, full power from standing and it just back flipped over on to its wheels again and braking was insane, the force thrown onto the front end lifted both rear wheels making it pretty much impossible to stop without taking evasive!
Will have to get some track time on the astro to get it all set up, the indoor racing is too small for the power and speed of the motor, unless the programmer lets me harness rpm to nearer 50% output.
May just stick a physical throttle limiter on the transmitter, got enough work to do on getting to grips with an indoor set up, felt more like r/c boating than car racing!
Phil... now understand your second car for indoors/outdoors split, its a very sensible idea, anyone racing short course in the winter series will probably have to put the set ups back to outdoor settings... considering i've changed everything on the car set up wise it will be a nightmare on the night before 1st round |
Edited by - frecklychimp on 11 October 2010 13:52:23 |
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ianholt
Average Member
United Kingdom
750 Posts |
Posted - 07 November 2010 : 08:53:10
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Howdi all, Ian is back! Came down to the track last Sunday and was impressed with the SCT's and then I came along on Tuesday evening to the indoor venue, now I have a Lossi strike! Its just what i wanted, cheep and basic fun, it is stock other than a modified 19t motor. I only have some old 7.2v 3900mah mimh batteries which seem a little slow (will go lipo soon). All being well I would like to come along an Tuesday evening for a shake down session just to sort out some settings etc if thats ok?
For those who dont know me, I was a club member from the very begining (dirty duck days)racing 1/8th buggy but lost touch with it for the last 18months or so due to family and financial comitments.
Chris, I will give you a call about membership etc tomorrow.
Ian. |
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ianholt
Average Member
United Kingdom
750 Posts |
Posted - 14 November 2010 : 18:24:21
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| Right. Had a great night last Tuesday and did better that expected with HMS losi strike. I am currently working on a better battery possition to get the CG lower. If any body else has a strike it is worth a look. I will be giving it a test run on Tuesday evening to test the theory. See you there. Ian |
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Bullet
Junior Member
United Kingdom
154 Posts |
Posted - 11 May 2011 : 19:56:59
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just got a blitz with 2 shells contoller and all electrictics, 2 batterys, plus a charger for £100
bargain |
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grasshopper
Senior Member
1652 Posts |
Posted - 12 May 2011 : 00:28:31
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You didn't do badly there Jake, a little maintenance, setting up and a few stickers and you should be sorted for the season.
I noticed the other posts regarding some of the questions you asked me on the night. In response:
Connectors - basically it's a budget and convenience thing, what you can afford and what everyone else is using in case you need to borrow or lend, compatability with other peoples chargers etc..
I use Powerpoles because they were popular once - still effective (up to 30A) and I have easy access to stocks at a reasonable cost.
Deans are as good and polarised so you can't connect them up incorrectly, as are most 'decent connectors used in the hobby.
Tamiya connectors are by far the most common but are really not any good for anything above 5-7 amps.
Whichever you decide to stick with, if you have any issues with fitting I am willing to help and can solder them up for you, a duff job of fitting will render the whole changover pointless - and lead to early failures break downs etc..
You also mentioned brushless motors - ok choice if the budget allows, but the SC10 you raced of mine was a box standard RTR brushed motor version, and apart from Tom's was as quick as anything else on the track. I think that Mark has already mentioned just going from crash to crash faster - I noticed as you got a bit more confident with mine that first Sunday you got quicker but more erratic and were all over the place and your lap times got worse.
The same applies to steering servoes, digital ACE or SAVOX servos are fantastic, pricy and something you can get later, the standard servo should be powerful enough and stop your truck being overly twitchy. Set up and tyre choice would be a better starting point.
Having all the right branded gear is always nice..it's a good bragging point - IT WILL NOT make you into a champion overnight, there is no substitute for practice, setup and general skill at driving. Making sure that all of your equipment's maintained in good order is always a sure fire way of having a succesful race meet. To finish first, first you have to finish. |
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ianholt
Average Member
United Kingdom
750 Posts |
Posted - 12 May 2011 : 20:09:50
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I use deans connectors but there is a trick to soldering them th large Turningy battery cables, I tin the wires saturating the ends with solder and then use a 2mm blade I cut a slot in the end of the cable which then slips nicely over the terminal on the deans connector, heat it up and hey presto!
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grasshopper
Senior Member
1652 Posts |
Posted - 12 May 2011 : 20:13:41
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| And then you do heatshrink for protection don't you? |
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ianholt
Average Member
United Kingdom
750 Posts |
Posted - 12 May 2011 : 20:34:57
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| Yes, usualy not until after I have soldered them on and then I de-solder them to slip the heat shrink on and re-solder them again. And then I say to Claire "I meant to do that". |
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grasshopper
Senior Member
1652 Posts |
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