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View Full Version : Mr-015 problems.


Netcon
2008.11.08, 06:25 AM
So, I've got my first Mr-015, actaully my first from the Mini-Z Racer series as I've had a Monster for just under a week now. There seems to be a problem with it and that is that my xmod WILL whip it round a track purely by handling! Speed is no concern, it doesnt like steering to the left that often, steering is real twitchy and it makes a horrible rubbery noise when reversing (tires presumeably). What should I do? Someone told me its the pot? Whats that? :L
Sorry for annoyingly bombarding you with questions but i just swapped a decent amount of stuff for it!
Thanks,
Netcon.

paul_england
2008.11.08, 01:49 PM
a pot is a potentiometer, its a small part on the mini z pcb, which has three legs.
Wikipedia explanation is
A potentiometer is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used (one side and the wiper), it acts as a variable resistor or Rheostat. Potentiometers are commonly used to control electrical devices such as a volume control of a radio. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick.

here is a picture of a mini z PCB, the pot is the bottom left part on the picture.
and thats about all i know, but im preety sure a new one can be bought like any other mini z part.
http://i89.photobucket.com/albums/k231/Schubs383/mini-zelectonics.jpg

paul.

Netcon
2008.11.08, 03:46 PM
Oh i see, thats fairly easy to get then. Thanks Paul!
Does anyone know for sure if this is what I need? Would kinda be a bit of a waste of time if I bought one and didn't need it!


EDIT: Seems ok now, have swapped xtals about and the steering isnt as bad. Is too snakey on carpet might have to find some more rcp style foam tiles! Also about to buy some better tires!

ianc
2008.11.11, 10:56 AM
The guts of the pot are only covered by that thin transparent plastic shield, which allows dust to get in and muck up the works. If you are having trouble with the steering, you can trying cleaning the pot with some type of electronics cleaning spray after removing the shield. Try blowing it out with compressed air if you have it. You can also try a light machine oil in it, but that may also attract dust if you don't seal the pot housing well. New ones are inexpensive and easy to solder in if that's what's necessary. Pay particular attention to the mounting of the pot when you reassemble. Any movement of the pot relative to the servo case will cause slop and non-centering of the steering. Some people have shimmed them to tighten things up.

Of course IMHO, the AM boards suck, so you are better off to just ditch it and get a 2.4, but that may be outside the bounds of your budget...

ianc

Netcon
2008.11.11, 11:05 AM
Hello, thanks for the info I will defently have to try it when I get home tonight. The problem has been half fixed! The xtals were in wrong when I recived it and I never really notice but I've changed them 'round so it seems slightly better. I also reckon my tires are on there way out as it centers fine but steers more to the left (theres some on the way). The steering is still twitchy at a stand still and yes I would say a 2.4 is sort of not worth it for me as I do not race. I just mess about with these things at home.

ianc
2008.11.11, 11:21 AM
The steering is still twitchy at a stand still and yes I would say a 2.4 is sort of not worth it for me as I do not race. I just mess about with these things at home.

No matter whether you race or not, the point of driving is to have fun. The driving experience is so much better with the 2.4 that it's worth it, believe me. The best mod you can make to the car IMO, so if you can afford it, don't hesitate...

ianc

byebye
2008.11.11, 11:24 AM
Did you buy it used?

You also have to center the steering on the chassis to the transmitter. This will make the steering more exact.

Do you know how to do this?

Also what tires are you running? Are they the stock tires? Are they aftermarket? I always runs Kyosho 30 fronts and 20 wide rears. They are good to start, have good grip and last a while if you are running stock.

Answer those questions and I'll get back to you.

Kris

Netcon
2008.11.11, 01:18 PM
No matter whether you race or not, the point of driving is to have fun. The driving experience is so much better with the 2.4 that it's worth it, believe me. The best mod you can make to the car IMO, so if you can afford it, don't hesitate...

ianc

Yes, I have been told this is great. If I did decide to go for it I think I'd buy a brand new MR-02 2.4Ghz. Thanks again!

Did you buy it used?

You also have to center the steering on the chassis to the transmitter. This will make the steering more exact.

Do you know how to do this?

Also what tires are you running? Are they the stock tires? Are they aftermarket? I always runs Kyosho 30 fronts and 20 wide rears. They are good to start, have good grip and last a while if you are running stock.

Answer those questions and I'll get back to you.

Kris

Yes it was bought used.

I think so, is this not just the st trim wheel on the TX?

Just the ones that came with it. They seem to be pretty hard slicks which is no use for the flooring I am running it on (hard polished wood). I'd like to find some wider softer slicks but don't know how to start with all this tire degrees, i think i now understand offsets :o

Thanks for the help people!
This is a brilliant forum and I'm pretty settled here :D

EMU
2008.11.11, 01:27 PM
Check to make sure that the rear end is straight, if the front wheels are straight and the car steers to the left then the rear pod may not be lined up correctly.

Also check for binding on the differential. It should spin freely when there is no motor installed. If the right wheel spins free, but left doesnt; then it is binding on the motormount. What differential are you using?

You may also want to check the servo gears, make sure that they do not bind. If they do, you can rotate the 2nd a third gear a little without the first one on to a point that they do not bind, and then install the first gear. The ASF chassis comes with better gears than the AM. You can swap out the gears for better ones. I have had good results with the Atomic High Precision gears.

Check that the tie rod doesnt bind, remove the tie rod, and look at the servo savers movement. If it is smooth, then that may be your problem. The servo saver could also cause a problem...

As said earlier, center the car to the transmitter. Transmitters trim should be set to the center, then adjust the small pot on the front left corner of the PCB in small increments. You can access this by peeling back the sticker on the chassis cover. Using a non conductive tool is advised. I had an F1 that had the shakes, I adjusted the pot a bit and it went away.

Netcon
2008.11.11, 01:44 PM
Check to make sure that the rear end is straight, if the front wheels are straight and the car steers to the left then the rear pod may not be lined up correctly.

Also check for binding on the differential. It should spin freely when there is no motor installed. If the right wheel spins free, but left doesnt; then it is binding on the motormount. What differential are you using?

You may also want to check the servo gears, make sure that they do not bind. If they do, you can rotate the 2nd a third gear a little without the first one on to a point that they do not bind, and then install the first gear. The ASF chassis comes with better gears than the AM. You can swap out the gears for better ones. I have had good results with the Atomic High Precision gears.

Check that the tie rod doesnt bind, remove the tie rod, and look at the servo savers movement. If it is smooth, then that may be your problem. The servo saver could also cause a problem...

As said earlier, center the car to the transmitter. Transmitters trim should be set to the center, then adjust the small pot on the front left corner of the PCB in small increments. You can access this by peeling back the sticker on the chassis cover. Using a non conductive tool is advised. I had an F1 that had the shakes, I adjusted the pot a bit and it went away.

Rear pod seems fine and lined up ok.

Diff spins freely, well it turns but there is no ball bearings for the moment so it wont spin on its own for more than a second or two. And its just a stock diff. as far as I know the only upgrades are an Iwaver X-Speed motor and a carbon fibre H plate.

Yeah, i'll check the servo gears. I'm waiting on my new screw diver as my last one for these micro cars has seen better days! The centering seems fine tbh. My only concern is the twitching but I guess that is just standard with an AM car.

Thanks again for the help,
your all so great on this forum!
Cheers,
Netcon.

EMU
2008.11.12, 01:51 AM
Make sure that the antenna is securely screwed down, and that it is connected to the board properly (not frayed).

lugnutz
2008.11.12, 05:44 PM
emu i have a problem with my mr015 i hope you can fix it for me:D

i don't have anytime to finish it!:eek:

EMU
2008.11.12, 07:51 PM
emu i have a problem with my mr015 i hope you can fix it for me:D

i don't have anytime to finish it!:eek:

Whats the problem buddy, hope I can help. I will be at the track Saturday.

lugnutz
2008.11.12, 07:58 PM
i need to finish building my car

EMU
2008.11.12, 08:38 PM
What is the current setup? MM or RM?

Netcon
2008.11.13, 04:04 PM
Thanks for the help guys! I'm pretty much just waiting on the stuff i need to fix it now.

lugnutz
2008.11.13, 04:10 PM
What is the current setup? MM or RM?

rm pn rear mount everything else is still stock with an alfa romero body

EMU
2008.11.13, 08:22 PM
rm pn rear mount everything else is still stock with an alfa romero body
Which Alfa? Brera or 156? 90 or 94mm? I would recommend 94mm MM.

lugnutz
2008.11.14, 06:22 PM
brera 90mm i think i'm working on it tonite