84km/h ACHIEVED-PICS on 2nd page-UPDATE

[jamiekulhanek]

Hey all,

Just a note to say that i have broken through the 75km/h barrier.

I am going to post some pics tomorrow, including shots of it on the mini 4wd speed checker.

This car….is….awesome….sooooooo much power and torque, i.e. pull a burnout/donut, and the tyres get hot and sticky (and smelly), but for some reason i cannot get these new tyres to make smoke like the old ones on my 2001 mini z (different chemicals??).

The plasma dash motor has held up extremely well due to the large heatsink i installed, and has lost very little performance through 4 battery packs.

The batteries get critically hot, so hot that they go straight into the freezer after a fang.

Pics coming v. soon all 🙂

Edited by – jamiekulhanek on 29 February 2004 02:52:34

Edited by – jamiekulhanek on 01 March 2004 09:59:31

[dgs73]

what about the GTR dude? You give that a speed check? Stinging to get that moving again… 😉
Congats on your success too, next stop 100kph+ eh?

[ph2t]

what specs man? I want specs!!!!

[dgs73]

oh, any chance of a video of it in action? (tire melting preferred, but not necessary…:D)

[jamiekulhanek]

hehe video….i might use the mini DV cams from school and upload it somehow……

Dave, i have almost finished your car, but i ran out of poly glue for the job (damn brother used it to fix ceiling console in his car) going to the LHS to get some tonight and this baby will be in the post 2morrow man. The servo has been tweaked and the bearings have been degreased for low mechanical resistance. Motor is done too. I am anticipating 36-42 km/h for yer car dave.

Specs:

6 cell 7.2v 750mAh NiMH soldered battery pack with deans 1/10 low loss connectors.

Tamiya 27t plasma dash motor with ball bearings, neodymium high power (Nd-Fe-B) magnets, copper magnet spacers (cheapest bang for buck mod) and massive heatsink with Deans 1/10 low loss connectors. The commutator has also been modded.

Internal 8×2 TURBO with heatsinks.

Lightened chassis (car weighs 240g, compared with stock 180g).

I am having a teeny bit of trouble with the ball diff at the moment, the monstrous torque being delivered through the GPM 13t Titanium pinion is enough to make a tight diff slip, which of course generates enough heat to make the aluminium diff plate thingies get quite hot.
The GPM titanium pinion is a necessity, as it does get hot, which would soften a plastic pinion and strip it.

Just when you though that wasn’t enough, i am going to rewind another TPD motor armature to 19t which should again double the power output. Bye bye batteries. This in theory should pass 100km/h.

I still have some work to do on this, i.e. perfecting gear mesh, re do the bearings and commutator, repair the diff.

I am hoping these few little fix ups will get me into the 80’s.

[jamiekulhanek]

The list of hopups parts is too long to write lol.

[oldtamiyaphile]

You can take the balls out of the diff. Won’t slip anymore!

[PandaBear]

… or use JB Weld as a diff lube. :):D

[jamiekulhanek]

I did try the no balls thing, but my left wheel adaptor is stuffed.

[micro_Amps]

Good work getting it up that high, but all the extra current is just to overcome the load of the drivetrain, with out any load from the road.
What speed does it actually run ON THE GROUND Jamie?
Either a timed run on a known distance between two points, or a radar.
:)uA

[merc-blue]

jamie i suggest running it on astro turf it slices up ur wheels but it will fly…. and it dont shatter the chassis as soon as u lose control and hi a big bump.. i did it i hit a bump and landed on back corner of chassis and it shattered

[jamiekulhanek]

Yes that is a mini 4wd time, so actual ground speed is probably 50km/h.

I tried loading the rollers with me finger :clown:, just to see what difference it made…..burnt my finger lol. It slowed down to about 60 clicks.

[oldtamiyaphile]

I think just pressing down on the car would work without burning your fingers!

[bithed]

…Well done Jamie…Im glad its YOUR z and not mine !! lol…BTW that Plasma is 25,000 rpm right…Did i EVER tell you about the 50,000 ones we have here ?

MUAWAHAHAHAHAAA:evil:

[oldtamiyaphile]

Tin motors are labeled 130k rpm. Doesn’t mean they actually spin that fast, and if they did, they’d barely have the torque to move a car.

[ph2t]

are there any good sites out there detailing hardcore motor theory?

ph2t.

[oldtamiyaphile]

What do you mean by hardcore? It’s all pretty basic and logical stuff.

Fewer turns will result in:
Increased current draw
Increased power output
Higher peak RPM
Less torque

It should be noted that the difference between a 13 and 14 turn motor is more noticeable than the difference between an 16 and 17 turn motor. This is because the change in wire length becomes a greater percentage of the total length as turns decrease.

Fewer strands will result in:
more torque
more current draw (esp. bottom end)

More strands will result in:
Less torque (esp. bottom end)
smoother top end power
reduced current drain

[betty.k]

hmm, i was wondering if you could define “winds” for me.:8ball:

[jamiekulhanek]

Quote:

…Well done Jamie…Im glad its YOUR z and not mine !! lol…BTW that Plasma is 25,000 rpm right…Did i EVER tell you about the 50,000 ones we have here ?

MUAWAHAHAHAHAAA:evil:

50,000 RPM??? HAHA PATHETIC!!!! Motor RPM increases with voltage, my plasma revs much higher than that, though the neodymium magnets reduced RPM but boosted torque dramatically.

[ph2t]

Quote:

What do you mean by hardcore? It’s all pretty basic and logical stuff.

Fewer turns will result in:
Increased current draw
Increased power output
Higher peak RPM
Less torque

It should be noted that the difference between a 13 and 14 turn motor is more noticeable than the difference between an 16 and 17 turn motor. This is because the change in wire length becomes a greater percentage of the total length as turns decrease.

Fewer strands will result in:
more torque
more current draw (esp. bottom end)

More strands will result in:
Less torque (esp. bottom end)
smoother top end power
reduced current drain

I’m more interested in the theory and stuff….. Also, what’s the diff between turns and strands? that’s confusing…..

ph2t.

[PandaBear]

Brushed Motors commonly used in RC are Tri-Pole… their armatures are made up of a stack of stamped laminations of three arms (poles).

On these arms you wind the wire.

Each loop around arm = 1 turn; all 3 arms would have the same # of turns, that motor is known as that “# turn”.

Now instead of using 1 fat wire to wind with, you can use multiple strands of skinnier wire running in parallel. Each turn with multiple wire still only counts as 1 turn even though there’s several loops of wire around the pole for every turn.

[ph2t]

thanks man. what motors/instances use this “stranded” turns version?

cheers,

ph2t.

[jamiekulhanek]

Usually only RC, but i’m not sure.

Most 1/10 ‘540’ use different variations of turns and strands. I have a 14×2 540 motor, which means there are 2 strands of wire, looped 14 times around each pole piece on the armature.

Different strand counts vary to give different power/torque curves etc.

[ph2t]

In my uni days I did a lot of AC motor theory, not DC motor theory, oh well….. Gotta learn more!

ph2t.

[jamiekulhanek]

im sick of learning cause everytime i learn something new i forget something else.

[betty.k]

cool, i meant to say turns in my earlier post.:smiley2: i might have a go at it myself!
i’m wondering what difference it makes using different thicknesses of wire? fatter wire, more torque?:8ball:

[jamiekulhanek]

There is only a certain amount of ‘space’ or ‘capacity’ for wire, the thicker the wire, the less turns you can fit on, the more power you have, the sooner the motor + batteries shit themselves.

[jamiekulhanek]

pics:

[jamiekulhanek]

[jamiekulhanek]

excuse the pics, i got my camera in ’97 when it was a ‘new fangled device’, now its a piece of crap!

[jamiekulhanek]

see that heatsink??? Best $0.43 I ever spent :D:D:D

[PandaBear]

Quote:

see that heatsink??? Best $0.43 I ever spent :D:D:D

Looks like something for a TO-220 transistor.. 🙂

Quote:

got my camera in ’97 when it was a ‘new fangled device’

Don’t sweat it… still got a Canon Powershot G2 from 1997. Does only 640×480 res, no zoom nor any fancy functions but it did come with rechargeable batteries!! Dad paid must have paid Over A Grand… :p

And get this… for the 15MB CF card in it… think he paid MORE than for the camera. :dead:

[jamiekulhanek]

My camera is a 320×240 Casio QV-10B, i guess it’s okay for webshots but it’s useless for photos. I was only like 10 when i got it.

The nice function that attracted me was the ability to plug the bugger into the TV and play a ‘slideshow’, though the res on the screen was truly awful:sad:

Yup that’s a TO220, perfect size. both surfaces were rubbed back, and a layer of heatsink compound was added. It works a damn sight better than the piddly little alloy heatsink made by Yeah Racing.

[jamiekulhanek]

man cf cards are dirt cheap these days. not exactly ‘compact’ anymore :smiley2:

[ph2t]

dude, can’t see the pics, I get an:

Forbidden
You don’t have permission to access /s/image9/8/38/94/121683894ocFcyz_ph.jpg on this server.

---

Apache/2.0.48 Server at community.webshots.com Port 80

ph2t.

[jamiekulhanek]

http://community.webshots.com/album/121683602wtRGml

It must be your browser, because i have tried the link on 3 computers and they all work fine.

[jamiekulhanek]

I guess you want to see videos???

[micro_Amps]

Yes please.
:)uA

[ph2t]

Yyah c’mon slacka, I wanna see some vid’s!

ph2t.

[jamiekulhanek]

Uh dude i am a full time student (5 pre tertiaries), i goto work almost every night till 12/1 AM + do homework/assignments. I haven’t had much time, but i can make a video, only problem is i have NO idea of how to upload it to ausmicro, can anybody point me in the right direction???

[Aaron]

At the moment file uploading is broken 🙁
Depending on size I can get you an FTP logon or something

--
Site Owner Guy.

[jamiekulhanek]

hmmmmm i understood the first few words…….

[Aaron]

Should have some fixes in place in the next few days…

A.

--
Site Owner Guy.

[jamiekulhanek]

Well vids are now gonna be down the track, the mini Z has a blown ESC and cooked motor.

I have fets on their way, and i have a replacement motor to chuck in. so performance should be upto 100% again.

[Aaron]

Aye – Your new stack left by 4:30pm today 😉

Yours for the weekend 😉

A.

--
Site Owner Guy.

[jamiekulhanek]

My twin towers collapsed-literally!!! They got so hot that the solder melted, and they went everywhere due to horizontal forces!!!

Nice, I am busting to get the mini Z racing again, it was a joy to drive, FANTASTIC grip/handling/balance, drivability and most importantly….POWER….immense POWER. On a 10 metre straight I could only hold full throttle for a fraction of a second before I had to put the brake on! The MR01 has no brake, but the neodymium magnets and big pinion make the car pull up fast when you throttle off.

[Aaron]

Next step silver solder?

*ponders* I wonder what else can be done to beef up stacking?

A.

--
Site Owner Guy.

[jamiekulhanek]

Nah silver solder needa a hot gas flame to melt, so the FETS would cook before they even got a chance to be used!!!

I am thinking be more careful/blade fuse…

[jamiekulhanek]

well this thread is old!

[Author]

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